Earth brush arrangement structure for electric vehicle

Abstract

To arrange a ground brush at a position with good serviceability.SOLUTION: A ground brush arrangement structure for an electric vehicle includes: a drive motor 5 for driving the vehicle by using power to rotate a motor shaft 20; a reduction gear 6 arranged on the rear of the drive motor for reducing the power from the drive motor to output the power; an oil accommodating part 107 arranged below the drive motor; a power conversion unit 100 arranged above the drive motor; and a ground brush 30 for eliminating static electricity of the motor shaft. The ground brush is brought in contact with the motor shaft from the front and from below.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The technology disclosed herein belongs to the technical field relating to an earth brush arrangement structure for an electric vehicle. [Background technology]

[0002] In an electric vehicle in which electric power is supplied to a drive motor to drive the vehicle, a structure in which an earth brush is brought into contact with the motor shaft of the drive motor to prevent electrolytic corrosion is known. For example, Patent Document 1 discloses a vehicle drive device in which an earth brush is brought into contact with the surface of a rotating shaft that is connected to a rotor shaft and can transmit power from the electric motor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-11441 Summary of the Invention [Problem to be solved by the invention]

[0004] Since the earth brush is a consumable item that needs to be replaced due to wear, it must be placed in a location that is easy to service and not affected by other components placed around the drive motor.

[0005] The technique disclosed herein has been made in view of the above points, and its purpose is to arrange the earth brush in a position that is convenient for service. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the technology disclosed herein comprises a drive motor that uses electric power to rotate a motor shaft to drive a vehicle, a reducer that is arranged behind the drive motor and reduces the power from the drive motor before outputting it, an oil storage section that is arranged below the drive motor, a power conversion unit that is arranged above the drive motor, and an earth brush that neutralizes the motor shaft, and the earth brush is configured to abut against the motor shaft from the front and below.

[0007] This configuration allows the earth brush to be placed in a convenient location where it is not affected by the reducer behind the drive motor, the power conversion unit above the drive motor, or the oil storage unit below the drive motor. Furthermore, by abutting the earth brush against the motor shaft from below, the earth brush is less susceptible to dust.

[0008] In one embodiment of the earth brush arrangement structure for the electric vehicle, the drive motor, the reducer, a generator that generates electricity to be supplied to the drive motor, and an engine that drives the generator are provided in this order in the vehicle width direction, and an earth brush housing is formed between a reducer housing that houses the reducer and a generator housing that houses the generator, and the motor shaft passes through the reducer housing and protrudes into the earth brush housing.

[0009] According to this configuration, the earth brush can be brought into contact with the motor shaft inside the earth brush housing, so that oil used around the motor shaft can be prevented from splashing onto the earth brush.

[0010] In one embodiment, the earth brush may be arranged so as to overlap a portion of the reducer when viewed in the vehicle front-rear direction.

[0011] According to this configuration, by arranging the earth brush so as to overlap the reducer in the front-rear direction, it is possible to reduce the length of the drive unit housing in the vehicle width direction.

[0012] In one embodiment, the motor shaft has an oil passage extending axially therein, and its tip is formed to reach from the reducer accommodating section to the generator accommodating section, the oil passage is configured to be able to supply oil to the generator accommodating section from an opening provided at the tip, and a sealing member is provided on the outer periphery of the motor shaft between the tip and the earth brush accommodating section.

[0013] According to this configuration, in a configuration in which oil is supplied from the tip of the motor shaft to the generator housing section, by providing a sealing member in front of the earth brush housing section, it is possible to prevent the oil supplied from the tip from entering the earth brush housing section. [Effects of the Invention]

[0014] As described above, according to the technique disclosed herein, the earth brush can be disposed in a position that is convenient for servicing. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a block diagram illustrating a drive train of an electric vehicle including an earth brush arrangement according to an exemplary embodiment. [Figure 2] FIG. 2 is a schematic front view of the power unit. [Figure 3] FIG. 3 is a cross-sectional view taken along a plane corresponding to line III-III in FIG. 2. [Figure 4] FIG. 4 is a cross-sectional view taken along a plane corresponding to line IV-IV in FIG. [Figure 5] FIG. 2 is a perspective view of the reducer housing portion as viewed from the front right. [Figure 6] FIG. 10 is a perspective view of a part of the third housing cut away, as viewed from the right front. [Figure 7] FIG. 2 is a perspective view showing an earth brush and a motor shaft. DETAILED DESCRIPTION OF THE INVENTION

[0016] Exemplary embodiments will be described in detail below with reference to the drawings. In the following description, the longitudinal direction of the vehicle will be simply referred to as the "longitudinal direction," the front side of the vehicle will be simply referred to as the "front side," and the rear side of the vehicle will be simply referred to as the "rear side." The vehicle width direction is the left-right direction of the vehicle, and the left side of the vehicle will be simply referred to as the "left side," and the right side of the vehicle will be simply referred to as the "right side." Note that, in the lateral direction, the left side when viewed from the rear side to the front side will be referred to as the left, and the right side will be referred to as the right.

[0017] Fig. 1 is a block diagram showing a drive system of an electric vehicle equipped with an earth brush arrangement structure according to an exemplary embodiment. Fig. 2 is a front view showing a schematic representation of a power unit. Figs. 1 and 2 only show a schematic representation of the drive system of vehicle 1, and the arrangement of each component in Fig. 2 does not limit the actual arrangement of each component.

[0018] Vehicle 1 is a series hybrid vehicle. Vehicle 1 is equipped with a power unit P consisting of an electric drive unit 10 for driving vehicle 1 using electric power and an engine body 8 for generating electricity. Electric drive unit 10 has a drive motor 5 that drives the vehicle using electric power, a reduction gear 6 that reduces the power from drive motor 5 and outputs it, and a generator 7 that generates electric power to be supplied to drive motor 5.

[0019] The engine has an engine body 8 and engine-related parts. The engine body 8 is mainly used to drive a generator 7 to generate electricity, and the power to run the vehicle 1 is generated by a drive motor 5. The power generated by the drive motor 5 is changed in speed by a reducer 6 and then transmitted to drive wheels 92 (here, the front wheels) via a differential device 91.

[0020] The vehicle 1 includes a high-voltage battery B1 and a low-voltage battery B2. The high-voltage battery B1 is charged with electricity generated by a generator 7. A power generation inverter 102 is provided between the generator 7 and the high-voltage battery B1. The power generation inverter 102 is electrically connected to the generator 7 and the high-voltage battery B1. Electricity generated by the generator 7 is supplied to the high-voltage battery B1 via the power generation inverter 102. A motor inverter 101 is provided between the drive motor 5 and the high-voltage battery B1. The motor inverter 101 is electrically connected to the drive motor 5 and the high-voltage battery B1. The motor inverter 101 converts electricity from the high-voltage battery B1 into power for driving the drive motor 5 and outputs the power to the drive motor 5. A DC-DC converter 103 is provided between the high-voltage battery B1 and the low-voltage battery B2. The DC-DC converter 103 is electrically connected to the high-voltage battery B1 and the low-voltage battery B2. Electricity from the high-voltage battery B1 is supplied to the low-voltage battery B2 via the DC-DC converter 103. The electricity generated by the generator 7 is supplied to the low-voltage battery B2 via a power generation inverter 102 and a DC-DC converter 103. The motor inverter 101, the power generation inverter 102, and the DC-DC converter 103 together constitute a power conversion unit 100.

[0021] The power unit P includes a drive motor 5, a reduction gear 6, a generator 7, and an engine body 8, arranged in this order in the vehicle width direction. A power conversion unit 100 including a motor inverter 101, a power generation inverter 102, and a DC-DC converter 103 is disposed above the drive motor 5, the reduction gear 6, and the generator 7. A parking lock actuator 105 is disposed above the reduction gear 6.

[0022] The engine body 8 is disposed adjacent to the left side of the generator 7. The engine is made up of the engine body 8 and engine-related parts disposed above the engine body 8. The engine-related parts include, for example, a low-voltage battery B2, an air cleaner 106, and oil-related parts (not shown). The engine body 8 is integrally formed with a drive unit housing 9.

[0023] The drive motor 5, the reducer 6, and the generator 7 are housed in a drive unit housing 9. The drive unit housing 9 is formed by integrally connecting a drive motor housing section 5a that houses the drive motor 5, a reducer housing section 6a that houses the reducer 6, and a generator housing section 7a that houses the generator 7 in the vehicle width direction.

[0024] Fig. 3 is a cross-sectional view taken along a plane corresponding to line III-III in Fig. 2, and Fig. 4 is a cross-sectional view taken along a plane corresponding to line IV-IV in Fig. 3. In Fig. 4, the structures of the drive motor 5, the reducer 6, the generator 7, and the engine body 8 are omitted or simplified.

[0025] 3 and 4, the drive motor 5 has a motor shaft 20, which is a rotating shaft. The motor shaft 20 extends in the vehicle width direction slightly above the vertical center of the drive unit housing 9. The motor shaft 20 passes through the reducer housing 6a from the drive motor housing 5a and protrudes into the earth brush housing 40, which will be described later. In the reducer housing 6a, the reducer 6 is disposed behind the motor shaft 20.

[0026] In the reducer housing 6a, an oil housing 107 is arranged below the drive motor 5. The oil housing 107 is connected to an oil pump (not shown), and oil is pumped upward by the oil pump and supplied to parts of the reducer 6 that require lubrication.

[0027] As shown in Figure 4, the drive unit housing 9 is formed by connecting a second housing 12 and a third housing 13, which are approximately cylindrical and extend in the vehicle width direction, and the openings on both the left and right sides are closed by a first housing 11 and a fourth housing 14, thereby forming an integrated drive unit housing 9.

[0028] The first housing 11 is located at the outermost position in the vehicle width direction of the drive unit housing 9. A first bearing portion 21a is provided in the first housing 11. The first bearing portion 21a rotatably supports one end portion 20a of the motor shaft 20.

[0029] The second housing 12 is connected to the left side of the first housing 11. The cylindrical interior of the second housing 12 is partitioned in the vehicle width direction by a partition wall 12a. A through-hole 12b is provided in the approximate center of the partition wall 12a, allowing the motor shaft 20 to pass through in the vehicle width direction. On the right side of the partition wall 12a, a drive motor 5 is disposed in a drive motor accommodating section 5a formed by the first housing 11 and the second housing 12. On the left side of the partition wall 12a, a reducer is disposed in a reducer accommodating section 6a formed by the second housing 12 and the third housing 13. The reducer accommodating section 6a is formed by expanding the left rear portion of the second housing 12 and the right rear portion of the third housing 13 rearward, so that the reducer 6 is disposed rearward of the motor shaft 20. In addition, a fifth bearing portion 62a is provided in the partition wall 12a, rearward of the motor shaft 20. The fifth bearing portion 62a rotatably supports one end of an intermediate shaft 62 of the reducer 6.

[0030] The third housing 13 is connected to the left side of the second housing 12. The third housing 13 has a partition wall 13a at its right end that divides the vehicle into a reducer housing 6a and a generator housing 7a in the vehicle width direction. A through-hole 13b is provided in the approximate center of the partition wall 13a, allowing the motor shaft 20 to pass through in the vehicle width direction. A boss is formed on the periphery of the through-hole 13b, and the boss protrudes to both the left and right sides from the partition wall 13a. A second bearing 21b is provided at the end of the through-hole 13b facing the reducer housing 6a. The second bearing 21b rotatably supports the motor shaft 20. A third bearing 51a is provided at the end of the through-hole 13b facing the generator housing 7a. The third bearing 51a rotatably supports one end of the generator shaft 50. An earth brush housing 40 is integrally formed with the partition wall 13a. A sixth bearing portion 62b is provided in the partition wall 13a behind the motor shaft 20. The sixth bearing portion 62b supports the other end portion of the intermediate shaft 62 of the reducer 6 so that the other end portion is rotatable.

[0031] The fourth housing 14 is connected to the third housing 13 on the left side of the partition wall 13a. The generator 7 is accommodated in a generator accommodating section 7a formed by the third housing 13 and the fourth housing 14 on the left side of the partition wall 13a. The fourth housing 14 is provided with a fourth bearing 51b. The fourth bearing 51b rotatably supports the other end of the generator shaft 50. The fourth housing 14 is configured integrally with the engine body 8 adjacent to it on the left side.

[0032] The drive motor 5 includes a rotor and a stator (not shown), and a motor shaft 20. A rotating magnetic field is generated when a three-phase alternating current is supplied to the stator, and the rotor and motor shaft 20 are rotated by the rotating magnetic field.

[0033] One end 20a of the motor shaft 20 is rotatably supported by the first bearing portion 21a, and extends from the first housing 11, through the drive motor accommodating portion 5a, and penetrating the partition wall 12a of the second housing 12 into the reducer accommodating portion 6a.

[0034] The other end 20b of the motor shaft 20 passes through the partition wall 13a from the reducer housing 6a through the through-hole 13b. The other end 20b of the motor shaft 20 protrudes from the through-hole 13b into the earth brush housing 40 and is formed to reach from the reducer housing 6a to the generator housing 7a.

[0035] Specifically, the other end 20b of the motor shaft 20 reaches closer to the generator housing 7a than the earth brush housing 40. In the through hole 13b of the third housing 13, a second bearing 21b is provided closer to the drive motor 5 than the earth brush housing 40.

[0036] The motor shaft 20 has an oil passage 20c extending in the axial direction inside it. The oil passage 20c has an opening at the other end 20b, and oil supplied to the oil passage 20c can be supplied from the opening and the inside of the oil passage 20c to parts that require lubrication, such as bearings.

[0037] An input shaft 61 of the reducer 6 is formed integrally with the motor shaft 20 in the reducer housing portion 6a. The rotational force of the drive motor 5 is input to the input shaft 61. The reducer 6 has an intermediate shaft 62 disposed behind the motor shaft 20 and substantially parallel to the motor shaft 20. A gear 63 is disposed between the input shaft 61 and the intermediate shaft 62. The intermediate shaft 62 transmits the power reduced by the gear 63 to an output shaft (not shown).

[0038] The generator 7 includes a rotor and a stator (not shown), and a generator shaft 50. When the generator shaft 50 and the rotor are rotated by the power of the engine, electricity is generated in the stator due to electromagnetic induction.

[0039] The generator shaft 50 is disposed closer to the generator 7 than the other end 20b of the motor shaft 20. One end of the generator shaft 50 is supported by a third bearing 51a provided in the third housing 13, and the other end is supported by a fourth bearing 51b provided in the fourth housing 14.

[0040] The generator shaft 50 has an oil passage 50a extending axially inside it. The oil passage 50a has an opening at one end 50c, and oil supplied into the oil passage 50a can be supplied from the opening and the oil passage 50a to parts that require lubrication, such as bearings.

[0041] The motor shaft 20 and the generator shaft 50 are arranged in a straight line with a gap in the vehicle width direction. The motor shaft 20 and the generator shaft 50 have their tip ends 20b, 50c facing each other within the through-hole 13b. An oil supply member 60 is arranged between the motor shaft 20 and the generator shaft 50.

[0042] The oil supply member 60 distributes oil to the motor shaft 20 and the generator shaft 50. The oil supply member 60 has a cylindrical portion 60a that extends left and right, and a flange portion 60b that extends radially outward from the outer periphery of the cylindrical portion 60a in a disk shape. An oil supply passage 60c that extends left and right is formed in the cylindrical portion 60a. The edge of the flange portion 60b abuts against the inner wall of the through hole 13b, holding the oil supply member 60 within the through hole 13b.

[0043] The right side of the cylindrical portion 60a is inserted into the oil passage 20c from the tip end 20b of the motor shaft 20, and the left side is inserted into the oil passage 50a from the tip end 50c of the generator shaft 50. Oil pumped up from the oil storage portion 107 by the oil pump flows into the oil supply passage 60c from the upper part of the oil supply member 60. The oil is supplied from both the left and right sides of the cylindrical portion 60a to the oil passages 20c and 50a of the motor shaft 20 and the generator shaft 50, respectively.

[0044] The motor shaft 20 causes the oil that has flowed into the oil passage 20c to flow toward the drive motor housing portion 5a, and supplies the oil from the oil passage 20c to the second bearing portion 21b and the stator of the drive motor 5. The motor shaft 20 also supplies the oil that has flowed into the oil passage 20c from an opening provided at the tip end 20b, through a gap between the motor shaft 20 and the oil supply member 60, to the third bearing portion 51a in the generator housing portion 7a.

[0045] The generator shaft 50 causes the oil that has flowed into the oil passage 50a to flow toward the generator housing portion 7a and is supplied from inside the oil passage 50a to the rotor of the generator 7. The generator shaft 50 also supplies the oil that has flowed into the oil passage 50a from an opening provided at the tip end 50c, through a gap between the generator shaft 50 and the oil supply member 60, to the third bearing portion 51a inside the generator housing portion 7a.

[0046] A seal member 22 is disposed around the outer periphery of the motor shaft 20 between the other end portion 20b of the motor shaft 20 and the earth brush housing 40. The seal member 22 is adjacent to the right side of the flange portion 60b of the oil supply member 60. The seal member 22 has a circular central opening through which the motor shaft 20 passes. The seal member 22 prevents oil flowing on the left side of the seal member 22 from infiltrating to the right of the seal member 22. This seal member 22 prevents oil that has flowed outside the motor shaft 20 from infiltrating into the earth brush housing 40 and can be supplied to the third bearing portion 51a of the generator shaft 50.

[0047] The drive unit housing 9 is provided with an earth brush 30 for neutralizing the motor shaft 20. As shown in Fig. 3, the earth brush 30 is housed in an earth brush housing 40 and abuts against the motor shaft 20 from the front and below, and is arranged so as to overlap with part of the reducer 6 when viewed in the vehicle longitudinal direction, as shown in Fig. 4.

[0048] Fig. 5 is a perspective view of the reducer accommodating section 6a as seen from the right front, and is a perspective view of the third housing 13. Fig. 6 is a perspective view of the front part of the third housing cut in the vertical direction as seen from the right front. As shown in Figs. 5 and 6, the earth brush accommodating section 40 is integrally formed with the partition wall 13a of the third housing 13 located between the reducer accommodating section 6a and the generator accommodating section 7a.

[0049] Specifically, the earth brush housing 40 is formed to protrude from the partition wall 13a toward the reducer housing 6a. Therefore, the intermediate shaft 62 of the reducer 6 is located behind the earth brush housing 40. The earth brush housing 40 has an opening 40a on the front side of the side wall of the third housing 13, a first housing portion 40b with a substantially cylindrical shape that extends from the opening 40a to near the motor shaft 20, and a second housing portion 40c formed by bulging out from the end of the first housing portion 40b to surround the outer periphery of the motor shaft 20.

[0050] An actuator shaft 105a extends vertically above the first accommodating portion 40b. The actuator shaft 105a penetrates the side wall from the top of the third housing 13 and is exposed to the outside. The actuator shaft 105a is connected to a parking lock actuator 105 disposed on the top of the third housing 13.

[0051] The opening 40a is formed slightly below the motor shaft 20. The first accommodating portion 40b is formed in an inclined shape extending upward from the opening 40a toward the motor shaft 20 and communicates with the through-hole 13b. The second accommodating portion 40c is formed by expanding the diameter of the inside of the through-hole 13b. As shown in FIG. 3, the second accommodating portion 40c expands in a circular shape centered on the motor shaft 20 when viewed in the vehicle width direction.

[0052] 7 is a perspective view showing the earth brush 30 and the motor shaft 20. The earth brush 30 has an operating part 31 exposed to the outside through the opening 40a, a bracket 32 ​​extending from the operating part 31 to the motor shaft 20, and an earth brush body 33 attached to the tip of the bracket 32. The bracket 32 ​​is provided with a biasing member 32a such as a leaf spring. The biasing member 32a abuts against the inner wall of the first housing part 40b and exerts a biasing force from the inside to the outside, thereby holding the earth brush 30 within the earth brush housing part 40.

[0053] One end 20a of the motor shaft 20 is supported by the first bearing portion 21a, and a rotor and a stator (not shown) are provided on the other side of the first bearing portion 21a. The other side of the motor shaft 20, which is opposite the rotor and stator, serves as the input shaft 61 of the reducer 6. The motor shaft 20 is supported by the second bearing portion 21b on the other side of the input shaft 61. An earth brush body 33 contacts the motor shaft 20 at the end 20b further on the other side of the second bearing portion 21b. The earth brush body 33 is positioned so as to be in direct contact with the outer circumferential surface of the motor shaft 20, thereby effectively neutralizing the motor shaft 20.

[0054] As described above, according to this embodiment, the reducer 6 is disposed behind the drive motor 5, the oil storage section 107 is disposed below the drive motor 5, and the power conversion unit 100 is disposed above the drive motor 5, so that a space can be secured in front of the motor shaft 20 that does not interfere with these peripheral components. With this configuration, the earth brush 30 can be disposed in a front location that is easy to service, and the earth brush 30 can be brought into direct contact with the motor shaft 20 to effectively neutralize static electricity. Furthermore, by abutting the earth brush 30 against the motor shaft 20 from the front and below, the earth brush 30 is less susceptible to the effects of dust.

[0055] Furthermore, in an electric vehicle having a drive motor 5, a reduction gear 6, a generator 7, and an engine body in this order in the vehicle width direction, an earth brush housing 40 is formed between the reduction gear housing 6a and the generator housing 7a, and the motor shaft 20 protrudes into the earth brush housing 40. The earth brush 30 can be brought into contact with the motor shaft 20 within the earth brush housing 40, which prevents oil used to lubricate the periphery of the motor shaft 20 from splashing onto the earth brush 30.

[0056] Furthermore, the earth brush 30 is positioned so as to overlap a portion of the reducer 6 when viewed from the front-to-rear direction of the vehicle, thereby shortening the length of the drive unit housing 9 in the vehicle width direction and making it possible to achieve a compact form. [Explanation of symbols]

[0057] 1 vehicle 5 Drive motor 5a Drive motor housing 6 Reducer 6a Reducer housing 7. Generator 7a Generator housing 8 Engine body 9 Drive unit housing 20 motor shaft 20c oil passage 20b Tip 22 Sealing material 30 Earth Brush 40 Earth brush storage compartment 50 Generator shaft 100 Power Conversion Unit 107 Oil storage section P Power Unit

Claims

1. a drive motor that uses electric power to rotate a motor shaft to drive the vehicle; a reducer disposed behind the drive motor and configured to reduce the speed of power from the drive motor before outputting the power; an oil storage section disposed below the drive motor; a power conversion unit disposed above the drive motor; an earth brush for neutralizing the motor shaft; The earth brush arrangement structure for an electric vehicle is characterized in that the earth brush abuts against the motor shaft from the front and below.

2. 2. The earth brush arrangement structure for an electric vehicle according to claim 1, the drive motor, the reduction gear, a generator that generates electric power to be supplied to the drive motor, and an engine that drives the generator are provided in this order in the vehicle width direction; an earth brush housing portion is formed between a reducer housing portion that houses the reducer and a generator housing portion that houses the generator; An earth brush arrangement structure for an electric vehicle, characterized in that the motor shaft passes through the reducer housing portion and protrudes into the earth brush housing portion.

3. 3. The earth brush arrangement structure for an electric vehicle according to claim 2, The earth brush arrangement structure for an electric vehicle is characterized in that the earth brush is arranged so as to overlap a part of the reducer when viewed in the front-rear direction of the vehicle.

4. 4. The earth brush arrangement structure for an electric vehicle according to claim 3, the motor shaft has an oil passage extending in the axial direction therein, and a tip end thereof is formed so as to reach from the reducer housing portion to the generator housing portion, the oil passage is configured to be able to supply oil to the generator housing portion from an opening provided at the tip portion, The earth brush arrangement structure for an electric vehicle is characterized in that a seal member is provided on the outer periphery of the motor shaft between the tip end portion and the earth brush housing portion.

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