CN216278446U

CN216278446U - Electric pump

Info

Publication number: CN216278446U
Application number: CN202122332464.0U
Authority: CN
Inventors: 片冈慈裕; 陈静
Original assignee: Nidec Tosok Corp
Current assignee: Nidec Tosok Corp
Priority date: 2020-09-30
Filing date: 2021-09-26
Publication date: 2022-04-12
Anticipated expiration: 2031-09-26
Also published as: JP2022056762A

Abstract

One embodiment of the electric pump of the present invention includes: a motor having a rotor rotatable about a central axis; a pump mechanism connected to one axial side of the motor; a motor housing that houses the motor and has an opening facing the other axial side; and a bearing holder that enables the shaft of the rotor to rotate. The motor has: a stator radially opposed to the rotor; and a bus bar unit located on the other axial side of the stator, the bearing holder having: a central cylindrical portion; and a flange portion for closing the opening of the motor case. The center cylindrical portion of the bearing holder is fixed to the bus bar unit via an elastic member, and the elastic member is accommodated between the bearing holder and the center cylindrical portion.

Description

Electric pump

Technical Field

The present invention relates to an electric pump.

Background

Conventionally, as an electric pump, the following structure is known: the pump body houses: a motor and pump mechanism; and a control board that controls the motor.

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 5969342

SUMMERY OF THE UTILITY MODEL

In an electric pump, a member for closing an opening of a pump body has a seal structure for preventing water and dust from entering. Therefore, when a plurality of members are disposed in one opening of the pump body, the structure is easily complicated. For example, a bus bar unit, a bearing holder, and a motor cover are disposed in an opening of a motor housing that houses a motor. These members are overlapped in the axial direction on the basis of being connected with other members or being fixed to the housing. Further, a seal member needs to be provided at a necessary portion. This makes the assembly work easy to be complicated.

According to one aspect of the present invention, there is provided an electric pump including: a motor having a rotor rotatable about a central axis and a stator facing in a radial direction of the rotor; a pump mechanism connected to one axial side of the motor; a motor housing that houses the motor and has an opening facing the other axial side; a bearing for rotatably supporting a shaft of the rotor; and a bearing holder that is located on the other axial side of the motor and holds the bearing. The motor includes an annular bus bar unit located on the other axial side of the stator and extending in the axial direction about the central axis, and the bus bar unit is in contact with the motor housing in the axial direction. The bearing holder includes: a central cylindrical portion extending in the axial direction with the central axis as the center; and a flange portion that is plate-shaped and perpendicular to the central axis and that closes an opening of the motor housing, wherein a cylindrical portion of the bearing holder is fixed to a radially inner side of the bus bar unit via an elastic member. The elastic member is accommodated between the cylindrical portion of the bearing holder and the bus bar unit.

The utility model provides an electric pump with excellent assembling workability.

Drawings

Fig. 1 is a sectional view of an electric pump of the embodiment.

Fig. 2 is a sectional view of the electric pump of the embodiment.

Fig. 3 is a sectional view of the electric pump of the embodiment.

Description of the symbols

100 … electric oil pump, 10 … pump body, 10a … first through hole, 10b … second through hole, 11 … motor housing, 11a … first accommodation recess, 12 … pump housing, 12a … second accommodation recess, 12b … pump cover, 13 … base plate housing, 13a … third accommodation recess, 20 … motor, 21 … shaft, 22 … rotor, 22a … rotor core, 22b … rotor magnet, 23 … stator, 23a … stator core, 23b … coil, 24a … bus bar, 24b … bus bar holder, 25 … elastic member, 25a … first contact portion, 25b … second contact portion, 26 … bearing holder, 26a … central cylindrical portion, 26b … flange portion, 26c … large diameter portion, 26d … small diameter portion, 26e … breather, 27 e … first bearing 8228, 26a …, … bearing base plate …, … control base plate …, … pump mechanism, 51 … joint bus and 120 … bus unit

Detailed Description

Hereinafter, the electric oil pump will be described as an embodiment of the electric oil pump. The electric oil pump of the embodiment is used to supply oil to equipment mounted on a vehicle or the like.

In the drawings referred to below, an XYZ coordinate system is appropriately shown as a three-dimensional orthogonal coordinate system. In the XYZ coordinate system, the X-axis direction is a direction parallel to the axial direction of the central axis J shown in fig. 1. The center axis J is a center axis of a shaft 21 of the motor 20 described later. The Y-axis direction is a direction parallel to the depth direction of fig. 1 among directions orthogonal to the X-axis. The Z-axis direction is a direction orthogonal to both the X-axis direction and the Y-axis direction, and is a direction parallel to the vertical direction in fig. 1. In any of the X-axis direction, the Y-axis direction, and the Z-axis direction, the side toward which the arrow shown in the figure is directed is the + side, and the opposite side is the-side.

In the following description, unless otherwise specified, a direction (X-axis direction) parallel to the central axis J is simply referred to as "axial direction". The radial direction centered on the central axis J is simply referred to as "radial direction". The circumferential direction around the central axis J, that is, the axial direction (θ direction) of the central axis J is simply referred to as "circumferential direction".

In addition, the positive side (+ X side) in the X axis direction is sometimes referred to as "front side". Likewise, the negative side (X side) in the X axis direction is sometimes referred to as "rear side". The front side (+ X side) corresponds to one axial side of the present invention. The rear side (X side) corresponds to the other axial side of the present invention.

As shown in fig. 1 and 2, the electric oil pump 100 of the present embodiment includes a pump main body 10, a motor 20, a pump mechanism 30, and a substrate unit 140 having a control substrate 40.

The pump body 10 has: a motor housing 11 for housing the motor 20; a pump housing 12 that houses a pump mechanism 30; and a substrate housing 13 provided with a control substrate 40. In the case of the present embodiment, the motor housing 11, the pump housing 12, and the substrate housing 13 are part of a single member. The motor housing 11 is located on the rear side (-X side) of the pump main body 10. The motor housing 11 is cylindrical and extends in the axial direction. The motor housing 11 includes a first housing recess 11a formed of a recess opening on the rear side. The first housing recess 11a is closed from the rear side by a bearing holder 26 described later.

The pump housing 12 is located on the front side (+ X side) of the pump main body 10. The pump housing 12 has a second housing recess 12a formed of a recess opened on the front side. The electric oil pump 100 includes a pump cover 12b that closes the second housing recess 12a from the front side. The pump cover 12b is a plate-shaped member having a circular shape when viewed from the axial direction. The pump housing 12b is screwed to the pump housing 12.

The substrate case 13 is located on the side of the motor case 11 and the pump case 12. The substrate case 13 is located on the illustrated lower side (-Z side) of the motor case 11 and the pump case 12. The substrate case 13 has a substantially rectangular shape when viewed from the radially outer side. The substrate case 13 has a third housing recess 13a that opens toward the lower side of the pump body 10 in the figure. A substrate unit 140 described later is mounted on the substrate case 13 from the lower side in the drawing.

As shown in fig. 2 and 3, the pump body 10 has a first through hole 10a and a second through hole 10b therein. The first through hole 10a axially connects the first housing recess 11a of the motor housing 11 and the second housing recess 12a of the pump housing 12. The second through hole 10b connects the first accommodating recess portion 11a of the motor housing 11 and the third accommodating recess portion 13a of the substrate housing 13 in the radial direction.

The motor 20 includes: a rotor 22 having a shaft 21; a stator 23; a bus bar unit 120; a bearing holder 26; and a first bearing 27 and a second bearing 28. The bearing holder 26 closes the opening of the motor housing 11.

The shaft 21 is a columnar member extending along the center axis J. As shown in fig. 2, the rotor 22 includes: a shaft 21; a rotor core 22a fixed to the outer peripheral surface of the shaft 21; and a plurality of rotor magnets 22b fixed to rotor core 22 a. The rotor magnet 22b may be an annular magnet surrounding the shaft 21.

The shaft 21 is supported by a first bearing 27 and a second bearing 28 so as to be rotatable around the shaft. The first bearing 27 supports a portion of the shaft 21 on the rear side of the rotor core 22a, and is held by a bearing holder 26 described later. Second bearing 28 supports a portion of shaft 21 on the front side of rotor core 22 a. The shaft 21 protrudes to the front side through the inner hole of the second bearing 28. The end portion on the front side of the shaft 21 is connected to a pump mechanism 30.

The stator 23 includes: an annular stator core 23a surrounding the rotor 22; an insulator, not shown, attached to the teeth of stator core 23 a; and a coil 23b wound around the pole teeth via an insulator. Stator core 23a is fixed to the inner circumferential surface of cylindrical motor case 11.

The bus bar unit 120 is located between the stator 23 and the bearing holder 26. The bus bar unit is annular and extends in the axial direction around the central axis J.

The bus bar unit 120 has a plurality of bus bars 24a (at least 3 bus bars in the present embodiment). The plurality of bus bars 24 are insert-molded to the bus bar holder 24 b. The fixing method of the bus bar 24a may be screw fastening, welding or snap-fitting.

As shown in fig. 2, the bus bar unit 120 is located at the rear side of the stator 23. The bus bar unit 120 is inserted into the first receiving recess 11a of the motor case 11 from the rear side. The outer peripheral front end 24c of the bus bar unit 120 axially contacts a stepped surface 11b facing rearward and provided on the inner surface of the first accommodating recess 11 a. One end of the bus bar 24a is hook-shaped. The hook-shaped end portions of the bus bars 24a are connected to coil wires 23c extending rearward from the coils 23b, respectively. The other end of the bus bar 24a is located at the end of the bus bar holder 24b on the substrate case 13 side (lower side in the drawing). The end portions of the bus bars 24a positioned below the bus bar holder 24b are connected to a plurality of tab bus bars 51 (3 in the present embodiment) described later.

As shown in fig. 3, the bearing holder 26 is located on the rear side of the bus bar unit 120 and is fixed to the motor case. The bearing holder 26 has a central cylindrical portion 26a extending in the axial direction about the central axis J. The bearing holder 26 has a plate-like flange portion 26b extending radially outward from the outer peripheral surface of the rear end portion of the central cylindrical portion 26a in a direction orthogonal to the central axis J, and the flange portion 26b closes the rear opening of the motor case 11.

The central cylindrical portion 26a of the bearing holder 26 is inserted radially inward of the busbar unit 120 from the rear side of the busbar unit 120. An elastic member 25 is accommodated between the outer peripheral surface of the central cylindrical portion and the inner side surface of the bus bar unit 120.

When the central cylindrical portion 26a is inserted radially inward of the bus bar unit 120, the outer peripheral front end portion 24c of the bus bar unit 120 abuts against the stepped surface 11b facing rearward provided on the inner surface of the first housing recess 11a of the motor housing 11 due to the reaction force of the elastic member 25 pressing forward, and the motor housing 11 is pressed forward, whereby the bus bar unit 120 can be supported. This enables bus bar unit 120 to be stably fixed. Therefore, the bus bar unit 120 does not need to be fixed by screws or the like, and the assembly work is improved.

In addition, according to the present embodiment, the flange portion 26b is provided in the bearing holder 26, and the flange portion 26b closes the opening portion on the rear side of the motor case 11, so that the motor cover is not necessary. Therefore, the number of components can be reduced, and the axial size can be reduced.

According to the present embodiment, the bus bar unit 120 has a first contact portion 25a on the front side thereof, and the first contact portion 25a is in contact with the front end portion of the elastic member 25 in the axial direction. The bearing holder 26 has a second contact portion 25b in the central cylindrical portion 26a, and the second contact portion 25b is in contact with the rear end of the elastic member 25 in the axial direction. Further, the elastic member 25 is disposed between the first contact portion 25a and the second contact portion 25 b. Therefore, when the bearing holder 26 is fixed, the front end portion of the elastic member 25 abuts against the first contact portion 25a, the elastic member 25 is compressed, and at the same time, the rear end portion of the elastic member 25 abuts against the second contact portion 25b due to the elastic restoring force of the elastic member 25, and acts in the direction of pressing to the rear side. This allows the elastic member 25 to be stably disposed between the bus bar unit 120 and the central cylindrical portion 26a of the bearing holder.

In the present embodiment, the inner peripheral surface of the front end portion of the bus bar unit 120 has a first contact portion 25a on the radially inner side, and the first contact portion 25a protrudes to a position facing the second contact portion 25 b. The first contact portion 25a is a support portion of the elastic member 25 by contacting the distal end portion of the elastic member 25. This can restrict the movement of the elastic member 25 to the front side. In addition, the bus bar unit 120 may continuously protrude to a position facing the second contact portion 25b over the entire inner circumferential surface.

In the present embodiment, the second contact portion 25b is a stepped portion facing the front side. The central cylindrical portion 26a of the bearing holder 26 has a large diameter portion 26c on the rear side connected to the flange portion 26 b. The small diameter portion 26d is provided continuously with the large diameter portion 26c, and the diameter of the small diameter portion 26d is smaller than that of the large diameter portion 26 c. A stepped portion toward the front side is formed at a boundary portion between the large diameter portion 26c and the small diameter portion 26 d. This allows the stepped portion to serve as a support portion for the elastic member 25, and the movement of the elastic member in the axial direction can be restricted. The small diameter portion 26d serves as a guide portion for the elastic member 25, and the elastic member 25 can be stably disposed.

Further, according to the present embodiment, the elastic member 25 is disposed radially inward of the small diameter portion 26c of the central cylindrical portion 26a of the bearing holder and the busbar unit. Therefore, a relatively inexpensive elastic member having a small diameter can be used.

In the present embodiment, the elastic member 25 composed of a coil spring is used. When the bearing holder 26 is inserted into the bus bar unit 120, the rear end of the coil spring abuts against the step of the central cylindrical portion 26a by the biasing force of the coil spring, and the outer peripheral front end of the bus bar unit 120 presses the step surface 11b provided in the motor housing 11a to the front side, whereby the bus bar unit 120 can be fixed.

As shown in fig. 1, a breather 26e is inserted into a rear end portion of the central cylindrical portion 26 a. That is, in the electric oil pump 100, the bearing holder 26 functioning as a motor cover has the breather 26 e. According to this structure, as compared with a structure in which the breather 26e is provided in the motor housing 11, manufacturing is facilitated, and assembling workability is improved.

The breather 26e circulates air inside and outside the bearing holder 26. The inner space of the bearing holder 26 is connected to the inside of the first housing recess 11a via the central cylindrical portion 26 a. The first receiving recess 11a is continuous with the second receiving recess 12a and the third receiving recess 13 a. Therefore, the breather 26e circulates air between the internal space and the external space of the pump main body 10.

In the electric oil pump 100, the bearing holder 26 functioning as a motor cover has a central cylindrical portion 26a, the central cylindrical portion 26a has a through hole through which the bearing holder 26 axially penetrates, a breather 26e is held at a rear end of the central cylindrical portion 26a, and a first bearing 27 is held at a front end of the central cylindrical portion 26 a. According to this configuration, in the bearing holder 26, the first bearing 27 and the breather 26e are arranged in the axial direction, and therefore, the space around the first bearing 27 can be effectively utilized inside the first accommodation recess 11 a. The electric oil pump 100 can be suppressed from being large.

The second bearing 28 is inserted from the rear side into the first through hole 10a connecting the first receiving recess 11a and the second receiving recess 12 a. The oil seal 15, the fixed ring 16, the wave washer 17, and the second bearing 28 are disposed in this order from the front side inside the first through hole 10 a.

As shown in fig. 2, the first through hole 10a is a stepped hole having a plurality of steps therein. The first through-hole 10a has therein a first step surface 10c and a second step surface 10d both facing the rear side. Therefore, the inner diameter of the first through-hole 10a becomes smaller each time it passes the step described above as it goes to the front side. The oil seal 15 is located between the first step face 10c and the fixed ring 16 in the axial direction. The fixing ring 16 abuts against the second step surface 10d from the rear side. The fixing ring 16 is supported by a facing corrugated washer 17 towards the rear side. The wave washer 17 presses the outer ring of the second bearing 28 from the front side toward the rear side.

The shaft 21 passes through the inner bores of the second bearing 28, the wave washer 17, the fixing ring 16 and the oil seal 15. The front end of the shaft 21 passes through the first through hole 10a and reaches the inside of the second receiving recess 12 a.

The pump mechanism 30 includes: an inner rotor 31 connected to a front end of the shaft 21; and an outer rotor 32 surrounding inner rotor 31 from the radially outer side. The inner rotor 31 and the outer rotor 32 are accommodated between the second accommodation recess 12a and the pump cover 12 b. The inner rotor 31 and the outer rotor 32 have trochoid tooth profiles, respectively. That is, the pump mechanism 30 is a trochoid pump.

The substrate unit 140 includes: a control substrate 40; and a substrate holder 141 that holds the control substrate 40 from the radial outside.

The substrate holder 141 is a box-shaped member that opens toward the substrate housing 13 side (+ Z side). The control board 40 is fixed to an opening of the board holder 141 facing upward in the figure. In the case of the present embodiment, the substrate holder 141 is made of resin. The substrate holder 141 includes a connector 141b in which a plurality of metal terminals (not shown) are insert-molded, and a bus bar support 141c in which tab bus bars 51 (at least 3 tab bus bars in the present embodiment) are insert-molded.

A plurality of metal terminals of the connector 141b are connected to the end portion of the front side of the control substrate 40. The tab bus bar 51 is connected to the end portion of the rear side of the control substrate 40.

The tab bus 51 connects the motor 20 and the control substrate 40. The joint busbar 51 is inserted from the radial outside into the second through hole 10b connecting the third accommodating recess 13a and the first accommodating recess 11 a. The tip of the joint busbar 51 is positioned in the first accommodation recess 11a, and overlaps the busbar unit 120 as viewed in the axial direction. The joint bus bar 51 is screwed to the bus bar 24a of the bus bar unit. Thereby, the control board 40 and the motor 20 are electrically connected via the joint bus 51.

The substrate unit 140 is fixed to the substrate case 13 of the pump main body 10 in a state where the control substrate 40 faces the motor 20 side. In the case of the present embodiment, the substrate holder 141 of the substrate unit 140 is screwed to the substrate housing 13. The control board 40 is enclosed between the pump body 10 and the board holder 141.

Although various embodiments of the present invention have been described above, the configurations and combinations thereof in the embodiments are examples, and additions, omissions, substitutions, and other modifications of the configurations can be made without departing from the spirit of the present invention. The present invention is not limited to the embodiments.

Claims

1. An electric pump, comprising:

a motor having a rotor rotatable about a central axis and a stator opposing in a radial direction of the rotor;

a pump mechanism connected to one axial side of the motor; and

a motor housing that houses the motor and has an opening portion facing the other side in the axial direction,

the motor has:

a bearing rotatably supporting a shaft of the rotor;

a bearing holder located on the other axial side of the motor, holding the bearing, and fixed to the motor housing; and

an annular bus bar unit located between the stator and the bearing holder and extending in an axial direction around a central axis,

the bus bar unit is in contact with the motor case in an axial direction,

the bearing holder has: a central cylindrical portion extending in the axial direction with the central axis as the center; and a flange portion which is plate-shaped and perpendicular to the central axis and which closes an opening portion of the motor case,

the central cylindrical portion is located radially inward of the busbar unit,

an elastic member is housed between the central cylindrical portion and the bus bar unit.

2. The electric pump of claim 1,

a first contact portion that is in contact with an end portion of the elastic member on one side in an axial direction is provided on one side in the axial direction of the bus bar unit,

the central cylindrical portion of the bearing holder has a second contact portion that is in contact with an end portion of the elastic member on the other side in the axial direction,

the elastic member is disposed between the first contact portion and the second contact portion.

3. The electric pump of claim 2,

the first contact portion protrudes radially inward from an inner peripheral surface of the bus bar unit, and contacts one end of an elastic member at the protruding portion.

4. The electric pump as claimed in claim 2 or 3,

the central cylindrical portion has a large diameter portion and a small diameter portion, and the second contact portion is formed at a boundary portion that transitions from the large diameter portion to the small diameter portion.

5. The electric pump of claim 3,

the first contact portion protrudes radially inward over the entire inner peripheral surface of the busbar unit.

6. The electric pump as recited in any one of claims 1 to 3,

the elastic member is a coil spring.