JPH07279871A - Drive shaft pivotally support structure in oil pump - Google Patents

Abstract

PURPOSE:To reduce the axial dimensions of a pump by interposing an oil seal between a pump body and a drive shaft, and by attaching a cover to the pump body so as to seal an outer side plate. CONSTITUTION:A drive shaft 13 piercing through a body pump 2 is spline-fitted in a rotor 7, and is rotatable fitted at its front end in an outer side plate 10, and a bushing collar 14 interposed between the pump body 2 and the drive shaft 13 is formed in a concave and convex shape, having smooth opposite end edges, and is formed of a cylindrically curved thin aluminum rectangular plate in which straight oil guide grooves are obliquely formed. Further, an annular protrusion 18 is formed on the outer side plate 10, surrounding around the front end part of the drive shaft 13 and directing toward the cover 11, and the outer peripheral of the front end thereof is fitted in a cylindrical recess 19 in the cover 11. As a result, the inner end of the bushing collar approaches the rotor, and accordingly, the axial dimensions of the pump body can be shortened, thereby it is possible to provide a small-sized oil pump.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention transmits the power of a prime mover such as an internal combustion engine through an endless power transmission belt such as an endless belt to supply pressurized oil to a power steering device of an automobile. The present invention relates to an oil pump, and particularly to a drive shaft support structure thereof.

[0002]

2. Description of the Related Art In an oil pump rotatably driven by power transmitted through an endless belt, a belt is attached to a pulley-side end portion 03 of a drive shaft 02 of the oil pump 01 as shown in FIG. Since the eccentric load P is applied along the tension direction of the drive shaft 02, the pulley side end 03 of the drive shaft 02 is pivotally supported on the pump body 05 via the ball bearing 04 so that the eccentric load P can be surely borne. And the other end 06 of the drive shaft 02
Was pivotally supported by the cover 08 of the oil pump 01 via the nylon bush 07.

The nylon bush 07 is a cylindrical fitting concave portion of the cover 08, which is formed by bending a belt-shaped one into a cylindrical shape so that its abutting portion is not located on the side opposite to the belt tension direction.
Bush 07 was pressed into 09.

Moreover, in order to prevent pressurized oil from leaking through the gap between the drive shaft 02 and the pump body 05, a ball bearing is used.
An oil seal 010 was installed between the drive shaft 02 and the pump body 05, which was located inside 04.

[0005]

[Problems to be solved] Oil pump 01 shown in FIG.
Since the ball bearing 04 is used, the number of parts is large, and the ball bearing fitting hole 011 of the pump body 05 is
Since the bush cylindrical fitting recess 09 of the cover 08 and the cover 08 need to be formed so as to match the center of the rotor 012 of the oil pump 01, the number of processing parts is increased and a step of press-fitting the bush 07 is required, resulting in cost increase. Was unavoidable.

Further, since it is necessary to secure a space for inserting the bush 07 into the cover 08, the cover 08 becomes thick, and the pump body 05 has a large diameter ball bearing fitting hole 011 and an oil seal inside thereof. Since the recess 013 for fitting 010 needs to be separated from the oil passage 014 of the oil pump 01 by a predetermined distance, the pump body 05 also has a large axial dimension, which makes it difficult to downsize the oil pump 01 in the axial direction. Met.

Further, when the tension direction of the endless belt changes,
The position of the contact portion of the bush 07 also had to be changed accordingly.

[0008]

SUMMARY OF THE INVENTION The present invention relates to an improvement in a drive shaft pivotal support structure of an oil pump which overcomes the above problems, and a power transmission to an oil pump drive shaft through an endless power transmission band. In the oil pump to which is transmitted, one end of the drive shaft on the endless power transmission band side is rotatably supported by the pump body via a metal bush collar, and the other end of the drive shaft is a rotor. Is rotatably supported by an outer side plate that sandwiches both side surfaces of the pump body in cooperation with the pump body, and an oil seal is provided between the pump body and the drive shaft at a position located outside the metal bush collar. It is characterized in that it is interposed and a cover is attached to the pump body so as to seal the outer side plate.

Since the present invention is configured as described above, the metal bush collar having a small outer diameter fitted to one end of the pump drive shaft on the endless power transmission band side interferes with the oil passage of the oil pump. The axial dimension of the pump body can be reduced without approaching the rotor side without rotating, and the thickness of the cover adjacent to the outer side plate can be reduced by pivotally supporting the other end of the pump drive shaft on the outer side plate. Can be made thin, and as a result, the axial dimension of the oil pump can be reduced.

According to the present invention, a ball bearing having a large number of parts does not pivotally support one end of the pump drive shaft on the endless power transmission band side, but one end of the pump drive shaft is pivoted by a single metal bush collar. In addition to supporting it, the other end of the pump drive shaft is pivotally supported directly on the outer side plate, so that the number of parts can be greatly reduced and the processing man-hour can be reduced. As a result, cost reduction can be promoted. it can.

Further, by constructing the present invention as set forth in claim 2, the other end of the pump drive shaft can be firmly supported without thickening the outer side plate.

According to the present invention as set forth in claim 3, the outer side plate is impregnated with oil to impart self-lubricating property to the pump drive shaft pivotal support portion, and the pump drive shaft The other end can be easily pivoted over a long period of time.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention shown in FIGS. 1 to 9 will be described below.

The oil pump 1 of the present embodiment is a vane type oil pump, in which a pump body 2 of the oil pump 1 is provided with a short cylindrical concave portion 3 and the short cylindrical concave portion 3 is provided with an inner side plate 4. The cam ring 5 is sequentially fitted,
A rotor 7 is fitted in the cam chamber 6 of the cam ring 5, a plurality of vane grooves 8 oriented in the radial direction are formed in the rotor 7, and vanes 9 are fitted in the vane grooves 8, respectively. Has been done.

An outer side plate 10 made of a ferrous sintered alloy is attached to the outer side surfaces of the cam ring 5 and the rotor 7, and the outer side plate 10 is in contact with the outer side surface.
The cam ring 5 and the rotor 7 by the 11 and the pump body 2.
Is sealed, and the pump body 2 and the cover 11 are integrally connected by a bolt 12.

Further, the drive shaft 13 penetrating the pump body 2
Is spline-fitted to the rotor 7, and the drive shaft
The tip of 13 is rotatably fitted to the outer side plate 10, and a bush collar 14 made of aluminum alloy is interposed between the pump body 2 and the drive shaft 13, and the bush collar 14 is
It is configured by bending a thin aluminum rectangular plate having both end edges formed into a smooth concave-convex shape and an oil guide groove 15 formed in a slanting linear shape on the inner surface into a cylindrical shape. Therefore, the oil guide groove 15 has a spiral shape.

The oil guide groove 15 formed on the inner surface of the bush collar 14 may be inclined in the opposite direction.

Furthermore, an oil seal 16 is interposed between the pump body 2 and the drive shaft 13 positioned outside the bush collar 14, and a driven pulley 17 is fitted to the outer end of the drive shaft 13 so that an internal combustion engine (not shown) is provided. An endless belt (not shown), which is an endless power transmission band, is spanned between a drive pulley (not shown) fitted to the crankshaft of the engine and the driven pulley 17.

On the outer side plate 10, an annular protrusion 18 is formed toward the cover 11 so as to surround the distal end of the drive shaft 13, and the outer periphery of the annular protrusion 18 has a cylindrical shape. It is fitted in the recess 19.

A suction joint 20 is fitted on the upper portion of the pump body 2, and the pump body 2 is fixed with a bolt 21.
The suction joint 20 is communicated with a suction passage 23 of the cover 11 via a suction passage 22 in the pump body 2, and the outer side plate 10 is provided with the suction passage 23 and the cam chamber 6. Two penetrating suction ports 24 communicating with each other are formed, and a discharge recess 25 is formed in the circumferential center of the two penetrating suction ports 24. An annular groove 26 is formed in the outer side plate 10, and a positioning notch 27 is formed in the outer peripheral portion of the outer side plate 10.

Further, the cam ring 5 is provided at a position corresponding to the two through suction ports 24 of the outer side plate 10,
Two through-suction passages 28 are formed to connect the through-suction port 24 and the suction recess 29 of the inner side plate 4, and the inner-side plate 4 penetrates and discharges in the middle in the circumferential direction of the two suction recesses 29. The port 30 is formed, and the pressure oil introduction through hole 31 and the pressure oil introduction recess 32 are alternately formed at a location where the radial position of the outer side plate 10 coincides with the annular groove 26, and the pressure oil introduction through hole 31 and The pressure oil introduction recess 32 is communicated with the annular groove 26 of the outer side plate 10 via the pressure oil introduction part 33 at the base of the vane groove 8 of the rotor 7, and the pressure oil introduction through hole is formed.
31 is also connected to the annular discharge passage 34 of the pump body 2.

Furthermore, in the pump body 2,
As shown in FIG. 8, a flow rate adjusting spool 38 is slidably fitted in a spool accommodating hole 37 of a relief valve 36 communicating with the discharge passage 34 through a through passage 35. A compression coil spring 41 is interposed in a pilot pressure chamber 39 partitioned by the flow rate adjusting spool 38,
The pressure oil introduced from the discharge passage 34 into the valve chamber 40 of the relief valve 36 through the through passage 35 flows into the pressure oil supply hole 43 through the throttle passage 42, and the pressure oil supply hole 43 passes through a pipe (not shown). Are supplied to the power steering device.

When the pressure in the valve chamber 40 rises above a predetermined pressure, the flow rate adjusting spool 38 overcomes the spring force of the compression coil spring 41 and is pushed toward the pilot pressure chamber 39, and the return passage 44 is passed. It is adapted to be returned to the suction passage 23. The pilot pressure chamber 39 and the pressure oil supply hole 43 communicate with each other via a relief passage 45.

A large-diameter O-ring 46 and a small-diameter O-ring 47 are provided between the pump body 2 and the inner side plate 4, and an O-ring 48 is provided between the pump body 2 and the cover 11. An O-ring 49 is also interposed between the body 2 and the suction joint 20.

Since the embodiment shown in FIGS. 1 to 9 is constructed as described above, when the driven pulley 17 is rotationally driven counterclockwise in FIG.
The volume of the space between the vanes 9 of the cam chamber 6 adjacent to the suction chamber 24 and the suction recess 29 increases with the rotation of the rotor 7, and due to the increase in the space volume, the suction joint 20 passes through the suction passages 22 and 23. When the oil is sucked into the cam chamber 6 and the space between the vanes 9 of the cam chamber 6 approaches the discharge recess 25 and the through discharge port 30, the space volume is reduced, and the space volume is reduced from the space. , Through discharge port
It is discharged to the annular discharge passage 34 through 30 and the discharge passage 34
The discharged oil therein is supplied to a power steering device (not shown) via a relief valve 36.

The pressure oil supply hole 43, that is, the valve chamber 40
When the internal oil pressure rises above a predetermined pressure, the flow rate adjusting spool 38 overcomes the spring force of the compression coil spring 41 and moves toward the pilot pressure chamber 39, and the valve chamber 40 and the return passage 44 are in communication. Then, excess oil flows back from the valve chamber 40 to the penetrating suction port 24 via the return passage 44 and the suction passage 23, and the oil having a constant pressure is supplied from the pressure oil supply hole 43 to the power steering device (not shown).

The pressure oil in the annular discharge passage 34 is
It is introduced into the pressure oil introduction portion 33 of the vane groove 8 of the rotor 7 through the pressure oil introduction through hole 31 of the inner side plate 4, and the pressure oil in the discharge passage 34 acts on the end face of the vane 9 on the center side. 9 is always brought into close contact with the inner peripheral surface of the cam chamber 6 of the cam ring 5, and the space partitioned by the vane 9 in the cam chamber 6 is kept oiltight.

Further, since the outer side plate 10 is made of a sintered alloy and is immersed in an oil atmosphere inside the pump body 2 and the cover 11, it is highly self-lubricating and the tip portion of the drive shaft 13 is rich. The rotational friction force of is small.

Further, the pressure oil in the pump body 2 is transferred from the pressure oil introducing through hole 31 of the inner side plate 4 to
Through the gap between the inner side plate 4 and the rotor 7 and the gap between the pump body 2 and the drive shaft 13, the bush collar
The oil guide groove of the bush collar 14 that reaches the inner end surface of the bush 14.
Since the periphery of the bush collar 14 is immersed in the oil atmosphere by the oil seal 16 while being introduced into the inside 15, the rotational frictional force of the base portion of the drive shaft 13 is small, and the tip portion of the drive shaft 13 described above is small. Drive shaft 13 with rotational friction
Can rotate lightly, and the power loss of the oil pump 1 is low.

In addition, since the bush collar 14 is thin, the bush collar 14 projects beyond the annular discharge passage 34 toward the rotor 7 and the axial dimension of the bush collar 14 becomes large. The bearing load per area is reduced, the drive shaft 13 can be reliably and reliably pivoted over a long period of time, and the durability is high.

Further, the annular protrusion 18 of the outer side plate 10
Since the drive shaft 13 is pivotally supported by the bush collar 14, the ball bearing is not required, the number of parts is reduced, and the cost can be reduced.

Further, the inner end of the bush collar 14 is connected to the rotor 7
Therefore, the axial dimension of the pump body 2 can be shortened, and the oil pump 1 can be downsized.

Furthermore, since the contacting edge of the bush collar 14 is curved, the supporting force of the bushing collar 14 does not suddenly change in the vicinity of the contacting edge.

Moreover, since the outer peripheral portion of the annular projection 18 of the outer side plate 10 is fitted in the cylindrical recess 19 of the cover 11, the pivotal strength of the annular projection 18 is high.

[Brief description of drawings]

FIG. 1 is a front view illustrating an embodiment of a drive shaft pivot structure of an oil pump according to the present invention.

FIG. 2 is a vertical sectional side view cut along a line II-II in FIG.

FIG. 3 is a vertical sectional side view cut along a line III-III in FIG.

FIG. 4 is a front view of the outer side plate viewed from the IV-IV direction in FIG.

5 is a rear view of the outer side plate viewed from the VV direction in FIG. 2. FIG.

FIG. 6 is a front view of a state in which the cam ring and the inner side plate are overlapped with each other as seen from the VI-VI direction in FIG.

7 is a cross-sectional view taken along the line VII-VII of FIG.

8 is a cross-sectional view taken along the line VIII-VIII of FIG.

FIG. 9 is a perspective view of a bush collar in the embodiment.

FIG. 10 is a vertical sectional side view of a conventional oil pump.

[Explanation of symbols]

1 ... Oil pump, 2 ... Bomb body, 3 ... Short cylindrical recess, 4 ... Inner side plate, 5 ... Cam ring, 6 ...
Cam chamber, 7 ... Rotor, 8 ... Vane groove, 9 ... Vane, 10 ...
Outer side plate, 11 ... Cover, 12 ... Bolt, 13 ...
Drive shaft, 14 ... Bush collar, 15 ... Oil guide groove, 16 ...
Oil seal, 17 ... Driven pulley, 18 ... Annular protrusion, 19
… Cylindrical recess, 20… Intake joint, 21… Bolt, 22,
23 ... Suction passage, 24 ... Through suction port, 25 ... Discharge recess, 26
... annular groove, 27 ... notch, 28 ... through suction passage, 29 ... suction recess, 30 ... through discharge port, 31 ... pressure oil introduction through hole, 32 ... pressure oil introduction recess, 33 ... pressure oil introduction section, 34 ... Discharge passage, 35 ... Communication passage, 36 ... Relief valve, 37 ... Spool housing hole, 38 ... Spool for flow rate adjustment, 39 ... Pilot pressure chamber, 40 ... Valve chamber,
41 ... compression coil spring, 42 ... throttle passage, 43 ... pressure oil supply hole, 44 ... return passage, 45 ... relief passage, 46, 4
7, 48, 49 ... O-ring,

Claims (3)

[Claims] 1. An oil pump in which power is transmitted to a drive shaft of an oil pump via an endless power transmission band, wherein one end of the drive shaft on the endless power transmission band side is connected to a pump body via a metal bush collar. The drive shaft is rotatably supported, and the other end of the drive shaft is rotatably supported by an outer side plate that sandwiches both side surfaces of a rotor together with the pump body, and is outside the metal bush collar. Drive of an oil pump characterized in that an oil seal is interposed between the pump body and a drive shaft at a position located at a portion, and a cover is attached to the pump body so as to seal the outer side plate. Axial support structure. 2. The drive shaft pivotally supporting portion of the outer side plate is formed with an annular protrusion projecting toward the cover, and the annular protrusion is fitted to the cover. Item 3. A drive shaft pivot support structure for an oil pump according to item 1. 3. The drive shaft pivot structure for an oil pump according to claim 1, wherein the outer side plate is made of a sintered material.