motorized unit

Abstract

The utility model discloses an electric unit, it can inhibit heat from transmission of variable speed drive axle housing to power control unit, and can inhibit unit overall large -scale. An electric unit, on accommodating variable speed drive axle housing including motor and gear train of variable speed drive axle, fixed with the PCU casing of accommodating the power control unit of the power of motor electrification, electric unit has: the connecting portion of tubular, it protrudes from variable speed drive axle housing. The PCU casing has the opening portion of the space opening to the inside of connecting portion, and is fixed to the end of connecting portion. At least a part of power control unit is arranged in the inside of connecting portion, and is fixed to the PCU casing with the clearance of variable speed drive axle housing apart.

Description

Technical Field

[0001] This utility model relates to an electric unit, which includes: a speed-changing drive axle comprising a motor or gear system, and a power control unit for controlling the motor. Background Technology

[0002] Patent Document 1 describes an integrated electric motor unit in which a PCU (Power Control Unit) housing for controlling the motor is fixed to the upper part of a transmission drive axle housing that houses the transmission drive axle including a motor or differential mechanism. To suppress the influence of radiant heat from the transmission drive axle housing on the power control unit, the integrated electric motor unit is configured with a cylindrical connecting portion protruding upwards from the transmission drive axle housing. A heat dissipation rib is provided inside the connecting portion, and the PCU housing is fixed to the upper end of the connecting portion. Furthermore, the rib is configured in a grid pattern within the inner region of the connecting portion, and its front end protrudes outwards from the connecting portion.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2023-035537 Utility Model Content

[0004] In Patent Document 1, the electric motor unit is configured in the vertical direction with the transmission drive axle housing, ribs, and PCU housing arranged in order to suppress the influence of radiant heat from the partition portion on the upper surface of the transmission drive axle housing on the power control unit. That is, a structure is provided with ribs between the transmission drive axle housing and the PCU housing. Therefore, the electric motor unit can be made larger.

[0005] This utility model was completed with regard to the above-mentioned technical issues. Its purpose is to provide an electric unit that can suppress the transfer of heat from the transmission drive axle housing to the power control unit and can also suppress the overall enlargement of the unit.

[0006] To achieve the above objectives, the present invention provides an electric unit, wherein a PCU housing for accommodating a power control unit that controls the power supply to the motor is fixed on a transmission drive axle housing that houses a transmission drive axle including a motor and a gear train. The electric unit is characterized by having: a cylindrical connecting portion that protrudes from the transmission drive axle housing; the PCU housing having an opening that faces the inner side of the connecting portion and is fixed to the end of the connecting portion; and at least a portion of the power control unit protruding towards the inner side of the connecting portion and fixed to the PCU housing with a predetermined gap from the transmission drive axle housing.

[0007] Utility Model Effect

[0008] According to this invention, a transmission drive axle housing housing including a motor and gear train is connected to a PCU housing housing a power control unit via a connecting portion protruding from the transmission drive axle housing. Furthermore, the power control unit is fixed to the PCU housing. Therefore, by dissipating heat from the transmission drive axle housing to the connecting portion through heat dissipation, heat transferred from the transmission drive axle housing to the PCU housing through conduction can be reduced, resulting in reduced heat transfer to the power control unit fixed to the PCU housing.

[0009] Furthermore, the PCU housing has an opening that faces inward toward the connecting portion, and at least a portion of the power control unit protrudes inward toward the connecting portion and is fixed to the PCU housing. That is, in addition to connecting the transmission drive axle housing and the PCU housing and dissipating heat transferred from the transmission drive axle housing, the connecting portion also accommodates the power control unit. Therefore, a heat dissipation unit is not required between the transmission drive axle housing and the power control unit, thus enabling miniaturization of the electric motor unit.

[0010] Furthermore, in order to form a predetermined gap between the power control unit, which is located inside the connection portion, and the transmission drive axle housing, the power control unit is fixed to the PCU housing. That is, an air layer with low thermal conductivity is present between the power control unit and the transmission drive axle housing. Therefore, heat transfer from the transmission drive axle housing to the power control unit can be suppressed. Attached Figure Description

[0011] Figure 1 This is a cross-sectional view schematically illustrating an example of an electric unit in an embodiment of the present invention. Detailed Implementation

[0012] The present invention will be described with reference to the illustrated embodiments. Furthermore, the embodiments described below are merely examples of how the present invention is embodied and are not intended to limit the scope of the invention.

[0013] The electric unit in the embodiments of this utility model can be applied to vehicles having a motor that functions as a driving force source and a transmission drive axle including a gear system that transmits the torque of the motor to the drive wheels. Figure 1 The image shows an enlarged cross-sectional view illustrating an example of the electric unit in an embodiment of the present invention. Figure 1 The electric unit 1 shown is constructed by combining a PCU housing 2 that houses the power control unit (hereinafter referred to as PCU.) 4 that controls the motor and a transmission drive axle housing 3 that houses the aforementioned transmission drive axle.

[0014] exist Figure 1In the example shown, PCU4 may consist, for example, a converter that steps up or down the output voltage of an energy storage device (not shown) or an inverter that converts the DC voltage of the energy storage device to AC voltage. Additionally, PCU4 may include other electronic components, such as a DC-DC converter for adjusting the voltage applied to electrical equipment in auxiliary devices installed in the vehicle. Figure 1 In this context, PCU4 has four constituent elements: first constituent element 4a, second constituent element 4b, third constituent element 4c, and fourth constituent element 4d.

[0015] PCU housing 2 includes: mounting plate 2a; in Figure 1 The cylindrical first sidewall portion 2b extends upward from the outer periphery of the mounting plate 2a; Figure 1 The first sidewall 2b has a generally tapered second sidewall portion 2c extending downward from near the outer periphery of the mounting plate 2a; and a flange portion 2d protruding outward from the lower end of the second sidewall portion 2c. At the upper end of the first sidewall portion 2b, for example, a flange portion 5a of a trapezoidal cover 5 is fixed by bolts (not shown). Within the upper space 6 surrounded by the cover 5, the mounting plate 2a of the PCU housing 2, and the second sidewall portion 2c, the first component 4a of the PCU 4 is disposed on the mounting plate 2a. Figure 1 The upper surface of the middle.

[0016] On the other hand, a [feature] is formed in the top plate portion 3a of the transmission drive axle housing 3. Figure 1 A cylindrical connecting portion 3b extends upward from the center, and the upper end of the connecting portion 3b is fixed to the flange portion 2d of the PCU housing 2 by, for example, a bolt (not shown). Thus, a receiving portion 7 is formed between the PCU housing 2 and the transmission drive axle housing 3 to receive the second component 4b, the third component 4c, and the fourth component 4d of the PCU 4.

[0017] Specifically, the receiving portion 7 is formed by the internal space 3c of the connecting portion 3b of the transmission drive axle housing 3 and the opening 2e of the PCU housing 2, which opens toward the internal space 3c, formed on the inner side of the second side wall portion 2c. In the receiving portion 7, the second component 4b of the PCU 4 is directly mounted to the mounting plate 2a of the PCU housing 2 within the opening 2e. Figure 1 The lower surface of the middle.

[0018] The third component 4c of PCU4 has a flange-shaped fastening portion 4e protruding from one side toward the connecting portion 3b of the transmission drive axle housing 3. The fastening portion 4e is fixed to a portion of the flange portion 2d of PCU housing 2 via a buffer 4f and bolts 8. The buffer 4f is preferably formed of a resin elastic component, thereby enabling the buffer 4f to function as a heat insulation material and a cushioning material. Thus, the third component 4c does not directly contact the second component 4b, but is only supported by the flange portion 2d of PCU housing 2 via the buffer 4f.

[0019] The fourth constituent element 4d of PCU4 is slightly smaller in its width direction compared to the second constituent element 4b and the third constituent element 4c. Specifically, the fourth constituent element 4d is smaller in the width direction than the third constituent element 4c. Figure 1 The lower surface of the PCU4 is mounted in such a way that a predetermined interval is maintained between it and the top plate portion 3a of the transmission drive axle housing 3. In this way, at least a portion of the PCU4 is accommodated in such a way that it protrudes toward the internal space 3c of the connection portion 3b of the transmission drive axle housing 3, and predetermined intervals are maintained between the PCU4 and the connection portion 3b of the transmission drive axle housing 3 and between the PCU4 and the top plate portion 3a of the transmission drive axle housing 3.

[0020] In addition, Figure 1 In the example shown, a stepped portion 3d corresponding to the shape of the fourth component 4d of the PCU4, which is disposed opposite to it, is formed on the top plate portion 3a of the transmission drive axle housing 3. That is, a portion of the top plate portion 3a of the transmission drive axle housing 3 protrudes into the interior of the receiving portion 7. As a result, the PCU4 can be offset downward relative to the transmission drive axle housing 3, and the electric motor unit 1 can be miniaturized.

[0021] The electric unit 1 configured as described above is combined with a transmission drive axle that includes a motor that functions as a driving force source and a gear train that transmits the motor's torque to the drive wheels. Therefore, for example, during vehicle operation, the motor generates heat due to copper losses from energizing the motor's coils or iron losses from the rotation of the motor's rotor. Furthermore, the gears constituting the gear train generate heat due to frictional forces corresponding to the sliding on the tooth surfaces when the gear train transmits torque.

[0022] Thus, the heat generated by the motor or gear system during vehicle operation... Figure 1 The heat is transmitted to the transmission drive axle housing 3 as indicated by the thick arrow, and finally conducted to the top plate portion 3a of the transmission drive axle housing 3. In this case, in the electric unit 1 of the embodiment of the present invention, the connecting portion 3b of the transmission drive axle housing 3 functions as a heat dissipation portion. Therefore, the heat transmitted from the motor or gear train to the top plate portion 3a of the transmission drive axle housing 3 is... Figure 1Heat is dissipated from the connection portion 3b as indicated by the thin arrow. As a result, the heat transferred from the transmission drive axle housing 3 to the PCU housing 2 is reduced, and consequently, damage to the first component 4a and the second component 4b of the PCU4 caused by heat from the mounting plate 2a that is in direct contact with the PCU housing 2 can be suppressed.

[0023] Furthermore, as described above, a predetermined gap exists between the top plate portion 3a of the transmission drive axle housing 3 and the fourth component 4d of the PCU4, and the thermal conductivity of the air within this gap is low. Therefore, the transfer of heat (radiative heat) dissipated from the top plate portion 3a of the transmission drive axle housing 3 to the PCU4 can be suppressed. As a result, the heat resistance (heat capacity) of the PCU4 can be reduced, the freedom of choice of components for the electric motor unit 1 can be increased, and thus the cost of the electric motor unit 1 can be reduced.

[0024] Furthermore, as described above, when the buffer 4f is formed from a resin elastic component, the buffer 4f can function as both a heat insulation material and a cushioning material. In this case, the heat transferred to the PCU housing 2, which is reduced by heat dissipation from the connection portion 3b, is further reduced by the buffer 4f when it is transferred to the third component 4c of the PCU 4. Therefore, heat-induced damage to the third component 4c can be further suppressed.

[0025] Furthermore, the PCU housing 2 has an opening 2e that opens toward the internal space 3c of the connecting portion 3b, and at least a portion of the PCU 4 is fixed to the PCU housing 2 in a manner that protrudes toward the internal space 3c of the connecting portion 3b. That is, the connecting portion 3b serves to connect the transmission drive axle housing 3 and the PCU housing 2, dissipate heat transferred from the transmission drive axle housing 3, and also accommodate the PCU 4. Therefore, a heat dissipation portion or the like is not required between the transmission drive axle housing 3 and the PCU 4, enabling miniaturization of the electric unit 1.

[0026] Furthermore, the PCU4 is fixed to the PCU housing 2 in such a way that a predetermined gap is formed between the PCU4 located inside the connecting portion 3b and the transmission drive axle housing 3. As a result, an air layer with low thermal conductivity is present between the PCU4 and the transmission drive axle housing 3, thus suppressing the transfer of heat from the transmission drive axle housing 3 to the PCU4.

[0027] Furthermore, this invention is not limited to the above-described embodiments, and appropriate modifications can be made within the scope of the structure described in the solution. For example, instead of bolts, the flange portion 5a of the cover 5 can also be fixed to the first side wall portion 2b of the PCU housing 2 by a suitable method such as welding. Similarly, the flange portion 2d of the PCU housing 2 can also be fixed to the connecting portion 3b of the transmission drive axle housing 3 by a suitable method such as welding. In addition, to reduce the number of parts, the buffer 4f can be omitted. In this case, by forming the fastening portion 4e with high-strength heat-resistant resin, the fastening portion 4e can have both heat insulation and buffering functions.

[0028] Symbol Explanation

[0029] 1-Electric unit, 2-PCU housing, 2e-Opening, 3-Transmission drive axle housing, 3a-Top plate, 3b-Connecting part, 3c-Internal space, 4-Power control unit (PCU), 4a-First component, 4b-Second component, 4c-Third component, 4d-Fourth component, 4e-Fastening part, 7-Receiving part.

Claims

1. An electric unit comprising, wherein a PCU housing for housing a power control unit for controlling the power supplied to the motor is fixed on a transmission drive axle housing that houses a transmission drive axle including a motor and a gear train, the electric unit being characterized in that it includes: A cylindrical connecting portion protrudes from the transmission drive axle housing. The PCU housing has an opening that faces the inside of the connector and is fixed to the end of the connector. At least a portion of the power control unit is disposed inside the connection portion and is fixed to the PCU housing by a predetermined gap from the transmission drive axle housing.

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