WO1986002126A1

WO1986002126A1 - Hydraulic gear motor/pump

Info

Publication number: WO1986002126A1
Application number: PCT/AU1985/000212
Authority: WO
Inventors: Sydney Graham Hooker
Original assignee: Sydney Graham Hooker
Priority date: 1984-09-28
Filing date: 1985-09-03
Publication date: 1986-04-10

Abstract

A fluid pump or motor comprising a stator or housing (11) supporting a plurality of pinion gears (13) each rotatably received within a chamber (12), the teeth of said pinion gears (13) being in substantially sealing engagement with the walls of the chamber (12), and annular gear (17), rotatable around said housing (11) having teeth on its internal face in a meshing engagement with the teeth of the pinion gears (13) and being in substantially sealing engagement with the exterior face of the housing (11), a fluid port (20) located in said housing (11) at each end limit of the meshing engagement between the teeth of each pinion gear (13) and the annular gear (17), the adjacent ports (20) of the said adjacent pinion gears (13) being of an opposite nature (inlet, outlet) to each other and the ports (20) associated with each pinion gear (13) being of an opposite nature (outlet, inlet) to each other.

Description

HTDEAϋXIC GEAR MOTOR/FϋMP THIS INVENTION relates to fluid pumps and fluid operated motors such as used in the hydraulic power transmission industry.

When used as a pump, the invention will permit a large number of pumps to be driven from a common input drive shaft, thus allowing many separate hydraulic circuits to be operated independently. It will also permit stepped variations in flow to a single hydraulic circuit by unloading or switching of any of the pumps.

10 When used as a motor its primary advantage is its capacity to produce high output torques at relatively low speeds, it would therefore be used in the final drives of tractors and mobile mining machinery for example.

In one form the invention resides in a hydraulic gear motor and/or pump comprising a housing supporting a pair of pinion gears each rotatably received within a chamber, the teeth of said pinion gear being in substantially sealing engagement with the walls of the 20 chamber, and annular gear rotatable around said housing

«f having teeth on its internal face in a meshing engagement with the teeth of the pinion gear and being in substantially sealing engagement with the exterior face of the housing, a fluid port located in said housing at each end limit of the meshing engagement between the teeth of each pinion gear and the annular gear, the adjacent ports of said adjacent pinion gears being of an opposite nature to each other and the ports associated with each pinion gear being of an opposite nature to each other.

According to a preferred feature of the invention the hydraulic gear motor and/or pump incorporates several pairs of pinion gears.

The invention will be more fully understood in the light of the following description of one specific embodiment. A description is made with reference to the accompanying drawings of which:-

Pigure 1 is a cross sectional side elevation of the embodiment;

Figure 2 is an end elevation of the embodiment having one end plate removed.

The embodiment comprises a hydraulic gear pump having a central housing or stator 11 formed with a plurality of cylindrical chambers 12. The stator 11 has fixed thereto a pair of end plates 14 to each side face of the stator 11. Each chamber 12 of the stator 11 support a pinion gear 13 which is rotatably supported by a shaft 16 from each end plate 14. The pinion gear 13 and chamber 12 are dimensioned such that minimal clearance is provided between the teeth of the pinion gear 13 and the walls of the chamber 12 in order that the two surfaces substantially sealing engage each other. The annular gear 17 is rotatably mounted over the stator 11 and is formed with teeth on its inner face which meshingly engage with the teeth of the pinion gear 13 which extend beyond the periphery of the stator 11 and substantially sealingly engage the outer face of the stator 11 between the pinion gears 13. The annular gear 17 is associated with a pair of end rings 18 which are rotatably supported from the end plates 14 through roller bearings 19.

The end plates are provided with a series of fluid ports 20 which communicate with the space defined between the stator 11, the pinion gear 13 and the annular gear 17 in the regions defined by the limits of the meshing engagement between the pinion gear 13 and the annular gear 17. As a result each pinion gear is associated with a pair of ports 20. At each location the port 20 comprise two ports to either side of the stator 11 which are formed in the end plate 14 and communicate with a substantially central passage extending from the end face of one end plate through the stator 11 to the other end plate. On rotation of the annular gear 17 the pinion gears 13 are caused to rotate and due to the volumetric changes occurring in the space defined between the stator, the pinion gear 13 and the annular gear 17 at the limits of the meshing engagement between the pinion gears 13 and the annular gear 17 fluid is drawn into that space where the teeth of the pinion gear and the annular gear are moving out of engagement as shown at A and fluid is forced from that space as the teeth of the pinion gear and the annular gear 17 move into engagement with each other as shown at B. Therefore the adjacent ports of a pair of adjacent pinion gears are of an opposite nature while the pair of ports of each pinion gear are also of an opposite nature. In use with the rotation of the annular gear in a counter clockwise direction fluid is drawn into the space defined between the teeth of the pinion gear and the annular gear where those teeth are moving away from each other. That fluid is then carried by the teeth of the pinion gear around the chamber 12 to the fluid port located to the other side of the pinion gear and fluid is carried by the teeth of the annular gear 17 to the next encountered fluid port of the following pinion gear 13. By connection of each of the inlet ports of each of the pinion gear and interconnection of each of the outlet ports of each of the pinion gears a common fluid input and discharge port 21 may be provided in the end plates 14. In addition if desired the inlet port and discharge port of a pinion gear may be selectively connected to each other in order that no pumping action is effected by the pinion gear and as a result the pinion gear does not exert any load upon the annular gear. This feature may be utilised to vary the flow rate produced from a pump and to vary the load exhibited upon the drive motor operating the pump. It should be appreciated that the embodiment may be readily modified to operate as a motor whereby the inlet ports are connected to a source of pressurised fluid which enduce a pressure at the zones A where the teeth of the pinion gear 13 and the annular gear 17 are departing from meshing engagement to effect rotation of the annular gear 17 and the pinion gear 13. In such an arrangement fluid flow may be cut off to any one of the pinion gear in order to increase the flow rate through the remaining pinion gear and increase the speed of rotation of the motor.

It should be appreciated that the scope of the present invention cannot be limited to the particular scope of the embodiment described above.

Claims

THE CLAIMS defining the invention are as follows :-

1. A fluid pump comprising a stator or housing supporting a plurality of pinion gears each rotatably received within a chamber, the teeth of said pinion gears being in substantially sealing engagement with the walls of the chamber, and annular gear, rotatable around said housing having teeth on its internal face in a meshing engagement with the teeth of the pinion gear and being in substantially sealing engagement with the exterior face of the housing, a fluid port located in said housing at each end limit of the meshing engagement between the teeth of each pinion gear and the annular gear, the adjacent ports of the said adjacent pinion gears being of an opposite nature to each other and the ports associated with each pinion gear being of an opposite nature to each other.

2. A fluid pump substantially as herein described with reference to the accompanying drawings.

3. A fluid pump having a plurality of pumping gear pinions as described in 1 with the discharge port of each pinion separate from the discharge port of all other pinions thus achieving a multiplicity of pump outputs from a single annular gear ring drive input.

4. A fluid pump having a plurality of pumping gear pinions as described in 1 with interconnected flow paths to produce a single output flow

5. A fluid pump as described in 1 with the annular gear ring held stationary and the drive to the pinions being accomplished by rotation of the housing.

6. A fluid motor comprising a stator or housing supporting a plurality of pinion gears each rotatably received within a chamber, the teeth of said pinion gears being in substantially sealing engagement with the walls of the chamber, and annular gear, rotatable around said housing having teeth on its internal face in a meshing engagement with the teeth of the pinion gears and being in substantially sealing engagement with the exterior face of the housing, a fluid port located in said housing at each end limit of the meshing engagement between the teeth of each pinion gear and the annular gear, the adjacent ports of said adjacent pinion gears being of an opposite nature to each other and the ports associated with each pinion gear being of an opposite nature to each other.

7. A fluid motor substantially as herein described with reference to the accompanying drawings.

8. A fluid motor having a plurality of gear pinions as described in 1 with the supply and discharge ports of each pinion separate from the supply and discharge ports of all other pinions thus achieving a multiplicity of motor displacements when connected to appropriate hydraulic switching elements.

9. A fluid motor having a plurality of gear pinions as described in 1 with the supply and discharge ports of all pinions interconnected to produce a single displacement motor.

10. A fluid motor having a plurality of gear pinions as described in 1 with the annular gear ring held stationary and the drive from the pinions being transferred to the housing causing the housing to rotate.