Unit

Abstract

[Problem] To more effectively prevent oil scattering to the outside of a unit in the case where the unit is provided with a breather. [Solution] Provided is a unit comprising a housing that has a motor accommodation chamber for accommodating a motor and an inverter accommodation chamber for accommodating an inverter. The inverter accommodation chamber comprises: a first bottom surface that also serves as a peripheral wall surrounding the outer periphery of the motor; and a second bottom surface and a third bottom surface that are disposed so as to sandwich the first bottom surface. A control substrate of the inverter is disposed in the second bottom surface side. The outlet of a breather is disposed in the third bottom surface side.

Description

unit

[0001] The present invention relates to a unit.

[0002] Patent Documents 1 to 4 disclose various arrangements of breathers that connect the inside and outside of a housing (case) to reduce the pressure difference between the inside and outside of the housing.

[0003] JP 2012-082930 JP 2016-019436 JP 8-065945 JP 9-182352

[0004] A breather such as the one described above is commonly provided in a housing that accommodates a reduction gear mechanism mounted on a vehicle. One approach is to locate the breather outlet in an enclosed space within the unit to prevent oil from leaking from the housing to the outside of the unit. However, if there are components in the enclosed space to which oil should not be attached, it is necessary to prevent oil from adhering to those components.

[0005] The present invention has been made in consideration of such technical problems, and aims to prevent oil from adhering to parts in an enclosed space that should not have oil attached thereto, when a breather is provided in the enclosed space within a unit.

[0006] According to one aspect of the present invention, there is provided a unit having a housing having a motor accommodating chamber that accommodates a motor and an inverter accommodating chamber that accommodates an inverter, wherein the inverter accommodating chamber has a first bottom surface portion that also serves as a peripheral wall portion that surrounds the outer periphery of the motor, and a second bottom surface portion and a third bottom surface portion that are respectively arranged on either side of the first bottom surface portion, wherein a control board for the inverter is arranged on the second bottom surface portion side, and a breather outlet is arranged on the third bottom surface portion side.

[0007] According to the above aspect, the second bottom surface portion and the third bottom surface portion are disposed on either side of the first bottom surface portion. As a result, even if oil comes out from the breather outlet disposed on the third bottom surface portion side, the oil is less likely to pass over the first bottom surface portion and travel to the second bottom surface portion, and is more likely to remain on the third bottom surface portion. Therefore, the oil coming out from the breather outlet can be retained on the third bottom surface portion within the inverter accommodating chamber without being guided to the inverter control board disposed on the second bottom surface portion side. Therefore, according to the above aspect, when a breather is provided in the sealed space within the unit, it is possible to prevent oil from adhering to the inverter control board, which is a component that should not be exposed to oil.

[0008] Fig. 1 is a view of a unit according to an embodiment of the present invention as seen from above. Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. Fig. 3 is a cross-sectional view taken along line III-III in Fig. 1. Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 1.

[0009] Hereinafter, a unit 100 according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0010] Fig. 1 is a view of a unit 100 according to this embodiment as seen from above. Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. Fig. 3 is a cross-sectional view taken along line III-III in Fig. 1. Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 1. In Fig. 1, the direction perpendicular to the paper surface corresponds to the direction of gravity. In Figs. 2 to 4, the vertical direction corresponds to the direction of gravity.

[0011] Regarding the term "unit," a unit can also be referred to as, for example, a motor unit (a unit having at least a motor) or a power transmission device (a device having at least a power transmission mechanism). A motor is a rotating electric machine having an electric motor function and / or a generator function (at least one of an electric motor function and a generator function). A power transmission mechanism is, for example, a gear mechanism and / or a differential gear mechanism. A device (unit) having a motor and a power transmission mechanism is included in the concepts of both a motor unit and a power transmission device.

[0012] As shown in Figure 1, the unit 100 includes a housing 10 having a first cover 11, a second cover 12, and a case 13. The unit 100 is mounted on a vehicle, which is an electric vehicle. The first cover 11 covers an opening of the cylindrical case 13 from one axial side (the lower side in Figure 1), and the second cover 12 covers the opening of the case 13 from the other axial side. The case 13 also has a third cover 13a that covers an opening on the upper side in the direction of gravity.

[0013] The unit 100 further includes a motor 20, an inverter 30, a reduction gear (not shown), and a differential gear (not shown). As shown in Figures 2 and 3, the housing 10 has a motor accommodating chamber 14 that accommodates the motor 20, and an inverter accommodating chamber 15 that accommodates the inverter 30. The reduction gear and differential gear are accommodated in a gear accommodating chamber 16 (see Figure 4) inside the second cover 12. The inverter 30 is electrically connected to the motor 20 and a battery (not shown).

[0014] As shown in FIGS. 2 and 3, the motor 20 has a stator 21 that is provided and fixed to the case 13, and a rotor 22 that is rotatable inside the stator 21, and constitutes a drive source for the vehicle.

[0015] The unit 100 contains oil in the housing 10, and the oil is supplied to, for example, the reduction mechanism and differential gear in the second cover 12 to lubricate the gears in the reduction mechanism and differential gear. The oil is also supplied to, for example, the motor 20 in the case 13 to lubricate the motor 20. Therefore, the oil that lubricates the motor 20 exists in the motor accommodating chamber 14 in a liquid, foam, or mist-like state.

[0016] The inverter accommodating chamber 15 has a first bottom surface portion 15a which also serves as a peripheral wall portion surrounding the outer periphery of the motor 20, and a second bottom surface portion 15b and a third bottom surface portion 15c which are arranged on either side of the first bottom surface portion 15a.

[0017] 2, the first bottom surface portion 15a surrounds the outer periphery of the motor 20 that is highest in the direction of gravity. Both ends of the first bottom surface portion 15a correspond to the dashed line portions of the peripheral wall of the motor 20 adjacent to the arrow A in FIG.

[0018] 2, the second bottom surface portion 15b is the bottom surface that extends from the peripheral wall of the motor 20 at the right end of the first bottom surface portion 15a to the right wall of the inverter accommodating chamber 15. The third bottom surface portion 15c is the bottom surface that extends from the peripheral wall of the motor 20 at the left end of the first bottom surface portion 15a to the left wall of the inverter accommodating chamber 15.

[0019] Furthermore, the inverter 30 is disposed above the second bottom surface 15b of the inverter accommodating chamber 15. A breather 40 is provided above the third bottom surface 15c of the inverter accommodating chamber 15 to communicate the interior of the sealed motor accommodating chamber 14 with the inverter accommodating chamber 15, thereby reducing the air pressure difference. Specifically, as shown in FIG. 4 , the breather 40 communicates the inverter accommodating chamber 15 with the motor accommodating chamber 14 on the gear accommodating chamber 16 side of an opening S formed in the motor accommodating chamber 14 of the housing 10. The width of the opening S is within the range enclosed by arrow A in FIG. 4 . The breather 40 has an inlet on the motor accommodating chamber 14 side and an outlet on the inverter accommodating chamber 15 side.

[0020] As described above, the first bottom surface portion 15a is disposed between the second bottom surface portion 15b and the third bottom surface portion 15c, surrounding the outer periphery of the motor 20 that is highest in the direction of gravity. Therefore, even if oil from the motor accommodating chamber 14 leaks into the inverter accommodating chamber 15 via the breather 40, the oil (particularly liquid or foamy oil) on the third bottom surface portion 15c is prevented from moving beyond the first bottom surface portion 15a to the second bottom surface portion 15b. As a result, even if oil leaks into the inverter accommodating chamber 15 via the breather 40, the oil is more likely to remain on the third bottom surface portion 15c, and the oil is prevented from flowing toward the inverter 30 located above the second bottom surface portion 15b.

[0021] An external breathing hole 50 with a breathable filter 51 is formed in the outer wall of the inverter accommodating chamber 15 on the third bottom surface 15c side. The external breathing hole 50 connects the inverter accommodating chamber 15 with the outside of the housing 10 to reduce the pressure difference between the inside and the outside, and also guides oil (particularly atomized oil) contained in the air in the inverter accommodating chamber 15 to the outer wall of the inverter accommodating chamber 15 on the third bottom surface 15c side where the filter 51 is located.

[0022] Furthermore, if oil from the motor accommodating chamber 14 were to flow into the inverter accommodating chamber 15 via the breather 40, the inverter accommodating chamber 15 would likely become positively pressurized due to the inflow of oil and air from the motor accommodating chamber 14. This would make it easier for air in the inverter accommodating chamber 15 to flow to the outside of the housing 10 via the external breathing hole 50. As a result, the oil that flows from the breather 40 into the inverter accommodating chamber 15 is guided to the outer wall on the third bottom portion 15c side of the inverter accommodating chamber 15, more effectively preventing oil from flowing toward the inverter 30.

[0023] Furthermore, if oil gradually accumulates over time on the third bottom surface portion 15c side of the inverter accommodating chamber 15, the oil accumulated on the third bottom surface portion 15c can be discharged by removing the detachable filter 51 and performing maintenance work to suck out the oil through the external breathing hole 50.

[0024] The main effects of the unit 100 according to the embodiment of the present invention will be summarized below.

[0025] (1) The unit 100 has a housing 10 having a motor accommodating chamber 14 that accommodates the motor 20 and an inverter accommodating chamber 15 that accommodates the inverter 30. The inverter accommodating chamber 15 has a first bottom surface 15a that also serves as a peripheral wall that surrounds the outer periphery of the motor 20, and a second bottom surface 15b and a third bottom surface 15c that are arranged on either side of the first bottom surface 15a. The control board 30a of the inverter 30 is arranged on the second bottom surface 15b side, and the outlet of the breather 40 is arranged on the third bottom surface 15c side.

[0026] According to this, the second bottom surface portion 15b and the third bottom surface portion 15c are disposed on either side of the first bottom surface portion 15a. As a result, even if oil comes out from the outlet of the breather 40 disposed on the third bottom surface portion 15c side, the oil is less likely to pass over the first bottom surface portion 15a and travel to the second bottom surface portion 15b, and is more likely to remain on the third bottom surface portion 15c. Therefore, the oil coming out from the outlet of the breather 40 can be retained on the third bottom surface portion 15c in the inverter accommodating chamber 15 without being guided to the control board 30a of the inverter 30 disposed on the second bottom surface portion 15b side. Therefore, according to the above aspect, when the breather 40 is provided in the sealed space of the unit 100, it is possible to prevent oil from adhering to the control board 30a of the inverter 30, which is a component that should not be exposed to oil.

[0027] (2) The breathable filter 51 is provided on the outer wall of the inverter housing chamber 15 on the side of the third bottom surface portion 15c.

[0028] With this, even if the oil coming out of the outlet of the breather 40 is in the form of a mist that is prone to scattering, it can be absorbed by the breathable filter 51 provided on the outside of the third bottom surface 15c of the inverter accommodating chamber 15, thereby preventing the oil from flowing toward the inverter 30. Furthermore, when the oil coming out of the outlet of the breather 40 creates a positive pressure inside the inverter accommodating chamber 15, air in the inverter accommodating chamber 15 is more likely to flow from the external breathing hole 50 to the outside of the housing 10. As a result, the mist of oil coming out of the outlet of the breather 40 is guided to the outside of the third bottom surface 15c of the inverter accommodating chamber 15, thereby more effectively preventing the oil from flowing toward the inverter 30. Therefore, with the above-described aspect, it is possible to more effectively prevent oil from adhering to the control board 30a of the inverter 30.

[0029] (3) The filter 51 is detachably attached to the outer wall.

[0030] This allows the oil accumulated in the third bottom surface portion 15c to be easily discharged by removing the filter 51 and performing maintenance work to suck out the oil through the external breathing hole 50, thereby more effectively preventing oil from adhering to the control board 30a of the inverter 30.

[0031] 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.

[0032] 100 Unit 10 Housing 14 Motor accommodating chamber 15 Inverter accommodating chamber 15a First bottom surface portion 15b Second bottom surface portion 15c Third bottom surface portion 20 Motor 30 Inverter 30a Control board 40 Breather 51 Filter

Claims

1. A unit having a housing with a motor accommodating chamber that accommodates a motor and an inverter accommodating chamber that accommodates an inverter, the inverter accommodating chamber having a first bottom surface portion that also serves as a peripheral wall portion that surrounds the outer periphery of the motor, and a second bottom surface portion and a third bottom surface portion that are respectively arranged to sandwich the first bottom surface portion, a control board for the inverter being arranged on the second bottom surface portion side, and a breather outlet being arranged on the third bottom surface portion side.

2. A unit according to claim 1, wherein an air-permeable filter is provided on an outer wall of the inverter housing chamber on the side of the third bottom portion.

3. A unit according to claim 2, wherein the filter is provided so as to be freely detachable from the outer wall.

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