A lubricating system for rotary piston compressors, in which the lubricating oil passes from a storage container in predetermined quantities to the lubricating points. The compression chamber of the rotary piston compressor, which compression chamber is under alternating pressure is through an opening in communication with a diaphragm piston pump. This pump draws lubricating oil from the storage container and conveys it to a rotating spray disc connected to the shaft of the rotary piston compressor. The lubricating oil centrifuged by the spray disc or splash disc passes to a minor part to wires within the effective range of the spray or splash disc, which wires are arranged at a decline to the horizontal plane and lead to the lubricating point.
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1. In combination in a rotary piston compressor: main housing means, lateral housing means adjacent and laterally connected to said main housing means, rotary piston means rotatable within said main housing means and with said main housing means and said lateral housing means defining a compression chamber, a reservoir for receiving and storing a lubricant, a diaphragm piston pump arranged in said lateral housing means, first conduit means establishing communication between said reservoir and said diaphragm piston pump, second conduit means leading from said compression chamber to said diaphragm piston pump, bearing means arranged within said lateral housing means, shaft means rotatably journalled in said bearing means and eccentrically connected to said rotary piston means, splash disc means fixedly and eccentrically connected to said rotary piston means and rotatable therewith, said diaphragm piston pump being operable to draw a lubricant from said reservoir and convey lubricant to said splash disc means, and wire means arranged within the sphere of action of said splash disc means and while being inclined relative to a horizontal plane leading to a point to be lubricated.
2. An arrangement according to claim 1, in which said second conduit means is arranged in that lateral wall portion of said lateral housing means which partially defines said compression chamber.
3. An arrangement according to claim 1, in which a counterweight is associated with said splash disc means.
4. An arrangement according to claim 1, in which said wire means are radially spaced from the axis of rotation of said splash disc means.
5. An arrangement according to claim 1, in which said wire means are round wires of different diameters.
The present invention relates to a lubricating system for rotary piston compressors in which the lubricating oil passes from a storage container in predetermined quantities to the lubricating points. With engines of this type it is necessary to supply all parts which move relative to each other and contact each other (if they are not provided with self-lubricating materials or consist of such self-lubricating materials), with a lubricant which reduces the friction and conducts away frictional heat. For this purpose, mostly lubricating oil is employed which is in various manners and at predetermined quantities conveyed from a storage container to the lubricating points.
For meeting these requirements it is known in order to overcome pressure differences between the supply or storage container and the lubricating points -- which pressure differences are sometimes rather high -- to employ between the storage container and the lubricating points gear pumps, piston pumps or diaphragm pumps and when no pressure difference exists between the storage container and the lubricating points, to employ drip oilers, atomizers, wicks, lubricating rings or splash rods. If only relatively small quantities of lubricating oil are to be conveyed in a continuous manner in the same quantities or in different quantities to one or more lubricating points, only piston pumps, drip oilers or wicks are suitable. In this connection, however, the piston pump must have a plurality of pistons and a multi-stage transmission with regard to the speed of the shaft of the rotary piston compressor which requires a greater number of parts and is expensive. Drip oilers and wicks are reliable only when the ambient temperature does not vary much, because otherwise the quantities of lubricating oil will, due to the change in viscosity, likewise change.
It is an object of the present invention to overcome the above mentioned drawbacks. More specifically, the problem underlying the present invention consists in providing a structurally simple lubricating system according to which very small predetermined quantities of lubricating oil can from a storage container be conveyed uniformly to one or more lubricating points while different temperatures of the lubricating oil will have no influence upon the efficiency of the lubrication, and only a minimum of movable parts will be necessary.
These and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawing diagrammatically illustrating in section a lubricating system according to the present invention.
The lubricating system according to the present invention for rotary piston compressors is characterized primarily in that the compression chamber of the rotary piston compressor, which compression chamber is under alternating pressure, communicates through an opening with a diaphragm piston pump which draws in lubricating oil from the storage container and conveys the lubricant to a rotating splash disc connected to the shaft of the rotary piston conveyor. From said splash disc the centrifuged-off lubricating oil passes to a minor portion to wires arranged within the range of effectiveness of the splash disc, said wires being arranged so as to decline with regard to the horizontal plane while leading to the lubricating points.
For purposes of obtaining short paths from the diaphragm piston pump to the lubricant to be drawn in and to the rotatable splash disc, according to a further development of the invention, the opening from the compression chamber to the diaphragm piston pump is preferably located in a lateral portion of the rotary piston compressor.
In conformity with the invention, the splash disc is connected to a counterweight on the shaft of the rotary piston compressor and the counterweight or a portion thereof serves as splash disc. In order to permit a finest dosing of the lubricating oil intended for the lubricating points, according to a further development of the invention, the wires provided within the range of efficiency of the splash disc are arranged, more or less far in radial direction with regard to the axis of rotation of the splash disc or the crosssectionally rounded wires have different diameters.
The timewise consumption of lubricating oil at each lubricating point can be selected at random due to the fact that the wires are variously spaced from the splash disc or are of different diameters. Moreover, any desired number of lubricating points may be supplied simultaneously.
Referring now to the drawing in detail, the most important details of the lubricating system will now be explained in connection with the circular piston compressor shown in a fragmentary longitudinal section.
The arrangement shown in FIG. 1 comprises a mantle 1, piston 2 with piston teeth 3, a shaft 4 with a shaft bearing 5, and a counterweight 6, an eccentric 7 of shaft 4 with eccentric bearing 8, a pinion 9 with teeth, and a side part 10. Side part 10 together with an axially extending wall 11 and a cover 12 defines a closed chamber 13. The arrangement according to the invention furthermore comprises a compression chamber 14 and a storage container 15 with the lubricating oil 16. The position of the opening 17 in the side part 10 is so selected that during a major portion of the compression interval in the course of one revolution of shaft 4, this opening 17 communicates with the compression chamber 14 and is then briefly passed over by the sealing (not illustrated) strip springs of the piston. The thus occurring pressure pulses in the opening 17 are conveyed to the diaphragms of the diaphragm piston pump 18 located in the chamber 13, and thus take care of the operation of said diaphragm piston pump 18. The opening 17 may likewise be provided in the mantle 1. The arrangement according to the invention furthermore comprises a suction pipe 19 and a pressure pump 20 associated with the diaphragm piston pump 18. The pressure pump 20 laterally ends in a sleeve 21 closed at one end. Within said sleeve 21, a pressure spring 22 causes a felt piece 23 to engage the splash disc 24 which latter is fixedly connected to shaft 4 and/or the counterweight 6. The wire 25 located in the radial plane of the splash disc 24 and in the chamber 13 is inclined toward the side part 10 to which it is connected. Below the connecting area of the wire 25, a bore 26 is provided in the side part 10 and leads at a decline downwardly to the lubricating point 27 which in this instance is identical to the teeth 9 of the pinion. From here the piston teeth 3 simultaneously receive lubricating oil. The connecting area of the wire 25 and the entry to the bore 26 are in communication with each other through an inclined recess. In wall 11 and in the supply container 15 there are provided bores 28 and 29 located one above the other.
The operation of the lubricating system is as follows: In the compression chamber 14, the pressure will, due to the compression and intake operations, alternate with each revolution of the shaft 4. This alternating pressure is conveyed through opening 17 to the diaphragm of the diaphragm piston pump 18 so that lubricating oil is drawn in from the supply container 15 through the suction pipe 19, and through the pressure pipe 20 is drawn into the sleeve 21 and thus pressed into the felt member 23, which latter releases lubricating oil to the rotating splash disc 24. Due to the effect of centrifugal force, the lubricating oil is drawn off in finest droplets from the rim of the splash disc 24. The by far major portion of the lubricating oil is splashed inwardly against the wall 11 and returns through bores 28 and 29 to the storage container 15. The minor portion of the lubricating oil is caught by the wires 25 which extend at an incline upwardly from their connecting points adjacent the bores 26 into the radial plane of action of the lubricating oil centrifuged off from the splash disc 24. The lubricating oil particles trickle downwardly along the wires 25 in view of the force of gravity and are passed either through the bores 26 alone which are likewise inclined relative to the horizontal plane to the lubricating points 27 or the lubricating particles pass through the above mentioned bores 26 and non-illustrated tubes to the lubricating points 27 which may be located, for instance, at the other end of the engine.
As will be evident from the above, the advantages realized in conformity with the present invention are seen primarily in that with this lubricating system for rotary piston compressors for supplying lubricating points with a very small lubricating oil consumption, first a relatively large quantity of lubricating oil is conveyed whereby a great safety, for instance, against clogging up of the oil feeding lines by dirt or foreign articles will be realized. The diaphragm piston pump which consists only of a few movable parts and has proved highly reliable in operation, is actuated by the pressure variations in the compression chamber which are present anyhow. With this arrangement cam linkage systems or gears usually liable to disorders are not required for the arrangement according to the invention.
It is, of course, to be understood that the present invention is, by no means, limited to the specific showing in the drawing, but also comprises any modifications within the scope of the appended claims.