US20200003210A1

US20200003210A1 - Oil pump

Info

Publication number: US20200003210A1
Application number: US16/489,711
Authority: US
Inventors: Yoshiyuki Kobayashi; Koji Higuchi; Shigehiro Kataoka
Original assignee: Nidec Tosok Corp
Current assignee: Nidec Powertrain Systems Corp
Priority date: 2017-03-23
Filing date: 2018-03-12
Publication date: 2020-01-02
Also published as: WO2018173828A1; JPWO2018173828A1; DE112018001500T5; CN211082239U

Abstract

An oil pump includes a motor including a shaft disposed along a center axis, a rotor rotating around the shaft, a stator disposed to face the rotor, a housing accommodating the rotor and the stator, and a pump. The pump includes a pump rotor rotating together with the shaft, and a pump housing including an accommodating portion that accommodates the pump rotor. The pump housing includes a suction port that suctions in oil, a discharge port that discharges oil, and a pressure sensor that detects hydraulic pressure of oil in a partial flow passage allowing communication between the discharge port and the accommodating portion. The pressure sensor is disposed outside the housing of the motor, and the housing includes a wall that blocks electromagnetic waves.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This is a U.S. national stage of PCT Application No. PCT/JP2018/009468, filed on Mar. 12, 2018, and priority under 35 U.S.C. § 119(a) and 35 U.S.C. § 365(b) is claimed from Japanese Application No. 2017-057116, filed Mar. 23, 2017; the entire disclosures of each application are hereby incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to an oil pump.

BACKGROUND

In recent years, since an electric oil pump used for a transmission or the like has been installed in an existing space of a vehicle, restrictions on mounting conditions have been severe, and thus miniaturization is required so that the electric oil pump can be installed in various mounting spaces.
Also, there is a concern that the operation of the transmission in a half clutch state may become unstable due to hydraulic vibrations of oil discharged from the electric oil pump. In order to eliminate this concern, it is conceivable to increase a rotational speed of the oil pump. However, simply raising the rotational speed increases a flow rate of oil, making pressure excessive, and therefore the pressure in the half clutch state cannot be maintained.
Meanwhile, Japanese Unexamined Patent Application Publication No. 2015-148310 discloses a control device for a continuously variable transmission which can inhibit amplification of hydraulic vibrations generated in a control valve unit due to hydraulic vibrations of oil discharged from an electric oil pump. In the control valve unit, a torque converter constituting the continuously variable transmission, a forward-reverse switching mechanism, and a plurality of valves for controlling respective operations of a belt-type continuously variable transmission mechanism are provided. The plurality of valves control supply and discharge of the oil discharged from the electric oil pump to control operations of a plurality of devices in the continuously variable transmission. When there is a concern that the hydraulic vibrations may be amplified in the control valve unit, the control device of the continuously variable transmission raises a line pressure to inhibit the amplification of the hydraulic vibrations.
The control device of the continuously variable transmission described in Japanese Unexamined Patent Application Publication No. 2015-148310 can inhibit amplification of hydraulic vibrations of oil discharged from the electric oil pump by raising the line pressure. However, in the control device of the continuously variable transmission described in Japanese Unexamined Patent Application Publication No. 2015-148310, there is no means for directly detecting the line pressure, and the line pressure is indirectly detected from command signals to a line pressure solenoid valve that controls the line pressure. For this reason, the detected line pressure may not be accurate.

SUMMARY

Example embodiments of the present disclosure to provide oil pumps each capable of accurately detecting hydraulic pressure of oil discharged and capable of being miniaturized.
An example embodiment of the present disclosure provides a motor including a shaft disposed along a center axis extending in an axial direction, a rotor rotating around the shaft, a stator disposed to face the rotor, a housing accommodating the rotor and the stator, and a pump. The pump includes a pump rotor rotating together with the shaft to suction and discharge oil, and a pump housing including an accommodating portion that accommodates the pump rotor. The pump housing includes a suction port that suctions in oil, a discharge port that discharges oil, and a pressure sensor that detects hydraulic pressure of oil in a flow passage allowing communication between the discharge port and the accommodating portion. The pressure sensor is disposed outside the housing of the motor, and the housing includes a wall that blocks electromagnetic waves.
According to an example embodiment of the present disclosure, it is possible to provide an oil pump that is able to accurately detect hydraulic pressure of oil discharged from the oil pump and is able to be miniaturized.
The above and other elements, features, steps, characteristics and advantages of the present disclosure will become more apparent from the following detailed description of the example embodiments with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective view of an oil pump according to a first example embodiment of the present disclosure.

FIG. 2 illustrates a cross-sectional view of the oil pump.

FIG. 3 illustrates a perspective view of the oil pump that shows an internal structure of a pump cover.

FIG. 4 illustrates a plan view of the oil pump that shows the internal structure of the pump cover.

FIG. 5 illustrates an exploded perspective view of the pump cover in which connectors are attached to respective terminals of a solenoid valve and a pressure sensor which are attached to the pump cover.

FIG. 6 illustrates an exploded perspective view of the oil pump in which the pump cover is attached to a motor provided with a pump body.

DETAILED DESCRIPTION

Hereinafter, oil pumps according to example embodiments of the present disclosure will be described with reference to the drawings. However, dimensions, materials, shapes, relative dispositions, etc. of constituent components described in example embodiments or shown in the drawings are not intended to limit the scope of the present disclosure to the contents described, but are merely illustrative examples. For example, expressions indicating a relative or definitive disposition such as “in a direction,” “along a direction,” “parallel,” “orthogonal,” “center,” “concentric,” or “coaxial” not only represent such a disposition strictly, but also represent a relatively displaced state with a tolerance, or an angle and a distance that allow the same function to be obtained. For example, expressions indicating that things are in the same state such as “identical,” “equal,” and “homogeneous” not only represent an equal state strictly, but also represent a state in which there is a tolerance or a difference with which the same function can be obtained. For example, expressions indicating shapes such as a square shape and a cylindrical shape not only represent shapes such as a square shape and a cylindrical shape in a geometrically strict sense but also represent shapes including an uneven portion, a chamfer, or the like within a range in which the same effect can be obtained. On the other hand, expressions “including,” “equipped with,” “provided with, “comprising,” or “having” a component are not exclusive expressions excluding the presence of other components.
In the drawings, an XYZ coordinate system is shown as a three-dimensional orthogonal coordinate system, as needed. In the XYZ coordinate system, a Z-axis direction is a direction parallel to one axial direction of a central axis J shown in FIG. 1. An X-axis direction is a direction parallel to a transverse direction of the oil pump shown in FIG. 1, that is, a vertical direction in FIG. 1. A Y-axis direction is a direction orthogonal to both the X-axis direction and the Z-axis direction.
In the following description, a positive side (+Z side) in the Z-axis direction is referred to as a “front side,” and a negative side (−Z side) in the Z-axis direction is referred to as a “rear side.” Also, the rear side and the front side are names used merely for the purpose of explanation and do not limit actual positional relationships and directions. In addition, unless otherwise noted, a direction parallel to the central axis J (Z-axis direction) is simply referred as an “axial direction,” a radial direction centered on the central axis J is simply referred as a “radial direction,” and a circumferential direction centered around the central axis J, that is, a direction around the central axis J (θ direction), is simply referred to as a “circumferential direction.”
Further, in the present specification, the term “extending in the axial direction” means not only a case of strictly extending in the axial direction (Z-axis direction), but also a case of extending in a direction inclined at an angle less than 45° with respect to the axial direction. Also, in the present specification, the term “extending in the radial direction” means not only a case of extending strictly in the radial direction, that is, in a direction perpendicular to the axial direction (Z-axis direction), but also a case of extending in a direction inclined by less than 45° with respect to the radial direction.

First Example Embodiment

FIG. 1 illustrates a perspective view of an oil pump according to a first example embodiment. FIG. 2 illustrates a cross-sectional view of essential parts of the oil pump.
The oil pump 1 of the present example embodiment has a motor 20 and a pump 3 as shown in FIGS. 1 and 2. The motor 20 has a shaft 41 disposed along the central axis J extending in the axial direction. The pump 3 is positioned on one side of the motor 20 in the axial direction, and is driven by the motor 20 via the shaft 41 to discharge oil. That is, the motor 20 and the pump 3 are provided side by side in the axial direction. Hereinafter, each component will be described in detail.

As shown in FIG. 2, the motor 20 has a housing 21, a rotor 40, the shaft 41, a stator 50, and a bearing 55.
The motor 20 is, for example, an inner rotor type motor, the rotor 40 is fixed to an outer circumferential surface of the shaft 41, and the stator 50 is positioned outside the rotor 40 in the radial direction. Also, the bearing 55 is disposed at an end portion of the shaft 41 on the rear side (−Z side) in the axial direction and rotatably supports the shaft 41. In addition, the motor 20 may be an outer rotor type motor in which a coil is disposed around the shaft 41, magnets are disposed outside the coil, and the magnets rotate.

(Housing 21)

The housing 21 has a thin-walled cylindrical shape with a bottom, and has a bottom surface portion 21 a, a stator holding portion 21 b, a pump body holding portion 21 c, a side wall portion 21 d, and flange portions 24 and 25. The bottom surface portion 21 a forms a bottomed part, and the stator holding portion 21 b, the pump body holding portion 21 c and the side wall portion 21 d form a cylindrical side wall surface centered on the central axis J. In the present example embodiment, an inner diameter of the stator holding portion 21 b is larger than an inner diameter of the pump body holding portion 21 c. An outer surface of the stator 50, that is, an outer surface of a core back portion 51, which will be described below, is fitted into an inner surface of the stator holding portion 21 b. Therefore, the stator 50 is accommodated in the housing 21. Also, the stator holding portion 21 b and the pump body holding portion 21 c of the housing 21 are collectively referred to as a wall section 21 e.
The flange portion 24 extends radially outward from an end portion of the side wall portion 21 d on the front side (+Z side). On the other hand, the flange portion 25 extends radially outward from an end portion of the stator holding portion 21 b on the rear side (−Z side). The flange portion 24 and the flange portion 25 are opposed to each other, and are fastened by fastening means (not shown). Therefore, the motor 20 and the pump 3 are sealed and fixed in the housing 21.
For example, a zinc-aluminum-magnesium-based alloy or the like can be used as a material of the housing 21, and specifically, a hot-dip zinc-aluminum-magnesium alloy plated steel plate and a steel strip can be used. Since the housing 21 is a magnesium-based alloy, electromagnetic waves leaking from the inside of the motor 20 through the wall section 21 e of the housing 21 to the outside can be effectively inhibited. Also, the housing 21 is made of a metal, has a high heat conductivity and a large surface area, and thus provides an excellent heat dissipation effect. In addition, a bearing holding portion 56 for holding the bearing 55 is provided on the bottom surface portion 21 a.

(Rotor 40)

The rotor 40 has a rotor core 43 and rotor magnets 44. The rotor core 43 is fixed to the shaft 41 to surround the shaft 41 around the axis (θ direction). The rotor magnets 44 are fixed to an outer surface around the axis (θ direction) of the rotor core 43. The rotor core 43 and the rotor magnets 44 rotate together with the shaft 41.

(Stator 50)

The stator 50 surrounds the rotor 40 around the axis (θ direction) and rotates the rotor 40 around the central axis J. The stator 50 has a core back portion 51, tooth portions 52, a coil 53, and an insulator (bobbin) 54.
The core back portion 51 has a cylindrical shape concentric with the shaft 41. The tooth portions 52 extend from an inner surface of the core back portion 51 toward the shaft 41. The plurality of tooth portions 52 are provided at equal intervals in the circumferential direction of the inner surface of the core back portion 51. The coil 53 is provided around the insulator (bobbin) 54, and a conductive wire 53a is wound therearound. The insulator (bobbin) 54 is attached to each tooth portion 52.

(Bearing 55)

The bearing 55 is disposed on the rear side (−Z side) of the rotor 40 and the stator 50, and is held by the bearing holding portion 56. The bearing 55 supports the shaft 41. A shape, a structure, and the like of the bearing 55 are not particularly limited, and any known bearing can be used.

(Shaft 41)

The shaft 41 extends along the central axis J and penetrates the motor 20. The front side of the shaft 41 protrudes from the motor 20 and extends into the pump 3. An end portion of the shaft 41 on the front side is disposed in a discharge port 11 of a pump cover 8, which will be described below. The rear side of the shaft 41 protrudes from the motor 20 to be supported by the bearing 55 provided in a bus bar holder 58.

The pump 3 is positioned on one side of the motor 20 in the axial direction, in particular, on the front side (+Z side). The pump 3 is driven by the motor 20 via the shaft 41. The pump 3 has a pump rotor 4 and a pump housing 5. The pump housing 5 has a suction port 9, a discharge port 11 and a pressure sensor 70. Further, the pump housing 5 has a pump body 6, a pump cover 8 and a receiving port 12.

(Pump Body 6)

The pump body 6 is fixed in a front side of the housing 21 on the front side (+Z side) of the motor 20. The pump body 6 has an accommodating portion 7 which accommodates the pump rotor 4 and has a side surface and a bottom surface positioned on the other side (rear side) of the motor 20 in the axial direction. The accommodating portion 7 opens toward the front side (+Z side) and is recessed toward the rear side (−Z side). A shape of the accommodating portion 7 viewed in the axial direction is a circular shape.
The pump body 6 has a through hole 6 a penetrating therethrough along the central axis J. Both ends of the through hole 6 a in the axial direction open to allow the shaft 41 to pass through, a front side (+Z side) opening thereof opens to the accommodating portion 7, and a rear side (−Z side) opening thereof opens to the motor 20 side. The through hole 6 a functions as a bearing that rotatably supports the shaft 41.

(Pump Rotor 4)

The pump rotor 4 is attached to the shaft 41. More specifically, the pump rotor 4 is attached to the front side (+Z side) of the shaft 41. The pump rotor 4 has an inner rotor 4 a attached to the shaft 41 and an outer rotor 4 b surrounding an outer side of the inner rotor 4 a in the radial direction. The inner rotor 4 a has an annular shape. The inner rotor 4 a is a gear having teeth on a radially outer surface thereof.
The inner rotor 4 a is fixed to the shaft 41. More specifically, the end portion of the shaft 41 on the front side is press-fitted into the inner rotor 4 a. The inner rotor 4 a rotates together with the shaft 41 around the axis (θ direction). The outer rotor 4 b has an annular shape surrounding a radially outer side of the inner rotor 4 a. The outer rotor 4 b is a gear having teeth on a radially inner surface thereof.
The inner rotor 4 a and the outer rotor 4 b engage with each other, and the outer rotor 4 b rotates as the inner rotor 4 a rotates. That is, the pump rotor 4 is rotated by the rotation of the shaft 41. In other words, the motor 20 and the pump 3 have the same rotational axis. Therefore, an increase in size of the electric oil pump in the axial direction can be inhibited. Also, as the inner rotor 4 a and the outer rotor 4 b rotate, a volume of the engaged portions between the inner rotor 4 a and the outer rotor 4 b changes. A region where the volume decreases forms a pressurized region, and a region where the volume increases forms a negative pressure region. The suction port 10 is disposed on one side (front side) of the negative pressure region of the pump rotor 4 in the axial direction. Further, the receiving port 12 is disposed on one side (front side) of the pressurized region of the pump rotor 4 in the axial direction. Here, oil suctioned from the suction port 9 into the accommodating portion 7 is accommodated in the volume portion between the inner rotor 4 a and the outer rotor 4 b and is sent to the discharge port 11 side. Then, the oil is discharged from the discharge port 11.

(Pump Cover 8)

The pump cover 8 is attached to the front side (+Z side) of the pump body 6 and closes an opening 7 a that opens toward one side (front side) of the accommodating portion 7 in the axial direction. In the example embodiment shown in FIGS. 1 and 2, the pump cover 8 has a disc-shaped cover main body portion 8 a that expands in the radial direction, and a protruding portion 8 b that protrudes from a radial end portion of the cover main body portion 8 a. The cover main body portion 8 a closes the opening 7 a of the housing 7 on the front side (+Z side).
As described above, the pump housing 5 has the pump body 6 and the pump cover 8, and the pump cover 8 closes the opening 7 a that opens toward one side (front side) of the accommodating portion 7 in the axial direction. Therefore, after the pump rotor 4 is accommodated in the accommodating portion 7, the opening 7 a is closed with the pump cover 8, and thus ease of assembling the pump housing 5 can be improved.

(Cover Main Body Portion 8 a)

The cover main body portion 8 a has a first stepped portion 8 a 1 and a second stepped portion 8 a 2 that protrude toward the front side (+Z side) in the axial direction. The first stepped portion 8 a 1 has a cylindrical shape, is provided substantially coaxially with the central axis J, and is connected to a central axis side end portion of a surface 8 a 3 on the front side (+Z side) of the cover main body portion 8 a in the axial direction. The cover main body portion 8 a has a through hole 8 a 4 along the central axis J. The through hole 8 a 4 penetrates between both end portions of the pump cover 8 in the axial direction. The shaft 41 passes through the through hole 8 a 4.
The second stepped portion 8 a 2 is provided substantially coaxially with the central axis J, and has a cylindrical shape smaller in diameter than the first stepped portion 8 a 1. The second stepped portion 8 a 2 is connected to a central axis side end portion of a surface 8 a 5 on the front side (+Z side) of the first stepped portion 8 a 1 in the axial direction. The second stepped portion 8 a 2 has a large diameter hole portion 8 a 6 having a diameter larger than that of the through hole 8 a 4 along the central axis J, and one end of the shaft 41 in the axial direction is disposed in the large diameter hole portion 8 a 6.
The discharge port 11 has a first discharge port 11 a and a second discharge port 11 b. In the present example embodiment, the first discharge port 11 a is the large diameter hole portion 8 a 6. The second discharge port 11 b is provided on a tip side of the protruding portion 8 b of the pump cover 8, which will be described in detail below. The suction port 10 and the receiving port 12 are provided at the other end portion of the cover main body portion 8 a. The suction port 10 is provided on a side opposite to the protruding portion 8 b with respect to the central axis J. The receiving port 12 is provided on the protruding portion 8 b side with respect to the central axis J.
More specifically, as shown in FIGS. 2 and 3, the suction port 10 is provided at a position facing the negative pressure region of the pump rotor 4 and is curved in the circumferential direction of the central axis J to extend in an elongated hole shape. Further, the receiving port 12 is provided at a position opposite to the pressurized region of the pump rotor 4 and is curved in the circumferential direction of the central axis J to extend in an elongated hole shape. For this reason, the oil suctioned from the suction port 9 can be supplied over substantially the entire negative pressure region. Also, all of the oil supplied from the pressurized region can be received by the receiving port 12.
The suction port 9 communicates with the suction port 10 and opens at one end of the first stepped portion 8 a 1 in the axial direction. That is, the suction port 9 is provided across the cover main body portion 8 a and the first stepped portion 8 a 1. For this reason, the suction port 9 is connected to the negative pressure region of the accommodating portion 7 via the suction port 10.
The first discharge port 11 a and the receiving port 12 are connected via a communication passage 15. In the example embodiment shown in FIG. 2, one end side of the communication passage 15 opens to an inner side surface of the first discharge port 11 a and the other end side thereof opens to one end side of the receiving port 12 in the axial direction. For this reason, the oil received in the receiving port 12 can flow to the first discharge port 11 a through the communication passage 15. Also, hereinafter, a flow passage 17 through which the oil flows between the receiving port 12 and the first discharge port 11 a will be referred to as a first flow passage 13.
A control valve 81 is connected to the first discharge port 11 a via a main flow passage 80. The main flow passage 80 supplies the oil discharged from the first discharge port 11 a to the control valve 81. The control valve 81 performs supply and discharge control for the oil supplied from the main flow passage 80 to, for example, an automatic transmission of a vehicle.

(Protruding Portion 8 b)

As shown in FIGS. 1 and 2, the protruding portion 8 b protrudes from the other radial end portion of the cover main body portion 8 a in a direction perpendicular to the axial direction. A tip of the protruding portion 8 b is positioned outside the housing 21 of the motor 20 in the radial direction. The protruding portion 8 b has a substantially square shape when viewed from one side in the axial direction. A solenoid insertion hole 8 b 1 (see FIG. 5) penetrating in the axial direction is provided on the tip side of the protruding portion 8 b. An opening that opens to one side (front side) of the solenoid insertion hole 8 b 1 in the axial direction is the second discharge port 11 b. Hereinafter, the flow passage 17 allowing communication between the second discharge port 11 b and the accommodating portion 7 will be referred to as a second flow passage 14.
As shown in FIGS. 2, 3 and 4, one end of the second flow passage 14 is connected to the receiving port 12 and the other end thereof is connected to the second discharge port 11 b via a solenoid valve 60. In the illustrated example embodiment, the second flow passage 14 extends in a first through hole 14 a and a second through hole 14 b which are provided in the protruding portion 8 b. The first through hole 14 a extends from the receiving port 12 to the tip side of the protruding portion 8 b and opens at the tip part of the protruding portion 8 b. The second through hole 14 b extends from an end portion of the protruding portion 8 b on one side in a lateral direction (a positive side in the Y-axis direction) toward the solenoid insertion hole 8 b 1 side and passes through the solenoid insertion hole 8 b 1, then intersects the first through hole 14 a to extend toward a pressure sensor insertion hole 8 b 2 and opens in the pressure sensor insertion hole 8 b 2. Sealing members 16 for closing the respective openings are provided at the opening of the first through hole 14 a on the tip side of the protruding portion 8 b and the opening of the second through hole 14 b on one side of the protruding portion in the lateral direction. In the illustrated example embodiment, the sealing members 16 are male screws.
Therefore, the second flow passage 14 passes through a partial flow passage 14 d in which the first through hole portion 14 a 1, which is positioned in the first through hole 14 a between an intersection portion 14 c where the first through hole 14 a and the second through hole 14 b intersect and the receiving port 12, and the second through hole portion 14 b 1, which is positioned in the second through hole 14 b between the intersection portion 14 c and the solenoid insertion hole 8 b 1, are connected. Also, the second through hole portion 14 b 1 is connected to a second suction port 62 of the solenoid valve 60, which will be described in detail below. In addition, a third discharge port 63 of the solenoid valve 60 is connected to the second discharge port 11 b. Therefore, the second flow passage 14 communicates the receiving port 12 with the second discharge port 11 b via the second suction port 62 of the solenoid valve 60.
Also, the second flow passage 14 is provided in the pump cover 8 through, for example, a cutting operation (for example, drilling). For example, after the first through hole 14 a is cut from the tip part of the protruding portion 8 b of the pump cover 8 toward the receiving port 12 side of the pump cover 8, the second through hole 14 b is cut from an end portion of the outer circumferential portion of the protruding portion 8 b on the positive side in the Y-axis direction toward the solenoid insertion hole 8 b 1, the first through hole 14 a, and the pressure sensor insertion hole 8 b 2 sides. Then, the sealing members 16 are screwed on and fixed to an opening end portion on the tip side of the protruding portion 8 b of the first through hole 14 a and an opening end portion on one side of the protruding portion 8 b of the second through hole 14 b in the lateral direction. Thus, the second flow passage 14 can be provided on the pump cover 8 by cutting. Therefore, workability of the work of providing the second flow passage 14 inside the pump cover 8 can be improved.
Thus, the pump cover 8 is configured to have the cover main body portion 8 a and the protruding portion 8 b, as shown in FIG. 2. Also, the pump cover 8 is disposed on one side (front side) of the motor 20 in the axial direction, and an axial region of the pump cover 8 is disposed in a region different from an axial region of the motor 20. In the illustrated example embodiment, the axial region of the pump cover 8 is disposed in a region on one side (front side) of the motor 20 in the axial direction. That is, the axial region of the pump cover 8 does not overlap the axial region of the motor 20 in the axial direction, and is disposed at a position not facing the axial region of the motor 20.
For this reason, as compared with a case where the second flow passage 14 is provided on the radially outer side of the motor 20, a flow passage length of the second flow passage 14 can be shortened. Therefore, since the pressure sensor 70 can be disposed in the vicinity of the pump rotor 4 that is a hydraulic pressure source, the pressure of the oil discharged from the pump rotor 4 can be detected more accurately.

FIG. 5 is an exploded perspective view showing the pump cover 8 in which a connector 85 is attached to each terminal of the solenoid valve 60 and the pressure sensor 70 which are attached to the pump cover 8.
As shown in FIGS. 2 and 5, the solenoid valve 60 is fixed to the protruding portion 8 b and has a valve housing 64, a drive 66, and a solenoid electrical line 67. The valve housing 64 movably accommodates a spool 68 therein. The drive 66 moves the spool 68 relative to the valve housing 64. The solenoid electrical line 67 has one end portion connected to the drive 66 and the other end portion provided with a solenoid side terminal 67 a. The spool 68 extends in the valve housing 64 in a longitudinal direction and is movably supported to open and close the second suction port 62.
The valve housing 64 has the second suction port 62 through which the oil flows in via the second flow passage 14 and the third discharge port 63 through which the flowed-in oil is discharged. The second suction port 62 is opened and closed by the movement of the spool 68. For this reason, by opening and closing the second suction port 62, the flow of oil flowing through the second flow passage 14 can be blocked and allowed. That is, the solenoid valve 60 has an opening and closing portion 65 capable of opening and closing the flow passage 17. In the illustrated example embodiment, the solenoid valve 60 has the spool 68 capable of opening and closing the second flow passage 14. In addition, when the second suction port 62 is opened, the second suction port 62 and the third discharge port 63 communicate with each other. For this reason, when the second suction port 62 is opened, the oil flowing through the second flow passage 14 is discharged from the second discharge port 11 b through the second suction port 62 and the third discharge port 63. For this reason, the operation of opening and closing the second flow passage 14 by using the opening and closing portion 65 of the solenoid valve 60 makes it possible to flow to the second flow passage 14 side, some of the oil flowing through the first flow passage 13. Therefore, a flow rate of the oil to a supply destination of the pressurized oil supplied from the first discharge port 11 a can be adjusted.
As described above, since the protruding portion 8 b further includes the solenoid valve 60 connected to the flow passage 17, some of the oil supplied from the discharge port 11 to a pressurized oil supply destination (for example, a clutch destination) can flow to the solenoid valve 60 side. Therefore, for example, when the pressurized oil supply destination is set to the clutch destination, even if the rotational speed of the oil pump 1 is increased from 400 rotations to 1200 rotations, for example, the increase in the flow rate of oil supplied to the clutch can be inhibited. For this reason, the frequency of hydraulic vibrations can be increased and shifted to a frequency for avoiding resonance. Therefore, the pressure in a half clutch state can be maintained while preventing judders in the half clutch state. In addition, since the protruding portion 8 b has the solenoid valve 60, the solenoid valve 60 can be disposed close to the motor 20, and thus enlargement of the entire oil pump 1 can be inhibited.
The drive 66 is, for example, an electromagnetic clutch. In the drive 66, when power is supplied to the drive 66, for example, the spool 68 is moved by the magnetic force generated from the drive 66 to open the second suction port 62, and when the power supply to the drive 66 is cut off, the spool 68 is returned to its original position by a biasing force of a spring (not shown) to close the second suction port 62. Therefore, by controlling the power supply to the drive 66, a position of the spool 68 can be adjusted to control the opening and closing of the second suction port 62.
The third discharge port 63 opens at one side end portion of the valve housing 64 in the axial direction. On the other hand, the second discharge port 11 b provided in the protruding portion 8 b is an opening on one side (front side) of the solenoid insertion hole 8 b 1 in the axial direction. The valve housing 64 of the solenoid valve 60 is inserted into the solenoid insertion hole 40b1, and the valve housing 64 is fixed to the protruding portion 8 b. The drive 66 extending from the protruding portion 8 b extends to the motor 20 side. In the illustrated example embodiment, the solenoid valve 60 extends along the axial direction of the motor 20 to the other end portion side of the motor 20. For this reason, since the solenoid valve 60 is disposed along the motor 20, enlargement of the oil pump 1 can be inhibited.
The valve housing 64 is supported in a state where one end portion thereof in the axial direction is positioned on substantially the same plane as the second discharge port 11 b. For this reason, the second discharge port 11 b and the third discharge port 63 are disposed on substantially the same plane, and the second discharge port 11 b and the third discharge port 63 are connected to be in a communication state. The second discharge port 11 b is connected to an oil pan T capable of storing oil. In the illustrated example embodiment, the second discharge port 11 b communicates with the oil pan T via a tank flow passage 83.
As described above, the solenoid valve 60 is connected to the partial flow passage 14 d in the second flow passage 14 that communicates the accommodating portion 7 and the second suction port 62. For this reason, some of the oil supplied from the first discharge port 11 a to the pressurized oil supply destination (for example, the clutch destination) can flow to the solenoid valve 60 side. Therefore, for example, in the case in which the pressurized oil supply destination is the clutch destination, even if a rotational speed of the oil pump 1 is increased, for example, from 400 rotations to 1200 rotations, an increase in the flow rate of oil supplied to the clutch can be inhibited. For this reason, a frequency of hydraulic vibrations can be increased and can be shifted to a frequency for avoiding resonance. Therefore, the pressure in the half clutch state can be maintained while preventing judders in the half clutch state. In addition, since the protruding portion 8 b has the solenoid valve 60, the solenoid valve 60 can be disposed close to the motor 20, and thus enlargement of the entire oil pump 1 can be inhibited.

As shown in FIG. 1, the pressure sensor 70 is fixed to the protruding portion 8 b and extends toward the motor 20. In the illustrated example embodiment, the pressure sensor 70 is disposed outside the housing 21 of the motor 20 and is fixed to the other end side (a negative side in the Y-axis direction) of the protruding portion 8 b in the lateral direction. Therefore, the pressure sensor 70 can be disposed close to the motor 20. For this reason, enlargement of the oil pump 1 can be inhibited.
As shown in FIG. 5, the pressure sensor 70 has a sensor 72 and an electrical line holder 74. The sensor 72 detects the hydraulic pressure of the oil. The electrical line holder 74 holds a sensor electrical line 75 electrically connected to the sensor 72. The sensor 72 has a cylindrical shape, and a male screw portion 72 a is provided on an outer circumferential surface of the sensor 72. A female screw portion to which the male screw portion 72 a can be screwed is provided in the pressure sensor insertion hole 8 b 2. For this reason, the pressure sensor 70 is fixed to the pump cover 8 by screwing the sensor 72 into the pressure sensor insertion hole 8 b 2.
As shown in FIG. 4, an opening 14 b 2 is provided on an inner surface of the second through hole 14 b in a portion of the pressure sensor insertion hole 8 b 2 into which the sensor 72 is inserted. The opening 14 b 2 communicates with the sensor 72. Thus, the pressure sensor 70 is connected to the accommodating portion 7 through the first through hole 14 a and the second through hole 14 b (flow passage 17). Therefore, the pressure sensor 70 can detect the hydraulic pressure of the oil in the first flow passage 13 and the second flow passage 14 via the first through hole 14 a and the second through hole 14 b. More specifically, when the second flow passage 14 is closed by the solenoid valve 60, the pressure sensor 70 can detect the hydraulic pressure of the oil in the first flow passage 13. Also, when the second flow passage 14 is opened by the solenoid valve 60, the pressure sensor 70 can detect the hydraulic pressure of the oil in the second flow passage 14.
Thus, the pressure sensor 70 is connected to the flow passage 17. For this reason, as compared with the case where the flow passage 17 is configured of another component, the number of components of the oil pump 1 can be reduced, and thus an increase of the cost for the oil pump 1 can be inhibited. Moreover, since the pressure sensor 70 is connected to the flow passage 17, the hydraulic pressure of the pressurized oil discharged from the accommodating portion 7 can be accurately detected by the pressure sensor 70 disposed in the vicinity of the accommodating portion 7 which is a supply source of the hydraulic pressure.
The sensor 72 of the pressure sensor 70 converts, for example, a change in electrical resistance due to a piezoresistive effect into an electrical signal. As shown in FIG. 5, the electrical signal is transmitted to a sensor side terminal 75 a via the sensor electrical line 75. The electrical signal transmitted to the sensor side terminal 75 a is sent to, for example, an engine controller. The engine controller controls operations of the automatic transmission, engine, or the like of the vehicle, and controls operations of the drive 66 of the solenoid valve 60 on the basis of the electrical signal from the pressure sensor 70 to control the opening and closing of the second suction port 62.
In this way, the sensor 72 of the pressure sensor 70 is fixed to the pressure sensor insertion hole 8 b 2 of the protruding portion 8 b. Also, the electrical line holder 74 of the pressure sensor 70 and the solenoid valve 60 are disposed adjacent to each other and extend in the axial direction of the motor 20, as shown in FIGS. 1 and 6. Further, the electrical line holder 74 and the solenoid valve 60 are disposed in a direction orthogonal to the surface on the rear side of the protruding portion 8 b in the axial direction. For this reason, since the pressure sensor 70 and the solenoid valve 60 are disposed outside the motor 20 in the radial direction and along the axial direction, the oil pump 1 can be miniaturized as compared with the case where the pressure sensor 70 and the solenoid valve 60 are disposed to face in different directions.
As shown in FIGS. 5 and 6, the sensor side terminal 75 a and the solenoid side terminal 67 a are integrally held via the connector 85. In the illustrated example embodiment, the solenoid electrical line 67 of the solenoid valve 60 extends along a side surface of the valve housing 64, and the solenoid side terminal 67 a is disposed at a position on the rear side behind the rear side end of the valve housing 64 in the axial direction.
On the other hand, the sensor electrical line 75 of the pressure sensor 70 extends along a side surface of the electrical line holder 74, and the sensor side terminal 75 a is disposed side by side with the solenoid side terminal 67 a. The sensor side terminal 75 a and the solenoid side terminal 67 a are inserted into and fixed to the connector 85. The connector 85 has a wall section 85 a made of an insulating material. In the illustrated example embodiment, the wall section 85 a has a hollow square cylinder shape.
Thus, since the sensor side terminal 75 a and the solenoid side terminal 67 a are integrally held via the connector 85, the sensor side terminal 75 a and the solenoid side terminal 67 a can be put together in one place as compared with the case where each of the sensor side terminal 75 a and the solenoid side terminal 67 a is held via a separate connector. Therefore, ease of electrically connecting to the terminals and wiring the electrical lines connected to the terminals can be improved.

Next, operations and effects of the oil pump 1 will be described. As shown in FIG. 2, when the motor 20 of the oil pump 1 is driven, the oil suctioned from the suction port 9 of the pump moves in the accommodating portion 7 of the pump 3 and is discharged from the first discharge port 11 a via the receiving port 12 and the communication passage 15. The oil discharged from the first discharge port 11 a is supplied to the control valve 81 via the main flow passage 80.
In the present disclosure, the pressure sensor 70 that detects the hydraulic pressure of the oil in the second flow passage 14 is disposed outside the housing 21 of the motor 20, and the housing 21 has the wall section 21 e that blocks electromagnetic waves. For this reason, when the motor 20 is driven, the electromagnetic waves generated from the motor 20 may adversely affect the pressure sensor 70. However, by disposing the pressure sensor 70 outside the housing 21 of the motor 20, the housing 21 can block at least some of the electromagnetic waves generated from the motor 20. For this reason, the adverse effect of the electromagnetic waves on the pressure sensor 70 is inhibited, and thus the hydraulic pressure of the oil discharged from the pump 3 can be accurately detected by the pressure sensor 70.
Also, the electrical line holder 74 of the pressure sensor 70 and the solenoid valve 60 according to the present example embodiment are disposed adjacent to each other and extend in the axial direction of the motor 20. For this reason, the electrical line holder 74 and the solenoid valve 60 can be disposed along the motor 20. Therefore, enlargement of the oil pump 1 can be inhibited.
Also, the pump cover 8 has the first discharge port 11 a, the second discharge port 11 b, the first flow passage 13 allowing communication between the first discharge port 11 a and the accommodating portion 7, and the second flow passage 14 allowing communication between the second discharge port 11 b and the accommodating portion 7. The second flow passage 14 is connected to the second suction port 62 of the solenoid valve 60, and the second discharge port 11 b of the pump cover 8 is connected to the third discharge port 63 of the solenoid valve 60. Thus, the second flow passage 14 connecting the pump 3 and the solenoid valve 60 can be shortened. Therefore, enlargement of the oil pump 1 can be inhibited. Moreover, as compared with the case where the second flow passage 14 is configured of another member, the number of components can be reduced and an increase of the cost for the oil pump 1 can be controlled.
Also, the solenoid valve 60 connects between any one of the first discharge port 11 a and the second discharge port 11 b and the accommodating portion 7 via the partial flow passage 14 d. For this reason, the oil discharged from the accommodating portion 7 can be discharged from any one of the first discharge port 11 a and the second discharge port 11 b via the solenoid valve 60. Therefore, some of the oil supplied from the other one of the first discharge port 11 a and the second discharge port 11 b to the pressurized oil supply destination (for example, the clutch destination) can flow to the solenoid valve 60 side.
The first discharge port 11 a can be connected to the main flow passage 80 that supplies the oil discharged from the first discharge port 11 a to the control valve 81, and the second discharge port 11 b can be connected to the oil pan T capable of storing oil. The solenoid valve 60 connects the accommodating portion 7 with the second discharge port 11 b via the partial flow passage 14 d. For this reason, when the partial flow passage 14 d is opened by the solenoid valve 60, some of the oil supplied from the discharge port 11 to the control valve 81 can flow to the solenoid valve 60 side. Also, when the partial flow passage 14 d is closed by the solenoid valve 60, all of the oil supplied from the discharge port 11 can be supplied to the control valve 81. That is, by opening and closing the partial flow passage 14 d by using the solenoid valve 60, a flow rate of the oil supplied to the control valve 81 can be adjusted.
While example embodiments of the present disclosure have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present disclosure. The scope of the present disclosure, therefore, is to be determined solely by the following claims.

Claims

1-13. (canceled)

14. An oil pump, comprising:

a motor including a shaft disposed along a center axis extending in an axial direction, a rotor rotating around the shaft, a stator disposed to face the rotor, and a housing accommodating the rotor and the stator; and

a pump including a pump rotor rotating together with the shaft to suction and discharge oil, and a pump housing including an accommodating portion that accommodates the pump rotor; wherein

the pump housing includes a suction port that suctions in oil, a discharge port that discharges oil, and a pressure sensor that detects hydraulic pressure of oil in a flow passage allowing communication between the discharge port and the accommodating portion;

the pressure sensor is disposed outside the housing of the motor; and

the housing includes a wall that blocks electromagnetic waves.

15. The oil pump according to claim 14, wherein

the pump is disposed on one side of the motor in an axial direction thereof; and

the pump housing includes a pump body including the accommodating portion that accommodates the pump rotor and further includes a side surface and a bottom surface positioned on another side of the motor in the axial direction, and a pump cover closing an opening that opens at one side of the accommodating portion in the axial direction.

16. The oil pump according to claim 15, wherein

the pump cover includes a protruding portion which protrudes outward beyond an outer circumference of the motor in a radial direction; and

the pressure sensor is fixed to the protruding portion.

17. The oil pump according to claim 16, wherein

the protruding portion includes the flow passage allowing communication between the discharge port and the accommodating portion; and

the pressure sensor is connected to the flow passage.

18. The oil pump according to claim 17, wherein the protruding portion further includes a solenoid valve connected to the flow passage.

19. The oil pump according to claim 18, wherein the solenoid valve is fixed to the protruding portion and extends to a side of the motor.

20. The oil pump according to claim 19, wherein

the pressure sensor includes a sensor electrical line electrically connected to the pressure sensor;

the sensor electrical line includes a sensor side terminal at one end portion thereof;

the solenoid valve includes a valve housing in which a spool is movably accommodated, a drive moving the spool relative to the housing, and a solenoid electrical line including one end portion connected to the drive and another end portion provided with a solenoid side terminal; and

the sensor side terminal and the solenoid side terminal are integrally held via a connector.

21. The oil pump according to claim 20, wherein

the pressure sensor includes a sensor which detects the hydraulic pressure of the oil, and an electrical line holder which holds the sensor electrical line electrically connected to the sensor; and

the electrical line holder of the pressure sensor and the solenoid valve are disposed adjacent to each other and extend in the axial direction of the motor.

22. The oil pump according to claim 18, wherein the solenoid valve includes an opening and closing portion.

23. The oil pump according to claim 22, wherein

the discharge port includes a first discharge port and a second discharge port; and

the solenoid valve connects between any one of the first discharge port, the second discharge port, and the accommodating portion via the flow passage.

24. The oil pump according to claim 23, wherein

the pump is attachable to a control valve that performs supply and discharge control of the oil;

the first discharge port is connectable to a main flow passage which supplies the oil discharged from the first discharge port, to the control valve;

the second discharge port is connectable to an oil pan that stores the oil; and

the solenoid valve connects the accommodating portion and the second discharge port via the flow passage.

25. The oil pump according to claim 24, wherein

the solenoid valve includes a second suction port through which pressurized oil discharged from the pump is suctioned, and a third discharge port through which the oil is discharged to the oil pan side that stores the pressurized oil;

the pump cover includes the first discharge port, the second discharge port, a first flow passage allowing communication between the first discharge port and the accommodating portion, and a second flow passage allowing communication between the second discharge port and the accommodating portion;

the second flow passage is connected to the second suction port of the solenoid valve; and

the second discharge port of the pump cover is connected to the third discharge port of the solenoid valve.

26. The oil pump according to claim 15, wherein

the second flow passage extends in a direction orthogonal to the axial direction of the motor, and penetrates from inside to an outer circumferential portion of the pump cover; and

a seal is disposed at an opening end portion of the second flow passage that opens to the outer circumferential portion of the pump cover.