Title:
Pressured fluid pump or motor
United States Patent 2392279


Abstract:
This invention relates to fluid pumps or motors, and more particularly to an improved wobble plate type variable displacement constant pressure pump or motor. A primary object of the invention is to provide a structurally simplified and improved pump or motor of the type referred to which...



Inventors:
Woods, Robert J.
Application Number:
US56150744A
Publication Date:
01/01/1946
Filing Date:
11/02/1944
Assignee:
BELL AIRCRAFT CORP
Primary Class:
Other Classes:
73/715, 74/18.1, 91/472, 91/499, 92/48, 92/71, 92/90, 417/269
International Classes:
F04B1/14; F04B1/16; F04B1/29; F04B43/00; F04B43/08
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Description:

This invention relates to fluid pumps or motors, and more particularly to an improved wobble plate type variable displacement constant pressure pump or motor.

A primary object of the invention is to provide a structurally simplified and improved pump or motor of the type referred to which is relatively inexpensive to manufacture and adapted to be trouble-free over long periods of service. Other objects and advantages of the invention will appear in the specification hereinafter. The invention contemplates generally pump and motor devices comprising elastic housings containing pluralities of fluid carrying cells and means for alternately expanding and contracting the cells incidental to actuation of the pump or motor mechanical drive means.

In the drawing: Fig. 1 is a vertical longitudinal section through a. low pressure pulsating flow type pump of the invention; Fig. 2 is a section, as along line II-II of Fig. 1; Fig. 3 is a vertical longitudinal section through a high pressure integrated flow type pump of the invention; and Fig. 4 is a section as along line IV-IV of Fig. 3.

In Figs. 1 and 2 the invention is illustrated by way of example in a pump comprising a housing 10 which is formed with a fluid intake port 12 leading to fluid channels 14-16. Check valves 17-8 are disposed within the fluid channels 14-1I, respectively, and are backed by compression springs 20-21 so as to be adapted to seat against flow of fluid in reverse direction or toward the intake port 12. The channels 14-16 lead into communication with chambers 22-24 respectively; and outlet channels 26-28 lead from the chambers 22-24 to corresponding outlet ports 30-32 of the pump casing. Check valves 34--36 are disposed within the channels 26-28 and are backed by compression springs 38-39 so as to be adapted to block flow of fluid in reverse directions as from the outlet ports 30-32 inwardly of the casing.

A diaphragm is provided as designated generally at 40 and is formed of some suitable elastic material such as rubber or the like to be shaped to comprise a cup-lile body having an outer rim 42 flanged and clamped in fluid-tight relation against the inner face of the pump casing 10, as by means of bolts 44. The diaphragm 40 also includes an elastic top cover portion 45, and a partitioning wall 46 is formed integrally with the top cover 46 to extend transversely of the interior of the diaphragm into fluid-tight abutting relation against a central face portion of the pump casing 10. Thus, as shown more clearly in Fig. 2, the pump diaphragm is provided with a pair of fluid chambers 50-52 at positions above and below the partition wall 46 thereof; and the chambers 50-52 are in open communication, respectively, with the chambers 22-24 of the pump casing I0.

A wobble plate type unit is operably connected to the end wall 45 of the diaphragm for actuating the latter so as to alternately expand and contract the volumetric capacities of the fluid chambers 50-52 interiorly of the diaphragm. For this purpose the wobble plate mechanism is illustrated to comprise a frame 55 carrying a dual race bearing 60; the outer race portion of the bearing being fixedly mounted within the frame 55 and the inner race portion thereof being pivotally mounted as by means of a transverse pin 62 upon the inner end of the pump drive shaft 65. The drive shaft 65 is carried by a bearing 66 to be rotatably mounted upon a housing 70 which encloses the diaphragm 40 and clamps to the casing 10, as by means of the bolts 44.

Thus, it will be understood that the pin connection betveen the shaft 65 and the inner race of the bearing 60 will cause the latter to rotate with the drive shaft while the outer race of the bearing 60 is non-rotative and fixed to the diaphragm 40. A wobble plate angle adjustment device is illustrated in the drawing to comprise an arm 72, the main body portion of which is slipfitted longitudinally within a bored portion of the drive shaft 65 so as to be guided thereby, while a bent end portion 74 of the arm 72 extends laterally of the drive shaft 65 through a suitable aperture therein and terminates in a bearing ball 15 which is so arranged to press against the inner race of the bearing 60. At its outer end 77 the arm 72 is formed to operatively connect to any suitable manual or automatic adjustment device, whereby it will be understood that the adjustment arm 72 may be displaced at will in directions axially of the drive shaft 65 by simple operations performed externally of the pump and pump drive mechanism.

Inasmuch as the inner bearing race and the angle adjuster arm bearing 75 both rotate with the drive shaft 65, it will be appreciated that whenever the adjuster arm 72 is positioned so as to set the wobble plate at an inclination relative to the drive shaft, for example as viewed in Fig. 1, subsequent rotation of the drive shaft 65 will cause the inner race of the wobble plate to c3 clically cam the outer rim portion of the diaphragm in such manner that the cells 56-62 interiorly of the diaphragm will be alternately squeezed and stretched so as to provide alternate fluid pumping and sucking effects in the connected chambers 22-24. The check valve devices of the casing S0 will thereupon operate automatically so as to permit fluid to be drawn from the intake port I2 into the diaphragm cells as they are stretched and then to be pushed out through the discharge ports 30-82 as the cells are com. pressed. Cords or coil springs or the like as indicated at 80 will preferably be embedded in the rubber material so as to encircle the fluid cells to reinforce the latter against lateral deformations during the pump operation.

Thus, it will be understod that a pump of the character of the pump illustrated in Figs. 1-2 may be provided to be of utmost structural simplicity and to embody a minimum of fluid-sealing rela- 2 tively moving parts such as require high precision manufacturing methods and careful servicing. A pump of this type is adapted to displace fluids at varying rates of displacement, as controlled simply by setting of the position of the 2 adjuster arm 72 from externally of the pump and drive devices; and such adjustments may be made while the pump is operating as well as when it is inoperative. Thus, the rate of displacement of the pump is infinitely variable between zero 3 rate of displacement and the maximum rate of displacement as determined by the dimensioning of the displacement providing elements of the mechanism.

It will be appreciated, however, that the pump of Figs. 1-2 will be of the so-called pulsating flow type because of the opposed settings of the fluid cells interiorly of the diaphragm; and that therefore a pump device of this form is best adapted for service wherever relatively low pressures and pulsating flow performances are satisfactory.

Figs. 3-4 illustrate another form of pump or motor of the invention which is adapted to provide relatively high pressure and integrated type flow performances. In this case the valve casing 100 is formed with a fluid inlet port 102 carrying a fluid sealing packing 104 through which extends one end of the drive shaft 105. A valve plate 106 is carried by the drive shaft 105 and is keyed thereto so as to rotate with the drive shaft. A packing 108 fluid-seals the periphery of the valve plate 106 relative to the casing 100, and the valve plate 106 is positioned so as to slidingly bear at its inner side face against a stationary valve plate 110 which is clamped to the casing 100 by bolts S12. The diaphragm I 15 of the pump of Figs. 3-4 is generally similar to the diaphragm of Figs. 1-2, but differs therefrom in that it contains a relatively large number of fluid cells 116 (see Fig. 4) spaced concentrically of the drive shaft axis.

The wobble plate and plate angle adjustment devices 120-122 respectively, are illustrated to be identical to the corresponding devices of the mechanism illustrated in Figs. 1-2.

The fixed valve plate I IC is formed with a plurality of apertures 125 which are disposed in open communication respectively with corresponding fluid cells 118 in the diaphragm IS.

The rotating valve plate 106 is formed with a fluid outlet aperture 126 in the segment of the plate 10B corresponding to the segment of the diaphragm 115 which is squeezed whenever the wobble plate is set at an inclination by adjustment of the control arm 122; and the valve plate ,i.: 106 also carries a fluid intake port 128 at a position therein diametrically opposed to the position of the fluid outlet port 128 thereof. The fluid inlet port of the valve plate 106 is in open communication with a channel 120 disposed interiorly of the valve plate and leading into a centrally bored portion 130 of the drive shaft 105; the bored portion 130 of the drive shaft being extended to open into the fluid inlet port 102 of the pump casing.

S Thus, it will be understood that upon rotation of the drive shaft 105 while the wobble plate 120 is set at an inclination relative to the axis of the drive shaft, the wobble plate will operate to successively compress and squeeze the fluid cells I 8 of the diaphragm as the depressed segment of the wobble plate cycles around the annulus of fluid cells; and that the fluid outlet aperture 126 of the rotating valve plate accompanies this progression of the wobble plate so as to permit the 0 fluid as it is squeezed out of the cells to pass into the interior of the valve casing 100 for discharge through a port 132 thereof. At the same time the fluid inlet port portion 128 .of the rotating valve plate progresses in parallel with the segment of the wobble plate which is causing successive stretching of the diaphragm cells as the retarded portion of the wobble plate cycles around the annulus of fluid cells.

The mechanism of Figs. 3-4 is suited to fune0 tion in the manner of a motor as well as a pump, as by response to introduction of pressured fluid through the port 102. In any case it will be appreciated that the mechanism of Figs. 3-4 will be adapted to provide a smoother flow of transmitted .5 power than in the case of Figs. 1-2; but it must also be appreciated that in either of the examples illustrated the power output will be relatively smooth because the elastic properties of the diaphragm in either case will tend auto4M matically to provide absorption of pressure peaks.

If desired, coil springs or the like may be employed to reinforce the cells 16, as explained in connection with the cells 50-52 of Fig. 1. Also, if desired, any suitable automatic control for a5 varying the displacement rate may be employed in conjunction with the devices of the invention, such as a pressure responsive control device adapted to automatically shift the angle of the wobble plate so as to provide a substantially uni5 form pressure on the fluid system.

Thus, it will be appreciated that the invention provides a simplified mechanism for variable delivery constant pressure pumping action; and that pump or motor devices of the invention may 55 be constructed more cheaply than similar type pumps or motors of the prior art and will give less service trouble than such prior art types.

Although only a lfmited number of forms of the invention have been shown and described in de60 tail it will be apparent to those skilled in the art that the invention is not so limited that various changes may be made therein without departing from the spirit of the invention or the scope of the appended claims.

65 I claim: 1. A pressured fluid displacement mechanism comprising an elastic body having a fluid cell therein adapted to be dimensionally increased and decreased in one direction upon elastic de70 formation of said body, a fluid inlet-outlet system in open communication with said fluid cell, check valve means associated with said fluid inlet-outlet system for controlling fluid to travel in only one direction therethrough in response TO to alternate suction and pressure forces therein, means operably connected to said elastic body for displacement incidental to elastic deformation of said body to procure alternate expansion and contraction of said fluid cell, and reinforcing means within said body encircling said cell and flexible in said one direction and substantially rigid against deflections radially thereof.

2. A fluid pump comprising an elastic body having a fluid cell therein, a fluid inlet-outlet system in open communication with said fluid cell, check valve means associated with said fluid inlet-outlet system for controlling fluid to travel in only one direction therethrough in response to alternate suction and pressure forces therein, means operably connected to said elastic body 13 for elastic deformation thereof to produce alternate expansion and contraction of said fluid cell in one direction, and means reinforcing said cell against elastic deformation in directions radially of said one direction. 3. A fluid pump comprising an elastic body having a plurality of annularly spaced fluid cells therein, fluid inlet and outlet conduits, valve means movable to provide alternate connection of said fluid cells successively with said fluid inlet 23 and outlet conduits, check valve means associated with said fluid inlet and outlet conduits for controlling fluid to travel in only one direction therethrough in response to alternate suction and pressure forces therein, and means operably connected to said elastic body for universal bending elastic deformation thereof to produce alternate expansion and contraction of said fluid cells in consonance with movements of said valve means.

4. A fluid pump comprising an elastic body having a fluid cell therein, a fluid inlet-outlet system in open communication with said fluid cell, check valve means associated with said fluid inlet-outlet system for controlling fluid to travel in only one direction therethrough in response to alternate suction and pressure forces therein, means operably connected to said elastic body for elastic elongation deformation thereof to procure and contraction of said cell, and means retarding radial expansion and contraction of said fluid cell while permitting longitudinal deformations thereof.

5. A fluid pump comprising an elastic body having a plurality of annularly spaced fluid cells therein, fluid inlet and outlet conduits, valve means movable to provide alternate connection of said fluid cells successively with said fluid inlet and outlet conduits, check valve means associated with said fluid inlet and outlet conduits for controlling fluid to travel in only one direction therethrough in response to alternate suction and pressure forces therein, means operably connected to said elastic body for cyclic elastic elongation and shortening of annular portions thereof in consonance with movements of said valve means for successively elongating and shortening said cells, and means retarding lateral expansion and contraction of said fluid cells incidental to longitudinal deformation thereof.

6. A pressured fluid displacement mechanism comprising an elastic body having a plurality of fluid cells therein arranged concentrically of an axis, fluid inlet and outlet conduits, check valve means associated with said fluid inlet and outlet conduits for controlling fluid to-travel in only one direction therethrough in response to alternate suction and pressure forces 'therein, valve means rotatable about said axis /to provide alternate connection of said fluid cells successively with said fluid inlet and outlet conduits, and means operably connected to said elastic body for elastic deformation thereof to produce alternate expansion and contraction of said fluid cells cyclically in synchronism with rotation of said valve means.

ROBERT J. WOODS.