JPH09184490A - Drive shaft support structure of vane pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce manufacturing cost while certainly carrying out slip-off preventing device of a drive shaft. SOLUTION: This structure stores a cam ring 30 storing a rotor 31 and a vane 32 spline-connected to a drive shaft 5 free to rotate and furnishes with a body 1 furnished with a shaft hole 100 to axially support the drive shaft 5, a side plate 8 provided with a communicating passage 81 interposed between this body 1 and an end surface of the cam ring 30 and communicated to a high pressure chamber 12 corresponding to a discharge region of the cam ring 30 and partitioned in the body and a cover 2 to seal the inside of the body 1. Additionally, the drive shaft 5 is furnished with a small diametrical part 54 to be connected to the rotor 31 and a large diametrical part 55 formed with an outside diameter larger than the small diametrical part 54 and projected outside, a step part 56 is formed between this small diametrical part 54 and the large diametrical part 55, a bearing 18 to support the large diametrical part 55 is furnished in the shaft hole 100, and a shoulder part 1E free to make contact with this step part 56 is provided in the shaft hole 100.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive shaft support structure for a vane pump, and more particularly to an improvement of a drive shaft support structure for a vane pump, which is optimal as a hydraulic power source for a vehicle power steering device or the like.

[0002]

2. Description of the Related Art Vehicles such as automobiles are equipped with a power steering device using hydraulic pressure.
Traditionally, vane pumps have been adopted.
As a drive shaft support structure for a vane pump, a structure shown in FIG. 3 is known.

The vane pump has a cam ring 30, a rotor 31 and a vane 32 constituting the pump cartridge 3 housed on the inner periphery of a body 107. The cam ring 30 and the rotor 31 include a cover 106 fastened to the body 107, It is disposed between the body 107 and a side plate 108 fixed to the inner periphery of the body 107.

The rotor 31 is splined to a drive shaft 90 penetrating the body 107. A pulley (not shown) connected to an engine is connected to the base end 90B of the drive shaft 90 to drive the rotor 31 and the vanes 32. To do.

The drive shaft 90 is rotatably supported by a bearing 120 provided on the inner periphery of the body 107 on the base end 90B side and a bearing 121 provided on the inner periphery of the cover 106 on the tip 90A side. Abutment is supported without penetrating 106.

The rotor 31 and the drive shaft 90 are the drive shaft 90.
When a retaining ring 33 such as a circlip is fitted into a ring groove 52 formed on a predetermined outer periphery of the rotor and a force is applied in a direction in which the drive shaft 90 comes out of the body 107, the retaining ring 33 slides on the side plate 108. The drive shaft 90 is locked by 31 so that the displacement of the drive shaft 90 in the direction along the axis toward the right side in the drawing is restricted.

On the contrary, when a force for pressing the drive shaft 90 toward the cover 106 is applied, the drive shaft 90 tries to displace toward the left side in the drawing, but the tip 90A abuts on the inner surface of the cover 106, so that the drive is performed. The displacement of the shaft 90 is restricted.

In this vane pump, the body 10
7, a high pressure chamber 101 defined between the high pressure chamber 101 and a side plate 108, a passage 111 communicating the high pressure chamber 101 with the valve hole of the flow rate control valve 4, a suction connector 105 communicating with the outside of the body 107, and a flow rate. A low-pressure communication passage 109 is formed to circulate excess hydraulic oil in the control valve 4 to the pump cartridge 3, and when the drive shaft 90 is driven,
The hydraulic oil pressure-fed from the pump cartridge 3 via the communication hole of the side plate 108 is supplied to the high-pressure chamber 101, the passage 1
A required flow rate is supplied to a power steering device (not shown) via the valve 11 and the flow rate control valve 4, while the excess flow rate from the flow rate control valve 4 and the hydraulic oil from the suction connector 105 flow from the low pressure communication passage 109 to the cover 106. It flows into the inside and is sent to the suction region of the pump cartridge 3 through the hollow bifurcated passages 102, 102 that are bent and formed so as to bifurcate inside the cover 106.

Further, as disclosed in Japanese Utility Model Laid-Open No. 63-118388, a drive shaft cantilever is known, which is composed of a body 207 and a cover 206 as shown in FIG. A pump cartridge 203 composed of a cam ring, a rotor, and a vane is sandwiched between them, and the rotor of the pump cartridge 203 is spline-coupled with a drive shaft 190 penetrating a body 207. The base end 190B side is cantilevered by a bearing 218 provided on the inner circumference of the body 207.

On the other hand, the tip 19 protruding into the cover 206
0A is accommodated without coming into contact with the inside of the recess 224 formed in the cover 206.

In this case, as means for preventing the drive shaft 190 from coming off, the drive shaft 190 spline-coupled with the rotor is used.
Snap rings 233, 234 are fitted in front and rear of the drive shaft 190, and when an axial force is applied to the drive shaft 190, the snap rings 233 or 2
Since 34 is locked by the rotor, axial displacement of the drive shaft 190 can be regulated.

[0012]

However, in the former conventional example described above, the drive shaft 90 is rotatably supported by the bearing 120 of the body 107 and the bearing 120 of the end face of the cover 106. In the assembling process, a process of press-fitting the bearing 121 on the cover 106 side is required, and in order to secure the perpendicularity between the end surface of the cover 106 and the drive shaft 90 and the coaxiality between the bearings 120 and 121 and the drive shaft 90, the cover 106 and the body 107 are required. 3 has to be finished with a predetermined surface accuracy, which causes a problem that the number of processing steps or processing time increases and the manufacturing cost increases, and the drive shaft 90 is moved rightward in FIG. However, when the cover 106 is displaced toward the cover 106 side, the tip 90A of the drive shaft 90 is not covered by the cover 106.
Since it abuts against the inner surface of the cover 106, it is necessary to ensure the wall thickness strength for that amount, and it is necessary to strictly control the dimensions such as the depth of the receiving hole in the cover 106 into which the bearing 121 is press-fitted. This requires machining, which causes an increase in machining man-hour and time, which is a factor of increasing manufacturing cost. Further, since the outer diameter of the drive shaft 90 penetrating the side plate 108 is large, the pressure on the rotor 31 is increased. There is a problem that it is difficult to secure a loading area and it is difficult to improve pump efficiency.

In the latter conventional example, the drive shaft 19
Retaining rings 23 in front of and behind the rotor are used as 0
3 and 234 were fitted, but in the assembly process of the vane pump, it is necessary to assemble the retaining rings 233 and 234 from both sides of the rotor, so the workability is poor and the assembly man-hour increases and the productivity decreases, Further, there is a problem that it is difficult to automate the assembly line by a robot or the like.

Therefore, the present invention has been made in view of the above-mentioned problems, and reduces the man-hours for assembling the vane pump and improves the assemblability while surely preventing the drive shaft from coming off, and also improves the pump efficiency. It is an object of the present invention to provide a drive shaft support structure for a vane pump capable of performing the above.

[0015]

SUMMARY OF THE INVENTION A first aspect of the present invention is a cam ring for rotatably accommodating a rotor spline-coupled to a drive shaft, and a vane provided in and out of the rotor, and the cam ring. A pump body having a shaft hole for supporting the drive shaft, and a high pressure chamber defined in the body by being interposed between the body and the end face of the cam ring, and a discharge region of the high pressure chamber and the cam ring. In a drive shaft supporting structure of a vane pump including a side plate provided with a communication passage communicating with each other, and a cover for sealing the opening end face of the body, the drive shaft has a small diameter portion coupled to the rotor, and a small diameter portion from the small diameter portion. Also has a large diameter portion formed with a large outer diameter and protruding to the outside of the body, a step portion is formed between the small diameter portion and the large diameter portion, and the large diameter portion is supported in the shaft hole. First bearing to In addition, a shoulder portion is provided in the shaft hole of the body, the shoulder portion being capable of contacting the step portion, and retaining means for restricting displacement in the direction in which the drive shaft is pulled out of the body is provided between the drive shaft and the rotor. Prepare

In a second aspect based on the first aspect, the drive shaft penetrating the side plate has a small diameter portion.

In a third aspect based on the first aspect, a second bearing for supporting the small diameter portion is provided in the shaft hole of the body.

[0018]

Therefore, according to the first aspect of the present invention, the drive shaft spline-coupled to the rotor is provided with a step portion between the small diameter portion and the large diameter portion, and the small diameter portion engages with the rotor through the retaining means. Since the displacement of the drive shaft in the direction of coming out of the body is restricted, the drive shaft does not fall out of the body, while the stepped portion provided inside the shaft hole of the body causes the drive shaft to move toward the cover side. Since the displacement in the direction along the axis is restricted, the tip of the drive shaft does not contact the cover, and there is no need to provide a means to restrict the displacement of the drive shaft on the cover side or increase the wall thickness strength of the cover. While the drive shaft is prevented from coming off, the cover is not required to support the shaft so that the structure of the cover can be simplified and the number of processing steps can be reduced. Then, the stage Is abutted against the shoulder of the shaft hole and displacement is restricted.In this state, after assembling the side plate, rotor, cam ring, etc. to the body, the retaining device may be installed between the drive shaft and the rotor. The step portion of the shaft and the shoulder portion of the shaft hole can be used as positioning means during assembly.

Further, according to the second aspect of the invention, since the drive shaft penetrating the side plate has a small diameter portion, the pressure receiving area at the end face of the side plate facing the high pressure chamber communicating with the discharge region of the cam ring can be increased accordingly. The high-pressure oil that has flowed into the high-pressure chamber reliably presses the side plate toward the end face of the cam ring, reducing the leakage of pressure oil from the contact surface between the cam ring and the side plate and improving the efficiency of the vane pump. You can

According to the third aspect of the invention, the drive shaft is rotatably supported by the first and second bearings at the large diameter portion and the small diameter portion, respectively.
It is possible to suppress the shake of the small diameter portion of the drive shaft that is cantilevered by the body.

[0021]

1 shows an embodiment of a vane pump to which the present invention is applied.

In FIG. 1, reference numeral 1 denotes a body for supporting a drive shaft 5 and for accommodating a pump cartridge 3 and a flow control valve 4 of a vane pump, which comprises a cam ring 30 in which a rotor 31 and a vane 32 are rotatably accommodated. A cover 2 is coupled to the open end surface 1A of the body 1.

Inside the body 1, a pump cartridge 3 and a side plate 8 are housed in order from the opening end face 1A side, and a high pressure chamber 12 defined between the side plate 8 and the body 1 and the high pressure chamber 12 are formed. A passage 11 communicating with the valve hole of the flow control valve 4 is formed, and further, the pump body 1
A low-pressure communication passage 9 is formed which circulates the excess working oil in the suction connector 7 and the flow control valve 4 communicating with the outside of the pump cartridge 3 to the pump cartridge 3.

The hydraulic oil is pressure-fed to the high-pressure chamber 12 through the communication hole 81 of the side plate 8 facing the discharge area of the pump cartridge 3, and is required for a power steering device (not shown) through the passage 11 and the flow control valve 4. While the flow rate is supplied, the surplus flow rate from the flow rate control valve 4 and the hydraulic oil from the suction connector 7 flow into the inside of the cover 2 from the low pressure communication passage 9 and branch into two in the cover 2. It is sent to the suction area of the pump cartridge 3 via the bifurcated passages 6 formed in a bent manner.

A pulley (not shown) connected to the engine is coupled to the base end 5B of the drive shaft 5, and the rotor 31 is connected to the tip 5A side opposite to the base end 5B via a spline portion 53.
While the drive shaft 5 and the drive shaft 5 are connected in the rotational direction, the displacement in the direction along the axis is allowed.

Here, the drive shaft 5 covers the tip 5A side of the cover 2
The outer diameter of the tip end 5A side is smaller than the outer diameter of the base end 5B, and the tip end 5A has a predetermined diameter in the direction along the axis. It is formed as a small-diameter portion 54 having an outer diameter, and on the opposite side of the small-diameter portion 54, the base end 5B side protruding to the outside of the body 1 is formed as a large-diameter portion 55 having an outer diameter larger than that of the small-diameter portion 54. The step portion 5 is provided between the diameter portion 55 and the small diameter portion 54.
6 are formed.

On the other hand, the drive shaft 5 is provided at the substantially central portion of the body 1.
A shaft hole 100 for supporting the
Is provided with a first bearing 18 that supports a large diameter portion 55 of the drive shaft 5, and a second bearing 1 that axially supports the small diameter portion 54.
9 is disposed on the inner circumference of the small diameter portion 100B of the shaft hole 100, and the drive shaft 5 has a large diameter portion 55 and a small diameter portion 54 inside the body 1.
The bearings 18 and 19 are respectively supported at two positions.

Then, from the tip 5A side to the small diameter portion 54,
A ring groove 52 for fitting a retaining ring 33 such as a circlip and a spline portion 53 for coupling with the rotor 31 in the rotational direction are formed in this order as retaining means, and between the spline portion 53 and the step portion 56. Is rotatably supported by the bearing 19 and penetrates the side plate 8 between the spline portion 53 and the bearing 19.

A shoulder portion 1E is formed in the shaft hole 100 of the body 1 in a radial direction between the shoulder portion 1E and the small diameter portion 100B, and the shoulder portion 1E faces the step portion 56 of the drive shaft 5 in a predetermined relationship. A gap Δx is formed, and the gap Δx is formed when the drive shaft 5 is pushed along its axis, and the step portion 56 and the shoulder portion 1E.
Is set to a predetermined value that allows contact with.

The outer periphery of the boss portion of the body 1 provided with the small diameter portion 100B of the shaft hole 100 is fitted to the inner periphery of the side plate 8 and the high pressure chamber 12 of the boss portion of the body 1 is fitted.
An O-ring 41 is interposed between the body 1 and the inner peripheral surface of the end surface of the side plate 8, and an O-ring 42 is also arranged between the outer peripheral surface of the end surface of the side plate 8 and the body 1. Is installed. These O-rings 41 and 42 prevent the pressure oil from leaking in the high-pressure chamber 12, and the high-pressure oil in the high-pressure chamber 12 acts on the annular end surface portion surrounded by the O-rings 41 and 42. Thereby, a pressure loading area for pressing the side plate 8 toward the end surface of the pump cartridge 3 is formed.

The configuration is as described above. Next, the operation will be described.

By driving the drive shaft 5 via a pulley (not shown), the rotor 31 of the pump cartridge 3 rotates, and the high pressure oil in the discharge region of the pump cartridge 3 flows from the high pressure port 81 of the side plate 8 to the high pressure chamber 12. The high pressure chamber 12 and the passage 11 inside the body 1 are pumped.
While being guided to the flow rate control valve 4 via the outlet, only the necessary flow rate is supplied to the power steering device from a discharge port (not shown), while the surplus flow rate is returned to the low pressure communication passage 9 and merges with the hydraulic oil from the suction connector 7. Then, it again flows into the suction area of the pump cartridge 3. On the other hand, the high-pressure oil introduced into the high-pressure chamber 12 presses the side plate 8 toward the end surface of the pump cartridge 3 in the pressure loading area between the O-rings 41 and 42, and the pressure from between the cam ring 30 and the side plate 8 is increased. Controls oil leakage.

The drive shaft 5, which is cantilevered in the shaft hole 100 of the body 1, has the large diameter portion 55 supported by the bearing 18 and the small diameter portion 54 supported by the bearing 19, respectively. As described above, while omitting the bearing on the cover side to simplify the structure of the cover 2, it is possible to suppress the deflection of the tip end portion of the drive shaft 5 as compared with the cantilever support as in the latter conventional example. The durability of the vane pump can be improved.

Then, when the displacement amount of the drive shaft 5 in the axial direction toward the left side in the figure exceeds a predetermined value, the step portion 56 causes the shoulder portion 1E.
The displacement of the drive shaft 5 toward the left side in the drawing is regulated by contacting with the drive shaft 5, and the tip portion 50A of the drive shaft 5 is inserted into the escape recess 24
It is possible to prevent the drive shaft 5 from coming into contact with the bottom part of the rotor 1. When the drive shaft 5 is displaced in the direction of coming out of the body 1, that is, in the right direction in the drawing, the snap ring 33 locks the rotor 31. Since 31 is slidably contacted with the side plate 8 and locked, the drive shaft 5 is locked in the direction along the axis, and the drive shaft 5 can be prevented from coming off the body 1. The gap Δx between the step portion 56 and the shoulder portion 1E is set to a predetermined value when the retaining ring 33 is in contact with the rotor 31. That is, the drive shaft 5 has some play in the axial direction between the drive shaft 5 and the shoulder portion 1E, and can absorb thermal expansion and the like.

Thus, the drive shaft 5 is supported by the shaft hole 100,
It is carried out at two locations of the bearings 18 and 19 fixed to the 100B, and the cover 2 is provided with only the recess 24 for avoiding contact with the tip 5A of the drive shaft 5. As described above, it is not necessary to pivotally support the drive shaft on the cover side, and it is not necessary to strictly finish the coaxiality, the right angle, and the like, and the structure of the cover 2 is simplified to reduce the number of parts and the processing man-hours, and It is possible to reliably prevent disengagement, the thickness of the cover 2 can be reduced while reducing the manufacturing cost, and the vane pump can be reduced in size and weight.

In the assembly of such a vane pump, the drive shaft 5 is mounted on the shaft hole 100 of the body 1 from the small diameter portion 54 side.
And the step portion 56 is brought into contact with the shoulder portion 1E on the body 1 side, and the side plate 8 and the pump cartridge 3 are sequentially assembled from the open end surface 1A side of the body 1 into the concave body thereof, and then the ring By mounting the retaining ring 33 in the groove 52, the rotor 31 and the drive shaft 5 are coupled in the axial direction, and as described above, the step portion 56 and the shoulder portion 1E merely regulate the displacement of the drive shaft 5 in the axial direction. Alternatively, the pump can be used for positioning during assembly, and the assembly of such a pump can be performed from the opening end face 1A side. Therefore, the workability is improved as compared with the latter conventional example, and the robot etc. The automation of the assembly line by can be easily promoted.

Since the bearings 18 and 19 are arranged in the shaft hole 100 and the small diameter portion 100B of the body 1, the body 1
In addition to the fact that the shaft hole 100 and the small diameter portion 100B can be machined by the same blade after molding, the coaxiality can be secured more easily than in the conventional example, and the number of machining steps is reduced. Both reduction and improvement of work precision can be aimed at.

Further, since the drive shaft 5 penetrates the side plate 8 at the small diameter portion 54 having a small outer diameter with the step portion 56 as a boundary, it is higher in pressure than the inner peripheral side of the end face of the side plate 8 as compared with the conventional example. The inner diameter of the O-ring 41 interposed between the chamber 12 and the chamber 12 can be reduced, and the pressure loading area of the side plate 8 can be increased by that amount, thereby improving the efficiency of the vane pump. By reducing the outer diameter of 54, weight reduction can be promoted.

FIG. 2 shows a second embodiment, in which the bearing 19 of the small diameter portion 54 of the first embodiment is abolished and cantilevered only by the bearing 18, and other configurations are the same as the first embodiment.
The configuration is almost the same as that of the embodiment.

The small diameter portion 100B 'of the shaft hole 100 formed in the body 1'is only inserted through the small diameter portion 54 of the drive shaft 50, and the side plate 8 is not provided because the bearing 19 of the first embodiment is not provided. Also, the outer diameter of the boss portion of the body 1 provided with the small diameter portion 100B ′ for fitting the O-ring 41 can be further reduced, and the pressure receiving area of the side plate 8 on which the hydraulic pressure of the high pressure chamber 12 acts can be increased to the end surface of the cam ring 30. It is possible to further expand the pressure loading area that is pressed toward the direction, further improve the efficiency of the pump in addition to the operation of the first embodiment, and shorten the small diameter portion 54 to reduce the drive shaft 50. The overall length can be shortened, and the vane pump can be made smaller and lighter.

[0041]

As described above, according to the first aspect of the present invention, the drive shaft spline-coupled with the rotor is provided with the step portion between the small diameter portion and the large diameter portion, and the small diameter portion is provided with the retaining means. The drive shaft does not drop from the body because it is engaged with the rotor and the displacement of the drive shaft in the direction of coming out of the body is restricted. Since the displacement of the drive shaft in the axial direction toward the cover side is regulated by the step portion, the tip of the drive shaft does not contact the cover, and means for regulating the displacement of the drive shaft toward the cover side as in the conventional example. Since it is unnecessary to provide the drive shaft, the cover structure is simplified while the drive shaft is securely prevented from coming off, and the number of processing steps on the cover side is reduced, and the total length of the drive shaft is shortened as compared with the conventional example. The wall thickness and strength can also be reduced The vane pump can be made smaller and lighter.When the vane pump is assembled, if the drive shaft is inserted from the small diameter part into the shaft hole, the stepped part comes into contact with the shoulder part of the shaft hole and displacement is restricted. After assembling the rotor, the cam ring, etc. to the body, the retaining means may be installed between the drive shaft and the rotor, and the step portion of the drive shaft and the shoulder portion of the shaft hole should be used as positioning means during assembly. Since it is possible to reduce the man-hours of the assembly process as compared with the latter conventional example, it is possible to promote the reduction of the manufacturing cost, and the vane pump can be assembled from a single direction. The assembly line can be easily automated.

In the second aspect of the invention, since the small diameter portion of the drive shaft penetrates the side plate, the high pressure chamber communicating with the discharge region of the cam ring can expand the region facing the side plate. The inflowing pressure oil reliably presses the side plate toward the cam ring, reducing the leakage of pressure oil from the contact surface between the cam ring and the side plate, and improving the efficiency of the vane pump. By reducing the diameter, the size and weight can be further promoted.

In the third aspect of the invention, the drive shaft is rotatably supported by the first and second bearings at the large diameter portion and the small diameter portion, respectively.
The swinging of the small diameter portion of the drive shaft that is cantilevered by the body can be suppressed, and the durability of the vane pump can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a vane pump showing an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view showing the second embodiment and the vicinity of a step portion of a drive shaft.

FIG. 3 is a cross-sectional view of a conventional vane pump.

FIG. 4 is a cross-sectional view of a vane pump showing another conventional example.

[Explanation of symbols]

 1 Body 1A Open End Face 1E Shoulder 2 Cover 3 Pump Cartridge 4 Flow Control Valve 5 Drive Shaft 5A Tip 5B Base End 8 Side Plate 12 High Pressure Chamber 18, 19 Bearing 24 Recess 30 Cam Ring 31 Rotor 32 Vane 33 Retaining Ring 52 Ring Groove 53 Spline 54 Small diameter 55 Large diameter 56 Step 100 Shaft hole 100B Small diameter

Claims (3)

[Claims] 1. A cam ring that rotatably accommodates a rotor that is spline-coupled to a drive shaft, and a vane that is installed in and out of the rotor, and a shaft hole that accommodates the cam ring and that axially supports the drive shaft. And a side plate provided between the body and the end surface of the cam ring to define a high pressure chamber in the body, and a communication passage that connects the high pressure chamber and the discharge region of the cam ring. And a drive shaft supporting structure for a vane pump including a cover that seals the opening end surface of the body, wherein the drive shaft is formed with a small diameter portion that is coupled to the rotor and an outer diameter that is larger than the small diameter portion. A large diameter portion protruding to the outside of the body, a step portion is formed between the small diameter portion and the large diameter portion, and the shaft hole includes a first bearing for supporting the large diameter portion, and Of the body The shaft hole is provided with a shoulder portion that can come into contact with the stepped portion, and a retaining means is provided between the drive shaft and the rotor to restrict displacement of the drive shaft in a direction in which the drive shaft is pulled out of the body. Vane pump drive shaft support structure. 2. The drive shaft support structure for a vane pump according to claim 1, wherein the drive shaft penetrating the side plate has a small diameter portion. 3. The drive shaft support structure for a vane pump according to claim 1, wherein a second bearing that supports the small diameter portion is provided in the shaft hole of the body.