JP4838696B2 - Oil pump and power steering device - Google Patents

Description

  The present invention relates to a power steering device for a vehicle and an oil pump used for a drive source of the power steering device, for example.

  For example, as a conventional oil pump applied to a power steering device of a vehicle, for example, one described in Patent Document 1 below is known.

  The oil pump includes a pump body having one end in the axial direction coupled to the electric motor, a cover member disposed opposite to the other end in the axial direction of the pump body, and being sandwiched between the cover member and the pump body And a substantially annular cam ring fixed together by a plurality of bolts together with the two members, and fitted into a rotor receiving hole formed at a substantially central position of the cam ring. An outer rotor having a plurality of inner teeth formed by a high-order function curve based on a trochoid curve, and an inner rotor having outer teeth arranged on the inner peripheral side of the outer rotor and meshing with the inner teeth, respectively. And a drive shaft that is inserted through a drive shaft insertion hole that is formed in the axial direction at a substantially central position of the pump body, and is fixed to the central hole of the inner rotor. There.

The cam ring is fixed to the pump body in a state where the rotor housing hole is eccentric by a predetermined dimension with respect to the drive shaft insertion hole of the pump body, and the outer rotor is fixed to the drive shaft accordingly. On the other hand, by engaging in an eccentric state, a plurality of pump chambers are formed between the inner and outer teeth of the rotors.
JP-A-2005-47296

  By the way, in a power steering apparatus, since the hydraulic circuit is constituted by a closed circuit, as a hydraulic pump applied to such a power steering apparatus, it is important to stabilize the discharge characteristics of the pump. However, recently, it is desired to improve the accuracy of the cam ring assembly position.

  However, in the conventional oil pump, since the cam ring is fastened to the pump body together with the cover member by the bolt as described above, the mounting holes formed in the pump body, the cover member, and the cam ring are not fixed. The positional tolerance of the cam ring relative to the pump body is shifted due to the accumulated tolerance of the hole position, and as a result, the positional shift is likely to occur in the relative hole position between the drive shaft insertion hole of the pump body and the rotor accommodation hole of the cam ring. There was a problem.

  Thus, the distance between the inner and outer teeth (clearance) between the outer rotor fitted into the rotor housing hole of the cam ring and the inner rotor attached and fixed to the drive shaft pivotally supported by the drive shaft insertion hole of the pump body. As a result, the discharge characteristics of the pump may become unstable.

  The present invention has been devised by paying attention to such a technical problem, and improves the relative assembly position accuracy of the pump body and the cam ring, and the clearance between the inner and outer teeth of the outer rotor and the inner rotor. The oil pump etc. which can ensure the precision of this are provided.

The invention according to claim 1 is an internal gear in which a pump element including an inner rotor and an outer rotor meshing in an eccentric state is accommodated on an inner peripheral side of a cam ring sandwiched between a first housing and a second housing. In particular, the pump is configured to fix the cam ring to the first housing with a plurality of bolts inserted from the second housing side, and each of the through holes for inserting bolts formed in the cam ring and the respective holes. A radial gap for adjusting a radial position of the cam ring with respect to the first housing is provided between the bolt and the bolt .

According to the present invention, for assembling the other components after fixing the cam ring to the first housing by the bolts, to minimize the effects of tolerance stack-based machining accuracy of each of the components it can.

  Therefore, the cam ring can be assembled at an appropriate radial position with respect to the first housing without being affected by the machining accuracy of the component parts. As a result, the machining accuracy of the component parts is improved. It is possible to improve the assembly accuracy of the pump without extremely increasing it, that is, while suppressing an increase in manufacturing cost.

In addition , since the cam ring is fixed to the first housing separately from the second housing by the bolts , even if the second housing is removed during maintenance work of the pump, the cam ring There is no risk of misalignment. Accordingly, it is not necessary to perform the cam ring positioning work again at the end of the maintenance work, and the workability during the maintenance work can be improved.

Furthermore , since it is possible to adjust the radial position of the cam ring by the radial gap, an appropriate radial direction with respect to the first housing without being affected by the hole position accuracy of each through hole. The cam ring can be reliably arranged at the position.

  The invention according to claim 3 limits the application of the oil pump according to claim 1 to a power steering device.

  According to the present invention, an oil pump having a stable discharge characteristic can be obtained by the same effect as that of the first aspect of the present invention, so that the steering feeling of the power steering device can be improved.

  Hereinafter, embodiments of an oil pump and a power steering apparatus according to the present invention will be described in detail with reference to the drawings. In each of the embodiments, the oil pump and the power steering device are applied to a vehicle power steering device as in the conventional case.

  1 to 5 show a first embodiment of the present invention. First, a power steering device to which the oil pump 1 is applied includes a steering shaft 2 connected to a steering wheel SW as shown in FIG. A torque sensor 3 for detecting a steering torque of the steering shaft 2, a rack and pinion mechanism 4 which is a steering mechanism linked to the steering shaft 2, and a power cylinder 5 linked to the rack and pinion mechanism 4. The power unit 11 mainly supplies and discharges hydraulic pressure to and from the power cylinder 5.

  In the power cylinder 5, a rack shaft 7 connected to the rack and pinion mechanism 4 is inserted into a cylindrical cylinder tube 6 extending in the width direction of the vehicle body, and the rack shaft 7 passes through the cylinder tube 6. A sliding annular piston 8 is fixed. In the cylinder tube 6, left and right first hydraulic chambers 9 a and second hydraulic chambers 9 b are separated by a piston 8.

  The power unit 11 includes an electronic controller 12 that controls a vehicle state, an electric motor 13 that is driven based on a control current input from the electronic controller 12, and each hydraulic chamber 9a that is driven by the electric motor 13. , 9b, and a reversible oil pump 1 that selectively supplies and discharges hydraulic pressure to and from the power cylinder 5 through a pair of first and second pipes 10a, 10b.

  A fuel safe valve 14 is disposed in the middle of both the pipes 10a and 10b so that the hydraulic pressure in the power cylinder 5 can be supplied and discharged when a malfunction occurs in the power unit 11. It has become.

  As shown in FIG. 5, the oil pump 1 is disposed in a vertical shape that is in abutting state in the axial direction with respect to the electric motor 13 disposed below, and is provided integrally with the reservoir tank T.

  As shown in FIGS. 3 and 4, the oil pump 1 has a pump body 21 that is a first housing coupled to the upper end portion of the electric motor 13, and the upper end side of the pump body 21 is closed. And a cover member 22 as a second housing that is coupled to the pump body 21 by four bolts 20 as coupling means, and is sandwiched between the cover member 22 and the pump body 21 A substantially annular cam ring 23 disposed on the inner ring side, an outer rotor 24 fitted on the inner peripheral side of the cam ring 23 so as to be slidable and rotatable and having inner teeth 24a on the inner peripheral side, An inner rotor 25 having outer teeth 25a arranged on the circumferential side and meshing with the inner teeth 24a, and a drive formed in the center of the pump body 21 along the axial direction. It is fitted through the shaft insertion hole 21a, and a, a drive shaft 26 which is locked fixed via a pin member 27 in the center hole 25b of the inner rotor 25.

  The pump body 21 is formed in a substantially cylindrical shape, has a flange portion 21d for coupling to the electric motor 13 at the lower end portion in FIG. 3, and has a flat upper end surface. On the upper end surface, the first and second crescent-shaped first and second parts are divided and formed every half circumference along the circumferential direction at a position corresponding to the pump chamber formed between the inner and outer teeth 24a and 25a of the rotors 24 and 25. Two ports P1 and P2 are provided substantially symmetrically with respect to the drive shaft insertion hole 21a.

  Further, the upper end surface of the pump body 21 is formed at substantially equal intervals in the circumferential direction of the four screw holes 21b into which the bolts 20 are screwed, and is adjacent to the screw holes 21b. A pair of positioning holes 21c, 21c are formed substantially symmetrically with respect to the drive shaft insertion hole 21a between the predetermined screw holes 21b, 21b. The positioning holes 21c, 21c have a pair of positioning holes 21c, 21c. The positioning pins 28 are inserted and arranged so as to protrude from the upper end surface of the pump body 21.

  A pair of first and second oil holes N1 communicated with the first and second ports P1 and P2 on the outer side of the pump body 21 and are relatively discharged or suctioned depending on the rotation direction of the pump. , N2 are drilled, and the pipes 10a, 10b are connected to the oil holes N1, N2, respectively.

  As shown in FIG. 1, the cover member 22 is formed in a substantially cylindrical shape having an oil passage therein, and the bolts 20 are inserted into positions corresponding to the screw holes 21 b of the pump body 21. Four attachment holes 22a are formed penetrating each other. The inner diameters r3 of the mounting holes 22a are set slightly larger than the outer diameters r4 of the insertion portions 20a of the bolts 20.

  Further, on the inner side surface of the cover member 22, as shown in FIG. 4, the positioning pins 28, 28 are located at positions corresponding to the positioning pins 28, 28 protruding from the upper end surface of the pump body 21. Positioning recesses 22b and 22b are respectively bored. The inner diameter r5 of the positioning recess 22b is set slightly larger than the outer diameter r6 of the positioning pin 28.

  One end side of the drive shaft 26 is formed on a bearing 29 a disposed in the drive shaft insertion hole 21 a of the pump body 21, and the other end is formed at a position corresponding to the drive shaft insertion hole 21 a in the cover member 22. The rotors 24 and 25 are rotatably supported by bearings 28b disposed in the support holes 22c, and the rotors 24 and 25 are driven to rotate by a driving force applied from the electric motor 13.

  The cam ring 23 is formed to have substantially the same thickness width d1 as the rotors 24 and 25, and has a rotor receiving hole 23a having an inner diameter r1 slightly larger than the outer diameter of the outer rotor 24 at the center position. Is formed penetrating along the axial direction.

  As shown in FIG. 2, the cam ring 23 is arranged with the rotor accommodating hole 23 a slightly decentered in the radial direction with respect to the drive shaft insertion hole 21 a of the pump body 21 by a jig 30 described later. ing. The eccentric amount X is set to about 1.18 mm.

  As shown in FIG. 2, the jig 30 has a shape in which two cylinders are combined in an eccentric state, has a thickness width D1 larger than a thickness width d1 of the cam ring 23, and the cam ring. A large-diameter portion 30a having an outer diameter R1 that fits into the rotor housing hole 23a, and an outer diameter R2 that has a predetermined axial length and fits into the drive shaft insertion hole 21a of the pump body 21. And a small diameter portion 30b.

  The outer diameters R1 and R2 of the large-diameter portion 30a and the small-diameter portion 30b of the jig 30 are clearance fits that do not have any interference with the inner diameter r1 of the rotor housing hole 23a and the inner diameter r2 of the drive shaft insertion hole 21a. The large diameter portion 30a can be inserted into the rotor housing hole 23a, and the small diameter portion 30b can be inserted into the drive shaft insertion hole 21a.

  The jig 30 has the small-diameter portion 30b fitted into the drive shaft insertion hole 21a from the upper end surface side of the pump body 21 with the cam ring 23 placed on the upper end surface of the pump body 21. The large-diameter portion 30a is fitted into the rotor receiving hole 23a and simultaneously fitted into both the holes 21a and 23a, whereby the cam ring 23 is positioned in an eccentric state with respect to the pump body 21. ing.

  Further, as shown in FIGS. 3 and 4, the positioning pins 28, 28 are inserted into the cam ring 23 at positions corresponding to the positioning pins 28, 28 protruding from the upper end surface of the pump body 21. Pin insertion holes 23b, 23b are formed penetratingly. The inner diameter r7 of the pin insertion hole 23b is slightly larger than the outer diameter r6 of the positioning pin 28, so that the cam ring 23 can be roughly positioned with respect to the pump body 21, and the positioning operation can be easily performed. It is like that.

  Further, as shown in FIG. 1, the cam ring 23 is located at a position corresponding to each screw hole 21 b of the pump body 21 in the eccentric state as described above than the outer diameter r4 of the insertion portion 20 a of each bolt 20. Four bolt insertion holes 23c each having a slightly larger inner diameter r8 are formed through. Thus, the cam ring 23 is coupled to the upper end portion of the pump body 21 by the bolts 20 together with the cover member 22 through the bolt insertion holes 23c.

  Further, as shown in FIG. 2, the rotors 24, 25 and the drive shaft 26 cannot be assembled to the pump body 21 with the jig 30 attached, so that the cam ring 23 is positioned by the jig 30. After that, as shown in FIG. 1, it is fixed to the pump body 21 by a pair of small diameter bolts 31, 31 as fixing means, and the radial position with respect to the pump body 21 positioned by the jig 30 is securely held. It has come to be.

  That is, as shown in FIG. 1, the cam ring 23 is independently fixed by the small-diameter bolts 31, 31 separately from the joint bolts with the cover member 22 by the bolts 20. It is fixed to the position. More specifically, it is assumed that the cam ring 23 is fixed to the pump body 21 by the small-diameter bolts 31, 31, and then the cover member 22 is fixed to the pump body 21 for the sake of convenience. The cover member 22 is fixed together with the cover member 22.

  Due to the mounting structure of the cam ring 23, the small diameters of the upper end surface of the pump body 21 are shifted to the positions shifted from the positioning holes 21 c, 21 c by approximately 90 ° as shown in FIG. A pair of small screw holes 32, 32 into which the bolts 31, 31 are screwed are formed along the axial direction.

  Further, as shown in FIG. 1, a pair of screw portions 31 a and 31 a of the small-diameter bolts 31 and 31 are inserted into the cam ring 23 at positions corresponding to the small screw holes 32 and 32 of the pump body 21. Through holes 33 and 33 are formed penetrating along the axial direction.

  Each of the through holes 33 and 33 has an inner diameter r9 that is set to be slightly larger than an outer diameter r10 of the top of the thread in the threaded portions 31a and 31a of the small-diameter bolts 31 and 31. Accordingly, radial gaps C and C are formed between the inner peripheral surfaces of the through holes 33 and 33 and the apexes of the threads of the screw portions 31a and 31a of the small diameter bolts 31 and 31, respectively. .

  The inner surface of the cover member 22 has a clearance having an inner diameter r12 slightly larger than the outer diameter r11 of the heads 31b and 31b of the small diameter bolts 31 and 31 at positions corresponding to the through holes 33 and 33. Holes 34 and 34 are formed, respectively.

  As shown in FIGS. 3 and 5, the oil pump 1 configured as described above has an outer rotor 24 arranged eccentrically with respect to the drive shaft 26 together with the cam ring 23 to rotate the inner rotor 25. In association with the eccentric rotation, the volume of the pump chamber formed between the inner and outer teeth 24a and 25a is increased and decreased continuously through the ports P1 and P2 and the oil holes N1 and N2. Oil is sucked and discharged. As a result, oil is supplied to and discharged from the hydraulic chambers 9 a and 9 b of the power cylinder 5 in accordance with the rotation direction of the electric motor 13 that is driven and controlled by the electronic controller 12.

  Below, the assembly method of the oil pump 1 which concerns on this invention is demonstrated based on FIGS.

  First, as shown in FIG. 3, the positioning pins 28 and 28 are inserted into the positioning holes 21c and 21c of the pump body 21, respectively. The positioning pins 28 and 28 are inserted into the pin insertion holes 23b of the cam ring 23, respectively. The cam ring 23 is placed on the upper surface of the pump body 21 using the positioning pins 28 and 28 as a guide.

  As shown in FIG. 2, the small diameter portion 30b of the jig 30 is fitted into the drive shaft insertion hole 21a of the pump body 21, and the cam ring 23 is moved in the radial direction while rotating the jig 30. The large-diameter portion 30a of the jig 30 is fitted into the rotor accommodating hole 23a of the cam ring 23, and the cam ring 23 is positioned in the radial direction with respect to the pump body 21.

  Subsequently, with the jig 30 attached, the screw portions 31a and 31a of the small-diameter bolts 31 and 31 are inserted into the through holes 33 and 33 of the cam ring 23 as shown in FIG. The cam ring 23 is fixed to the pump body 21 at the upper end by screwing it into the small screw holes 32 of the pump body 21.

  Next, the jig 30 is removed, and the inner rotor 25 is locked and fixed to the other end side of the drive shaft 26 via the pin member 27 as shown in FIGS. 3 and 4. One end side of the drive shaft 26 is inserted into the drive shaft insertion hole 21a of the pump body 21 from the upper end side until the inner surface of the inner rotor 25 contacts the upper end surface of the pump body 21. Subsequently, the outer rotor 24 is fitted to the inner peripheral side of the cam ring 23 while the inner teeth 24 a of the outer rotor 24 and the outer teeth 25 a of the inner rotor 25 are engaged.

  The positioning pins 28 and 28 are fitted into the positioning recesses 22b and 22b of the cover member 22, respectively, and the escape holes 34 and 34 are connected to the small-diameter bolts using the positioning pins 28 and 28 as guides. The cover member 22 is placed on the outer surface of the cam ring 23 by being fitted to the heads 31 b and 31 b of 31 and 31, respectively.

  Finally, the bolts 20 are inserted into the mounting holes 22a of the cover member 22 and tightened to fix the cover member 22 together with the cam ring 23 to the pump body 21, thereby fixing the oil pump 1. Assembly is complete.

  In this way, the structure in which the cam ring 23 is fixed to the pump body 21 independently by the small-diameter bolts 31, 31 separately from the joint fastening with the cover member 22 by the bolts 20 is adopted. The cam ring 23 can be disposed at an appropriate radial position without depending on the processing accuracy of each component such as the hole position accuracy of each mounting hole 22a. It has become.

  Since the cam ring 23 is fixed to the pump body 21 while the cam ring 23 is positioned by the jig 30, the cam ring 23 is removed when the jig 30 is removed or during the subsequent assembly process. There is no risk of misalignment. As a result, the oil pump 1 can be assembled while the radial position of the cam ring 23 positioned by the jig 30 is maintained, and the assembly position accuracy of the cam ring 23 can be reliably ensured.

  Therefore, according to this embodiment, since the cam ring 23 is previously fixed to the pump body 21 by the small-diameter bolts 31, 31, the relative positional accuracy between the pump body 21 and the cam ring 23 is the most important. In this case, the influence of the accumulated tolerance based on the machining accuracy of each component such as the cover member 22 and the cam ring 23 can be minimized.

  Thus, the proper assembly accuracy of the cam ring 23 can be ensured without extremely increasing the processing accuracy of each component, that is, without causing an increase in manufacturing cost. The interdental clearance between the inner and outer teeth 24a and 25a can be optimized. As a result, the oil pump 1 having stable discharge characteristics is obtained, and the steering feeling of the power steering device is improved.

  Moreover, since the cam ring 23 can be adjusted in radial position by the radial gaps C and C, it is not affected by the accuracy of the hole positions of the through holes 33 and 33. The cam ring 23 can be securely assembled to the pump body 21 at an appropriate radial position, and a decrease in yield due to poor hole position accuracy of the through holes 33 and 33 can be suppressed.

  Since the cam ring 23 is fixed to the pump body 21 independently of the cover member 22, when performing maintenance work of the pump, each rotor 24 is not accompanied by a displacement of the cam ring 23. , 25 and the drive shaft 26 can be detached. Thereby, it is not necessary to perform the positioning operation of the cam ring 23 again when the pump is reassembled after the maintenance operation, and as a result, the maintainability of the pump can be improved.

  Further, since the cam ring 23 is fixed to the pump body 21 by the small-diameter bolts 31, 31, the cam ring 23 can be firmly fixed to the pump body 21, and the radial position of the cam ring 23 is determined. It can be reliably maintained.

  On the other hand, since the fixing means of the cam ring 23 to the pump body 21 is simply fastened by the small diameter bolts 31, 31, the radial position of the cam ring 23 can be adjusted by loosening the small diameter bolts 31, 31. Since the correction can be made, a decrease in the yield of the oil pump 1 caused by directly fixing the cam ring 23 to the pump body 21 is also suppressed.

  FIG. 6 shows a second embodiment of the present invention, in which the positioning pins 28 and 28 in the first embodiment are eliminated, and the heads 31b and 31b of the small-diameter bolts 31 and 31 are used instead. Projecting portions 35, 35 projecting in the axial direction are formed on the upper end portions of the cover members 22, and the projections 35, 35 are located at positions corresponding to the projecting portions 35, 35 at the bottoms of the escape holes 34, 34 of the cover member 22 The positioning recesses 22b and 22b into which the portions 35 and 35 are fitted are formed, and the cover member 22 is positioned by the projections 35 and 35. The outer diameters of the protrusions 35 and 35 are set to be substantially the same as the outer diameter r6 of the positioning pins 28 and 28 in the first embodiment.

  Also in this embodiment, the same operation and effect as in the first embodiment can be obtained, as well as the drilling operation for forming the positioning holes 21c and 21c in the pump body 21 and the positioning holes 21c, Since it is possible to omit the pin insertion work for inserting the positioning pins 28 and 28 into 21c, the assembly work of the oil pump 1 can be further facilitated.

FIG. 7 shows a first reference example of the present invention, in which the means for fixing the cam ring 23 to the pump body 21 in the first embodiment is changed, and the cam ring 23 is connected to the pump body 21. And is fixed to the pump body 21 by welding rather than fastening by the small-diameter bolts 31, 31.

  That is, after the cam ring 23 is positioned in the radial direction with respect to the pump body 21 by the jig 30 as in the first embodiment, the pump body 21 and the cam ring 23 are joined with the jig 30 attached. A plurality of welded portions 36 are formed by spot welding at an arbitrary interval along the circumferential direction at a peripheral portion, that is, a boundary portion between the upper end surface of the pump body 21 and the inner surface of the cam ring 23. A cam ring 23 is fixed to the pump body 21 via a welded portion 36.

Therefore, according to this reference example , since the cam ring 23 is fixed to the pump body 21 by welding, both can be more firmly fixed, so that the radial direction position of the cam ring 23 can be more reliably maintained. Can do. Furthermore, since it is not necessary to provide other members such as bolts to fix the both, it is possible to suppress an increase in manufacturing cost, and it is possible to easily fix the both. Assembling workability can be improved.

FIG. 8 shows a second reference example of the present invention, which shows another example of the fixing means of the cam ring 23 in the first embodiment, and each of the small parts in the first embodiment. The screw holes 32, 32 are changed to bottomed cylindrical concave portions 37, 37 having an inner diameter r13 substantially the same as the inner diameter r9 of the through holes 33, 33 of the cam ring 23, respectively. The spaces S1 and S1 defined by the holes 33 and 33 are filled with the thermosetting resins 38 and 38, which are fillers, and cured to pump the cam ring 23 through the resins 38 and 38, respectively. It is fixed to the body 21.

  That is, after positioning the cam ring 23 in the radial direction with respect to the pump body 21 by the jig 30, the resin 38 is inserted from the upper end openings of the through holes 33, 33 of the cam ring 23 with the jig 30 attached. , 38 are poured into the respective spaces S1, S1. Then, by heating and curing these resins 38, 38, the cam ring 23 is fixed to the pump body 21 via the resins 38, 38.

According to this reference example , after positioning the cam ring 23 with respect to the pump body 21, the both are easily fixed simply by pouring the resins 38, 38 from the upper end openings of the through holes 33, 33 of the cam ring 23. Therefore, the assembling workability of the apparatus can be improved.

FIG. 9 shows a third reference example of the present invention, in which the usage mode of each of the resins 38, 38 in the second reference example is changed, and each of the recesses 37, 37 of the pump body 21 and The respective through holes 33, 33 of the cam ring 23 are eliminated, and the spaces S2 formed between the inner peripheral surfaces of the pin insertion holes 23b, 23b of the cam ring 23 and the outer peripheral surfaces of the positioning pins 28, 28, respectively. The thermosetting resins 38, 38 are poured into the S2 in the same manner as in the second reference example , so that the cam ring 23 is fixed to the pump body 21 via the positioning pins 28, 28 by the resins 38, 38. Is.

  The inner diameter r14 of each of the pin insertion holes 23b, 23b is set larger than the inner diameter r7 of the pin insertion holes 23b, 23b in the fourth embodiment, and the outer diameter r6 of the positioning pins 28, 28 is set. Is sufficiently large.

According to this reference example , the same effect as the second reference example can be obtained, as well as the respective recesses 37, 37 of the pump body 21 and the through holes 33, 33 of the cam ring 23. Therefore, it is possible to further reduce the processing man-hours of the pump body 21 and the cam ring 23, thereby more effectively suppressing an increase in manufacturing cost.

  The technical ideas other than the invention described in each of the claims ascertained from the respective embodiments will be described below.

( 1 ) While forming the protrusion part which protrudes in an axial direction at the head of the bolt,
2. The oil pump according to claim 1 , wherein a positioning recess for positioning the second housing by fitting the projection is formed at a position corresponding to the projection of the second housing.

  According to this invention, since it becomes possible to position the second housing while fixing the cam ring to the first housing, it is possible to improve the assembling workability of the pump.

  The fillers 38 in the fourth and fifth embodiments are not limited to the thermosetting resin, and other curable resin materials such as an ultraviolet curable resin are used. Also, the same operational effects as those of the fourth and fifth embodiments can be obtained.

It is a front view of an oil pump which shows a 1st embodiment concerning the present invention and shows a mode of maintenance of a cam ring. It is a perspective view which shows the same embodiment and shows the mode of positioning with a jig | tool. It is a perspective view which shows the same embodiment and shows the structure of an oil pump. It is a longitudinal cross-sectional view of the oil pump which shows the embodiment. 1 is a schematic diagram of a power steering device for an automobile to which the oil pump according to the present invention is applied, showing the embodiment. It is a front view of the oil pump which shows the 2nd Embodiment which concerns on this invention, and shows the aspect of holding | maintenance of a cam ring. It is a front view of the oil pump which shows the 1st reference example which concerns on this invention, and shows the aspect of holding | maintenance of a cam ring. It is a front view of the oil pump which shows the 2nd reference example which concerns on this invention, and shows the aspect of holding | maintenance of a cam ring. It is a front view of the oil pump which shows the 3rd reference example which concerns on this invention, and shows the aspect of holding | maintenance of a cam ring.

Explanation of symbols

20 ... Bolt (coupling means)
21 ... Pump body (first housing)
21a ... Drive shaft insertion hole 22 ... Cover member (second housing)
23 ... cam ring 24 ... outer row data 25 ... inner row data 26 ... drive shaft 31 ... small diameter bolts (V)

Claims (2)

A first housing having a drive shaft insertion hole formed therethrough along the axial direction;
A second housing disposed opposite the first housing;
A cam ring sandwiched between the first housing and the second housing;
An outer rotor fitted to the inner peripheral side of the cam ring so as to be slidable and rotatable, and having a plurality of internal teeth on the inner peripheral side;
An inner rotor disposed on the inner peripheral side of the outer rotor and having a plurality of external teeth meshing with the inner teeth on the outer peripheral side ;
A drive shaft that is rotatably inserted in the drive shaft insertion hole of the first housing and rotationally drives the inner rotor ;
Coupling means for coupling the first housing and the second housing;
A plurality of through holes formed through the cam ring in the axial direction;
A plurality of bolts for fixing the cam ring to the first housing by being inserted into the through-holes from the second housing side and screwed into the first housing ;
An oil pump comprising: a radial gap provided between each of the through holes and each of the bolts to adjust a radial position of the cam ring . A steering mechanism that changes the direction of the steering wheel by converting the rotational force input from the steering wheel into a steering force;
A power cylinder for assisting the steering force of the steering mechanism;
An oil pump that selectively supplies hydraulic pressure to the first pressure chamber and the second pressure chamber separated by a piston in the power cylinder;
An electric motor for rotationally driving the oil pump;
Control means for outputting a drive signal to the electric motor in accordance with the rotational force input from the steering wheel,
The oil pump includes a first housing having a drive shaft insertion hole formed along the axial direction;
A second housing disposed opposite the first housing;
A cam ring sandwiched between the first housing and the second housing;
An outer rotor fitted to the inner peripheral side of the cam ring so as to be slidable and rotatable, and having a plurality of internal teeth on the inner peripheral side;
An inner rotor disposed on the inner peripheral side of the outer rotor and having a plurality of external teeth meshing with the inner teeth on the outer peripheral side;
A drive shaft that is rotatably inserted in the drive shaft insertion hole of the first housing and rotationally drives the inner rotor;
Coupling means for coupling the first housing and the second housing;
A plurality of through holes formed through the cam ring in the axial direction;
A plurality of bolts for fixing the cam ring to the first housing by being inserted into the through-holes from the second housing side and screwed into the first housing;
A power steering device comprising: a radial gap provided between each of the through holes and each of the bolts to adjust a radial position of the cam ring .

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