DETAILED DESCRIPTION

[0038] First, an embodiment of a first invention will be described with reference to FIGS. 1 a and 1 b. In embodiments of the inventions described below, a heat exchanging circuit comprising a four-way switching valve, an outdoor-side heat exchanger, an expansion valve (or a capillary tube), and an indoor-side heat exchanger is essentially the same as that of the prior art described with reference to FIGS. 20 and 21 , so that the same reference numerals are applied.

[0039] An air conditioner in accordance with the first invention has a refrigerant circuit comprising a compressor 100 , a four-way switching valve 8 , an outdoor-side heat exchanger 9 and an indoor-side heat exchanger 11 which are selectively switched and connected to the high-pressure refrigerant discharge side and the low-pressure refrigerant suction side of the compressor 100 via the four-way switching valve 8 , and an expansion valve 10 between the outdoor-side heat exchanger 9 and the indoor-side heat exchanger 11 . The expansion valve 10 may be a capillary tube.

[0040] The compressor 100 has a cylindrical enclosed vessel 101 , and the enclosed vessel 101 contains a refrigerant compressing section 110 having a suction port 111 and a discharge port 112 , and an electric motor 120 for driving the refrigerant compressing section 110 . In this embodiment, the enclosed vessel 101 is horizontally disposed on a base frame, not shown, with the axis thereof being substantially horizontal.

[0041] Although not shown in detail, the refrigerant compressing section 110 , being of a scroll type, has a compression chamber formed by engaging a fixed scroll having a spiral wrap on an end plate with an orbiting scroll driven by the electric motor 120 .

[0042] The interior of the enclosed vessel 101 is airtightly divided into two chambers, a refrigerant discharge chamber 102 on the side of the discharge port 112 and an electric motor chamber 103 containing the electric motor 120 , by the end plate on the side of the fixed scroll in the refrigerant compressing section 110 . Also, the electric motor chamber 103 is provided with a bearer plate 122 which pivotally supports a driving shaft 121 of the electric motor 120 . A subsidiary electric motor chamber 104 is formed on the side opposite to the refrigerant discharge chamber 102 of the electric motor chamber 103 by the bearer plate 122 . The bearer plate 122 is formed with an arbitrary number of refrigerant flowing holes 123 .

[0043] The suction port 111 of the refrigerant compressing section 110 is connected with a refrigerant suction pipe 130 for sucking a low-pressure refrigerant from a first switching port 8 a, which is on the low-pressure refrigerant introduction side of the four-way switching valve 8 . The refrigerant discharge chamber 102 is connected with a refrigerant discharge pipe 140 for supplying a high-pressure refrigerant produced in the refrigerant compressing section 110 to a second switching port 8 b, which is on the high-pressure refrigerant discharge side of the four-way switching valve 8 .

[0044] The electric motor chamber 103 is connected to one end of a first refrigerant flow path pipe 150 , and the other end of the first refrigerant flow path pipe 150 is connected to a third switching port 8 c of the four-way switching valve 8 . The subsidiary electric motor chamber 104 is connected with one end of a second refrigerant flow path pipe 160 , and the other end of the second refrigerant flow path pipe 160 is connected to the outdoor-side heat exchanger 9 . A remaining one switching port 8 d of the four-way switching valve 8 is connected with the indoor-side heat exchanger 11 .

[0045] At the time of cooling operation, the four-way switching valve 8 is switched as shown in FIG. 1 a so that the first switching port 8 a and the fourth switching port 8 d are in a communicating state, and the second switching port 8 b and the third switching port 8 c are in a communicating state.

[0046] Thereupon, a high-temperature high-pressure refrigerant gas produced in the refrigerant compressing section 110 flows into the electric motor chamber 103 from the refrigerant discharge chamber 102 through the refrigerant discharge pipe 140 , the second switching port 8 b, the third switching port 8 c, and the first refrigerant flow path pipe 150 , increasing the pressure in the compressor 100 , and is supplied to the outdoor-side heat exchanger 9 through the second refrigerant flow path pipe 160 .

[0047] The high-temperature high-pressure refrigerant gas is heat exchanged with the outdoor air in the outdoor-side heat exchanger 9 , and is condensed and liquefied by discharging heat to the outside of the room. This liquid refrigerant is decompressed by the expansion valve 10 , becoming in a low-temperature low-pressure gas-liquid two-phase state, and is sent to the indoor-side heat exchanger 11 .

[0048] While flowing in the indoor-side heat exchanger 11 , the refrigerant is evaporated by taking heat away from the indoor air, becoming a low-temperature low-pressure refrigerant gas, and is returned to the refrigerant compressing section 110 through the fourth switching port 8 d and the first switching port 8 a of the four-way switching valve 8 , the refrigerant suction pipe 130 , and the suction port 111 .

[0049] At the time of heating operation, the four-way switching valve 8 is switched as shown in FIG. 1 b so that the second switching port 8 b and the fourth switching port 8 d are in a communicating state, and the first switching port 8 a and the third switching port 8 c are in a communicating state.

[0050] Thereupon, the high-temperature high-pressure refrigerant gas produced in the refrigerant compressing section 110 is supplied from the refrigerant discharge chamber 102 to the side of the indoor-side heat exchanger 11 through the refrigerant discharge pipe 140 , the second switching port 8 b, and the fourth switching port 8 d, by which heating of the room is performed. The low-pressure refrigerant gas passing through the expansion valve 10 and the outdoor-side heat exchanger 9 flows into the electric motor chamber 103 from the side of the subsidiary electric motor chamber 104 through the second refrigerant flow path pipe 160 , decreasing the pressure in the compressor 100 , and is returned to the refrigerant compressing section 110 through the first refrigerant flow path pipe 150 , the third switching port 8 c, the first switching port 8 a, the refrigerant suction pipe 130 , and the suction port 111 .

[0051] Thus, according to the first invention, merely by switching the four-way switching valve 8 , the compressor 100 can be made the internal high pressure type at the time of cooling operation, and the compressor 100 can be made the internal low pressure type at the time of heating operation.

[0052] Therefore, at the time of cooling operation, since the temperature of the enclosed vessel 101 is higher than the outdoor air temperature, the heat dissipation amount is increased, so that the cooling capacity is enhanced.

[0053] Contrarily, at the time of heating operation, the refrigerant, which has been accumulated in the compression chamber at the time of stoppage, is compressed simultaneously with the start, and the high-temperature high-pressure refrigerant gas is directly supplied to the indoor-side heat exchanger, not being caused to pass through the electric motor chamber, unlike the internal high pressure type. Therefore, a sufficient refrigerant circulating amount is secured from the start, so that the temperature can be increased properly.

[0054] Next, modifications of the first invention will be explained. First, as shown in FIGS. 2 a and 2 b as a first modification, the four-way switching valve 8 may be installed integrally with the compressor 100 . FIG. 2 a shows a state in which the four-way switching valve 8 is switched to the internal high pressure type, and FIG. 2 b shows a state in which the four-way switching valve 8 is switched to the internal low pressure type.

[0055] In this case, the low-pressure refrigerant suction pipe 130 and the first refrigerant flow path pipe 150 are not laid on the outside of the enclosed vessel 101 as in the case of the above-described embodiment, but should preferably be attached to an end face 101 a on the side of the refrigerant discharge chamber 102 of the enclosed vessel 101 .

[0056] Specifically, the low-pressure refrigerant suction pipe 130 is caused to pass through the refrigerant discharge chamber 102 and is connected to the suction port 111 of the refrigerant compressing section 110 , and the first refrigerant flow path pipe 150 is caused to pass through the refrigerant discharge chamber 102 and the refrigerant compressing section 110 and is drawn into the electric motor chamber 103 , by which the installation space for the low-pressure refrigerant suction pipe 130 and the first refrigerant flow path pipe 150 need not be provided on the peripheral surface (shell periphery) side of the enclosed vessel 101 . Also, in a similar sense, the second refrigerant flow path pipe 160 should also preferably be connected to an end face 101 b on the side of the subsidiary electric motor chamber 104 of the enclosed vessel 101 .

[0057] Also, as shown in FIG. 3 as a second modification, the first and second refrigerant flow path pipes 150 and 160 are laid so as to be opposed to coils 124 , 124 exposed at both ends of the electric motor 120 so that the refrigerant gas is blown to the coils 124 , 124 . Thereby, a lubricating oil is separated from the gas efficiently, so that especially at the time of heating operation, the oil surface level H in the electric motor chamber 103 and the subsidiary electric motor chamber 104 can be secured.

[0058] As indicated by a chain line in FIG. 3 , the low-pressure refrigerant suction pipe 130 may be drawn into the refrigerant discharge chamber 102 from the end face 101 a on the side of the refrigerant discharge chamber 102 of the enclosed vessel 101 , and may be connected to the suction port 111 of the refrigerant compressing section 110 . Also, of the first and second refrigerant flow path pipes 150 and 160 , for example, the second refrigerant flow path pipe 160 may be laid at a corner portion above the subsidiary electric motor chamber 104 or on the end face 101 b on the side of the subsidiary electric motor chamber 104 .

[0059] Also, as shown in FIG. 4 as a third modification, the low-pressure refrigerant suction pipe 130 , the first refrigerant flow path pipe 150 , and the high-pressure refrigerant discharge pipe 140 are installed on the side of one end face 101 a of the enclosed vessel 101 , and the second refrigerant flow path pipe 160 is installed on the side of the other end face 101 b of the enclosed vessel 101 .

[0060] According to this configuration, a pipe need not be laid at the shell periphery 101 c of the enclosed vessel 101 . Therefore, when a heat insulating material is installed around the compressor 100 , the work is made easy. Also, the enclosed vessel 101 can be assembled accurately without distortion.

[0061] In this third modification, the low-pressure refrigerant suction pipe 130 passes through the refrigerant discharge chamber 102 and is connected to the suction port 111 of the refrigerant compressing section 110 , and the first refrigerant flow path pipe 150 passes through the refrigerant discharge chamber 102 and the refrigerant compressing section 110 and is drawn into the electric motor chamber 103 .

[0062] As shown in FIG. 5 as a fourth modification, the first refrigerant flow path pipe 150 is laid on the coil 124 close to the subsidiary electric motor chamber 104 of the electric motor 120 , and the second refrigerant flow path pipe 160 is installed at the upper part of the subsidiary electric motor chamber 104 or on the end face 101 b on the side of the subsidiary electric motor chamber 104 as indicated by the chain line in the figure. According to this configuration, the heating of the refrigerant gas due to the electric motor 120 is less, so that the compression performance at the time of heating operation is increased. Also, the pressure difference between the electric motor chamber 103 on the side of the refrigerant compressing section 110 and the subsidiary electric motor chamber 104 decreases, so that the decrease in the oil surface level H in the subsidiary electric motor chamber 104 can be minimized.

[0063] Also, as shown in FIGS. 6 a and 6 b as a fifth modification, both of the first refrigerant flow path pipe 150 and the second refrigerant flow path pipe 160 are installed at the upper part of the subsidiary electric motor chamber 104 . In this case, both of the refrigerant flow path pipes 150 and 160 are preferably installed symmetrically with respect to the axis of the enclosed vessel 101 , that is, with respect to an imaginary vertical plane comprising the axis of the driving shaft 121 , and at an angle such as to point at the axis, and also a oil separating plate 125 is provided therebetween. According to this configuration, the lubricating oil can be separated from the refrigerant gas efficiently. Also, like the above-described fourth modification, the heating of the refrigerant gas due to the electric motor 120 is less, so that the compression performance at the time of heating operation is increased.

[0064] As shown in FIG. 7 as a sixth modification, the first refrigerant flow path pipe 150 is provided at a position opposing to the upper center of the electric motor 120 , and the second refrigerant flow path pipe 160 is provided on the side of the subsidiary electric motor chamber 104 . Thereby, the oil surface levels H on both sides of the electric motor 120 can be kept approximately equal. Also, as in case of the fourth modification, the heating of the refrigerant gas due to the electric motor 120 is less, so that the compression performance at the time of heating operation is increased. In the sixth modification, as indicated by a chain line in FIG. 7 , the second refrigerant flow path pipe 160 may be provided at a position opposing to the coil 124 on the side of the subsidiary electric motor chamber 104 of the electric motor 120 .

[0065] Also, as shown in FIG. 8 as a seventh modification, both of the first refrigerant flow path pipe 150 and the second refrigerant flow path pipe 160 are arranged at positions opposing to the upper center of the electric motor 120 so as to be shifted at a predetermined interval along the peripheral direction of the enclosed vessel 101 , and the refrigerant gas is blown to the electric motor 120 from either one of the refrigerant flow path pipes. Thereby, the lubricating oil can be separated from the refrigerant gas efficiently. Also, the oil surface levels H on both sides of the electric motor 120 can be kept approximately equal.

[0066] Unlike the above-described seventh modification, as shown in FIG. 9 as an eighth modification, both of the first refrigerant flow path pipe 150 and the second refrigerant flow path pipe 160 may be arranged at positions between the electric motor 120 and the refrigerant compressing section 110 so as to be shifted at a predetermined interval along the peripheral direction of the enclosed vessel 101 . In this configuration as well, the oil surface levels H on both sides of the electric motor 120 can be kept approximately equal. Also, the heating of the refrigerant gas due to the electric motor 120 is less, so that the compression performance at the time of heating operation is increased.

[0067] In the above-described second to eighth modifications, the low-pressure refrigerant suction pipe 130 and the high-pressure refrigerant discharge pipe 140 are installed on the end face 101 a on the side of the refrigerant discharge chamber 102 of the enclosed vessel 101 . However, as shown in FIG. 10 as a ninth modification, both of the first refrigerant flow path pipe 150 and the second refrigerant flow path pipe 160 may also be arranged on the end face 101 b on the side of the subsidiary electric motor chamber 104 . According to this configuration, like the above-described third modification, a pipe need not be laid at the shell periphery 101 c of the enclosed vessel 101 . Therefore, when a heat insulating material is installed around the compressor 100 , the work is made easy.

[0068] Also, not only the enclosed vessel 101 can be assembled accurately without distortion, but also the oil surface levels H on both sides of the electric motor 120 can be kept approximately equal. Also, the heating of the refrigerant gas due to the electric motor 120 is less, so that the compression performance at the time of heating operation can be increased.

[0069] FIG. 11 shows a tenth modification. This figure shows a case where the compressor 100 is used as a so-called vertical type. In this modification, when the enclosed vessel 101 is placed on the base frame, not shown, with the axis thereof being substantially vertical, the refrigerant compressing section 110 and the electric motor 120 serving as driving means therefor are contained in the enclosed vessel 101 in such a manner that the former is positioned above and the latter is below. Therefore, in the enclosed vessel 101 , the refrigerant discharge chamber 102 , the electric motor chamber 103 , and the subsidiary electric motor chamber 104 are arranged in that order from the upside.

[0070] In case of the vertical type, it is preferable that the high-pressure refrigerant discharge pipe 140 connected to the refrigerant discharge chamber 102 and the first refrigerant flow path pipe 150 connected to the electric motor chamber 103 be arranged at the side on, for example, the right of the enclosed vessel 101 in FIG. 11 , and the low-pressure refrigerant suction pipe 130 connected to the suction port 111 and the second refrigerant flow path pipe 160 connected to the electric motor chamber 103 be arranged at the side on, for example, the left of the enclosed vessel 101 . According to this configuration, a pipe need not be laid on the side of the end faces 101 a and 101 b of the enclosed vessel 101 . Accordingly, of the installation space of the compressor 100 , the space in the height direction can be decreased.

[0071] Also, since the first and second refrigerant flow path pipes 150 and 160 are arranged at a part of the upper coil 124 of the electric motor 120 , the separation efficiency of the refrigerant gas and lubricating oil can be increased. Also, the heating of the refrigerant gas due to the electric motor 120 is less, so that the compression performance at the time of heating operation can be increased.

[0072] FIG. 12 shows an eleventh modification. This figure shows a case where the compressor 100 is of a so-called horizontal type, and is exclusively used as an internal low pressure type. In this modification, the low-pressure refrigerant suction pipe 130 is disposed so as to be opposed to the coil 124 on the side of the refrigerant compressing section 110 of the electric motor 120 in the electric motor chamber 103 , and a bypass pipe 170 is drawn from a portion corresponding to the coil 124 on the side of the subsidiary electric motor chamber 104 of the electric motor 120 , and is connected to the suction port 111 of the refrigerant compressing section 110 .

[0073] In this case, the low-pressure refrigerant suction pipe 130 is connected to the first switching port 8 a of the four-way switching valve 8 , and the high-pressure refrigerant discharge pipe 140 of the refrigerant discharge chamber 102 is connected to the second switching port 8 b of the four-way switching valve 8 . Also, the third switching port 8 c of the four-way switching valve 8 is connected with, for example, the outdoor-side heat exchanger 9 , and the remaining fourth switching port 8 d is connected with, for example, the indoor-side heat exchanger 11 .

[0074] According to this eleventh modification, at the time of either of cooling operation and heating operation, the low-pressure refrigerant gas from the low-pressure refrigerant suction pipe 130 always passes through the electric motor chamber 103 and is returned to the refrigerant compressing section 110 . For the internal low pressure type of this construction, the oil surface level H in the subsidiary electric motor chamber 104 can be kept high.

[0075] FIG. 13 shows a twelfth modification. This figure shows the case where the compressor 100 is of a so-called horizontal type, and is exclusively used as an internal high pressure type. This modification is based on the second modification shown in FIG. 3 . In this modification, the low-pressure refrigerant suction pipe 130 is directly connected to the suction port 111 of the refrigerant compressing section 110 . Also, the second refrigerant flow path pipe 160 is drawn from a portion corresponding to the coil 124 on the side of the subsidiary electric motor chamber 104 of the electric motor 102 . A bypass pipe 171 is drawn from a portion corresponding to the coil 124 on the side of the refrigerant compressing section 110 of the electric motor 102 , and the bypass pipe 171 is connected to the refrigerant discharge chamber 102 .

[0076] In this case, the low-pressure refrigerant suction pipe 130 is connected to the first switching port 8 a of the four-way switching valve 8 , and the second refrigerant flow path pipe 160 is connected to the second switching port 8 b of the four-way switching valve 8 . Also, the third switching port 8 c of the four-way switching valve 8 is connected with, for example, the outdoor-side heat exchanger 9 , and the remaining fourth switching port 8 d is connected with, for example, the indoor-side heat exchanger 11 .

[0077] In case of this twelfth modification, at the time of either of cooling operation and heating operation, the high-temperature high-pressure refrigerant gas from the refrigerant discharge chamber 102 always passes through the electric motor chamber 103 and is discharged through the second refrigerant flow path pipe 160 . For the internal high pressure type of this construction as well, like the above-described eleventh modification, the oil surface level H in the subsidiary electric motor chamber 104 can be kept high.

[0078] Next, a second invention will be described with reference to an embodiment shown in FIGS. 14 a to 14 c. According to this second invention, cooling operation by means of the internal high pressure type ( FIG. 14 a ), heating operation by means of the internal low pressure type ( FIG. 14 b ), and further heating operation by means of the internal high pressure type ( FIG. 14 c ) can be performed by using one compressor.

[0079] In this second invention, the compressor, which is denoted by reference numeral 200 , has the same basic configuration as that of the compressor 100 used for the first invention. Therefore, reference numerals for the compressor 100 are applied to the configuring elements of the compressor 200 which are the same or regarded as the same. For the details, the above-described first invention should be referred to.

[0080] That is, like the above-described compressor 100 , this compressor 200 also has a horizontal-type cylindrical enclosed vessel 101 , and the enclosed vessel 101 contains the refrigerant compressing section 110 having the suction port 111 and the discharge port 112 , and the electric motor 120 for driving the refrigerant compressing section 110 .

[0081] The interior of the enclosed vessel 101 is divided airtightly into two chambers, the refrigerant discharge chamber 102 on the side of the discharge port of the refrigerant compressing section and the electric motor chamber 103 containing the electric motor 120 , by the refrigerant compressing section 110 serving as partitioning means.

[0082] On the side opposite to the refrigerant discharge chamber 102 of the electric motor chamber 103 , the subsidiary electric motor chamber 104 is formed by the bearer plate 122 which pivotally supports the driving shaft 121 of the electric motor 120 . The bearer plate 122 is formed with an arbitrary number of refrigerant flowing holes, so that the electric motor chamber 103 and the subsidiary electric motor chamber 104 communicate with each other.

[0083] In this second invention, the low-pressure refrigerant suction pipe 130 which is drawn from the first switching port 8 a on the low-pressure refrigerant discharge side of the four-way switching valve 8 branches into two pipes at an intermediate position. A first branch suction pipe 131 , one of the branch pipes, is connected directly to the suction port 111 of the refrigerant compressing section 110 . This first branch suction pipe 131 is provided with a first opening/closing valve 210 . A second branch suction pipe 132 , the other of the branch pipes, is connected to the electric motor chamber 103 , and this second branch suction pipe 132 is provided with a second opening/closing valve 211 .

[0084] Also, the high-pressure refrigerant discharge pipe 140 connected to the second switching port 8 b on the high-pressure refrigerant introduction side of the four-way switching valve 8 also branches into two pipes at an intermediate position. A first branch discharge pipe 141 , one of the branch pipes, is connected to the subsidiary electric motor chamber 104 . This first branch discharge pipe 141 is provided with a third opening/closing valve 212 . A second branch discharge pipe 142 , the other of the branch pipes, is connected to the refrigerant discharge chamber 102 . This second branch discharge pipe 142 is provided with a fourth opening/closing valve 213 .

[0085] Further, a first bypass pipe 133 reaching the subsidiary electric motor chamber 104 branches off from the downstream side of the first opening/closing valve 210 of the first branch suction pipe 131 . This first bypass pipe 133 is provided with a fifth opening/closing valve 214 . Also, a second bypass pipe 143 is provided between the electric motor chamber 103 and the refrigerant discharge chamber 102 . This second bypass pipe 143 is provided with a sixth opening/closing valve 215 . The second bypass pipe 143 may be laid between the upstream side of the fourth opening/closing valve of the second branch discharge pipe 142 and the electric motor chamber 103 .

[0086] In this embodiment, the third switching port 8 c of the four-way switching valve 8 is connected with the outdoor-side heat exchanger 9 , and the fourth switching port 8 d of the four-way switching valve 8 is connected with the indoor-side heat exchanger 11 .

[0087] At the time of cooling operation, as shown in FIG. 14 a, the second switching port 8 b and the third switching port 8 c are made in a communicating state, and the first switching port 8 a and the fourth switching port 8 d are made in a communicating state by the four-way switching valve 8 . Also, the first opening/closing valve 210 , the third opening/closing valve 212 , and the sixth opening/closing valve 215 are opened, and the second opening/closing valve 211 , the fourth opening/closing valve 213 , and the fifth opening/closing valve 214 are closed.

[0088] Thereby, the low-pressure refrigerant gas is sucked into the refrigerant compressing section 110 through the low-pressure refrigerant suction pipe 130 and the first branch suction pipe 131 , and the high-temperature high-pressure refrigerant gas produced in the refrigerant compressing section 110 is supplied to the side of the outdoor-side heat exchanger 9 through the refrigerant discharge chamber 102 , the second bypass pipe 143 , the electric motor chamber 103 , the subsidiary electric motor chamber 104 , the first branch discharge pipe 141 , the high-pressure refrigerant discharge pipe 140 , and the four-way switching valve 8 .

[0089] Thus, at the time of cooling operation, the compressor 200 is used as the internal high pressure type, so that a high-performance steady operation is performed as compared with the internal low pressure type.

[0090] On the other hand, at the time of heating operation, as shown in FIG. 14 b, the second switching port 8 b and the fourth switching port 8 d are made in a communicating state, and the first switching port 8 a and the third switching port 8 c are made in a communicating state by the four-way switching valve 8 . Also, the second opening/closing valve 211 , the fourth opening/closing valve 213 , and the fifth opening/closing valve 214 are opened, and the first opening/closing valve 210 , the third opening/closing valve 212 , and the sixth opening/closing valve 215 are closed.

[0091] Thereby, the low-pressure refrigerant gas enters the electric motor chamber 103 through the low pressure refrigerant suction pipe 130 and the second branch suction pipe 132 , and is sucked into the suction port 111 of the refrigerant compressing section 110 from the subsidiary electric motor chamber 104 through the first bypass pipe 133 . The high-temperature high-pressure refrigerant gas produced in the refrigerant compressing section 110 is supplied to the side of the indoor-side heat exchanger 11 through the refrigerant discharge chamber 102 , the second branch discharge pipe 142 , the high-pressure refrigerant discharge pipe 140 , and the four-way switching valve 8 .

[0092] Thus, at the time of heating operation, the compressor 200 is used as the internal low pressure type, so that warm air can be blown out from the indoor-side heat exchanger 11 in a short period of time from the start by preventing the high-temperature high-pressure refrigerant gas from passing through the electric motor chamber 103 . For example, when heating operation is performed by means of a compressor of internal high pressure type, the required time from the start to the warm air blowout is about 3 minutes. Contrarily, according to this invention, the required time can be shortened to about 1 minute.

[0093] After a predetermined time has passed from the start of heating operation, in the state in which the second switching port 8 b and the fourth switching port 8 d communicate with each other and the first switching port 8 a and the third switching port 8 c communicate with each other, the first opening/closing valve 210 , the third opening/closing valve 212 , and the sixth opening/closing valve 215 are opened, and contrarily the second opening/closing vale 211 , the fourth opening/closing valve 213 , and the fifth opening/closing valve 214 are closed. Thereby, the compressor 200 is switched to the internal high pressure type. The flow of refrigerant at this time is shown in FIG. 14 c. According to this embodiment, as in the case of cooling operation, a high-performance heating operation can be performed.

[0094] In the above-described embodiment, by using solenoid valves for the first opening/closing valve 210 , the third opening/closing valve 212 , the fourth opening/closing valve 213 , the fifth opening/closing valve 214 , and the sixth opening/closing valve 215 , the switching control of the refrigerant circuit can be carried out exactly. The second opening/closing valve 211 may be a check valve. Also, the third opening/closing valve 212 may be a check valve.

[0095] Next, a modification of the second invention will be described with reference to FIG. 15 . According to this modification, the compressor 200 has pipes and switching valves as described below.

[0096] The low-pressure refrigerant suction pipe 130 drawn from the first switching port 8 a on the low-pressure refrigerant discharge side of the four-way switching valve 8 branches into two pipes at an intermediate position. A first branch suction pipe 135 , one of the branch pipes, is connected directly to the suction port 111 of the refrigerant compressing section 110 . This first branch suction pipe 135 is provided with a first opening/closing valve 220 .

[0097] A second branch suction pipe 136 , the other of the branch pipes, is connected to the electric motor chamber 103 . In this case, at the pipe end of the second branch suction pipe 136 , there is provided a first check valve 230 for checking a reverse flow from the side of the electric motor chamber 103 .

[0098] Also, a first bypass pipe 137 is provided between the downstream side of the first opening/closing valve 220 of the first branch suction pipe 135 and the electric motor chamber 103 . This first bypass pipe 137 is provided with a second opening/closing valve 221 .

[0099] The second switching port 8 b (for example, see FIG. 14 a ) on the high-pressure refrigerant introduction side of the four-way switching valve 8 and the subsidiary electric motor chamber 104 are connected to each other by the high-pressure refrigerant discharge pipe 140 .

[0100] Also, the refrigerant discharge chamber 102 and the electric motor chamber 103 are connected to each other via a second bypass pipe 145 . This second bypass pipe 145 is provided with a third opening/closing valve 222 . Taking the refrigerant flow direction in the second bypass pipe 145 as the direction from the refrigerant discharge chamber 102 toward the electric motor chamber 103 , a third bypass pipe 146 having a fourth opening/closing valve 223 is provided between the upstream side of the third opening/closing valve 222 of the second bypass pipe 145 and the subsidiary electric motor chamber 104 .

[0101] In this modification, a partition 126 having a communicating hole 127 is provided between the electric motor chamber 103 and the subsidiary electric motor chamber 104 separately from the bearer plate 122 . The communicating hole 127 in this partition 126 is provided with a second check valve 231 for checking a reverse flow from the side of the subsidiary electric motor chamber 104 to the side of the electric motor chamber 103 . The second check valve 231 may be provided at the communicating hole in the bearer plate 122 . In this case, the partition 126 need not be provided especially.

[0102] Although not shown in FIG. 15 , like the above-described embodiment, the third switching port 8 c of the four-way switching valve 8 is connected with the outdoor-side heat exchanger 9 , and the fourth switching port 8 d of the four-way switching valve 8 is connected with the indoor-side heat exchanger 11 .

[0103] In this modification, at the time of cooling operation, the high-pressure refrigerant discharge pipe 140 of the second switching port 8 b and the outdoor-side heat exchanger 9 of the third switching port 8 c are caused to communicate with each other and the low-pressure refrigerant suction pipe 130 of the first switching port 8 a and the indoor-side heat exchanger 11 of the fourth switching port 8 d are caused to communicate with each other by the four-way switching valve 8 . Also, the first opening/closing valve 220 and the third opening/closing valve 222 are opened, and the second opening/closing valve 221 and the fourth opening/closing valve 223 are closed. Thereby, the compressor 200 is operated as the internal high pressure type.

[0104] Specifically, the low-pressure refrigerant from the indoor-side heat exchanger 11 is sucked into the refrigerant compressing section 110 from the suction port 111 through the low-pressure refrigerant suction pipe 130 and the first branch suction pipe 135 . The high-temperature high-pressure refrigerant gas produced in the refrigerant compressing section 110 is supplied to the electric motor chamber 103 through the second bypass pipe 145 . Thereby, the first check valve 230 is closed. Thereafter, the high-temperature high-pressure refrigerant gas pushes to open the second check valve 231 and flows into the subsidiary electric motor chamber 104 , and then is supplied to the outdoor-side heat exchanger 9 through the high-pressure refrigerant discharge pipe 140 and the four-way switching valve 8 .

[0105] On the other hand, at the time of heating operation, the high-pressure refrigerant discharge pipe 140 of the second switching port 8 b and the indoor-side heat exchanger 11 of the fourth switching port 8 d are caused to communicate with each other and the low-pressure refrigerant suction pipe 130 of the first switching port 8 a and the outdoor-side heat exchanger 9 of the third switching port 8 c are caused to communicate with each other by the four-way switching valve 8 . Also, the second opening/closing valve 221 and the fourth opening/closing valve 223 are opened, and the first opening/closing valve 220 and the third opening/closing valve 222 are closed. Thereby, the compressor 200 is operated as the internal low pressure type.

[0106] Specifically, in this case, the low-pressure refrigerant from the outdoor-side heat exchanger 9 flows into the electric motor chamber 103 through the low-pressure refrigerant suction pipe 130 and the second branch suction pipe 136 , decreasing the pressure in the compressor, and then is sucked into the refrigerant compressing section 110 from the suction port 111 through the first bypass pipe 137 . Then, the high-temperature high-pressure refrigerant gas produced in the refrigerant compressing section 110 is supplied from the refrigerant discharge chamber 102 to the subsidiary electric motor chamber 104 through the second bypass pipe 146 . Thereby, the second check valve 231 is closed. Thereafter, the high-temperature high-pressure refrigerant gas is supplied to the indoor-side heat exchanger 11 through the high-pressure refrigerant discharge pipe 140 and the four-way switching valve 8 .

[0107] After a predetermined time has passed from the start of heating operation, the four-way switching valve 8 being as it is, the first opening/closing valve 220 and the third opening/closing valve 222 are opened, and the second opening/closing valve 221 and the fourth opening/closing valve 223 are closed. Thereby, the compressor 200 is operated as the internal high pressure type.

[0108] In this modification, the first opening/closing valve 220 and the second opening/closing valve 221 should preferably be interlocking valves, in which when either one of the valves is opened, the other valve is closed, from the viewpoint of the valve switching control. Similarly, the third opening/closing valve 222 and the fourth opening/closing valve 223 should preferably be interlocking valves, in which when either one of the valves is opened, the other valve is closed.

[0109] Next, a third invention will be described with reference to an embodiment shown in FIGS. 16 a to 16 c. In this third invention as well, cooling operation by means of the internal high pressure type ( FIG. 16 a ), heating operation by means of the internal low pressure type ( FIG. 16 b ), and further heating operation by means of the internal high pressure type ( FIG. 16 c ) can be performed by using one compressor.

[0110] In this third invention, the compressor, which is denoted by reference numeral 300 , has the same basic configuration as that of the compressor 100 used for the first invention. Therefore, reference numerals for the compressor 100 are applied to the elements of the compressor 300 which are the same or regarded as the same. For the details, the above-described first invention should be referred to.

[0111] Specifically, like the above-described compressor 100 , this compressor 300 also has a horizontal-type cylindrical enclosed vessel 101 , and the enclosed vessel 101 contains the refrigerant compressing section 110 having the suction port 111 and the discharge port 112 , and the electric motor 120 for driving the refrigerant compressing section 110 .

[0112] The interior of the enclosed vessel 101 is divided airtightly into two chambers, the refrigerant discharge chamber 102 on the side of the discharge port of the refrigerant compressing section and the electric motor chamber 103 containing the electric motor 120 , by the refrigerant compressing section 110 serving as partitioning means.

[0113] On the side opposite to the refrigerant discharge chamber 102 of the electric motor chamber 103 , the subsidiary electric motor chamber 104 is formed by the bearer plate 122 which pivotally supports the driving shaft 121 of the electric motor 120 . The bearer plate 122 is formed with an arbitrary number of refrigerant flowing holes, so that the electric motor chamber 103 and the subsidiary electric motor chamber 104 communicate with each other. Therefore, these two chambers may be regarded substantially as one chamber.

[0114] According to the third invention, as shown enlargedly in FIG. 17 , the refrigerant compressing section 110 has a refrigerant inflow port 113 reaching the suction port 111 from the side of the electric motor chamber 103 , separately from the suction port 111 .

[0115] The suction port 111 is connected with the low-pressure refrigerant suction pipe 130 drawn from the first switching port 8 a on the low-pressure refrigerant discharge side of the four-way switching valve 8 . The refrigerant inflow port 113 is provided with a first opening/closing valve 310 . In this case, the first opening/closing valve 310 is urged by spring means 311 in the direction such that the inflow port is always opened. The spring urging force is regulated so that when the pressure in the electric motor chamber 103 reaches a predetermined value, the refrigerant inflow port 113 is closed.

[0116] The subsidiary electric motor chamber 104 and the second switching port 8 b on the high-pressure refrigerant introduction side of the four-way switching valve 8 are connected to each other by the high-pressure refrigerant discharge pipe 140 . This high-pressure refrigerant discharge pipe 140 is provided with a second opening/closing valve 320 . In this embodiment, the second opening/closing valve 320 , comprising a check valve for checking a reverse flow from the side of high-pressure refrigerant discharge pipe 140 to the side of the subsidiary electric motor chamber 104 , is disposed at a connecting portion of the subsidiary electric motor chamber 104 and the high-pressure refrigerant discharge pipe 140 .

[0117] The downstream side of the second opening/closing valve 320 of the high-pressure refrigerant discharge pipe 140 and the refrigerant discharge chamber 102 are connected to each other by a first bypass pipe 172 . This first bypass pipe 172 is provided with a third opening/closing valve 330 .

[0118] Also, taking the refrigerant flow direction in the first bypass pipe 172 as the direction from the refrigerant discharge chamber 102 toward the high-pressure refrigerant discharge pipe 140 , a second bypass pipe 173 having a fourth opening/closing valve 340 is provided between the upstream side of the third opening/closing valve 330 of the first bypass pipe 172 and the electric motor chamber 103 . The interlocking valves, in which when either one of the valves is opened, the other valve is closed, are used for the third opening/closing valve 330 and the fourth opening/closing valve 340 .

[0119] In this embodiment as well, the third switching port 8 c of the four-way switching valve 8 is connected with the outdoor-side heat exchanger 9 , and the fourth switching port 8 d of the four-way switching valve 8 is connected with the indoor-side heat exchanger 11 .

[0120] At the time of cooling operation, as shown in FIG. 16 a, the high-pressure refrigerant discharge pipe 140 of the second switching port 8 b and the outdoor-side heat exchanger 9 of the third switching port 8 c are caused to communicate with each other and the low-pressure refrigerant suction pipe 130 of the first switching port 8 a and the indoor-side heat exchanger 11 of the fourth switching port 8 d are caused to communicate with each other by the four-way switching valve 8 . Also, the fourth opening/closing valve 340 is opened, and the third opening/closing valve 330 is closed. Thereby, the compressor 300 is operated as the internal high pressure type.

[0121] That is, the low-pressure refrigerant gas from the side of the indoor-side heat exchanger 11 is sucked into the refrigerant compressing section 110 from the suction port 111 through the low-pressure refrigerant suction pipe 130 , and the high-temperature high-pressure refrigerant gas produced in the refrigerant compressing section 110 is supplied from the refrigerant discharge chamber 102 to the electric motor chamber 103 through the second bypass pipe 173 . Thereby, the pressure in the electric motor chamber 103 is made high, and the refrigerant inflow port 113 is closed by the first opening/closing valve 310 . Thereafter, the high-temperature high-pressure refrigerant gas is supplied to the side of the outdoor-side heat exchanger 9 through the subsidiary electric motor chamber 104 , the second opening/closing valve 320 , the high-pressure refrigerant discharge pipe 140 , and the four-way switching valve 8 .

[0122] At the time of heating operation, as shown in FIG. 16 b, the high-pressure refrigerant discharge pipe 140 of the second switching port 8 b and the indoor-side heat exchanger 11 of the fourth switching port 8 d are caused to communicate with each other and the low-pressure refrigerant suction pipe 130 of the first switching port 8 a and the outdoor-side heat exchanger 9 of the third switching port 8 c are caused to communicate with each other by the four-way switching valve 8 . Also, the third opening/closing valve 330 is opened, and the second opening/closing valve 320 is closed. Thereby, the compressor 300 is operated as the internal low pressure type.

[0123] That is, at the time of heating operation, the low-pressure refrigerant gas from the side of the outdoor-side heat exchanger 9 is sucked into the refrigerant compressing section 110 from the suction port 111 through the low-pressure refrigerant suction pipe 130 . The high-temperature high-pressure refrigerant gas produced in the refrigerant compressing section 110 reaches the high-pressure refrigerant discharge pipe 140 from the first bypass pipe 172 without flowing in the electric motor chamber 103 from the refrigerant discharge chamber 102 , and is supplied to the indoor-side heat exchanger 11 through the four-way switching valve 8 . Thus, since the high-temperature high-pressure refrigerant gas is not supplied to the electric motor chamber 103 , the first opening/closing valve 310 is opened, and therefore the pressure in the electric motor chamber 103 is kept low.

[0124] After a predetermined time has passed from the start of heating operation, the four-way switching valve 8 being as it is, the fourth opening/closing valve 340 is opened, and the third opening/closing valve 330 is closed. Thereby, heating operation is continued with the compressor 300 being operated as the internal high pressure type.

[0125] Next, a fourth invention will be described with reference to an embodiment shown in FIGS. 18 a to 18 c. In this fourth invention as well, cooling operation by means of the internal high pressure type ( FIG. 18 a ), heating operation by means of the internal low pressure type ( FIG. 18 b ), and further heating operation by means of the internal high pressure type ( FIG. 18 c ) can be performed by using one compressor.

[0126] In this fourth invention, the compressor, which is denoted by reference numeral 400 , has the same basic configuration as that of the compressor 100 used for the first invention. Therefore, reference numerals for the compressor 100 are applied to the elements of the compressor 400 which are the same or regarded as the same, and the explanation of these elements is omitted.

[0127] In this fourth invention, taking the four-way switching valve 8 used in the first invention as a first four-way switching valve, a second four-way switching valve 81 is provided separately from the first four-way switching valve 8 .

[0128] The suction port 111 of the refrigerant compressing section 110 is connected with the low-pressure refrigerant suction pipe 130 drawn from a first switching port 81 a on the low-pressure refrigerant discharge side of the second four-way switching valve 81 . Also, the refrigerant discharge chamber 102 is connected with the high-pressure refrigerant discharge pipe 140 reaching a second switching port 81 b on the high-pressure refrigerant introduction side of the second four-way switching valve 81 .

[0129] The electric motor chamber 103 is connected with one end of the first refrigerant flow path pipe 150 , and the other end of the first refrigerant flow path pipe 150 is connected to a third switching port 81 c of the second four-way switching valve 81 . The subsidiary electric motor chamber 104 is connected with one end of the second refrigerant flow path pipe 160 .

[0130] The other end side of the second refrigerant flow path pipe 160 branches into two pipes. One branch pipe 161 is connected to the first switching port 8 a of the first four-way switching valve 8 via a first opening/closing valve 410 . The other branch pipe 162 is connected to the second switching port 8 b of the first four-way switching valve 8 via a second opening/closing valve 420 .

[0131] Also, a fourth switching port 81 d of the second four-way switching valve 81 is connected to the first four-way switching valve 8 via a pipe 180 . This pipe 180 also branches into two pipes. One branch pipe 181 is connected to the second switching port 8 b of the first four-way switching valve 8 via a third opening/closing valve 430 , and the other branch pipe 182 is connected to the first switching port 8 a of the first four-way switching valve 8 via a fourth opening/closing valve 440 . The third switching port 8 c of the first four-way switching valve 8 is connected with the outdoor-side heat exchanger 9 , and the fourth switching port 8 d thereof is connected with the indoor-side heat exchanger 11 .

[0132] In this embodiment, the first refrigerant flow path pipe 150 is connected to the electric motor chamber 103 , and the second refrigerant flow path pipe 160 is connected to the subsidiary electric motor chamber 104 . The electric motor chamber 103 and the subsidiary electric motor chamber 104 are caused to communicate with each other by the refrigerant communicating hole 123 in the bearer plate 122 , so that these two chambers may be regarded substantially as one chamber. Therefore, both of the first refrigerant flow path pipe 150 and the second refrigerant flow path pipe 160 may be connected to the electric motor chamber 103 or the subsidiary electric motor chamber 104 .

[0133] At the time of cooling operation, as shown in FIG. 18 a, both of the first and second four-way switching valves 8 and 81 are switched so that the first switching port 8 a, 81 a thereof communicates with the fourth switching port 8 d, 81 d, and at the same time the second switching port 8 b, 81 b communicates with the third switching port 8 c, 81 c. Also, the second opening/closing valve 420 and the fourth opening/closing valve 440 are opened, and the first opening/closing valve 410 and the third opening/closing valve 430 are closed.

[0134] Thereby, the low-pressure refrigerant gas from the indoor-side heat exchanger 11 is sucked into the refrigerant compressing section 110 through the switching ports 8 d and 8 a of the first four-way switching valve 8 , the fourth opening/closing valve 440 , the switching ports 81 d and 81 a of the second four-way switching valve 81 , and the low-pressure refrigerant suction pipe 130 . The high-temperature high-pressure refrigerant gas produced in the refrigerant compressing section 110 is supplied to the electric motor chamber 103 through the high-pressure refrigerant discharge pipe 140 , the switching ports 81 b and 81 c of the second four-way switching valve 81 , and the first refrigerant flow path pipe 150 , and is supplied from the subsidiary electric motor chamber 104 to the outdoor-side heat exchanger 9 through the second refrigerant flow path pipe 160 , the second opening/closing valve 420 , and the switching ports 8 b and 8 c of the first four-way switching valve 8 . Thus, at the time of cooling operation, the compressor 400 is operated as the internal high pressure type.

[0135] Contrarily, at the time of heating operation, as shown in FIG. 18 b, both of the first and second four-way switching valves 8 and 81 are switched so that the second switching port 8 b, 81 b thereof communicates with the fourth switching port 8 d, 81 d, and at the same time the first switching port 8 a, 81 a communicates with the third switching port 8 c, 81 c. Also, the first opening/closing valve 410 and the third opening/closing valve 430 are opened, and the second opening/closing valve 420 and the fourth opening/closing valve 440 are closed.

[0136] Thereby, the low-pressure refrigerant gas from the outdoor-side heat exchanger 9 flows to the side of the subsidiary electric motor chamber 104 through the switching ports 8 c and 8 a of the first four-way switching valve 8 , the first opening/closing valve 410 , and the second refrigerant flow path pipe 160 , and is sucked into the refrigerant compressing section 110 from the electric motor chamber 103 through the first refrigerant flow path pipe 150 , the switching ports 81 c and 81 a of the second four-way switching valve 81 , and the low-pressure refrigerant suction pipe 130 . The high-temperature high-pressure refrigerant gas produced in the refrigerant compressing section 110 is supplied to the indoor-side heat exchanger 11 through the high-pressure refrigerant discharge pipe 140 , the switching ports 81 b and 81 d of the second four-way switching valve 81 , the third opening/closing valve 430 , and the switching ports 8 b and 8 d of the first four-way switching valve 8 . Thus, at the time of heating operation, the compressor 400 is operated as the internal low pressure type.

[0137] After a predetermined time has passed from the start of heating operation, as shown in FIG. 18 c, the first four-way switching valve 8 still being in the switching state at the time of heating operation, the second four-way switching valve 81 is switched to the state of cooling operation. Specifically, the switching ports 81 a and 81 d are caused to communicate with each other, and the switching ports 81 b and 81 c are caused to communicate with each other. Thereby, the compressor 400 can be operated as the internal high pressure type.

[0138] Each opening/closing valve may be a solenoid valve, but it should preferably be a check valve because the check valve does not require electrical valve control.

[0139] At this time, a check valve in which the direction from the side of the first four-way switching valve 8 toward the electric motor chamber 103 is the forward direction is used as the first opening/closing valve 410 , a check valve in which the direction from the side of the electric motor chamber 103 toward the first four-way switching valve 8 is the forward direction is used as the second opening/closing valve 420 , a check valve in which the direction from the side of the second four-way switching valve 81 toward the first four-way switching valve 8 is the forward direction is used as the third opening/closing valve 430 , and a check valve in which the direction from the side of the first four-way switching valve 8 toward the second four-way switching valve 81 is the forward direction is used as the fourth opening/closing valve 440 .

[0140] The fourth invention can be modified as shown in FIGS. 19 a to 19 c. In this modification as well, cooling operation by means of the internal high pressure type ( FIG. 19 a ), heating operation by means of the internal low pressure type ( FIG. 19 b ), and further heating operation by means of the internal high pressure type ( FIG. 19 c ) can be performed by using one compressor 400 .

[0141] In this modification, unlike the above-described embodiment, the second refrigerant flow path pipe 160 and the pipe 180 do not branch, and the opening/closing valves are not used. The second refrigerant flow path pipe 160 is connected directly to the second switching port 8 b of the first four-way switching valve 8 , and the pipe 180 is also connected directly to the first switching port 8 a of the first four-way switching valve 8 .

[0142] At the time of cooling operation, as shown in FIG. 19 a, the low-pressure refrigerant suction pipe 130 and the pipe 180 are caused to communicate with each other and the high-pressure refrigerant discharge pipe 140 and the first refrigerant flow path pipe 150 are caused to communicate with each other by the second four-way switching valve 81 . Also, the second refrigerant flow path pipe 160 and the outdoor-side heat exchanger 9 are caused to communicate with each other and the pipe 180 and the indoor-side heat exchanger 11 are caused to communicate with each other by the first four-way switching valve 8 . Thereby, the compressor 400 is operated as the internal high pressure type.

[0143] At the time of heating operation, as shown in FIG. 19 b, only the second four-way switching valve 81 is switched so that the high-pressure refrigerant discharge pipe 140 and the pipe 180 communicate with each other and the first refrigerant flow path pipe 150 and the low-pressure refrigerant suction pipe 130 communicate with each other. The first four-way switching valve 8 remains in the state of cooling operation. Thereby, the compressor 400 is operated as the internal low pressure type.

[0144] After a predetermined time has passed from the start of heating operation, as shown in FIG. 19 c, the second four-way switching valve 81 is switched so that the low-pressure refrigerant suction pipe 130 and the pipe 180 communicate with each other and the high-pressure refrigerant discharge pipe 140 and the first refrigerant flow path pipe 150 communicate with each other. Also, the first four-way switching valve 8 is switched so that the second refrigerant flow path pipe 160 and the indoor-side heat exchanger 11 communicate with each other and the outdoor-side heat exchanger 9 and the pipe 180 communicate with each other. Thereby, the heating operation can be continued with the compressor 400 being operated as the internal high pressure type.

[0145] The invention has been described above in detail with reference to some embodiments. Those skilled in the art who have understood the details of the present invention will easily think out the modifications, changes, and equivalence. Therefore, the scope of the present invention should be the accompanying claims and the equivalent scope thereof.