WO2016175242A1

WO2016175242A1 - Gear pump device

Info

Publication number: WO2016175242A1
Application number: PCT/JP2016/063197
Authority: WO
Inventors: 隆志羽柴; 袴田　尚樹; 貴寛永沼; 倫明川端
Original assignee: 株式会社アドヴィックス
Priority date: 2015-04-28
Filing date: 2016-04-27
Publication date: 2016-11-03
Also published as: CN107407275A; US20180112662A1; CN107407275B; JP6311644B2; JP2016205339A

Abstract

In the present invention, polishing lines 71f are connected to an outer circumferential high-pressure region, but are not connected to each area that is a low-pressure region. In this configuration, the polishing lines 71f are connected to the outer circumferential high-pressure region where there is high discharge pressure, so high-pressure brake fluid is introduced within the polishing lines 71f. Therefore, a pushback effect is obtained, wherein gear pumps 19 and 39 are pushed back on the basis of the high-pressure brake fluid pressure. Furthermore, the polishing lines 71f are connected to the outer circumferential high-pressure region but are not connected to each area that is a low-pressure region, so high-pressure can be maintained within the polishing lines 71f, and a reduction in the pushback effect can be prevented. Accordingly, a decrease in the loss torque reduction effect can be prevented, and the loss torque can be further reduced.

Description

Gear pump device

The present invention relates to a gear pump device such as a trochoid pump that pumps fluid by meshing gears.

Conventionally, in a gear pump device, adopting a sealing method using a sealing member formed of resin or the like on both end faces in the axial direction of the gear pump has been a factor in cost increase, so one of them is a mechanical seal to reduce costs. A structure has been proposed. Specifically, only one end face side of the inner rotor and outer rotor provided in the gear pump is sealed with a seal member, and the other end face is a mechanical that directly presses each rotor against the sliding surface of the case in which each rotor is accommodated. It is a seal.

This mechanical seal has a structure in which a metal inner rotor and an outer rotor are strongly pressed against a metal case based on the elastic force of the seal member and the pressure of the high-pressure fluid for sealing. Therefore, if the loss torque of the sliding surfaces of the outer rotor, the inner rotor, and the case is large, the pump discharge capacity is affected, and there is a problem that the motor size must be increased. Also, when there are large and small portions of torque loss in rotation on the sliding surface between the outer rotor and inner rotor and the case, heat is generated in portions where the loss torque is large due to high-speed or long-time rotation of the pump. . An adverse effect on the pump discharge capacity due to the expansion of the heat generating portion is also considered.

Therefore, Patent Document 1 proposes a gear pump device corresponding to these problems. Specifically, radial polishing bars are provided on the sliding surface of the case that bears the mechanical seal function. As a result, the contact area between the sliding surface of the case and both rotors can be reduced and the friction coefficient can be reduced, so that the supply of oil to the sliding surface is promoted. Thereby, it is possible to measure the reduction of the loss torque.

JP 2003-129964 A

However, in the gear pump device described in Patent Document 1, radial polishing bars are provided on the entire surface of the sliding surface of the case from the outer side of the outer rotor to the inner side of the inner rotor where the shaft is disposed. For this reason, the high-pressure region outside the outer rotor and the low-pressure region inside the inner rotor communicate with each other via the polishing bar, and high-pressure fluid leaks from the high-pressure region to the low-pressure region side. As a result, with respect to the elastic force of the seal member, the effect of pushing back from the sliding surface side of the case toward both rotors by the high-pressure fluid in the high-pressure region cannot be sufficiently obtained, and the loss torque reduction effect is reduced. There's a problem.

In view of the above points, the present invention provides a gear pump device that improves the push-back effect of pushing back from the sliding surface side of the case toward both rotor sides and can further reduce the loss torque.

In order to achieve the above object, according to the first aspect of the present invention, an outer rotor having an inner tooth portion and an inner rotor that meshes with the outer rotor while forming a plurality of gap portions are formed. A gear pump that performs suction and discharge operations of fluid by rotating the outer rotor and the inner rotor based on rotation of the inserted shaft, a case that forms a housing portion that houses the gear pump, and a pump axial direction in the case and the gear pump One of the gaps between the suction side of the gear pump and the low pressure side including the periphery of the shaft, the discharge side from which the fluid is discharged, and the outer periphery of the outer rotor and the case are disposed between one of the end faces. And a seal mechanism for partitioning the high pressure side including the portion, and the pump axial direction in the gear pump based on the pressing force of the seal mechanism In the gear pump device in which the gap between the low pressure side and the high pressure side of the gear pump at the end surface is sealed by contacting the other end surface of the surface with the sliding surface of the case, the sliding surface includes the center of the gear pump. And a fluid introduction groove into which a fluid in a gap between the outer periphery of the outer rotor on the high pressure side and the case is introduced. The fluid introduction groove is separated from the center hole and the suction side. It is characterized by being.

When the fluid introduction groove having such a configuration is formed, the high pressure fluid is introduced into the fluid introduction groove because the fluid introduction groove is communicated with the outer peripheral high pressure region that has a high discharge pressure. For this reason, the pushing-back effect which pushes back a gear pump based on a high pressure fluid can be acquired.

And even though the fluid introduction groove communicates with the outer peripheral high pressure region, it does not communicate with each part that becomes the low pressure region. For this reason, the inside of the fluid introduction groove can be maintained at a high pressure, and a reduction in the pushing back effect can be suppressed. Therefore, it is possible to prevent a reduction in the loss torque reduction effect and further reduce the loss torque.

It is a figure which shows the hydraulic circuit of the brake device 1 for vehicles to which the gear pump apparatus concerning 1st Embodiment of this invention is applied. It is sectional drawing of a gear pump apparatus. FIG. 3 is a cross-sectional view taken along the line III-III ′ of FIG. It is the figure which showed the cylinder 71 when it sees from the gear pump 19 or the gear pump 39 side. FIG. 6 is a diagram showing a relationship between polishing bars 71f formed on a cylinder 71 and pressure distribution on sliding

surfaces

71b and 71c of the cylinder 71 and the like. It is the figure which showed the cylinder 71 when it sees from the gear pump 19 provided in the gear pump apparatus concerning 2nd Embodiment of this invention or the gear pump 39 side. FIG. 6 is a diagram showing a relationship between polishing bars 71f formed on a cylinder 71 and pressure distribution on sliding

surfaces

71b and 71c of the cylinder 71 and the like. It is the figure which showed the discharge pressure area | region Ra, the suction pressure area | region Rb, and the intermediate pressure area | region Rc in a gear pump apparatus. FIG. 6 is a view showing a pressure distribution between the

gear pumps

19 and 39 and sliding

surfaces

71b and 71c of a cylinder 71. It is the figure which showed the cylinder 71 when it sees from the gear pump 19 provided in the gear pump apparatus concerning 3rd Embodiment of this invention or the gear pump 39 side. It is the figure which showed the cylinder 71 when it sees from the gear pump 19 with which the gear pump apparatus concerning 4th Embodiment of this invention is equipped, or the gear pump 39 side.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other will be described with the same reference numerals.

(First embodiment)
A hydraulic circuit of a vehicle brake device 1 to which a gear pump device according to an embodiment of the present invention is applied will be described with reference to FIG. Here, an example in which the vehicle brake device 1 according to the present invention is applied to a vehicle constituting a hydraulic circuit of front and rear pipes will be described. The right front wheel and the left rear wheel are connected to the first piping system, and the left front wheel and the right rear wheel. It is applicable also to X piping etc. which make 2nd piping system.

As shown in FIG. 1, the vehicle brake device 1 includes a brake pedal 11, a booster device 12, an M / C 13, W /

Cs

14, 15, 34, and 35, and a brake fluid pressure control actuator 50. And are provided. A brake ECU 70 is assembled to the brake fluid pressure control actuator 50, and the brake ECU 70 controls the braking force generated by the vehicle brake device 1.

The brake pedal 11 is connected to the booster 12 and the M / C 13, and when the driver depresses the brake pedal 11, the pedaling force is boosted by the booster 12, and the master piston disposed in the M / C 13. Press 13a, 13b. As a result, the same M / C pressure is generated in the primary chamber 13c and the secondary chamber 13d defined by the master pistons 13a and 13b. The M / C pressure generated in the M / C 13 is transmitted to each of the W /

Cs

14, 15, 34, 35 through the brake hydraulic pressure control actuator 50 constituting the hydraulic pressure path.

Also, a master reservoir 13e having a passage communicating with each of the primary chamber 13c and the secondary chamber 13d is connected to the M / C 13. The master reservoir 13e supplies brake fluid into the M / C 13 and stores excess brake fluid in the M / C 13.

The brake fluid pressure control actuator 50 has a first piping system 50a and a second piping system 50b. The first piping system 50a is a rear system that controls the brake fluid pressure applied to the right rear wheel RR and the left rear wheel RL, and the second piping system 50b is the brake fluid pressure that is applied to the left front wheel FL and the right front wheel FR. It is assumed to be a front system.

Hereinafter, the first and

second piping systems

50a and 50b will be described. However, since the first piping system 50a and the second piping system 50b have substantially the same configuration, the first piping system 50a will be described here. For the second piping system 50b, refer to the first piping system 50a.

The first piping system 50a transmits the M / C pressure described above to the W / C 14 provided in the left rear wheel RL and the W / C 15 provided in the right rear wheel RR, and generates a W / C pressure. A conduit A is provided. A braking force is generated by generating a W / C pressure in each of the W / Cs 14 and 15 through the pipeline A.

The pipe A is provided with a differential pressure control valve 16 that can be controlled to a communication state and a differential pressure state. The valve position of this differential pressure control valve 16 is adjusted so that it is in a communicating state during normal braking (when motion control is not executed) that generates a braking force corresponding to the operation of the brake pedal 11 by the driver. Yes. When a current flows through a solenoid coil provided in the differential pressure control valve 16, the valve position of the differential pressure control valve 16 is adjusted so that the larger the current value, the larger the differential pressure state. When the differential pressure control valve 16 is in the differential pressure state, the flow of the brake fluid is regulated so that the W / C pressure is higher than the M / C pressure by the amount of the differential pressure.

The pipe A branches into two pipes A1 and A2 on the W / C 14 and 15 side downstream of the differential pressure control valve 16. The line A1 is provided with a pressure increase control valve 17 for controlling the increase of the brake fluid pressure to the W / C 14, and the line A2 is a pressure increase control for controlling the increase of the brake fluid pressure to the W / C 15. A valve 18 is provided.

The pressure

increase control valves

17 and 18 are constituted by two-position solenoid valves capable of controlling the communication / blocking state. The pressure-increasing

control valves

17 and 18 are normally controlled to be in a communication state when no control current is supplied to the solenoid coils provided in the pressure-increasing

control valves

17 and 18 and in a disconnected state when the control current is supplied to the solenoid coils. It is an open type.

A pressure reduction control valve 21 and a pressure reduction control valve 22 are provided in a pressure reduction control line 17 connecting the pressure

increase control valves

17 and 18 and the W / Cs 14 and 15 and the pressure regulating reservoir 20 in the line A. Each is arranged. These pressure

reduction control valves

21 and 22 are constituted by two-position solenoid valves that can control the communication / cutoff state, and are of a normally closed type that is cut off when not energized.

Between the pressure regulating reservoir 20 and the pipe A, a pipe C serving as a reflux pipe is disposed. The pipe C is provided with a self-priming gear pump 19 driven by a motor 60 so as to suck and discharge brake fluid from the pressure regulating reservoir 20 toward the M / C 13 side or the W / C 14, 15 side. Yes.

Further, a conduit D serving as an auxiliary conduit is provided between the pressure regulating reservoir 20 and the M / C 13. The brake fluid is sucked from the M / C 13 by the gear pump 19 through this pipe D and discharged to the pipe A, so that the brake is applied to the W / C 14 and 15 side during motion control such as skid prevention control and traction control. Liquid is supplied, and the W / C pressure of the wheel to be controlled is increased.

On the other hand, as described above, the second piping system 50b has substantially the same configuration as the first piping system 50a. Specifically, the differential pressure control valve 16 corresponds to the differential pressure control valve 36. The pressure

increase control valves

17 and 18 correspond to the pressure

increase control valves

37 and 38, respectively, and the pressure

reduction control valves

21 and 22 correspond to the pressure

reduction control valves

41 and 42, respectively. The pressure regulation reservoir 20 corresponds to the pressure regulation reservoir 40. The gear pump 19 corresponds to the gear pump 39. Further, the pipeline A, the pipeline B, the pipeline C, and the pipeline D correspond to the pipeline E, the pipeline F, the pipeline G, and the pipeline H, respectively. As described above, the hydraulic circuit of the vehicle brake device 1 is configured, and the gear pump device is obtained by integrating the gear pumps 19 and 39 among them. The detailed structure of the gear pump device will be described later.

The brake ECU 70 controls a control system of the vehicle brake device 1 and is configured by a known microcomputer including a CPU, a ROM, a RAM, an I / O, and the like. The brake ECU 70 executes processing such as various calculations according to a program stored in a ROM or the like, and executes vehicle motion control such as skid prevention control. Specifically, the brake ECU 70 calculates various physical quantities based on detection of sensors (not shown), and determines whether or not to execute vehicle motion control based on the calculation results. When executing the vehicle motion control, the brake ECU 70 obtains a control amount for the wheel to be controlled, that is, a W / C pressure generated in the W / C of the wheel to be controlled. Based on the result, the brake ECU 70 controls each control valve 16-18, 21, 22, 36-38, 41, 42 and the motor 60 for driving the gear pumps 19, 39, so that the W of the wheel to be controlled is controlled. / C pressure is controlled and vehicle motion control is performed.

For example, when pressure is not generated in the M / C 13 as in traction control or skid prevention control, the gear pumps 19 and 39 are driven and the differential

pressure control valves

16 and 36 are set in a differential pressure state. As a result, the brake fluid is supplied to the downstream side of the differential

pressure control valves

16, 36, that is, the W /

C

14, 15, 34, 35 side through the pipelines D, H. And the pressure

increase control valve

17, 18, 37, 38 and the pressure

reduction control valves

21, 22, 41, 42 are appropriately controlled to control the pressure increase / decrease of the wheel to be controlled. Control to achieve a desired control amount.

Further, at the time of anti-skid (ABS) control, the pressure

increase control valves

17, 18, 37, and 38 and the pressure

reduction control valves

21, 22, 41, and 42 are appropriately controlled, and the gear pumps 19 and 39 are driven to drive the W / C. The pressure increase / decrease is controlled so that the W / C pressure becomes a desired control amount.

Next, a detailed structure of the gear pump device in the vehicle brake device 1 configured as described above will be described with reference to FIGS. FIG. 2 shows a state where the pump body 100 is assembled to the housing 101 of the brake fluid pressure control actuator 50. For example, the vertical direction in FIG. 2 and FIG. Assembled to.

As described above, the vehicle brake device 1 includes two systems, the first piping system 50a and the second piping system 50b. For this reason, the pump main body 100 includes two gear pumps 19 for the first piping system 50a and a gear pump 39 for the second piping system 50b.

The gear pumps 19 and 39 built in the pump main body 100 are driven by the motor 60 rotating the rotary shaft 54 supported by the first bearing 51 and the second bearing 52. The outer shape of the pump body 100 is constituted by an aluminum cylinder 71 and a plug 72. The first bearing 51 is disposed on the cylinder 71, and the second bearing 52 is disposed on the plug 72.

In the state where the cylinder 71 and the plug 72 are coaxially arranged, one end side of the cylinder 71 is pressed into the plug 72 to be integrated, and the outer shape of the pump body 100 is configured. And the pump main body 100 is comprised by providing the gear pumps 19 and 39, various sealing members, etc. with the cylinder 71 and the plug 72. FIG.

In this way, the pump body 100 having an integral structure is configured. The pump body 100 having an integral structure is inserted into a substantially cylindrical recess 101a formed in an aluminum housing 101 from the right side of the drawing. Then, a ring-shaped male screw member (screw) 102 is screwed into the female screw groove 101 b dug in the entrance of the recess 101 a, and the pump body 100 is fixed to the housing 101. The pump main body 100 is structured not to be detached from the housing 101 by screwing the male screw member 102.

The gear pump device is configured by fixing the pump main body 100 to the housing 101 in this way. The cylinder 71, the plug 72 and the housing 101 constitute a gear pump device case, and the gear pumps 19 and 39 are accommodated in the case.

In this specification, the direction of insertion of the pump body 100 into the recess 101a of the housing 101 is simply referred to as the insertion direction. The axial direction and the circumferential direction of the pump main body 100 and the gear pumps 19 and 39, in other words, the pump axial direction and the pump axial circumferential direction that coincide with the axial direction and circumferential direction of the rotary shaft 54 are simply referred to as axial direction and circumferential direction.

A circular second concave portion 101c is formed at the front end position in the insertion direction of the concave portion 101a, that is, at the position corresponding to the front end (left end portion in FIG. 2) of the rotating shaft 54 in the bottom portion of the concave portion 101a. The diameter of the second recess 101c is larger than the diameter of the rotation shaft 54, and the tip of the rotation shaft 54 is located in the second recess 101c so that the rotation shaft 54 does not contact the housing 101. Yes.

The cylinder 71 and the plug 72 are provided with

center holes

71a and 72a, respectively. The rotation shaft 54 is inserted into the center holes 71 a and 72 a, and the first bearing 51 fixed to the inner periphery of the center hole 71 a in the cylinder 71 and the second bearing 52 fixed to the inner periphery of the center hole 72 a in the plug 72. It is supported by.

Gear pumps 19 and 39 are provided on both sides of the first bearing 51, that is, in a region in front of the first bearing 51 in the insertion direction and a region sandwiched between the first and second bearings 51 and 52, respectively.

As shown in FIG. 3, the gear pump 19 is disposed in a rotor chamber (accommodating portion) 100 a constituted by a recess in which one end surface of the cylinder 71 is recessed in a circular shape. The gear pump 19 is constituted by an inscribed gear pump (trochoid pump) driven by a rotating shaft 54 inserted into the rotor chamber 100a.

Specifically, the gear pump 19 includes a rotating portion including an outer rotor 19a having an inner tooth portion formed on the inner periphery and an inner rotor 19b having an outer tooth portion formed on the outer periphery, and the center of the inner rotor 19b. The rotary shaft 54 is inserted into the hole 19ba. A key 54b is inserted into a hole 54a formed in the rotating shaft 54, and torque is transmitted to the inner rotor 19b by the key 54b.

The outer rotor 19a and the inner rotor 19b have a plurality of gaps 19c formed by meshing inner teeth and outer teeth formed respectively. Then, the suction and discharge of the brake fluid is performed by changing the size of the gap 19c by the rotation of the rotating shaft 54.

On the other hand, as shown in FIG. 2, the gear pump 39 is disposed in a rotor chamber (accommodating portion) 100b constituted by a concave portion in which the other end surface of the cylinder 71 is recessed in a circular shape. It is driven by a rotating shaft 54 inserted into the inside. Similarly to the gear pump 19, the gear pump 39 includes an outer rotor 39a and an inner rotor 39b, and a rotation shaft 54 is inserted into the center hole 39ba of the inner rotor 39b. Each

rotor

39a, 39b is constituted by an internal gear pump that sucks and discharges brake fluid in a plurality of gaps 39c formed by meshing both teeth. The gear pump 39 is arranged such that the gear pump 19 is rotated approximately 180 ° around the rotation shaft 54. By arranging in this way, the

gaps

19c, 39c on the suction side and the

gaps

19c, 39c on the discharge side of the gear pumps 19, 39 are symmetrical with respect to the rotation shaft 54. The force applied to the first bearing 51 by the high brake fluid pressure can be offset.

These gear pumps 19 and 39 basically have the same structure. In the present embodiment, the polishing bars 71f formed on the sliding

surfaces

71b and 71c of the cylinder 71 that constitutes a part of the case of the gear pumps 19 and 39 (see FIGS. 4 and 5). The configuration is changed from the conventional one. As a result, the loss torque is reduced. Details of the structure of the polishing bar 71f will be described later.

Further, on one end face side of the cylinder 71, a seal mechanism 111 that presses the gear pump 19 toward the cylinder 71 is provided on the opposite side of the cylinder 71 with the gear pump 19 interposed therebetween, that is, between the cylinder 71 and the gear pump 19 and the housing 101. It has been. Further, on the other end face side of the cylinder 71, a seal mechanism 115 that presses the gear pump 39 toward the cylinder 71 on the opposite side of the cylinder 71 with the gear pump 39 interposed therebetween, that is, between the cylinder 71 and the gear pump 39 and the plug 72. Is provided.

The seal mechanism 111 is composed of a ring-shaped member having a hollow portion into which the rotating shaft 54 is inserted. With this sealing mechanism 111, the outer rotor 19a and the inner rotor 19b are pressed toward the cylinder 71, thereby sealing a relatively low pressure portion and a relatively high pressure portion on one end face side of the gear pump 19. Yes. Specifically, the sealing mechanism 111 exhibits a sealing function by contacting the bottom surface of the concave portion 101a that is an outline of the housing 101 and desired positions of the outer rotor 19a and the inner rotor 19b.

In the case of this embodiment, the seal mechanism 111 is configured to include an inner member 112 having a hollow frame shape, an annular rubber member 113, and an outer member 114 having a hollow frame shape. Then, the inner member 112 is fitted into the outer member 114 with the annular rubber member 113 disposed between the outer peripheral wall of the inner member 112 and the inner peripheral wall of the outer member 114.

Further, the outer diameter of the seal mechanism 111 is set to be smaller than the inner diameter of the concave portion 101a of the housing 101 at least above the plane of FIG. For this reason, it is set as the structure which can flow brake fluid through the clearance gap between the sealing mechanism 111 and the recessed part 101a of the housing 101 above the paper surface. This gap constitutes the discharge chamber 80 and is connected to a discharge conduit 90 formed at the bottom of the recess 101 a of the housing 101. With such a structure, the gear pump 19 can discharge brake fluid using the discharge chamber 80 and the discharge conduit 90 as a discharge path. During the operation of the pump 19, the outer member 114 is pressed against the gear pump 19 by the high brake fluid pressure on the discharge side, and the sealing performance of one end face of the gear pump 19 by the seal mechanism 111 is further ensured. Yes.

Further, the cylinder 71 is formed with a suction port 81 communicating with the gap portion 19c on the suction side of the gear pump 19. The suction port 81 extends from the end surface of the cylinder 71 on the gear pump 19 side to the outer peripheral surface, and is connected to a suction pipe 91 provided on the side surface of the recess 101 a of the housing 101. As shown in FIGS. 2 and 4, a suction groove 71 d that connects the center hole 71 a and the suction port 81 is formed on the end surface of the cylinder 71 on the gear pump 19 side. With such a structure, the gear pump 19 can introduce brake fluid using the suction pipe 91 and the suction port 81 as a suction path.

On the other hand, the seal mechanism 115 is also composed of a ring-shaped member having a central part into which the rotating shaft 54 is inserted. With this sealing mechanism 115, the outer rotor 39a and the inner rotor 39b are pressed toward the cylinder 71, thereby sealing a relatively low pressure portion and a relatively high pressure portion on one end face side of the gear pump 39. Yes. Specifically, the sealing mechanism 115 exhibits a sealing function by contacting the end surface of the portion of the plug 72 in which the sealing mechanism 115 is accommodated and the desired positions of the outer rotor 39a and the inner rotor 39b.

The seal mechanism 115 is also configured to include an inner member 116 having a hollow frame shape, an annular rubber member 117, and an outer member 118 having a hollow frame shape. The inner member 116 is fitted into the outer member 118 with the annular rubber member 117 disposed between the outer peripheral wall of the inner member 116 and the inner peripheral wall of the outer member 118.

The basic structure of the seal mechanism 115 is the same as that of the seal mechanism 111, but the structure constituting the seal is opposite to that of the seal mechanism 111 described above, and the structure is changed accordingly. Specifically, the sealing mechanism 115 is configured to have a symmetrical shape with respect to the sealing mechanism 111, and is arranged with a 180 ° phase shift with respect to the sealing mechanism 111 around the rotation shaft 54. Other than that, the seal mechanism 115 has the same structure as the seal mechanism 111.

Note that the outer diameter of the seal mechanism 115 is smaller than the inner diameter of the plug 72 at least on the lower side of the drawing. For this reason, the brake fluid can flow through the gap between the seal mechanism 115 and the plug 72 below the paper surface. This gap constitutes the discharge chamber 82, and is connected to a communication path 72 b formed in the plug 72 and a discharge conduit 92 formed on the side surface of the recess 101 a of the housing 101. With such a structure, the gear pump 39 can discharge brake fluid using the discharge chamber 82, the communication path 72b, and the discharge pipe line 92 as discharge paths. During the operation of the pump 39, the outer member 118 is pressed toward the gear pump 39 by the brake fluid pressure on the high discharge side, and the sealing performance of one end face of the gear pump 39 by the seal mechanism 115 is further ensured. Yes.

On the other hand, the end faces of the cylinder 71 on the side of the gear pumps 19 and 39 also serve as sliding

surfaces

71b and 71c, that is, the surfaces on which the

rotors

19a, 19b, 39a and 39b slide, A seal (mechanical seal) is made by contact. Thus, the relatively low pressure portion and the relatively high pressure portion on the other end face side of the gear pumps 19 and 39 are sealed.

Also, the cylinder 71 is formed with a suction port 83 communicating with the suction side gap 39c of the gear pump 39. The suction port 83 extends from the end surface of the cylinder 71 on the gear pump 39 side to the outer peripheral surface, and is connected to a suction conduit 93 provided on the side surface of the recess 101 a of the housing 101. With such a structure, the gear pump 39 can introduce brake fluid using the suction pipe 93 and the suction port 83 as a suction path.

In FIG. 2, the suction conduit 91 and the discharge conduit 90 correspond to the conduit C in FIG. 1, and the suction conduit 93 and the discharge conduit 92 correspond to the conduit G in FIG.

In addition, an annular resin member 120a having a U-shaped radial cross section and an annular rubber member fitted in the annular resin member 120a at the rear of the first bearing 51 in the center hole 71a of the cylinder 71 in the insertion direction. The sealing member 120 provided with 120b is accommodated. The seal member 120 provides a seal between the two systems in the center hole 71a of the cylinder 71.

Further, the center hole 72a of the plug 72 has a stepped shape in which the inner diameter is reduced in three steps from the front to the rear in the insertion direction, and the first stepped portion on the rearmost side in the insertion direction. The seal member 121 is accommodated in the housing. The seal member 121 is obtained by fitting a ring-shaped elastic ring 121a made of an elastic member such as rubber into a ring-shaped resin member 121b in which a groove having a radial direction as a depth direction is formed. The resin member 121b is pressed by the elastic force of 121a and comes into contact with the rotating shaft 54.

In addition, the sealing mechanism 115 mentioned above is accommodated in the step part of the 2nd step used as the step next to the step in which the sealing member 121 is arrange | positioned among the center holes 72a. The communication passage 72b described above is formed so as to reach from the stepped portion to the outer peripheral surface of the plug 72. In addition, an end of the cylinder 71 on the rear side in the insertion direction is press-fitted into a third stepped portion on the front side in the insertion direction of the center hole 72a. A portion of the cylinder 71 that is fitted into the center hole 72 a of the plug 72 has a smaller outer diameter than other portions of the cylinder 71. Since the axial dimension of the portion of the cylinder 71 whose outer diameter is reduced is made larger than the axial dimension of the third stepped portion of the center hole 72 a, the cylinder 71 is connected to the center hole 72 a of the plug 72. A groove 74c formed by the cylinder 71 and the plug 72 is formed at the tip end position of the plug 72 when press-fitted into the plug 72.

Furthermore, the diameter of the central hole 72a of the plug 72 is partially enlarged even in the rear in the insertion direction, and an oil seal (seal member) 122 is provided in this portion. Thus, by disposing the oil seal 122 closer to the motor 60 than the seal member 121, basically, leakage of brake fluid to the outside through the center hole 72 a is prevented by the seal member 121, and the oil seal 122 , So that the effect can be obtained more reliably.

O-rings 73a to 73d as annular seal members are provided on the outer periphery of the pump main body 100 thus configured so as to seal each part. These O-rings 73a to 73d seal brake fluid between the two systems formed in the housing 101 or between the discharge path and the suction path of each system. The O-ring 73 a is disposed between the discharge chamber 80 and the discharge conduit 90 and the suction port 81 and the suction conduit 91. The O-ring 73 b is disposed between the suction port 81 and the suction conduit 91 and the suction port 83 and the suction conduit 93. The O-ring 73 c is disposed between the suction port 83 and the suction conduit 93 and the discharge chamber 82 and the discharge conduit 92. The O-ring 73 d is disposed between the discharge chamber 82 and the discharge conduit 92 and the outside of the housing 101. The O-

rings

73a, 73c, and 73d are simply arranged in a circular shape so as to wrap around the circumferential direction around the rotation axis 54, but the O-ring 73b is an axis that surrounds the circumferential direction around the rotation axis 54. By disposing in the direction, the size can be reduced in the axial direction of the rotating shaft 54.

In addition, groove portions 74a to 74d are provided on the outer periphery of the pump body 100 so that the O-rings 73a to 73d can be arranged. The

groove portions

74 a and 74 b are formed by partially denting the outer periphery of the cylinder 71. The groove 74 c is formed by a recessed portion on the outer periphery of the cylinder 71 and a tip portion of the plug 72. The recess 74d is formed by partially denting the outer periphery of the plug 72. By inserting the pump body 100 into the recess 101a of the housing 101 with the O-rings 73a to 73d fitted in the grooves 74a to 74d, the O-rings 73a to 73d are formed on the inner wall surface of the recess 101a. It is crushed and made to function as a seal.

Furthermore, the outer peripheral surface of the plug 72 is reduced in diameter in the rear in the insertion direction to form a stepped portion. The ring-shaped male screw member 102 described above is fitted into the reduced diameter portion, and the pump body 100 is fixed.

The gear pump device is configured by the above structure. Next, the detailed structure of the sliding

surfaces

71b and 71c of the cylinder 71 constituting part of the case of the gear pumps 19 and 39 described above will be described. Since the sliding

surfaces

71b and 71c have the same configuration, both the sliding

surfaces

71b and 71c are illustrated as being the same in FIGS.

Sliding

surfaces

71b and 71c as shown in FIG. 4 and FIG. 5 are configured by the end surface of the cylinder 71 opposite to the

seal mechanisms

111 and 115 with the gear pumps 19 and 39 interposed therebetween. Specifically, a central hole 71a is formed at the center position of the end surface, and the discharge grooves are disposed at positions corresponding to the suction ports 81 and 83 and the

discharge chambers

80 and 82 on both sides of the center hole 71a. 71e is formed. The portions other than the central hole 71a, the suction port 81, and the discharge groove 71e on the end surface are formed as sliding

surfaces

71b, 71c on which the

rotors

19a, 19b, 39a, 39b slide when the gear pumps 19, 39 are driven. Yes.

The sliding surfaces 71b and 71c are formed with polishing bars 71f constituting fluid introduction grooves. The polishing streaks 71f are formed by polishing, for example. In the present embodiment, a plurality of polishing bars 71 f are formed so as to extend radially from the centers of the gear pumps 19 and 39. Here, the center of the gear pumps 19 and 39 is the center of the center hole 71a. However, it is only necessary that the polishing bars 71f be formed radially with respect to the center hole 71a, and the center is not set at a specific position. good.

The plurality of polishing bars 71f are communicated with portions of the

rotor chambers

100a and 100b outside the

outer rotors

19a and 39a (hereinafter referred to as outer peripheral high pressure regions). The plurality of polishing bars 71f are configured not to communicate with the central hole 71a, the suction ports 81 and 83, and the suction groove 71d in which the portion communicated with the outer peripheral high pressure region becomes the low pressure region. In the present embodiment, the end on the inner peripheral side of the plurality of polishing bars 71f is separated from the center hole 71a, the suction ports 81 and 83, and the suction groove 71d.

As described above, the polishing bars 71 f are formed on the sliding

surfaces

71 b and 71 c of the cylinder 71.

When the polishing bar 71f having such a configuration is formed, since the polishing bar 71f is in communication with the outer peripheral high-pressure region having a high discharge pressure, a high-pressure brake fluid is introduced into the polishing bar 71f. For this reason, it is possible to obtain a push-back effect of pushing back the gear pumps 19 and 39 based on a high brake fluid pressure. Even if the polishing bar 71f communicates with the outer peripheral high-pressure region, it does not communicate with each part that becomes the low-pressure region. For this reason, the inside of the polishing bar 71f can be maintained at a high pressure, and a reduction in the pushing back effect can be suppressed. Therefore, it is possible to prevent a reduction in the loss torque reduction effect and further reduce the loss torque.

(Second Embodiment)
A second embodiment of the present invention will be described. In the present embodiment, the polishing bar 71f is changed with respect to the first embodiment, and the others are the same as those in the first embodiment. Therefore, only the parts different from the first embodiment will be described.

As shown in FIGS. 6 and 7, in the present embodiment, a plurality of the polishing bars 71f are formed so as to extend radially from the centers of the gear pumps 19 and 39, while the low-pressure gap 19c of the polishing bars 71f is formed. The low pressure portion 71fa that can communicate with 39c is separated from the high pressure portion 71fb that communicates with the outer peripheral high pressure region on the outer peripheral side.

Specifically, the fluid pressure of each part in the gear pumps 19 and 39 is shown as shown in FIG. 8, and the high pressure region Ra into which the discharge pressure is introduced, the low pressure region Rb into which the suction pressure is introduced, and the intermediate pressure between them. Region Rc exists. The pressure between the gear pumps 19 and 39 and the sliding

surfaces

71b and 71c of the cylinder 71 is shown in FIG. Therefore, based on the pressure relationship shown in FIGS. 8 and 9, the low pressure portion 71fa is formed in a range including the low pressure region Rb, and the high pressure portion 71fb is not formed in the low pressure region Rb.

As shown in FIG. 8, the suction ports 81 and 83, the suction groove 71d, and the center hole 71a are at a low pressure. The

gaps

19c and 39c are in a low pressure state when communicating with the suction ports 81 and 83 and the suction groove 71d, and further until the volume increases after communicating with the suction ports 81 and 83 and the suction groove 71d. For this reason, the place which can be communicated with the

low pressure gaps

19c and 39c in the polishing bar 71f is the low pressure part 71fa, and the place where the gap between the outer circumference of the high pressure

outer rotor

19a and 39a and the cylinder 71 is communicated. These are separated as the high-pressure portion 71fb.

In other words, the polishing bar 71f is not formed in the predetermined region. Specifically, as shown in FIGS. 6 and 8, the confined

portions

19d and 39d that become the intermediate pressure region Rc in which neither the high-pressure region Ra nor the low-pressure region Rb communicates among the

gaps

19c and 39c. The polishing streaks 71f are not formed in the range where the is located. That is, the polishing streaks 71f are not formed in the range of the trajectory of the

closing portions

19d and 39d. Further, the polishing bar 71f is not formed in a range along the movement locus of the

gaps

19c, 39c on the outer peripheral side of the area where the

gaps

19c, 39c are in a low pressure state.

The binding

portions

19d and 39d referred to here mean that of the

gap portions

19c and 39c when the volume is maximum. Specifically, in the rotational direction of the gear pumps 19 and 39, the

gaps

19 c and 39 c are moved from the site communicating with the suction ports 81 and 83 to the site communicating with the

discharge chambers

80 and 82. The

gaps

19c and 39c when the volume becomes the maximum are called the

closed portions

19d and 39d.

The

gaps

19c and 39c also have closed

portions

19e and 39e when the volume is minimized, and the

closed portions

19e and 39e communicate with the low pressure portion 71fa of the polishing bar 71f. Since the volumes of the

confinement portions

19e and 39e are small, even if the

confinement portions

19e and 39e communicate with the low pressure portion 71fa, the influence of pressure fluctuations is small. For this reason, the low-pressure part 71fa communicates with the confining

parts

19e, 39e. However, the polishing bar 71f may not be provided in this region.

In this way, the polishing bar 71f is configured to separate the low pressure portion 71fa communicated with the low pressure region Rb such as the suction ports 81 and 83 and the high pressure portion 71fb communicated with the high pressure region Ra such as the

discharge chambers

80 and 82. You may do it. If it does in this way, it can control that a high pressure fluid leaks from a higher pressure field to the low pressure field side. Therefore, it is possible to further prevent the loss torque from being reduced, and it is possible to further reduce the loss torque.

(Third embodiment)
A third embodiment of the present invention will be described. In the present embodiment, the polishing bar 71f is changed with respect to the second embodiment, and the others are the same as those in the second embodiment. Therefore, only the parts different from the second embodiment will be described.

As shown in FIG. 10, in this embodiment, the polishing bar 71 f is configured by a radial curve extending from the center of the gear pumps 19 and 39. The low pressure portion 71fa and the high pressure portion 71fb of each polishing bar 71f are positioned so that their intermediate positions are located in front of the rotation direction of the gear pumps 19 and 39 rather than both ends. That is, the low-pressure part 71fa and the high-pressure part 71fb are curved to have a convex shape so that the convex part faces the front in the rotational direction.

As described above, when the low-pressure portion 71fa and the high-pressure portion 71fb are configured with radial curves, the curved portions when the gear pumps 19 and 39 are rotated serve as wedges, and the brake fluid introduced into the interior is contained inside. This hinders the flow in the circumferential direction. For this reason, it becomes difficult for the brake fluid in the polishing bar 71f to escape from the high pressure region to the low pressure region side, and the high pressure state of the polishing bar 71f can be maintained. As a result, it is possible to further prevent the loss torque from being reduced, and to further reduce the loss torque.

(Fourth embodiment)
A fourth embodiment of the present invention will be described. In the present embodiment, the polishing bar 71f is changed with respect to the first embodiment, and the others are the same as those in the first embodiment. Therefore, only the parts different from the first embodiment will be described.

As shown in FIG. 11, in this embodiment, a virtual circle C indicated by a one-dot chain line in the figure is set at the center position of the gear pumps 19 and 39, and a polishing bar 71f is provided so as to extend in the tangential direction of the virtual circle C. I am doing so. Specifically, the polishing bar 71f is provided so that the inner peripheral side ends of the gear pumps 19 and 39 of the polishing bar 71f are located in front of the outer peripheral side in the rotational direction. The size of the imaginary circle C is arbitrary and is, for example, equal to or smaller than the diameter of the center hole 71a.

As described above, the same effect as that of the first embodiment can be obtained even when the polishing bar 71f has a layout extending in the tangential direction with respect to the virtual circle C. Further, the polishing bar 71f is provided so that the inner peripheral side end portions of the gear pumps 19 and 39 of the polishing bar 71f are located in front of the outer peripheral side end portion in the rotational direction. For this reason, based on the rotational movement of the gear pumps 19 and 39, the brake fluid that has flowed in from the outer peripheral end is easily flowed to the inner peripheral end. Therefore, it becomes easy to ensure a high pressure state in the entire area of the polishing bar 71f, and the effect shown in the first embodiment can be obtained.

(Other embodiments)
The present invention is not limited to the above-described embodiment, and can be appropriately changed within the scope described in the claims.

For example, although an example in which the radial polishing bar 71f is provided as the fluid introduction groove has been described, the fluid introduction groove may be configured by a groove other than the polishing line 71f. For example, the fluid introduction groove may be constituted by a laser processing groove by laser processing. In the case of the laser processing groove, since no burrs are generated by machining, the influence of burrs can be eliminated. Further, in the case of laser processing, since it is possible to perform processing even when the processing surface is at a deep position, it is possible to facilitate formation of the fluid introduction groove.

Further, in each of the above embodiments, the gear pump device having the two gear pumps 19 and 39 constituted by the inscribed gear pump is taken as an example. However, it may be a gear pump device to which only one gear pump is applied. Further, in each of the above embodiments, a gear pump device including two gear pumps 19 and 39 is used, and a case constituting a housing portion (

rotor chamber

100a and 100b) of each

gear pump

19 and 39 is formed by a housing 101, a cylinder 71, and a plug 72. It is composed. However, this is also merely an example, and the case may be configured only by what constitutes the outer shape of the pump body 100, for example.

Further, although the suction groove 71d is formed on one end surface of the cylinder 71, a structure without the suction groove 71d may be employed. In that case, it is preferable that the polishing bar 71f is also formed in the portion where the suction groove 71d is located.

DESCRIPTION OF SYMBOLS 100 ... Pump main body, 101 ... Housing, 101a ... Recessed part, 19, 39 ... Rotary pump, 19a, 39a ... Outer rotor, 19b, 39b ... Inner rotor, 54 ... Rotary shaft, 71 ... Cylinder, 71a ... Center hole, 71b 71c ... sliding surface, 71d ... suction groove, 71e ... discharge groove, 71f ... polishing streaks, 71fa ... low pressure part, 71fb ... high pressure part, 72 ... plug, 80, 82 ... discharge chamber, 81, 83 ... suction port, 90, 92 ... discharge line, 91, 93 ... suction line, 111, 115 ... sealing mechanism

Claims

An outer rotor having an inner tooth portion, an inner rotor meshed with the outer rotor while forming a plurality of gaps, and the outer rotor and the outer rotor based on rotation of a shaft inserted through a central hole of the inner rotor A gear pump that performs a suction and discharge operation of fluid by rotating the inner rotor;
A case forming an accommodating portion in which the gear pump is accommodated;
A suction side of the gear pump for sucking the fluid, a low pressure side including the periphery of the shaft, a discharge side for discharging the fluid, and a suction pump disposed between the case and one of the end faces in the pump axial direction of the gear pump. A sealing mechanism that partitions a high pressure side including a part of a gap between the outer periphery of the outer rotor and the case;
The other end surface of the pump axial end surface of the gear pump is brought into contact with the sliding surface of the case based on the pressing force of the seal mechanism, so that the gap between the low pressure side and the high pressure side of the gear pump at the end surface is reached. In the gear pump device that is sealed,
The sliding surface includes a fluid introduction groove that is configured by a line extending radially from the center of the gear pump and into which a fluid in a gap between the outer periphery of the outer rotor on the high pressure side and the case is introduced. ,
The gear pump device, wherein the fluid introduction groove is separated from the center hole and the suction side.
2. The gear pump device according to claim 1, wherein the fluid introduction groove is not formed in a range where a confining portion having a maximum volume among the plurality of gap portions is located.
The fluid introduction groove has a portion formed at a place where it can communicate with the suction side of the plurality of gaps that can communicate with the suction side as a low pressure portion, and an outer periphery of the outer rotor that is in a high pressure state. 3. The gear pump device according to claim 1, wherein the low pressure portion and the high pressure portion are separated by using a place communicating with a gap between the case and the case as a high pressure portion. 4.
The fluid introduction groove is configured by a radial curve, and an intermediate position located between both ends of the fluid introduction groove is located in front of the rotation direction of the gear pump. The gear pump device according to any one of claims 1 to 3.
4. The gear pump according to claim 1, wherein the fluid introduction groove has a virtual circle set at a center position of the gear pump and is radially extended in a tangential direction of the virtual circle. 5. apparatus.
The fluid introduction groove is formed such that an end portion on the inner peripheral side of the gear pump in the fluid introduction groove is located in front of an end portion on the outer peripheral side in the rotation direction of the gear pump. The gear pump device according to claim 5.