US-12620864-B2 - Cover member and a motor unit

US12620864B2US 12620864 B2US12620864 B2US 12620864B2US-12620864-B2

Abstract

A cover member for a motor unit is disclosed. The cover member is interposed between a motor and a control substrate for controlling operation of the motor. The motor has a bus bar terminal electrically connected to a coil of a stator of the motor. The control substrate has a connection terminal that is fitted to the bus bar terminal and is made to electrically connect the control substrate to the stator. The cover member has a through hole, through which the bus bar terminal pierces, and an enclosing part for enclosing a fitting location for the bus bar terminal and the connection terminal, as seen in a piercing direction of the bus bar terminal.

Inventors

Akihiko Eguchi
Shota Nogiwa
Yuki Suzuki
Tamotsu Tanaka
Ryosuke Tonooka

Assignees

MAHLE INTERNATIONAL GMBH

Dates

Publication Date: 20260505
Application Date: 20230911

Claims (15)

1 . A cover member for a motor unit interposed between a motor and a control substrate for controlling operation of the motor, comprising: the motor has a bus bar terminal electrically connected to a stator coil; the control substrate has a connection terminal that is fitted to the bus bar terminal and is structured and arranged to electrically connect the control substrate to a stator; the cover member has a through hole, through which the bus bar terminal pierces, and an enclosing part for enclosing a fitting location for the bus bar terminal and the connection terminal, as seen in a piercing direction of the bus bar terminal; and wherein the enclosing part has an inner radial extent greater than that of the through hole relative to the piercing direction.
2 . The cover member according to claim 1 , wherein an inner surface of the through hole has an inclined surface, which is tilted such that, the farther the bus bar terminal proceeds in a direction of insertion, the smaller the width becomes.
3 . The cover member according to claim 1 , wherein the cover member is composed of resin.
4 . The cover member according to claim 1 , wherein the cover member includes a bottom plate, and the enclosing part has a cylindrical shape that projects axially from the bottom plate towards the base substrate.
5 . The cover member according to claim 4 , wherein the through hole has a part projecting perpendicularly from the bottom plate axially away from the base substrate.
6 . The cover member according to claim 5 , wherein the through hole opens into the enclosing part.
7 . A motor unit, comprising: a control substrate, a motor, and a cover member interposed between the control substrate and the motor, the motor having a bus bar terminal electrically connected to a stator coil of the motor, the control substrate having a connection terminal that is fitted to the bus bar terminal and is structured and arranged to electrically connect the control substrate to the stator, the cover member having a through hole, through which the bus bar terminal pierces in a piercing direction, and an enclosing part for enclosing a fitting location for the bus bar terminal and the connection terminal, as seen in the piercing direction of the bus bar terminal; and wherein the enclosing part has an inner radial extent greater than that of the through hole relative to the piercing direction.
8 . The motor unit according to claim 7 , wherein an inner surface of the through hole has an inclined surface.
9 . The motor unit according to claim 8 , wherein the inclined surface is tilted such that, the farther the bus bar terminal proceeds in a direction of insertion, the smaller the width becomes.
10 . The motor unit according to claim 8 , wherein the cover member is composed of resin.
11 . The motor unit according to claim 7 , wherein the cover member is composed of resin.
12 . The motor unit according to claim 7 , wherein the motor is a 3-phase motor.
13 . The motor unit according to claim 7 , wherein the cover member includes a bottom plate, and wherein the enclosing part has a cylindrical shape that projects axially from the bottom plate towards the base substrate.
14 . The motor unit according to claim 13 , wherein the through hole has a part projecting perpendicularly from the bottom plate axially away from the base substrate.
15 . The motor unit according to claim 14 , wherein the through hole opens into the enclosing part.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to Japanese Patent Application No. JP 2022-144318 filed on Sep. 12, 2022, the contents of which is hereby incorporated by reference in its entirety. TECHNICAL FIELD The present invention relates to a cover member for a motor unit, and a motor unit. BACKGROUND A bus bar is widely used in order to supply the stator of a motor with electric power. This bus bar extends from the motor side toward a control substrate and is fitted to a contact terminal disposed on the control substrate (see, for example, Patent Literature 1). CITATION LIST [Patent Literature 1] JP 2017-157418 A SUMMARY In above Patent Literature 1, a fitting location for the bus bar and the contact terminal is exposed. However, when dirt and foreign substances enter the fitting location for the bus bar and the contact terminal, short-circuiting may occur with respect to an adjacent conductor. Therefore, there has been a problem about easily preventing dirt and foreign substances from entering the fitting location for the bus bar and the contact terminal, at low cost. The present invention is made inconsideration of the above problem and its object is to prevent dirt and foreign substances from entering the fitting location for the bus bar and the contact terminal by means of a simple configuration. In order to solve the above problem, the cover member for the motor unit according to the present invention is interposed between the motor having a rotor and a stator and the control substrate for controlling operation of the motor. The motor has a bus bar terminal electrically connected to a coil of the stator. The control substrate has a connection terminal, which is fitted to the bus bar terminal and is made to electrically connect the control substrate to the stator. The cover member has a through hole, through which the bus bar terminal pierces, and an enclosing part for enclosing the fitting location for the bus bar terminal and the connection terminal, as seen in the piercing direction of the bus bar terminal. This mode can suppress the entry of dirt and foreign substances into the fitting location. Therefore, the short-circuiting with respect to the adjacent conductor can be avoided. An inner surface of the through hole may have an inclined surface, which is tilted in such a manner that, the farther the bus bar terminal proceeds in a direction of insertion, the smaller the width becomes. According to this mode, the bus bar terminal can be correctly guided and entanglement at the fitting location for the bus bar terminal and the connection terminal can be suppressed. Due to this, increase of electrical resistance and thermal resistance possibly caused by the entanglement can be avoided, so that reliability can be enhanced. The cover member may be composed of resin. This mode can reduce a thermal influence between the motor and the control substrate in comparison with a case in which the cover member is composed of metal. Therefore, for example, an expensive element with high thermal resistance does not need to be mounted on the control substrate, so that the costs can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a motor unit according to the present embodiment. FIG. 2 is a front view showing the motor unit according to the present embodiment. FIG. 3 is a perspective view showing the cover member. FIG. 4 is a sectional view taken along the P-P line in FIG. 2. FIG. 5 is an enlarged view showing an area Q in FIG. 4. FIG. 6 is a sectional view taken along the R-R line in FIG. 5. DETAILED DESCRIPTION FIG. 1 is a perspective view showing a motor unit 10 according to the present embodiment. FIG. 2 is a front view showing the motor unit 10 according to the present embodiment. The motor unit 10 includes a motor 12 and an electronic control unit 14. The motor 12 includes a motor housing 20 and a motor shaft 22. The motor housing 20 has a cylindrical part 20a. A (non-illustrated) stator composed of a cylindrically wound coil is housed in the cylindrical part 20a. A (non-illustrated) rotor is further housed in the center of the stator. The rotor is fixed to the motor shaft 22, which is rotatably supported on the motor housing 20. The motor shaft 22 has its tip protruding from one end side of the motor housing 20. A flange 20b is formed at the other end of the motor housing 20. An electronic control unit 14 is attached to the flange 20b by using a fastening tool such as a screw. The electronic control unit 14 includes a cover member 30 and a heat sink 32. The below-described control substrate is housed in the interior of the cover member 30. After the control substrate is housed, the heat sink 32 is attached to the cover member 30. The heat sink 32 has a large number of fins 32a for heat radiation. The heat sink 32 externally radiates heat generated by the control substrate housed in the cover member 30 to cool the control substrate. FIG. 3 is a pe