CA1315153C - Bi directional lubrication for a reversible hydraulic gear device - Google Patents
Bi directional lubrication for a reversible hydraulic gear deviceInfo
- Publication number
- CA1315153C CA1315153C CA000568127A CA568127A CA1315153C CA 1315153 C CA1315153 C CA 1315153C CA 000568127 A CA000568127 A CA 000568127A CA 568127 A CA568127 A CA 568127A CA 1315153 C CA1315153 C CA 1315153C
- Authority
- CA
- Canada
- Prior art keywords
- lubrication
- shaft
- commutator
- fluid
- journal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Rotary Pumps (AREA)
Abstract
ABSTRACT OF THE INVENTION
A bidirectional lubrication is provided for the shaft journal bearing of a reversible hydraulic gear device of the type having a journal bearing disposed in the commutator of the pump. A pair of lubrication ports on opposite sides of the journal bearing are connected to the inlet/outlet and outlet/inlet portions of the commutator to provide a flow of lubrication and cooling fluid across the bearing regardless of which direction the pump is operating.
A bidirectional lubrication is provided for the shaft journal bearing of a reversible hydraulic gear device of the type having a journal bearing disposed in the commutator of the pump. A pair of lubrication ports on opposite sides of the journal bearing are connected to the inlet/outlet and outlet/inlet portions of the commutator to provide a flow of lubrication and cooling fluid across the bearing regardless of which direction the pump is operating.
Description
BACKGRG-~JND OF THE INVENTION
Field of the Invention The present invention relates generally to internal gear hydraulic devices that can be used as pumps or motors and, more particularly, to reversible internal gear hydraulic devices with journal bearings.
Description of the Prior Art Many types of prior art hydraulic devices have utilized internal gear sets which are often called gerotors or rotors.
Such devices can be used as pumps where shaft work is converted to hydraulic work and as motors where hydraulic work is converted to shaft work. Examples of gerotor pumps and motors are shown in U.S. Patent Nos. 3,572,983; 4,411,607; 4,545,748;
and 4,586,885. In an internal gear pump or motor, an inner gear having outwardly directed teeth cooperates with an external gear having inwardly directed teeth so that fluid chambers therebetween increase and decrease in volume as the inner and outer gears rotate in a housing. By connecting the inlet and outlet of the device to the proper location along the sides of the gear set, the variable displacement chambers receive and discharge hydraulic fluid so that the device can function as a pump or motor. A shaft or other mechanical device can be connected to either the inner or outer gear depending upon the type of device.
1315~3 Many of the internal gear pumps and motors of the prior art utilize a housing having a fixed inlet and outlet. In other gerotor pumps and motors, a rotary valve plate or disc is used. An example of gear devices with a rotary valve plate are shown in U.S. Patent Nos.
4,411, 607; 4,545,748; 4,586,885; and 4,699,577. As described in these patents, the internal gear devices with rotary valves have a control plate or commutator with a plurality of inlet and outlet openings or windows on an axial face thereof. A valve plate with a plurality of openings extending axially therethrough is disposed between the gear set and the commutator to selectively communicate the inlet and outlet openings with the variable displacement chambers in the gear set. The valve plate is connected to rotate with the gear set such that the closing variable displacement chambers in the gear set are connected with the outlet openings of the commutator while the opening variable displacement chambers of the gear set are connected with the inlet.
In most of these devices a shaft extends through the commutator to internal gear set. The commutator has a journal bearing therein which receives and supports in rotation the journal of the shaft. Of course, clearance be~ween the journal of the shaft and the journal bearing of the commutator is small so that the shaft rotates smoothly.
A well known problem with respect to the operation of these internal gear devices is how to provide sufficient lubrication to the shaft, journal and journal bearing. This is especially a problem where non-axial forces act on the shaft and where variable pressure fluids are encountered in the operation of the device.
'~
SUMMARY OF THE INVENTION
It is accordingly an object of the present invention to provide and improve reversible internal gear hydraulic device which lubricates the shaft journal and journal bearing.
It is also an object of the present invention to provide such a device which lubricates the shaft journal and journal bearing with hydraulic oil in a manner which reverses with the reversing of the rotation of the shaft.
In accordance with these objects, the present invention provides an improved reversible hydraulic gear device of the type having a gear set connected to a shaft and a housing which has a commutator therein. The commutator has a journal bearing which supports in rotation a journal of the shaft. The commutator has first and ~econd fluid ports for communicating fluid to and from the gear set with the first ar.d second fluid ports reversing their respective functions as inlets and outlets of fluid with the reversing of the rotation of the shaft. The commutator has a first lubrication port extending from the first fluid port in the commutator through the journal bearing to the journal of the shaft. A commutator also has a second lubrication port extending from the second fluid port in the commutator through the journal bearing to the journal of the shaft. These lubrication ports allow hydraulic fluid conveyed through the commutator to the internal gear set to be utilized as lubrication for the journal of the shaft and the journal bearing. The first and second lubrication ports reverse their respective functions as inlets and outlets of lubrication fluid with the reversing of the rptation of the shaft. Preferably, the lubrication ports are disposed on opposing sides of the t 3 1 5 1 53 shaft to allow a more even distribution of the lubrication fluid over the bearing surface between the journal of the shaft and journal bearing of commutator.
For a further understanding of the in~ention and further objects, features and advantages thereof, reference may now be had to the following description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE ~RAWINGS
Figure 1 is a cross sectional view of an improved internal gear hydraulic device constructed in accordance with the present invention.
Figure 2 is an end view of the device illustrated in Figure 1.
~SCRIPTION OF TH~ PREF~RRED EMBODIM~NT
The present invention provides an improved internal gear hydraulic motor or pump of the type shown in U.S. Patent No. 4,545,748. The operation of the internal gears and other parts of the machine are well known in the art and are described in this patent. The general description of the operation of these parts contained in this patent is not described herein.
Referring now to Figure 1, an internal gear hydraulic device constructed in accordance with the present invention is shown at 11. The device includes a front housing piece 13 a rear housing piece 15 connected by bolts 17. An outer gear 19 ....
;~
c''.
and a plate spacer 21 are sandwiched between the rear housing piece 15 and the front housing piece 13 with the bolts 17 extending therethrough. These pieces together form the outside of the device 11.
Extending into the interior of the device 11 through the front housing piece 13 is a shaft 23. The shaft 23 is connected by a wobbling double ended gear shaft 25 to an inner gear 27. The wobbling doubled ended gear shaft 25 is often referred to as dog bone gear because it has gear teeth 29 and 31 extending outwardly on opposite ends of this device which cause it to have a dog bone shape. Gear teeth 29 engage mating teeth on the interior of the inner gear 27 and gear teeth 31 engage mating teeth on the interior of shaft 23.
The gear set formed by the outer gear 19 and the inner gear 27 combine so that the inner gear 27 rotates in an orbiting motion inside outer gear 19. The outwardly directed teeth of the inner gear 27 cooperate with the external gear having inwardly directed teeth so that fluid chambers therebetween increase and decrease in volume as the inner gear rotates in a wobbling motion. By connecting the increasing and decreasing fluid chambers to hydraulic inlets and outlets the device can function as a pump or motor to drive or be drived by the shaft 23.
Connecting the increasing and decreasing fluid chambers of the inner and outer gears 27 and 29 are inlet and outlet ports or conduits which extend through valve plate 33 commutator 35 and front housing piece 13. Since the device is reversible, the inlet and outlet ports reverse their function with the reversal of the rotation of the shaft 23. Thus, port 37 functions as an inlet during counter clockwise rotation of the 1 3 ! 5 1 '3 shaft ;23 and port 39 serves as an inlet an clockwise rotation of the shaft 23. When the port 37 is an inlet the port 39 is an outlet and vice versa. Port 37 is connected to an array of ports 41 in commutator 35 and port 39 is connected to an array of ports 43 in commutator 35. The array of ports 41 alternates with the array of ports 43. These parts selectively join with openings in valve plate 33 as valve plate 33 rotates to coordinate the flow of hydraulic fluid into and out of the increasing and decreasing fluid chambers between the inner and outer gears 27 and 29.
The commutator 35 has journal bearing surface 45 on its interior which receives the journal 47 of shaft 23. Thus, the shaft 23 is retained in rotation by this journal bearing connection. To provide lubrication to this journal bearing connection, a first lubrication port 49 extends from port 41 through the journal bearing surface on the interior of commutator 35 to the journal 47 of shaft 23. A second lubrication port 51 extends from the port 43 through the journal bearing surface 45 of commutator 35 to the journal 47 of shaft 23. These lubrication ports 49 and 51 are disposed on opposite sides of the shaft 23 so that lubrication fluid will be evenly distributed over the journal bearing surfaces.
The journal 47 has a diameter of approximately 1.4 inches and has a clearance from the bearing surface 45 of approximately 0.001 inches. The shaft 23 may rotate at speeds greater than 500 rpm and have very significant radial loads placed on it. Pressure drop from the port 37 to port 39 may be approximately a maximum of 2500 psi. Lubrication fluid in the journal bearing cavity forms a hydrodynamic sleeve bearing fluid wedge to prevent metal to metal contact under these conditions.
In order to maintain the proper amount of fluid for lubrication 1 ~15~53 and cc,oling it is desirable for the lubrication port 43 and 51 to have a diameter in the range of approximately 0.025 inches to approximately 0.100 inches. Most preferable is for the lubrication ports 49 and 51 to have a diameter of about 0.05 inches.
The port size described for ports 49 and 51 produces a low enough flow so as not to significantly reduce the efficiency of the pump while produces enough flow to cool and lubricate this bearing. Such flow is approximately .25 gallons per minute.
As can be seen, as the shaft 23 rotates in a counterclockwise direction hydraulic fluid enters through port 37 into commutator 35 and ports 41. It then passes through the valve plate 33 into increasing volume chambers between the inner and outer gears 27, 29. Fluid in decreasing volume chambers between inner and outer gears 27 and 29 move through the valve plate 33 into ports 43 and commutator 35 and out of port 39 in the housing 13.
As this occurs, hydraulic fluid moves through the lubrication port 49 into the journal bearing between shaft 23 and commutator 35 and exits the bearing at port 51. Thus, as hydraulic fluid is moved into and out of the increasing and decreasing fluid chambers between the inner and outer gears 27 and 29 an automatic lubrication flow into and out of the journal bearing between the shaft 23 and commutator 35 occurs.
During a clockwise rotation of the shaft 23 a reversal of the fluid flow occurs and a corresponding reversal of the lubrication flow occurs. Thus, lubrication port 51 becomes the inlet and lubrication port 49 becomes the outlet for lubrication fluid.
Thus, the internal gear hydraulic device with bidirectional lubrication as described is well adapted to obtain the objects and advantages mentioned as well as those inherent therein. While presently preferred embodiments of the invention have been described for the purpose of the disclosure, numerous changes in the construction and arrangement of parts can be made by those skilled in the art, which changes are encompassed within the spirit of this invention as defined by the appended claims.
The foregoing disclosure and showings made in the drawings were merely illustrative of the principles of this invention and are not to be interpreted in a limiting sense.
Field of the Invention The present invention relates generally to internal gear hydraulic devices that can be used as pumps or motors and, more particularly, to reversible internal gear hydraulic devices with journal bearings.
Description of the Prior Art Many types of prior art hydraulic devices have utilized internal gear sets which are often called gerotors or rotors.
Such devices can be used as pumps where shaft work is converted to hydraulic work and as motors where hydraulic work is converted to shaft work. Examples of gerotor pumps and motors are shown in U.S. Patent Nos. 3,572,983; 4,411,607; 4,545,748;
and 4,586,885. In an internal gear pump or motor, an inner gear having outwardly directed teeth cooperates with an external gear having inwardly directed teeth so that fluid chambers therebetween increase and decrease in volume as the inner and outer gears rotate in a housing. By connecting the inlet and outlet of the device to the proper location along the sides of the gear set, the variable displacement chambers receive and discharge hydraulic fluid so that the device can function as a pump or motor. A shaft or other mechanical device can be connected to either the inner or outer gear depending upon the type of device.
1315~3 Many of the internal gear pumps and motors of the prior art utilize a housing having a fixed inlet and outlet. In other gerotor pumps and motors, a rotary valve plate or disc is used. An example of gear devices with a rotary valve plate are shown in U.S. Patent Nos.
4,411, 607; 4,545,748; 4,586,885; and 4,699,577. As described in these patents, the internal gear devices with rotary valves have a control plate or commutator with a plurality of inlet and outlet openings or windows on an axial face thereof. A valve plate with a plurality of openings extending axially therethrough is disposed between the gear set and the commutator to selectively communicate the inlet and outlet openings with the variable displacement chambers in the gear set. The valve plate is connected to rotate with the gear set such that the closing variable displacement chambers in the gear set are connected with the outlet openings of the commutator while the opening variable displacement chambers of the gear set are connected with the inlet.
In most of these devices a shaft extends through the commutator to internal gear set. The commutator has a journal bearing therein which receives and supports in rotation the journal of the shaft. Of course, clearance be~ween the journal of the shaft and the journal bearing of the commutator is small so that the shaft rotates smoothly.
A well known problem with respect to the operation of these internal gear devices is how to provide sufficient lubrication to the shaft, journal and journal bearing. This is especially a problem where non-axial forces act on the shaft and where variable pressure fluids are encountered in the operation of the device.
'~
SUMMARY OF THE INVENTION
It is accordingly an object of the present invention to provide and improve reversible internal gear hydraulic device which lubricates the shaft journal and journal bearing.
It is also an object of the present invention to provide such a device which lubricates the shaft journal and journal bearing with hydraulic oil in a manner which reverses with the reversing of the rotation of the shaft.
In accordance with these objects, the present invention provides an improved reversible hydraulic gear device of the type having a gear set connected to a shaft and a housing which has a commutator therein. The commutator has a journal bearing which supports in rotation a journal of the shaft. The commutator has first and ~econd fluid ports for communicating fluid to and from the gear set with the first ar.d second fluid ports reversing their respective functions as inlets and outlets of fluid with the reversing of the rotation of the shaft. The commutator has a first lubrication port extending from the first fluid port in the commutator through the journal bearing to the journal of the shaft. A commutator also has a second lubrication port extending from the second fluid port in the commutator through the journal bearing to the journal of the shaft. These lubrication ports allow hydraulic fluid conveyed through the commutator to the internal gear set to be utilized as lubrication for the journal of the shaft and the journal bearing. The first and second lubrication ports reverse their respective functions as inlets and outlets of lubrication fluid with the reversing of the rptation of the shaft. Preferably, the lubrication ports are disposed on opposing sides of the t 3 1 5 1 53 shaft to allow a more even distribution of the lubrication fluid over the bearing surface between the journal of the shaft and journal bearing of commutator.
For a further understanding of the in~ention and further objects, features and advantages thereof, reference may now be had to the following description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE ~RAWINGS
Figure 1 is a cross sectional view of an improved internal gear hydraulic device constructed in accordance with the present invention.
Figure 2 is an end view of the device illustrated in Figure 1.
~SCRIPTION OF TH~ PREF~RRED EMBODIM~NT
The present invention provides an improved internal gear hydraulic motor or pump of the type shown in U.S. Patent No. 4,545,748. The operation of the internal gears and other parts of the machine are well known in the art and are described in this patent. The general description of the operation of these parts contained in this patent is not described herein.
Referring now to Figure 1, an internal gear hydraulic device constructed in accordance with the present invention is shown at 11. The device includes a front housing piece 13 a rear housing piece 15 connected by bolts 17. An outer gear 19 ....
;~
c''.
and a plate spacer 21 are sandwiched between the rear housing piece 15 and the front housing piece 13 with the bolts 17 extending therethrough. These pieces together form the outside of the device 11.
Extending into the interior of the device 11 through the front housing piece 13 is a shaft 23. The shaft 23 is connected by a wobbling double ended gear shaft 25 to an inner gear 27. The wobbling doubled ended gear shaft 25 is often referred to as dog bone gear because it has gear teeth 29 and 31 extending outwardly on opposite ends of this device which cause it to have a dog bone shape. Gear teeth 29 engage mating teeth on the interior of the inner gear 27 and gear teeth 31 engage mating teeth on the interior of shaft 23.
The gear set formed by the outer gear 19 and the inner gear 27 combine so that the inner gear 27 rotates in an orbiting motion inside outer gear 19. The outwardly directed teeth of the inner gear 27 cooperate with the external gear having inwardly directed teeth so that fluid chambers therebetween increase and decrease in volume as the inner gear rotates in a wobbling motion. By connecting the increasing and decreasing fluid chambers to hydraulic inlets and outlets the device can function as a pump or motor to drive or be drived by the shaft 23.
Connecting the increasing and decreasing fluid chambers of the inner and outer gears 27 and 29 are inlet and outlet ports or conduits which extend through valve plate 33 commutator 35 and front housing piece 13. Since the device is reversible, the inlet and outlet ports reverse their function with the reversal of the rotation of the shaft 23. Thus, port 37 functions as an inlet during counter clockwise rotation of the 1 3 ! 5 1 '3 shaft ;23 and port 39 serves as an inlet an clockwise rotation of the shaft 23. When the port 37 is an inlet the port 39 is an outlet and vice versa. Port 37 is connected to an array of ports 41 in commutator 35 and port 39 is connected to an array of ports 43 in commutator 35. The array of ports 41 alternates with the array of ports 43. These parts selectively join with openings in valve plate 33 as valve plate 33 rotates to coordinate the flow of hydraulic fluid into and out of the increasing and decreasing fluid chambers between the inner and outer gears 27 and 29.
The commutator 35 has journal bearing surface 45 on its interior which receives the journal 47 of shaft 23. Thus, the shaft 23 is retained in rotation by this journal bearing connection. To provide lubrication to this journal bearing connection, a first lubrication port 49 extends from port 41 through the journal bearing surface on the interior of commutator 35 to the journal 47 of shaft 23. A second lubrication port 51 extends from the port 43 through the journal bearing surface 45 of commutator 35 to the journal 47 of shaft 23. These lubrication ports 49 and 51 are disposed on opposite sides of the shaft 23 so that lubrication fluid will be evenly distributed over the journal bearing surfaces.
The journal 47 has a diameter of approximately 1.4 inches and has a clearance from the bearing surface 45 of approximately 0.001 inches. The shaft 23 may rotate at speeds greater than 500 rpm and have very significant radial loads placed on it. Pressure drop from the port 37 to port 39 may be approximately a maximum of 2500 psi. Lubrication fluid in the journal bearing cavity forms a hydrodynamic sleeve bearing fluid wedge to prevent metal to metal contact under these conditions.
In order to maintain the proper amount of fluid for lubrication 1 ~15~53 and cc,oling it is desirable for the lubrication port 43 and 51 to have a diameter in the range of approximately 0.025 inches to approximately 0.100 inches. Most preferable is for the lubrication ports 49 and 51 to have a diameter of about 0.05 inches.
The port size described for ports 49 and 51 produces a low enough flow so as not to significantly reduce the efficiency of the pump while produces enough flow to cool and lubricate this bearing. Such flow is approximately .25 gallons per minute.
As can be seen, as the shaft 23 rotates in a counterclockwise direction hydraulic fluid enters through port 37 into commutator 35 and ports 41. It then passes through the valve plate 33 into increasing volume chambers between the inner and outer gears 27, 29. Fluid in decreasing volume chambers between inner and outer gears 27 and 29 move through the valve plate 33 into ports 43 and commutator 35 and out of port 39 in the housing 13.
As this occurs, hydraulic fluid moves through the lubrication port 49 into the journal bearing between shaft 23 and commutator 35 and exits the bearing at port 51. Thus, as hydraulic fluid is moved into and out of the increasing and decreasing fluid chambers between the inner and outer gears 27 and 29 an automatic lubrication flow into and out of the journal bearing between the shaft 23 and commutator 35 occurs.
During a clockwise rotation of the shaft 23 a reversal of the fluid flow occurs and a corresponding reversal of the lubrication flow occurs. Thus, lubrication port 51 becomes the inlet and lubrication port 49 becomes the outlet for lubrication fluid.
Thus, the internal gear hydraulic device with bidirectional lubrication as described is well adapted to obtain the objects and advantages mentioned as well as those inherent therein. While presently preferred embodiments of the invention have been described for the purpose of the disclosure, numerous changes in the construction and arrangement of parts can be made by those skilled in the art, which changes are encompassed within the spirit of this invention as defined by the appended claims.
The foregoing disclosure and showings made in the drawings were merely illustrative of the principles of this invention and are not to be interpreted in a limiting sense.
Claims (3)
1. An improved reversible hydraulic gear device of the type having a gear set connected to a shaft and a housing which has a commutator therein with a journal bearing disposed in said commutator which supports in rotation a journal of the shaft, the commutator having first and second fluid ports for communicating fluid to and from the gear set, the first and second fluid ports reversing their respective functions as inlets and outlets of fluid to said gear set with the reversing of the rotation of the shaft; the improvement comprising:
the commutator having a first lubrication port extending from the first fluid port in said commutator through said journal bearing to said journal of said shaft;
the commutator having a second lubrication port extending from the second fluid port in said commutator through said journal bearing to said journal of said shaft; and said first and second lubrication port conveying fluid for lubrication to and from said journal and journal bearing from said first and second fluid ports, and said first and second lubrication ports reversing their respective functions as inlets and outlets of lubrication fluid with the reversing of the rotation of said shaft.
the commutator having a first lubrication port extending from the first fluid port in said commutator through said journal bearing to said journal of said shaft;
the commutator having a second lubrication port extending from the second fluid port in said commutator through said journal bearing to said journal of said shaft; and said first and second lubrication port conveying fluid for lubrication to and from said journal and journal bearing from said first and second fluid ports, and said first and second lubrication ports reversing their respective functions as inlets and outlets of lubrication fluid with the reversing of the rotation of said shaft.
2. The improved reversible hydraulic gear device of claim 1 wherein said first and second lubrication ports are disposed opposing each other with respect to said shaft.
3. The improved reversible hydraulic gear device of claim 2 wherein the size of said first and second lubrication ports provides a regulated flow of lubrication fluid to and from said journal and journal bearing.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000568127A CA1315153C (en) | 1988-05-30 | 1988-05-30 | Bi directional lubrication for a reversible hydraulic gear device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000568127A CA1315153C (en) | 1988-05-30 | 1988-05-30 | Bi directional lubrication for a reversible hydraulic gear device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1315153C true CA1315153C (en) | 1993-03-30 |
Family
ID=4138105
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000568127A Expired - Fee Related CA1315153C (en) | 1988-05-30 | 1988-05-30 | Bi directional lubrication for a reversible hydraulic gear device |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1315153C (en) |
-
1988
- 1988-05-30 CA CA000568127A patent/CA1315153C/en not_active Expired - Fee Related
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |