JPH0893640A - Hydraulic pump - Google Patents

Abstract

PURPOSE: To provide a hydraulic pump whose outer shape is made compact so as to improve its workability, by integrally forming a flange for retaining a rolling element, which is provided with valves to suck fluid from an inlet and discharge the fluid from an outlet, and by which the rolling element can be supportably arranged in the cylinder direction of a bearing inner ring,. CONSTITUTION: Pistons 10, 11 which are reciprocated between a top dead center and a bottom dead center under a pressure contact condition to a bearing outer ring 7, are stored in cylinders 8, 34 arranged in a pump case 6. A flange 7f for retaining a rolling element, which is provided with valves 15, 16 to suck fluid from an inlet 8b and discharge the fluid from an outlet 28b by the reciprocating movement of this pistons 10, 11, and by which the rolling element 7b can be supportably arranged in the cylinder direction of a bearing inner ring 7a, is integrally formed. Hereby, the outer shape of a hydraulic pump can be made compact so that the workability thereof can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic pump used for supplying hydraulically controlled brake oil in an antilock brake system for a vehicle.

[0002]

2. Description of the Related Art As a hydraulic pump for supplying brake oil whose hydraulic pressure is controlled in an antilock brake system for a vehicle, one disclosed in Japanese Patent Laid-Open No. 4-350371 is known. In FIG. 7 which illustrates the hydraulic pump described in the above publication, when the shaft 50 of the motor rotates, the bearing 51 has a cam-shaped bearing inner ring 52 fixed to the shaft 50 with a rotation center eccentric to the shaft 50. Since the bearing outer ring 54, which rotates and is provided outside the bearing inner ring 52 through the rolling elements 53, reciprocates while pressing the piston, the reciprocating motion of the piston actuates the valve to feed the brake oil to the master cylinder. .

[0003]

In the above-described conventional hydraulic pump, the bearing 51 having the bearing inner ring 52 fixed to the shaft 50 has two ring-shaped rolling element retainers on both sides of the rolling element 53 and the bearing outer ring 54. Since the working members 55 and 56 are mounted on the shaft 50 by press fitting, the length dimension of the bearing mounting portion of the shaft 50 is a mounting dimension L1 which is a press fitting allowance for mounting the plurality of rolling element pressing members 55 and 56. , L2 including L2, there is a limit in reducing the length of the shaft, and if the length of the shaft 50 is large, the pump case must be increased in size, so that the entire outer shape of the hydraulic pump is reduced. If the hydraulic pump, which has the potential to increase in size and is located near the brake master cylinder in the vehicle's engine room, is large, it can be removed and adjusted in the engine room. During, for easily interfere with other auxiliaries, work there is a problem that can become complicated, there is a problem that it is necessary to set a compact little.

[0004]

An object of the present invention is to provide a hydraulic pump which has a compact outer shape and can improve workability.

[0005]

Configuration of the Invention

[0006]

According to a first aspect of the present invention, there is provided a hydraulic pump in which a yoke, a magnet fixed to the inside of the yoke, and a coil disposed in the inner circumference of the magnet and provided in the center are energized. And a pump case connected to the yoke, and a bearing inner ring disposed in the pump case and having an eccentric center of rotation with respect to the shaft of the armature and rotating integrally with the shaft of the armature. The bearing is equipped with a bearing outer ring that is arranged outside the bearing inner ring via rolling elements, and is housed in a cylinder that is arranged in the pump case. It is equipped with a piston that reciprocates between them, and this piston reciprocates between top dead center and bottom dead center to allow fluid to flow from the inlet. The bearing inner ring has a valve that sucks in and discharges fluid from the outlet, and the bearing inner ring is integrally formed with a rolling element holding flange that is arranged to support the rolling element in the cylinder direction of the bearing inner ring. The hydraulic pump according to claim 2 of the present invention is characterized in that the rolling element pressing flange of the bearing inner ring projects thinly in the radial direction of the bearing inner ring on either side of the bearing inner ring along the axial direction of the shaft. In the hydraulic pump according to claim 3 of the present invention, the rolling element pressing flange of the bearing inner ring has a projecting dimension larger than the inner diameter of the bearing outer ring. In the hydraulic pump according to No. 4, the bearing inner ring is provided with the rolling element pressing flange on the coil side of the armature, and the shaft is independent of the bearing inner ring on the end side opposite to the coil. And the fact that a single rolling element pressing member is attached formed Te,
In the hydraulic pump according to claim 5 of the present invention, the bearing inner ring has a rolling element pressing flange arranged on the end side of the shaft opposite to the armature coil, and the shaft is independent of the bearing inner ring on the coil side of the bearing inner ring. It is assumed that a single rolling element pressing member formed in this way is attached.

[0007]

In the hydraulic pump according to the first aspect of the present invention, the rolling element of the bearing is supported in the cylinder direction of the inner ring of the bearing by the flange for pressing the rolling element of the inner ring of the bearing, and is arranged between the inner ring of the bearing and the outer ring of the bearing. Since they are provided, the members for pressing the rolling elements are not arranged on both sides of the rolling elements. Therefore,
It is not necessary to set the mounting margin of the member for pressing the plurality of rolling elements on the shaft with a large size. In the hydraulic pump according to the second aspect of the present invention, the rolling element of the bearing is supported in the cylindrical direction of the inner ring of the bearing by one of the inner ring of the bearing by a flange for pressing the rolling element that thinly projects in the radial direction of the inner ring of the bearing. Since it is arranged between the bearing inner ring and the bearing outer ring, members for pressing the rolling elements are not arranged on both sides of the rolling elements. Therefore, it is not necessary to set the mounting margin of the member for pressing the plurality of rolling elements on the shaft with a large size. In the hydraulic pump according to claim 3 of the present invention, the rolling element of the bearing is a bearing pressing flange that protrudes in a radial direction of the inner ring of the bearing in a radial direction of the inner ring of the bearing and is thinner than the inner diameter of the outer ring of the bearing. Since the inner ring is supported in the cylinder direction and arranged between the bearing inner ring and the bearing outer ring, members for pressing the rolling elements are not arranged on both sides of the rolling elements. Therefore, it is not necessary to set the mounting margin of the member for pressing the plurality of rolling elements on the shaft with a large size. In the hydraulic pump according to claim 4 of the present invention, the rolling element of the bearing is a rolling element pressing flange arranged on the coil side of the shaft of the armature and a single rolling element arranged at the end of the shaft opposite to the coil. Since the pressing member supports the bearing inner ring in the cylinder direction and is arranged between the bearing inner ring and the bearing outer ring, rolling element pressing members for pressing the rolling elements are not arranged on both sides of the rolling element. Therefore, it is not necessary to set the mounting allowance of the plurality of rolling element pressing members on the shaft with a large size. In the hydraulic pump according to claim 5 of the present invention, the rolling element of the bearing is a rolling element retaining flange arranged at an end portion of the shaft opposite to the coil, and a single rolling element retaining member disposed on the coil side of the shaft. Since it is supported in the cylinder direction of the bearing inner ring and is disposed between the bearing inner ring and the bearing outer ring, the rolling element pressing members for pressing the rolling elements are not arranged on both sides of the rolling element. Therefore, it is not necessary to set the mounting allowance of the plurality of rolling element pressing members on the shaft with a large size.

[0008]

1 to 5, there is shown a first embodiment of a hydraulic pump according to the present invention.

The illustrated hydraulic pump 1 is built in an actuator of an anti-lock brake system, and mainly includes a yoke 2, magnets 3, 4, an armature 5, a pump case 6, a first bearing (bearing) 7, and a first valve. (Valve) 15 and a second valve (valve) 16.

The yoke 2 is attached by crimping a disk-shaped end 2b to one end of a cylindrical tubular portion 2a, and a screw (not shown) is screwed into the pump case 6 at the other end of the tubular portion 2a. It is assembled by letting it. A second bearing 18 is attached to the center of the end 2b, and the second bearing 18 rotatably supports one end of a shaft 5a included in an armature 5 described later.

Magnets 3 and 4 are arranged inside the cylindrical portion 2a of the yoke 2, and both magnets 3 and 4 form a magnetic field inside.

An armature 5 is arranged on the inner peripheral side of the magnets 3, 4. Armature 5 is shaft 5
An armature core 5b made of a magnetic material is attached to the center of a, and a commutator 5c is attached near the armature core 5b. The shaft 5a is rotatably supported by the second bearing 18 at one end side thereof. The other end side is extended to the inside of the pump case 6, and is rotatably supported by a third bearing 19 attached to the pump case 6.

A coil 5d having a predetermined number of slots is wound around the armature core 5b of the armature 5, and the winding of the coil 5d is electrically connected to a plurality of commutator pieces 5c1 provided in the commutator 5c. It is connected.

Brushes 20 and 21 are pressed against respective commutator pieces 5c1 of the commutator 5c of the armature 5 by brush springs (not shown).
21 is electrically connected to an external ABS controller (anti-lock brake system controller) (not shown), so that when the brush controller 20 supplies a current to the brushes 20 and 21, the commutator pieces 5c of the armature 5 are not shown.
The coil 5d is sequentially excited via 1 to form a magnetic field, and the magnetic field formed by the armature 5 and the magnet 3,
It rotates by the magnetic field formed by 4.

The pump case 6 into which the shaft 5a of the armature 5 is inserted has a cylindrical opening-shaped bearing chamber 6a formed substantially in the center thereof, and the first and second cylinders are provided at the opposite positions of the bearing chamber 6a. Chambers 6b and 6c are formed. The first bearing 7 is housed in the bearing chamber 6a, the first valve 15 is housed in the first cylinder chamber 6b, and the second valve 16 is housed in the second cylinder chamber 6c.

As shown in FIG. 2, the pump case 6 is provided with a fluid introduction passage 6d and a fluid introduction passage 6e, respectively, and one end of the fluid introduction passage 6d has the first cylinder chamber 6 at its one end.
b and the second cylinder chamber 6c are communicatively connected at a predetermined position, and the other end is communicatively connected to a reservoir (not shown) outside the pump case 6. Also, the fluid outlet path 6e
Has a first cylinder chamber 6b and a second cylinder chamber 6c at one of the predetermined positions independent of the fluid introduction passage 6d.
, And the other end is connected to the brake master cylinder outside the pump case 6 via a damper chamber (not shown).

The first bearing 7 housed in the bearing chamber 6a of the pump case 6 is a needle roller bearing and includes a bearing inner ring 7a, a roller-shaped rolling element 7b, and a bearing outer ring 7.
c, the rolling element pressing member 7d.

The bearing inner ring 7a is integrally provided with a tubular inner ring body 7e and a rolling element pressing flange 7f. As shown in FIG. 2, the inner ring main body 7e includes an inner ring main body 7e.
A shaft mounting portion 7e1 in the shape of a round hole having a center of rotation C1 eccentric from a center C2 of the armature 5 is formed, and the shaft 5a of the armature 5 is press-fitted into the shaft mounting portion 7e1. There is. The shaft 5a of the armature 5 remains in the shape of a round bar, and the inner ring body 7
Since the shaft 5a is connected to the shaft mounting portion 7e1 of e by press fitting, the shaft 5a is formed into a D shape and is attached to the bearing inner ring 7a.
Since it is not necessary to prevent rotation by forming a hole having a shape, and it is not necessary to prevent rotation by a clevis pin for assembly, the shaft 5a and the bearing inner ring 7a can be connected very easily.

Flange 7f for holding rolling element of bearing inner ring 7a
Is projecting annularly in the radial direction of the bearing inner ring 7a toward one end on the coil 5d side of the shaft 5a along the cylinder direction of the inner ring body 7e. Since the projection size of the rolling element pressing flange 7f is larger than the inner diameter of the bearing outer ring 7c described later, the rolling element 7b does not move in the cylinder direction of the bearing inner ring 7a and the bearing outer ring 7c outside the bearing outer ring 7c. By preventing the above, it has a function of pressing and supporting the thrust load applied to the rolling element 7b toward the coil 5d side of the shaft 5a. The bearing inner ring 7a has a rolling member pressing flange 7f formed near one end of the inner ring body 7e, and the other end side of the inner ring body 7e is tubular and is not provided with anything. A bearing outer ring 7c is arranged on the outer periphery of the inner ring body 7e of the bearing inner ring 7a via a plurality of rolling elements 7b.

The bearing outer ring 7c is formed in a substantially cylindrical shape, and as shown in FIG. 3, the rolling element 7b is formed on the entire inner circumference.
Since the rolling element accommodating portion 7c1 formed in a groove shape with a width slightly larger than the axial length of the rolling element accommodating portion 7c1 is provided, the bearing inner ring 7 is accommodated in the rolling element accommodating portion 7c1.
It is rotatably arranged outside a. Further, the one end side of the bearing outer ring 7c is arranged so that the third bearing 19 side can slidably contact the rolling element pressing flange 7f of the bearing inner ring 7a, so that one end side slidably contacts the rolling element pressing flange 7f. Thus, the rolling element 7b is supported. A single rolling element pressing member 7d is arranged on the other end side of the shaft 5a opposite to the coil 5d side along the cylinder direction of the bearing outer ring 7c.

As shown in FIG. 4, the rolling element pressing member 7d is eccentric to the shaft hole 7d1 corresponding to the shaft mounting portion 7e1 formed in the inner ring body 7e of the bearing inner ring 7a.
And has the shaft hole 7d1 press-fitted into the shaft 5a to couple them. Rolling body pressing member 7
d is in contact with the other end of the bearing inner ring 7a and the other end of the bearing outer ring 7c.

Here, in the first bearing 7, a rolling element pressing flange 7f is formed on the bearing inner ring 7a, and the rolling element pressing flange 7f is applied to the rolling element 7b toward the coil 5d side of the shaft 5a. Since the load is being held, it is not necessary to dispose another rolling element holding member 7d on the coil 5d side of the shaft 5a of the first bearing 7, and the mounting allowance for attaching the rolling element holding member 7d to the shaft 5a is eliminated. Since it is not necessary to determine the length on the shaft 5a, the length dimension L5 of the bearing mounting portion of the shaft 5a is the length L3 when a plurality of rolling element pressing members are mounted, as shown in FIG. (See FIG. 7). As a result, the load point of the first and second pistons 10 and 11, which will be described later, brought into pressure contact with the bearing outer ring 7c of the first bearing 7 is relatively thick. Compared with the case where the bearing 7 is arranged on the coil 5d side, the bearing 7 is closer to the third bearing 19, so that the bending stress applied in the radial direction of the shaft 5a is reduced.

In the first bearing 7a, when the shaft 5a of the armature 5 rotates, the bearing inner ring 7a rotates eccentrically with respect to this shaft 5a, so that the outer peripheral surface of the bearing outer ring 7c is arranged so that its outer peripheral surface can move forward and backward. The first piston 10 described later is reciprocated by the 7c between the top dead center A and the bottom dead center B, and the second piston 11 described later that is horizontally opposed to the first piston 10 is also top dead center. Reciprocate between A and bottom dead center B.

A first cylinder 8 is housed in the first cylinder chamber 6b of the pump case 6. The first cylinder 8 is formed into a cylindrical liner shape, has an inner side having a piston hole 8a, and has an outer side through two O-rings (O-rings) 22 and 23 to form the first cylinder. Room 6
It is attached to b. Further, between both the O-rings 22 and 23 of the first cylinder 8, there is formed an annular groove 8b which is an annular concave groove serving as an inlet of the first valve 15, and the annular grooves 8b are opposed to each other. Since the two parts are communicated with the piston hole 8a of the first cylinder 8 through the round hole 8c, the piston hole 8a of the first cylinder 8 is the round hole 8c.
c, annular groove 8b and fluid introduction path 6d of pump case 6
Is connected to and connected to a reservoir (not shown). First
In the piston hole 8a of the cylinder 8 of the first piston 10
Has been inserted.

The first piston 10 has a substantially T-shaped cross section, is a disk-shaped piston head 10b which is pressed against the bearing outer ring 7c of the first bearing 7, and is a substantially cylindrical O-ring (O-ring). ) 46, and the skirt 10c inserted into the piston hole 8a through the boss 46.

The first piston 10 is the piston head 1
0b and the first cylinder 8, a valve spring 13 is arranged between the first cylinder 8 and the piston head 10b.
It is pressed against the bearing outer ring 7 c of the first bearing 7 by the elastic repulsive force of 3.

The first piston 10 is the piston head 1
The bearing outer ring 7c side of 0b is formed into a smooth surface, and the first oil sump 10a formed in the shape of a round hole having a slight depth toward the skirt 10c is provided substantially in the center, The first oil sump 10a is filled with a lubricating oil and fat. Since the first oil sump 10a is formed in a concave shape in the center of the piston head 10b, the lubricating oil and fat filled in the first oil sump 10a is retained in the pressure contact portion between the bearing outer ring 7b and the piston head 10b. It doesn't flow easily. Therefore, the first piston 10 is brought into pressure contact with the bearing outer ring 7c of the first bearing 7 in a state where the lubricating oil is interposed, so that the first piston 10 and the bearing outer ring 7c are The frictional resistance between them is kept small, and minute vibrational slippage is unlikely to occur during the pressure contact between the first piston 10 and the bearing outer ring 7c.

The inner circumference of the skirt 10c of the first piston 10 is a first valve chamber 10d which is closed on the piston head 10b side, and the outer circumference of the skirt 10c has an annular groove 10e which is a concave groove. Is formed in this annular groove 1
Two points 0e facing each other are communicatively connected to the first valve chamber 10d via the round holes 10f.

Since the valve seat 24 is fitted on the opposite side of the first valve chamber 10d from the first piston 10 of the first cylinder 8, the valve seat 24 and the first piston 1 are opposed to each other.
A second valve chamber 25 is formed between 0 and 0.
A first check ball 27, which is biased by a first return spring 26 toward the side that closes the first valve chamber 10d, is arranged in the second valve chamber 25. When the hydraulic pressure of the brake oil introduced into the first valve chamber 10d exceeds a predetermined value due to the reciprocating movement of the first piston 10, the first valve chamber is resisted against the first return spring 26. 10d is the second valve chamber 2
5 has a function of transferring the brake oil in the first valve chamber 10d to the second valve chamber 25 in order to communicate with the second valve chamber 25.

Further, a communication hole 24 is provided in the center of the valve seat 24.
a is formed and a lid 28 is assembled to the first cylinder chamber 6b via an O-ring 29 at a position opposite to the communication hole 24a. A third valve chamber 30 is formed between them. A second check ball 32, which is biased by the second return spring 31 toward the side that closes the communication hole 24a, is arranged in the third valve chamber 30, and the second check ball 32 is the second check ball 32. When the hydraulic pressure of the brake oil introduced into the valve chamber 25 exceeds a predetermined value, the second valve chamber 25 is moved to the third valve chamber 3 against the second return spring 31.
In order to communicate with 0, it has a function of transferring the brake oil of the second valve chamber 25 to the third valve chamber 30.

Since the lid 28 is formed with a flow path 28a serving as an outlet for communicating the third valve chamber 30 with the fluid outlet path 6e of the pump case 6, it is introduced into the third valve chamber 30. Flowed brake oil is flow path 2
8a through the fluid derivation path 6e of the pump case 6 and transferred to the brake master cylinder via a damper chamber (not shown). The lid 28 is pressed and fixed by a stopper 33 screwed into the pump case 6.

The first cylinder 8, the first piston 10,
Valve seat 24, first check ball 27, first return spring 26, second check ball 32, second return spring 3
The first valve 15 is formed by 1, the lid 28, and the stopper 33.

On the other hand, the second valve 16 housed in the second cylinder chamber 6c of the pump case 6 has the same structure as the first valve 15 described above, and the second cylinder 34 is
It has a piston hole 34a and two O-rings (O
Ring) 35, 36 are arranged, an annular groove 34b serving as an inlet and a round hole 34c are formed, the second piston 11 is inserted into the piston hole 34a of the second cylinder 34, and the second piston 11 is , O-ring with piston head 11b pressed against bearing outer ring 7c
Skirt 1 inserted into piston hole 34a through 47
1c integrally, the valve spring 14 is arranged between the piston head 11b and the second cylinder 34, and has a slight depth toward the skirt 11c on the bearing outer ring 7c side of the piston head 11b. A second oil sump 11a formed in a round hole is provided, and the first valve chamber 1
Fourth valve chamber 11d, annular groove 1 opposed to 0d
1e, a round hole 11f is formed, a valve seat 37 having a communication hole 37a, a flow path 38a serving as an outlet, and a lid 38 assembled to the second cylinder chamber 6c via an O-ring 39. , Stopper 33, second valve chamber 25
A fifth valve chamber 40, a third return spring 41, a third check ball 42, and a third valve chamber 30 that are arranged to face each other.
A sixth valve chamber 43, a third check ball 44, and a fourth return spring 45, which are arranged to face each other.

The first and second valves 15 and 16 are pressed against the bearing outer ring 7c by rotating the bearing inner ring 7a of the first bearing 7 eccentrically with respect to the shaft 5a when the shaft 5a of the armature 5 rotates. The first piston 10 and the second piston 11 are
Reciprocates between each.

When the first piston 10 moves from the bottom dead center B to the top dead center A, the second check ball 32 moves to the valve seat 24.
Since the communication hole 24a of the first cylinder 8 is closed, the second valve chamber 25 in the negative pressure is connected to the annular groove 8b and the round hole 8c of the first cylinder 8 from the fluid introduction path 6d of the pump case 6.
The brake oil is sucked into the first valve chamber 10d through the annular groove 10e and the round hole 10f of the piston 10, and the brake oil is sucked and moved from the first valve chamber 10d to the second valve chamber 25.

Since the first piston 10 having reached the top dead center A is moved toward the bottom dead center B, the first check ball 27 does not move the first valve chamber 10d into the second valve chamber 25. The brake oil transferred to the second valve chamber 25 in the communication state is transferred to the third valve chamber 30 because the second check ball 32 opens the communication hole 24a of the valve seat 24, and the brake oil is transferred to the third valve chamber 30. The brake oil in the valve chamber 30 is sent out to the fluid outlet path 6e of the pump case 6 through the flow path 28a of the lid 28.

Since the first piston 10 reciprocates between the top dead center A and the bottom dead center B with the rotation of the bearing inner ring 7a of the first bearing 7, the first valve chamber 10d,
Brake oil is sucked from the fluid introduction passage 6d of the pump case 6 through the second valve chamber 25 and the third valve chamber 30 and sent out from the fluid discharge passage 6e.

The second piston 11 is also the first piston 10
In the same manner as above, the reciprocating motion is performed between the top dead center A and the bottom dead center B, and the fourth valve chamber 11d, the fifth valve chamber 40, and the sixth valve chamber 11d.
Fluid introduction path 6d of the pump case 6 through the valve chamber 43 of
The brake oil is sucked from and discharged from the fluid discharge path 6e.

The hydraulic pump 1 having such a structure is built in the actuator of the antilock brake system, the fluid introduction path 6d of the pump case 6 is connected to the reservoir, and the fluid is discharged from the pump case 6 through the damper chamber. The path 6e is communicatively connected to the brake master cylinder, and the brushes 20 and 21 are electrically connected to an external ABS controller and mounted on the vehicle.

When the brake is operated, the ABS controller generates a holding signal when the slip state of the wheel is recognized, and when the brake of the wheel is recognized to be large, a decompression signal is generated, and the ABS signal is generated. When it is recognized that the slip has become smaller, a pressure increase signal is generated and each signal is transferred to the actuator. When the pressure reduction signal is generated, current is supplied to both brushes 20 and 21 of the hydraulic pump 1.

When the pressure reducing signal is generated from the ABS controller, the pressure increasing solenoid valve and the pressure reducing solenoid valve that are connected to the wheel cylinder are activated, so that the pressure increasing solenoid valve has its port closed and the pressure reducing solenoid is closed. The valve opens the port. In the hydraulic pump 1, the current is supplied to the brushes 20 and 21, and the armature 5 rotates, so that the first bearing 7
Bearing inner ring 7a rotates, and the first piston and the second piston 11, which are in pressure contact with the bearing outer ring 7b, reciprocate, and the brake oil in the wheel cylinder is stored through the pressure reducing solenoid valve. By sucking the brake oil from the reservoir and returning it to the brake master cylinder, the pressure of the brake oil in the wheel cylinder is reduced to make the wheel slip proper and the hydraulic pressure of the brake oil is adjusted to prevent excessive slip. It will be in control.

First piston 10 and second piston 11
While reciprocating, the lubricating oil and oil filled in the first oil sump 10a of the piston head 10b of the first piston 10 is held in the pressure contact portion between the bearing outer ring 7b and the piston head 10b, and the second piston 11 The lubricating oil / fat filled in the second oil sump 11a of the piston head 11b is also held in the pressure contact portion between the bearing outer ring 7b and the piston head 11b, so that the pistons 10 and 11 and the bearing outer ring 7b have extremely small frictional resistance. Is pressed in.

Further, while the first piston 10 and the second piston 11 reciprocate, these first and second pistons 1
The first bearing 7 pressed against 0, 11 presses the thrust load applied to the rolling element 7b toward the coil 5d side of the shaft 5a by the rolling element pressing flange 7f, and the first and second pistons 10, The load point 11 is brought closer to the third bearing 19 to reduce the bending stress applied in the radial direction of the shaft 5a.

FIG. 6 shows a second embodiment of the hydraulic pump according to the present invention. FIG. 6 shows only the circumference of the first bearing and the other parts are the same as those of the first embodiment. .

In this case, the position of the rolling element pressing flange 7f of the bearing inner ring 7a is opposite to that of the first embodiment,
A flange 7 for pressing a rolling element, which is formed thinly and annularly toward the radial direction of the bearing inner ring 7a near the other end of the shaft 5a opposite to the coil 5d along the cylinder direction of the inner ring body 7e.
f is provided, and the one end of the shaft 5a on the coil 5d side along the cylinder direction of the inner race body 7e is cylindrical.
At the other end of the bearing inner ring 7a, a rolling element pressing member 7d having the shaft 5a attached by press fitting is disposed slidably in a shaft hole 7d1 corresponding to the shaft attaching portion 7e1 of the inner ring main body 7e. Member 7d and third
The bearing inner ring contacting plate member 7g formed thinly is disposed between the bearing 19 and the bearing 19. The plate member 7g may be formed integrally with the rolling element pressing member 7d.

In this case, since the projecting dimension of the rolling element pressing flange 7f is also larger than the inner diameter of the bearing outer ring 7c, the rolling element 7b is arranged outside the bearing outer ring 7c in the cylinder direction of the bearing inner ring 7a and the bearing outer ring 7c. By preventing the movement, it has a function of pressing and supporting the thrust load applied to the rolling element 7b toward the side opposite to the coil 5d of the shaft 5a.

Also in this second embodiment, the first bearing 7
Has a rolling element pressing flange 7f formed on the bearing inner ring 7a, and this rolling element pressing flange 7f presses the thrust load applied to the rolling element 7b toward the side opposite to the coil 5d of the shaft 5a. It is not necessary to dispose another rolling element pressing member 7d on the side opposite to the coil 5d of the shaft 5a of the bearing 7, and the rolling element pressing member 7d can be attached to the shaft 5a.
Since it is not necessary to determine a mounting allowance for mounting on the shaft 5a on the shaft 5a, the length dimension L6 of the bearing mounting portion of the shaft 5a is the length L3 when a plurality of rolling element pressing members are mounted ( 7)) and the end of the shaft 5a does not serve as a mounting allowance.
A large range of chamfering can be performed at the end of the shaft 5a, which is the starting point for press-fitting, without extending a, and the large chamfering facilitates positioning of the press-fitting.

[0048]

As described above, according to the hydraulic pump according to the present invention, the rolling element is supported in the cylinder inner direction of the bearing inner ring by the flange for rolling element pressing of the inner ring of the bearing, and the rolling element is supported between the inner ring of the bearing and the outer ring of the bearing. Since it is not necessary to arrange the members for pressing the rolling elements on both sides of the rolling element, it is necessary to determine the mounting allowance of the members for pressing the rolling elements with a large size on the shaft. Can be reduced and the length of the shaft can be reduced, thereby
The pump case also has a small size, and the hydraulic pump has a compact outer shape, which has the excellent effect of improving workability in the engine room and the like.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of a first embodiment of a hydraulic pump according to the present invention.

FIG. 2 is a right side view in vertical section of the hydraulic pump shown in FIG.

FIG. 3 is a vertical sectional view around a bearing in the hydraulic pump shown in FIG.

4 is an external perspective explanatory view showing an assembling relationship between a bearing and a piston in the hydraulic pump shown in FIG.

5 is a vertical cross-sectional view around a valve in the hydraulic pump shown in FIG.

FIG. 6 is a vertical sectional view around a bearing in a second embodiment of the hydraulic pump according to the present invention.

FIG. 7 is a longitudinal sectional view around a bearing of a conventional hydraulic pump.

[Explanation of symbols]

 1 hydraulic pump 2 yoke 3 magnet 4 magnet 5 armature 5d coil 6 pump case 7 bearing 7a bearing inner ring 7b rolling element 7c bearing outer ring 7d rolling element pressing member 7f rolling element pressing flange 8 (cylinder) first cylinder 8b (inlet) Annular groove 10 (piston) first piston 11 (piston) second piston 15 (valve) first valve 16 (valve) second valve 28a (outlet) flow path 34 (cylinder) second cylinder

Claims (5)

[Claims] 1. A yoke, a magnet fixed to the inside of the yoke, an armature arranged on the inner peripheral side of the magnet and rotated by energizing a coil provided at the center, and a pump case coupled to the yoke. And a bearing inner ring that is disposed in the pump case and that has an eccentric center of rotation with respect to the armature shaft and that rotates integrally with the armature shaft, and that is disposed outside the bearing inner ring via a rolling element. A bearing having an outer bearing outer ring, and a piston housed in a cylinder arranged in the pump case and reciprocating between a top dead center and a bottom dead center in a pressure contact state with the bearing outer ring, This piston reciprocates between top dead center and bottom dead center to draw fluid from the inlet and flow it from the outlet. Includes a valve for delivering, said bearing inner race, a hydraulic pump, characterized in that integrally formed rolling element flange retainer disposed rolling elements in the cylindrical direction of the bearing inner ring so as to be supported. 2. The hydraulic pressure according to claim 1, wherein the rolling element pressing flange of the bearing inner ring is formed so as to be thin and project in the radial direction of the bearing inner ring on either side of the bearing inner ring along the axial direction of the shaft. pump. 3. The hydraulic pump according to claim 1, wherein the rolling element pressing flange of the bearing inner ring has a protruding dimension larger than the inner diameter of the bearing outer ring. 4. The bearing inner ring has a rolling element pressing flange arranged on the coil side of the armature, and the shaft has a single rolling element pressing member formed independently of the bearing inner ring on the end side opposite to the coil. The hydraulic pump according to claim 1, wherein the hydraulic pump is attached. 5. The bearing inner ring has a rolling element pressing flange arranged on the end side of the shaft opposite to the armature coil, and the shaft is a single unit formed independently of the bearing inner ring on the coil side of the bearing inner ring. The hydraulic pump according to any one of claims 1, 2, and 3, wherein the rolling element pressing member is attached.