Unit

Abstract

[Problem] To reduce vibration transmitted to an inverter. [Solution] This unit has a motor accommodated in a motor accommodating chamber, an inverter accommodated in an inverter accommodating chamber, and a connection portion connecting a stator of the motor to an inner wall of the motor accommodating chamber. If viewed from a rotation-axis direction, the connection portion is not located between the center of rotation of the motor and the entire area of a boundary portion between the inverter accommodating chamber and the motor accommodating chamber.

Description

unit

[0001] The present invention relates to a unit.

[0002] Patent Document 1 discloses a drive unit for an electric vehicle having a motor.

[0003] Japanese Patent Application Laid-Open No. 2021-131097

[0004] In the above-described unit, vibrations generated by the motor are transmitted to the inverter via the connection between the motor and the motor housing chamber and the boundary between the motor housing chamber and the inverter housing chamber.

[0005] The present invention has been made in view of the above technical problems, and has an object to reduce vibrations transmitted to an inverter.

[0006] According to one aspect of the present invention, the unit has a motor accommodated in a motor accommodating chamber, an inverter accommodated in an inverter accommodating chamber, and a connection portion connecting the stator of the motor to the inner wall of the motor accommodating chamber, and when viewed from the direction of the rotation axis, the connection portion is not positioned between the center of rotation of the motor and the entire area of ​​the boundary between the inverter accommodating chamber and the motor accommodating chamber.

[0007] In the above-described embodiment, the connection portion is not disposed at the position of the stator closest to the inverter housing chamber, which increases the distance over which vibrations are transmitted from the connection portion to the inverter housing chamber, thereby reducing the vibrations transmitted to the inverter.

[0008] Fig. 1 is a skeleton diagram of a unit according to an embodiment of the present invention. Fig. 2 is a schematic diagram of the periphery of a motor as viewed in the direction of arrow II in Fig. 1. Fig. 3 is a diagram showing a first modified example of the unit. Fig. 4 is a diagram showing a second modified example of the unit. Fig. 5 is a diagram showing a third modified example of the unit.

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In this specification, the same elements are designated by the same reference numerals throughout.

[0010] FIG. 1 is a skeleton diagram of a unit 100 according to an embodiment of the present invention.

[0011] As shown in FIG. 1, the unit 100 includes a case 1, an inverter 2, a motor 3, a planetary gear mechanism 5 that reduces the output rotation of the motor 3 and inputs it to a differential mechanism 4, and drive shafts D1 and D2 as drive shafts.

[0012] In the unit 100, a planetary gear mechanism 5, a differential mechanism 4, and drive shafts D1 and D2 are provided along a transmission path of the output rotation around the rotation axis X of the motor 3. The rotation center of the motor 3, the planetary gear mechanism 5, the differential mechanism 4, and the drive shafts D1 and D2 is the rotation axis X.

[0013] In unit 100, the output rotation of motor 3 is decelerated by planetary gear mechanism 5 and input to differential mechanism 4, and then transmitted via drive shafts D1 and D2 to the left and right drive wheels W of the vehicle on which unit 100 is mounted.

[0014] The case 1 is made up of one or more members and houses an inverter 2, a motor 3, and power transmission mechanisms such as a differential mechanism 4 and a planetary gear mechanism 5. The case 1 is fixed to the vehicle by a mount member (not shown) so that it cannot rotate.

[0015] The inverter 2 is accommodated in an inverter accommodating chamber 20 of the case 1. In this embodiment, the inverter 2 and the inverter accommodating chamber 20 overlap with the motor 3, the differential mechanism 4, the planetary gear mechanism 5, and motor bearings 7 and 8 that support the motor shaft 31 of the motor 3 when viewed in the radial direction.

[0016] "Element A and element B overlap when viewed in a predetermined direction" refers to a state in which element A and element B are aligned in a predetermined direction (axial direction, radial direction, gravity direction, etc.) and at least partially overlap when observed from the predetermined direction. "Element A and element B overlap when viewed in a predetermined direction" is synonymous with "element A and element B overlap in a predetermined direction."

[0017] In contrast, "element A and element B do not overlap when viewed in a predetermined direction" refers to a state in which element A and element B are not lined up in a predetermined direction (axial direction, radial direction, gravity direction, vehicle running direction, etc.), and there is no overlapping portion between element A and element B when observed from the predetermined direction. "element A and element B do not overlap when viewed in a predetermined direction" is synonymous with "element A and element B do not overlap in a predetermined direction."

[0018] The planetary gear mechanism 5 is accommodated in the gear accommodating chamber 17 of the case 1. The planetary gear mechanism 5 is a stepped pinion planetary gear mechanism having a sun gear S, a plurality of stepped pinion gears (hereinafter simply referred to as pinion gears) P, a carrier C that rotatably supports the plurality of pinion gears P, and a ring gear R.

[0019] The sun gear S meshes with a plurality of pinion gears P (large pinions), and the plurality of pinion gears P (small pinions) mesh with a ring gear R. The number of pinion gears P is set appropriately. The planetary gear mechanism 5 may be a stepped pinion planetary gear mechanism, a single pinion planetary gear mechanism, or a double pinion planetary gear mechanism.

[0020] The sun gear S is connected to the motor shaft 31 of the motor 3. The ring gear R is fixed to the case 1. The carrier C is connected to the differential mechanism 4. The carrier C is supported by the case 1 via carrier bearings 13 and 14.

[0021] The motor 3 is housed in a motor housing chamber 11 of the case 1. The motor 3 is electrically connected to a battery (not shown) outside the unit 100 via the inverter 2, and functions as an electric motor by receiving power from the battery. The motor 3 can also function as a generator.

[0022] The motor 3 has a rotor 32 and a stator 33. The rotor 32 has a motor shaft 31. The rotor 32 is supported by the case 1 via motor bearings 7 and 8. In FIG. 1 , the stator 33 is fastened to the inner wall of the motor housing chamber 11 by a plurality of bolts 9.

[0023] The motor bearing 8 is supported by a bearing retainer 10. The bearing retainer 10 is fastened to the inner wall of the motor housing chamber 11 by a plurality of bolts 12. The bearing retainer 10 is also applicable to the motor bearing 7. The bearing retainer 10 may be applied to either the motor bearing 7 or 8, or to both.

[0024] Fig. 2 is a schematic diagram of the motor 3 and its surroundings as viewed in the direction of arrow II in Fig. 1. In Fig. 2, some components are omitted for ease of understanding.

[0025] The unit 100 has a connection portion that connects the stator 33 of the motor 3 to the inner wall of the motor housing chamber 11. That is, the motor 3 is fixed to the inner wall of the motor housing chamber 11 by the connection portion. The connection portion can be formed as a fastening structure 40 that connects the stator 33 to the inner wall of the motor housing chamber 11 via bolts 9 as fastening members, for example, as shown in FIG. 2 .

[0026] The "fastening structure" refers to a protrusion protruding from the outer wall of the stator 33 and / or a protrusion protruding from the inner wall of the motor accommodating chamber 11, and the stator 33 and the motor accommodating chamber 11 are connected by inserting a fastening member (e.g., a bolt) into the protrusion.

[0027] In the example shown in FIG. 2 , the fastening structures 40 are protrusions 41 protruding from the outer wall of the stator 33. The stator 33 and the motor housing 11 are connected by inserting bolts 9 into holes provided in the protrusions 41 and fastening the bolts 9 to internal threads formed in the motor housing 11. In the example shown in FIG. 2 , there are two fastening structures 40, which are arranged at equal intervals in the circumferential direction. In other words, the two fastening structures 40 are arranged point-symmetrically about the rotation center (rotation axis X) of the motor 3. The number of fastening structures 40 can be set as appropriate. Furthermore, the multiple fastening structures 40 may be arranged at non-equidistant intervals in the circumferential direction.

[0028] The inverter accommodating chamber 20 is connected to the case 1 by bolts via a plurality of mounting portions 18 formed on the outer wall side of the case 1 .

[0029] Therefore, vibrations generated in the motor 3 are transmitted to the inverter 2 via the connection between the motor 3 and the motor housing chamber 11 and the boundary between the motor housing chamber 11 and the inverter housing chamber 20 .

[0030] 2 , in order to reduce vibration transmitted from the motor 3 to the inverter 2, the fastening structure 40 serving as a connection is not disposed between the rotation center (rotation axis X) of the motor 3 and the entire boundary between the inverter accommodating chamber 20 and the motor accommodating chamber 11 when viewed from the direction of the rotation axis X. In the example shown in FIG. 2 , the boundary is the base region of the mounting portion 18. The boundary constitutes a vibration transmission path from the fastening structure 40 to the inverter accommodating chamber 20.

[0031] That is, a toothless portion 53 is formed on the outer periphery of the motor 3 as a non-connected portion where the fastening structure 40 is not present, and when viewed from the direction of the rotation axis X, the toothless portion 53 is disposed between the rotation center of the motor 3 and the entire area of ​​the boundary between the inverter accommodating chamber 20 and the motor accommodating chamber 11. When the inverter accommodating chamber 20 and the motor accommodating chamber 11 overlap in the radial direction, when the outer periphery in the radial direction is viewed from the rotation center of the motor 3, the entire area of ​​the boundary between the inverter accommodating chamber 20 and the motor accommodating chamber 11 does not overlap with the connection portion.

[0032] The non-connected portions (tooth-missing portions 53) can be provided as appropriate, taking into consideration the position, number, and range of the boundary portion. In the example shown in Fig. 2, two tooth-missing portions 53 are provided.

[0033] As described above, in the unit 100 of this embodiment, no connection portion is disposed at the position of the stator 33 closest to the inverter accommodating chamber 20. This increases the distance over which vibration is transmitted from the connection portion to the inverter accommodating chamber 20. This reduces the vibration transmitted to the inverter 2.

[0034] When the connection portion is formed as the fastening structure 40, the above structure can be provided by forming a toothless portion 53 where the fastening structure 40 is not provided.

[0035] Next, a first modification of the unit 100 will be described.

[0036] Fig. 3 is a diagram showing a first modified example of the unit 100. In Fig. 3, some components are omitted for ease of understanding.

[0037] 3, the fastening structure 40 is three protrusions 41 protruding from the outer wall of the stator 33. The number of missing tooth portions 53 is three.

[0038] In the example shown in FIG. 3 , similarly to the example shown in FIG. 2 , when viewed from the direction of the rotation axis X, the toothless portion 53 is arranged between the center of rotation (rotation axis X) of the motor 3 and the entire area of ​​the boundary between the inverter accommodating chamber 20 and the motor accommodating chamber 11.

[0039] 3, the connection portion is not disposed at the position of the stator 33 closest to the inverter accommodating chamber 20. This increases the distance over which vibration is transmitted from the connection portion to the inverter accommodating chamber 20. This reduces the vibration transmitted to the inverter 2.

[0040] When the connection portion is formed as a fastening structure 40, it is preferable to provide three or more connection points (protrusions 41) connecting the stator 33 and the motor accommodating chamber 11, as in the example shown in Fig. 3. Furthermore, when the side of the motor 3 on which the inverter accommodating chamber 20 is located with respect to the rotation center of the motor 3 (above the dashed dotted line passing through the rotation axis X in Fig. 3) is defined as the first side, and the side of the motor 3 on which the inverter accommodating chamber 20 is not located with respect to the rotation center of the motor 3 (below the dashed dotted line passing through the rotation axis X in Fig. 3) is defined as the second side, it is preferable to provide the third point on the second side.

[0041] This improves the support performance of the stator 33 .

[0042] Next, a second modification of the unit 100 will be described.

[0043] Fig. 4 is a diagram showing a second modified example of the unit 100. In Fig. 4, some components are omitted for ease of understanding.

[0044] 4, the fastening structure 40 is three protrusions 41 protruding from the outer wall of the stator 33. The number of missing tooth portions is three.

[0045] In the example shown in FIG. 4 , similarly to the example shown in FIG. 2 , when viewed from the direction of the rotation axis X, the toothless portion 53 is arranged between the center of rotation (rotation axis X) of the motor 3 and the entire area of ​​the boundary between the inverter accommodating chamber 20 and the motor accommodating chamber 11.

[0046] 4 , the connection portion is not disposed at the position of the stator 33 closest to the inverter accommodating chamber 20. This increases the distance over which vibration is transmitted from the connection portion to the inverter accommodating chamber 20. This reduces the vibration transmitted to the inverter 2.

[0047] In the example shown in Figure 4, the side where the inverter accommodating chamber 20 is located with respect to the rotation center of the motor 3 (in Figure 4, the side above the dotted line passing through the rotation axis X) is defined as the first side, and the side where the inverter accommodating chamber 20 is not located with respect to the rotation center of the motor 3 (in Figure 4, the side below the dotted line passing through the rotation axis X) is defined as the second side, and connection portions (fastening structures 40) are located on both the first side and the second side.

[0048] When considering the influence of vibration, it is preferable to provide a connection portion only on the second side, but by providing a connection portion on the first side as well in an area that does not overlap with the boundary portion and is less affected by vibration, it is possible to achieve both the support performance of the stator 33 and vibration reduction.

[0049] Here, when the connection portion is formed as the fastening structure 40, it is preferable to arrange the multiple connection points at equal intervals in the circumferential direction from the viewpoint of improving the support performance of the stator 33. On the other hand, from the viewpoint of reducing vibration, as shown in Fig. 4, it is preferable that the connection points on the first side be arranged outside the V-shaped region formed by the boundary line (two-dot chain line) passing through the joint (mounting portion 18) between the inverter accommodating chamber 20 and the motor accommodating chamber 11 and the rotation center (rotation axis X) of the motor 3, and it is more preferable that they be arranged outside the joint between the inverter accommodating chamber 20 and the motor accommodating chamber 11 (outside the two dotted lines).

[0050] In the example shown in Figure 4, multiple connection points are arranged outside the joint between the inverter accommodating chamber 20 and the motor accommodating chamber 11 (outside the two dotted lines) so as to be as equally spaced as possible in the circumferential direction.

[0051] Next, a third modification of the unit 100 will be described.

[0052] Fig. 5 is a diagram showing a third modified example of the unit 100 according to the first embodiment. In Fig. 5, some components are omitted for ease of understanding.

[0053] In the example shown in Fig. 5, the inverter accommodating chamber 20 is integrally formed with the motor accommodating chamber 11. The other configurations are the same as those in the example shown in Fig. 4.

[0054] 5, as in the example shown in Fig. 2, when viewed from the direction of the rotation axis X, the toothless portion 53 is disposed between the rotation center (rotation axis X) of the motor 3 and the entire area of ​​the boundary between the inverter accommodating chamber 20 and the motor accommodating chamber 11. In the example shown in Fig. 5, the boundary is the entire area from the bottom surface of the inverter accommodating chamber 20 to the ends of both side walls.

[0055] 5 , the connection portion is not disposed at the position of the stator 33 closest to the inverter accommodating chamber 20. This increases the distance over which vibration is transmitted from the connection portion to the inverter accommodating chamber 20. This reduces the vibration transmitted to the inverter 2.

[0056] In the example shown in FIG. 5, similarly to the example shown in FIG. 4, fastening structures 40 are arranged on both the first side and the second side.

[0057] Therefore, it is possible to achieve both the support performance of the stator 33 and the reduction of vibration.

[0058] In the example shown in Figure 5, similar to the example shown in Figure 4, multiple connection points are arranged outside the joint between the inverter accommodating chamber 20 and the motor accommodating chamber 11 (outside the two dotted lines) so as to be as equally spaced as possible in the circumferential direction.

[0059] The main effects of the unit 100 according to the embodiment of the present invention will be summarized below.

[0060] (1) The unit 100 has a motor 3 accommodated in the motor accommodating chamber 11, an inverter 2 accommodated in the inverter accommodating chamber 20, and a connection portion (fastening structure 40) connecting the stator 33 of the motor 3 to the inner wall of the motor accommodating chamber 11. When viewed from the direction of the rotation axis X, no connection portion is located between the center of rotation of the motor 3 (rotation axis X) and the entire area of ​​the boundary between the inverter accommodating chamber 20 and the motor accommodating chamber 11.

[0061] According to this, no connection portion is disposed at the position of the stator 33 closest to the inverter accommodating chamber 20. This increases the distance over which vibration is transmitted from the connection portion to the inverter accommodating chamber 20. This reduces the vibration transmitted to the inverter 2.

[0062] (2) The connection portion is formed as a fastening structure 40 that connects to the inner wall of the motor accommodating chamber 11 via a bolt 16, and a toothless portion 53 where the fastening structure 40 does not exist is formed on the outer periphery of the motor 3. When viewed from the direction of the rotation axis X, the toothless portion 53 is arranged between the rotation center (rotation axis X) of the motor 3 and the entire area of ​​the boundary between the inverter accommodating chamber 20 and the motor accommodating chamber 11.

[0063] When the connection portion is formed as the fastening structure 40, the above structure can be provided by forming a toothless portion 53 where the fastening structure 40 is not provided.

[0064] (3) In the unit 100 (second and third variants), the side where the inverter accommodating chamber 20 is located relative to the rotation center (rotation axis X) of the motor 3 is defined as the first side, and the side where the inverter accommodating chamber 20 is not located relative to the rotation center of the motor 3 is defined as the second side. Connection portions (fastening structures 40) are arranged on both the first side and the second side.

[0065] When considering the influence of vibration, it is preferable to provide a connection portion only on the second side, but by providing a connection portion on the first side as well in an area that does not overlap with the boundary portion and is less affected by vibration, it is possible to achieve both the support performance of the stator 33 and vibration reduction.

[0066] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above embodiments.

[0067] For example, in the above embodiment, the connection portion is described as the fastening structure 40. However, the connection portion may be formed as, for example, a spline structure. Note that the distance (circumferential length) between adjacent spline teeth in the spline structure is smaller than the circumferential length of the toothless portion 53. In other words, the space between adjacent spline teeth in the spline structure is not the toothless portion 53.

[0068] In the above embodiment, the unit 100 is a single-axis drive unit equipped with the planetary gear mechanism 5. However, the unit 100 does not have to be equipped with the planetary gear mechanism 5. The unit 100 may be a two-axis drive unit or a three-axis drive unit.

[0069] 2 inverter 3 motor 11 motor housing 16 bolt (fastening member) 20 inverter housing 33 stator 40 fastening structure (connection portion) 53 toothless portion (non-connection portion) 100 unit X rotation axis (center of rotation)

Claims

1. A unit having a motor accommodated in a motor accommodating chamber, an inverter accommodated in an inverter accommodating chamber, and a connection portion connecting a stator of the motor to the inner wall of the motor accommodating chamber, wherein, when viewed from the direction of the rotation axis, the connection portion is not located between the center of rotation of the motor and the entire area of ​​the boundary between the inverter accommodating chamber and the motor accommodating chamber.

2. A unit as claimed in claim 1, wherein the connection portion is formed as a fastening structure that connects to the inner wall of the motor housing chamber via a fastening member, and a non-connection portion where the fastening structure is not present is formed on the outer periphery of the motor, and when viewed from the direction of the rotation axis, the non-connection portion is located between the center of rotation of the motor and the entire area of ​​the boundary portion between the inverter housing chamber and the motor housing chamber.

3. A unit as claimed in claim 1 or 2, wherein the side of the motor's rotation centre on which the inverter accommodating chamber is located is defined as a first side, and the side of the motor's rotation centre on which the inverter accommodating chamber is not located is defined as a second side, and the connection parts are located on both the first side and the second side.

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