Vehicle drive device

Abstract

The invention relates to a vehicle drive device. Disclosed is a drive device for a vehicle, which is provided with: a transmission mechanism that transmits a driving force from a driving source to a wheel via a shaft member; and a housing that accommodates at least a portion of the transmission mechanism and the shaft member. The housing includes: a gear housing portion that stores therein oil that can be raised by rotation of a gear of the transmission mechanism; a wall portion demarcating at least the lower side of the space around the shaft member and a wall portion extending in the extending direction of the shaft member communicate with the inside of the gear housing portion on one side of the space around the shaft member in the extending direction of the shaft member. The other side includes an object placement space in which an object to be lubricated lubricated by oil is placed or communicates with the object placement space, and the oil raised by the rotation of the gear of the transmission mechanism is supplied to the object to be lubricated in the space around the shaft member or is supplied to the object to be lubricated via the space around the shaft member.

Description

Technical Field

[0001] The invention relates to a vehicle driving device. Background Art

[0002] A technology is known in which a housing is formed with a first housing chamber for housing a rotating electrical machine and a second housing chamber for housing a transmission mechanism, and oil stored in the lower portion of the second housing chamber is lifted up by the rotation of gears of the transmission mechanism and supplied to various bearings of the transmission mechanism.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2021-112052

[0004] However, in the above-mentioned prior art, the oil stirred up by the rotation of the gears of the transmission mechanism cannot be used for lubrication of the ends of the shaft members (for example, the ends of the intermediate shaft connected to the differential gear mechanism away from the differential gear mechanism). Summary of the invention

[0005] Therefore, in one aspect, an object of the present invention is to supply oil kicked up by the rotation of the gears of the transmission mechanism to the end of the shaft member.

[0006] In one aspect, a vehicle drive device is provided, comprising: a transmission mechanism that transmits a driving force from a driving source to a wheel via a shaft component; and a housing that accommodates the transmission mechanism and at least a portion of the shaft component, the housing including: a gear housing portion that stores oil that can be lifted up by the rotation of the gears of the transmission mechanism; and a wall portion that delimits at least the lower side of a space around the shaft component and extends along an extension direction of the shaft component, the space around the shaft component being connected to the interior of the gear housing portion on one side in the extension direction of the shaft component, and the other side including an object configuration space for a lubricated object in which oil is configured or is connected to the object configuration space, the oil lifted up by the rotation of the gears of the transmission mechanism is supplied to the lubricated object in the space around the shaft component, or is supplied to the lubricated object via the space around the shaft component.

[0007] In one aspect, according to the present invention, oil stirred up by the rotation of the gear of the transmission mechanism can be supplied to the end of the shaft member. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a schematic plan view showing a state in which a vehicle drive device is mounted on a vehicle.

[0009] Figure 2 It is a cross-sectional view of a vehicle drive device.

[0010] Figure 2A It is a schematic diagram showing a vehicle drive device.

[0011] Figure 3 This is a side view schematically showing the vehicle drive device of this embodiment as viewed from the A1 side.

[0012] Figure 4 It is a perspective view of a flow path forming member.

[0013] Figure 5 yes Figure 2 An enlarged view of the Q6 section.

[0014] Figure 6 It is a side view schematically showing the vehicle drive device of this embodiment as viewed from the A2 side.

[0015] Figure 7 This is a perspective view schematically showing the vehicle drive device of this embodiment as viewed from the A2 side. DETAILED DESCRIPTION

[0016] Hereinafter, each embodiment will be described in detail with reference to the drawings. In addition, the dimensional ratios in the drawings are merely examples and are not limited thereto. In addition, for the convenience of description, the shapes and the like in the drawings may be partially exaggerated.

[0017] In the following description, the Y direction (refer to Figure 3 A, etc.) corresponds to the up-down direction in the use state of the vehicle drive device 100, that is, the up-down direction when the vehicle drive device 100 is arranged in its use state. Moreover, the Y1 side and the Y2 side correspond to the upper side and the lower side along the Y direction. In addition, the up-down direction does not necessarily need to be parallel to the vertical direction, as long as it mainly has a vertical direction component. In addition, the directions of the various components in the following description represent the directions in which they are assembled in the vehicle drive device 100. In addition, terms related to the size, configuration direction, configuration position, etc. of each component are concepts that include states with differences caused by errors (errors to an allowable degree in manufacturing). A direction (refer to Figure 2 etc.) corresponds to the axial direction. Figure 2 The A1 side and the A2 side along the A direction are defined in the above. Figure 3 etc.) is a direction orthogonal to both the A direction and the Y direction. Figure 3 The X1 side and the X2 side along the X direction are defined in FIG.

[0018] In this specification, "drive connection" refers to the state of connecting two rotating members in a manner that can transmit driving force (synonymous with torque), including the state of connecting the two rotating members in a manner that rotates as a whole, or the state of connecting the two rotating members in a manner that can transmit driving force via one or more transmission parts. Such transmission parts include various parts that transmit rotation at the same speed or at a variable speed (for example, shafts, gear mechanisms, belts, chains, etc.). In addition, as transmission parts, engaging devices that selectively transmit rotation and driving force (for example, friction engaging devices, meshing engaging devices, etc.) may also be included.

[0019] In addition, in this specification, "connected" refers to a state in which two space components are fluidically connected to each other. That is, it refers to a state in which a fluid can travel back and forth between the two space components. In this case, the two space components can be connected directly or indirectly (that is, via other space components).

[0020] In this specification, "rotating electric machine" is used as a concept including any one of a motor (electric motor), a generator (generator), and a motor / generator that performs the functions of both a motor and a generator as needed. In addition, in this specification, regarding the configuration of two components, "overlapping when viewed in a specific direction" means that when an imaginary straight line parallel to the line of sight is moved in directions orthogonal to the imaginary straight line, the area where the imaginary straight line intersects with both components at least partially exists. In addition, in this specification, regarding the configuration of two components, "overlapping of configuration areas in a specific direction" means that at least a part of the configuration area in a specific direction of one component is included in the configuration area in a specific direction of another component.

[0021] Figure 1 It is a schematic plan view showing a state in which the vehicle drive device 100 is mounted on the vehicle VC. Figure 2 It is a cross-sectional view of the vehicle drive device 100 . Figure 2A 1 is a schematic diagram showing a vehicle drive device 100 .

[0022] like Figure 2A As shown schematically, the vehicle drive device 100 includes a rotating electrical machine 1, and a pair of wheels W (see Figure 1) is connected to the rotating electrical machine 1 by a pair of output components 6, and a transmission mechanism 3 that transmits driving force between the rotating electrical machine 1 and the pair of output components 6. The vehicle drive device 100 also includes a housing 2 that accommodates the rotating electrical machine 1. The housing 2 also accommodates a pair of output components 6 and the transmission mechanism 3. In addition, in a modified example, the housing 2 may accommodate only one of the pair of output components 6 (for example, the first output component 61). In addition, as for the use of the vehicle drive device 100, it can be applied to any vehicle having a rotating electrical machine 1, such as an electric vehicle or a hybrid vehicle, and can also be applied to any vehicle whose driving mode is front-wheel drive, rear-wheel drive, etc. In addition, the driving source may also be only an engine (internal combustion engine).

[0023] The first output member 61 as one of the pair of output members 6 is drivingly connected to the first wheel W1 as one of the pair of wheels W, and the second output member 62 as the other of the pair of output members 6 is drivingly connected to the second wheel W2 as the other of the pair of wheels W. Figure 1 As shown, the vehicle VC equipped with the vehicle drive device 100 includes a first drive shaft 63 that rotates integrally with the first wheel W1, and a second drive shaft 64 that rotates integrally with the second wheel W2. The first drive shaft 63 is connected to the first wheel W1 via a constant velocity coupling, for example, and the second drive shaft 64 is connected to the second wheel W2 via a constant velocity coupling, for example. Moreover, the first output member 61 is connected to the first drive shaft 63 in a manner that it rotates integrally with the first drive shaft 63, and the second output member 62 is connected to the second drive shaft 64 in a manner that it rotates integrally with the second drive shaft 64. In addition, the first output member 61 may be in the form of an intermediate shaft. The first output member 61 is supported by the housing 2 via a bearing BR1 on the axial A2 side so as to be rotatable, and is supported by the housing 2 via a bearing BR2 on the axial A1 side so as to be rotatable. In addition, in this embodiment, as an example, the bearings BR1 and BR2 are in the form of ball bearings, but they may also be in other forms.

[0024] The vehicle drive device 100 transmits the output torque of the rotary electric machine 1 to a pair of wheels W via a pair of output members 6, so that the vehicle VC equipped with the vehicle drive device 100 travels. That is, the rotary electric machine 1 is a driving force source for the pair of wheels W. The pair of wheels W is a pair of left and right wheels of the vehicle VC (for example, a pair of left and right front wheels or a pair of left and right rear wheels). The rotary electric machine 1 can be, for example, an AC rotary electric machine driven by a three-phase AC.

[0025] like Figure 2As shown, the rotating electric machine 1 and the pair of output members 6 are separately arranged on two axes parallel to each other (specifically, the first axis C1 and the second axis C2). Specifically, the rotating electric machine 1 is arranged on the first axis C1, and the pair of output members 6 are arranged on the second axis C2 different from the first axis C1. The first axis C1 and the second axis C2 are axes (imaginary axes) arranged parallel to each other. The transmission mechanism 3 has an output gear (ring gear) 30 drivingly connected to at least one of the pair of output members 6, and the output gear 30 is coaxial with the pair of output members 6 (that is, on the second axis C2).

[0026] The rotating electrical machine 1 is, for example, an inner rotor type. The rotating electrical machine 1 has a stator 11 (see Figure 2 ) is arranged radially inside the rotor 14 which can rotate around the first axis C1.

[0027] The transmission mechanism 3 has a reduction mechanism 34 in the power transmission path between the rotating motor 1 and the output gear 30. The reduction mechanism 34 is arbitrary and may include a reduction mechanism using a counter gear, a reduction mechanism using a planetary gear, etc. In the present embodiment, as an example, the reduction mechanism 34 includes a planetary gear mechanism, and the reduction mechanism 34 is coaxially arranged with the rotating motor 1. The output gear (planetary carrier) 342 of the reduction mechanism 34 is radially meshed with the output gear 30 of the differential gear mechanism 5. Such a vehicle drive device 100 can have a compact structure consisting of two shafts (a first shaft C1 and a second shaft C2). In addition, in a modified example, the vehicle drive device 100 may also have more than three shafts.

[0028] In this embodiment, the speed reduction mechanism 34 is arranged coaxially with the rotating electrical machine 1 (i.e., on the first axis C1) in a manner drivingly connected to the rotating electrical machine 1. In this embodiment, as an example, the rotor 14 of the rotating electrical machine 1 rotates integrally with the input member 16 together with the sun gear 341 of the speed reduction mechanism 34.

[0029] The transmission mechanism 3 also includes a differential gear mechanism 5. The differential gear mechanism 5 distributes the driving force transmitted from the rotating electrical machine 1 to a pair of output members 6. Figure 2 In the example shown, the differential gear mechanism 5 distributes the rotation of the output gear 30 to the first side gear 51 and the second side gear 52. The differential gear mechanism 5 can be arranged coaxially (i.e., on the second axis C2) with the pair of output members 6. In addition, the differential gear mechanism 5 can be a bevel gear type differential gear mechanism, and the output gear 30 is connected to the differential case portion 50 provided in the differential gear mechanism 5 in a manner that the output gear 30 rotates integrally with the differential case portion 50.

[0030] Next, refer to Figure 3 The following drawings illustrate the water cooling structure of the rotary electric machine 1 of the present embodiment and its related structural components (flow path forming member 90 ) and the like.

[0031] Figure 3 FIG. 1 is a side view schematically showing the vehicle drive device 100 of this embodiment. Figure 3 In order to make the state in the motor housing chamber S1 clear, the motor cover member 201 is omitted from the illustration. Figure 3 In FIG. 2 , the inverter device 70 inside the inverter housing portion 24 is schematically shown by a dotted line. Figure 4 It is a perspective view of the flow path forming member 90 .

[0032] The water cooling structure of the rotating electric machine 1 of the present embodiment is a structure for cooling the rotating electric machine 1 by cooling water. In addition, the cooling water may be, for example, water containing LLC: Long Life Coolant (long-term coolant), which may be circulated by a water pump (not shown). In addition, a heat dissipation unit such as a radiator (not shown) may be provided in the circulation path of the cooling water. In addition, the cooling water may be used not only for cooling the rotating electric machine 1, but also for cooling other structural members, such as an inverter (not shown) electrically connected to the rotating electric machine 1.

[0033] The water cooling structure of the rotating electrical machine 1 of the present embodiment includes a coolant supply portion 40 , a coolant discharge portion 42 , and a flow path forming member 90 .

[0034] The refrigerant supply unit 40 communicates with, for example, a discharge side of a water pump (not shown), and supplies cooling water to the refrigerant flow path 300 formed by the flow path forming member 90 .

[0035] The coolant discharge portion 42 communicates with, for example, a suction side of a water pump (not shown), and supplies (discharges) cooling water from the coolant flow path 300 formed by the flow path forming member 90 to the water pump (not shown).

[0036] The refrigerant supply unit 40 and the refrigerant discharge unit 42 may be provided on the upper and lower sides respectively with the first output member 61 interposed therebetween. In this case, the refrigerant supply unit 40 and the refrigerant discharge unit 42 can be established by effectively utilizing the space around the first output member 61.

[0037] like Figure 4 As shown in FIG. 1 , the flow path forming member 90 is a cylindrical member having an inner peripheral surface radially opposed to the outer peripheral surface of the rotating electrical machine 1. The flow path forming member 90 forms a refrigerant flow path 300 around the rotating electrical machine 1. Figure 4 In the illustrated example, the refrigerant flow path 300 includes a plurality of flow path portions SC1 to SC4 in the circumferential direction, but the structure of the refrigerant flow path 300 is arbitrary.

[0038] The flow path forming member 90 can be formed of a material having good thermal conductivity, such as aluminum. In the present embodiment, as an example, the flow path forming member 90 is embedded in the stator core 12 of the stator 11 by, for example, sintering. In other embodiments, the flow path forming member 90 can also be formed integrally with the stator core 12 by casting or the like.

[0039] In this embodiment, as an example, the flow path forming member 90 is as follows Figure 3 As shown, it is a form of an inner shell fastened to the shell 2. In this case, as Figure 3 As shown, the flow path forming member 90 may have a plurality of fastening portions 500 at one axial end. The plurality of fastening portions 500 are fastened to the housing 2 by bolts (not shown) (see bolt holes BT4). In addition, in a modified example, the flow path forming member 90 may also be formed as a part of the housing 2.

[0040] The flow path forming member 90 is inserted into the cylindrical space of the housing 2. At this time, the outer peripheral surface of the flow path forming member 90 is opposite to the inner peripheral surface of the housing 2 (the inner peripheral surface bounded by the plurality of fastening portions 500) in the radial direction. In addition, hereinafter, the inner peripheral surface of the housing 2 surrounding the flow path forming member 90 is also referred to as the "flow path forming surface 209 of the housing 2" (refer to Figure 5 ). In addition, the inner diameter of the flow path forming surface 209 of the housing 2 may be a constant value larger than the basic outer diameter of the stator core 12 by the basic thickness of the flow path forming member 90 .

[0041] The flow path forming member 90 cooperates with the flow path forming surface 209 of the housing 2 to form the refrigerant flow path 300. Specifically, the refrigerant flow path 300 is formed between the outer peripheral surface of the flow path forming member 90 and the flow path forming surface 209 of the housing 2 in the radial direction.

[0042] The refrigerant flow path 300 may extend in the circumferential direction in such a manner that cooling water flows in the circumferential direction throughout the entire circumference. In addition, the refrigerant flow path 300 may also be formed to extend throughout the entire axial direction of the stator core 12 of the rotating electrical machine 1 and to be radially opposed to the outer peripheral surface of the stator core 12. In addition, the refrigerant flow path 300 is closed at both axial ends. For example, a sealing member 97 may be provided between the flow path forming member 90 and the flow path forming surface 209 of the housing 2, at both axial ends of the flow path forming member 90 throughout the entire circumference (see Figure 5 ).

[0043] Next, refer to Figure 5The following figures illustrate the oil circuit structure of the vehicle drive device 100 of this embodiment and the structural components related thereto. The various oil circuits of the oil circuit structure described below are formed by the housing 2 unless otherwise specified. In this specification, the various oil circuits formed by the housing 2 are not only oil circuits formed by the housing 2 alone, but also include the concept of oil circuits formed by the combination of the housing 2 and other structural components (structural components other than the housing 2). In addition, a storage chamber such as the output shaft storage chamber S3 also constitutes an oil circuit.

[0044] Here, first refer to Figure 2 After describing the structure of the housing 2, refer to Figure 5 The following figures illustrate the oil circuit structure.

[0045] In this embodiment, the housing 2 includes a motor housing portion 21, a transmission mechanism housing portion 22, an output shaft housing portion 23, and an inverter housing portion 24 in an integrated form. Here, the "integrated form" includes a form integrated by fastening components such as bolts, and a form integrated by integral molding (for example, casting, casting using aluminum plating, etc.).

[0046] The motor housing portion 21 forms a motor housing chamber S1 for housing the rotating electrical machine 1, the transmission mechanism housing portion 22 forms a transmission mechanism housing chamber S2 for housing the transmission mechanism 3, the output shaft housing portion 23 forms an output shaft housing chamber S3 for housing the first output member 61, and the inverter housing portion 24 forms an inverter housing chamber S4 for housing the inverter device 70. In addition, the motor housing portion 21 forms the motor housing chamber S1, which means that the wall portion that delimits the motor housing chamber S1 forms the motor housing portion 21. This is also the same for the transmission mechanism housing portion 22, the output shaft housing portion 23, and the inverter housing portion 24.

[0047] The motor housing 21 is a cylindrical shape corresponding to the outer shape of the rotating electrical machine 1. However, the motor housing 21 does not need to close all the cylindrical outer peripheral portions. For example, the motor housing chamber S1 and the output shaft housing chamber S3 may also be connected. In this case, the side of the motor housing 21 opposite to the output shaft housing chamber S3 may not form a wall portion (partition wall portion).

[0048] The transmission mechanism housing portion 22 is disposed on the axial direction A2 side relative to the motor housing portion 21 and the output shaft housing portion 23. The output shaft housing portion 23 is disposed on the X direction X2 side relative to the motor housing portion 21. The inverter housing portion 24 is disposed on the upper side of the transmission mechanism housing portion 22 and the output shaft housing portion 23. The details of the inverter housing portion 24 will be described later.

[0049] In this embodiment, since the output shaft housing portion 23 is provided, the first output member 61 can be effectively protected from the external environment (for example, flying stones, etc.) compared to the case where the first output member 61 is arranged outside the housing 2. In addition, the gap to be ensured between the first output member 61 and the surrounding components can be reduced. However, in a modified example, the first output member 61 can also be arranged outside the housing 2.

[0050] In addition, the housing 2 can be formed by joining multiple parts (housing parts, cover parts). Therefore, one housing part forming the housing 2 often forms two or more housing parts among the motor housing part 21, the transmission mechanism housing part 22, the output shaft housing part 23 and the inverter housing part 24.

[0051] In addition, the motor storage chamber S1, the transmission mechanism storage chamber S2, the output shaft storage chamber S3, and the inverter storage chamber S4 formed by the housing 2 can be completely isolated from each other, can be partially connected, or can be shared in a manner without having boundaries. For example, the motor storage chamber S1 and the output shaft storage chamber S3 can also be shared in a manner without having a partition separating each other. In this case, the rotating electric machine 1 and the first output component 61 are stored in a common storage chamber formed by the housing 2 (specifically, the motor storage chamber S1 and the output shaft storage chamber S3). In addition, when the rotating electric machine 1 is oil-cooled, the motor storage chamber S1 and the inverter storage chamber S4 can be separated, but when the rotating electric machine 1 is completely water-cooled, the motor storage chamber S1 and the inverter storage chamber S4 may not be separated.

[0052] In the following description, as an example, the case member 200, the motor cover member 201, the differential cover member 202, and the inverter cover member 203 are joined to form the case 2. The joining method may be fastening with bolts or the like.

[0053] The housing member 200 may be formed as a single member (for example, a single member formed by die casting and made of the same material). In this case, the motor housing chamber S1 and the transmission mechanism housing chamber S2 may be partitioned by a single partition wall 26 .

[0054] The housing member 200 is opened in the axial direction on the axial direction A1 side, and is opened in the axial direction on the axial direction A2 side.

[0055] The motor cover member 201 is provided to cover the opening on the axial A1 side of the housing member 200 (i.e., the opening on the axial A1 side of the motor housing chamber S1). The motor cover member 201 may be formed as a single piece. The motor cover member 201 may be joined to an end face (joining face) on the axial A1 side of the housing member 200. In this case, the joining face (matching face) 221 between the motor cover member 201 and the housing member 200 may extend in a plane perpendicular to the axial direction.

[0056] The differential cover member 202 is provided to cover the opening on the axial A2 side of the housing member 200 (i.e., the opening on the axial A2 side of the transmission mechanism storage chamber S2). The differential cover member 202 may be formed as a single member. The differential cover member 202 may be joined to the end face (joining face) on the axial A2 side of the housing member 200. In this case, the joint face (matching face) 222 between the differential cover member 202 and the housing member 200 may extend in a plane perpendicular to the axial direction.

[0057] The inverter cover member 203 is provided to cover the opening of the inverter housing chamber S4 of the housing member 200. The inverter cover member 203 may be formed as a one-piece member.

[0058] The inverter device 70 may be in the form of a module, or may be fixed to a wall portion forming the inverter housing portion 24 by bolts or the like. The inverter device 70 includes a plurality of switching elements (power semiconductor elements, not shown) constituting an inverter circuit, a control substrate (not shown) on which a control device for controlling the inverter circuit is mounted, a smoothing capacitor, and the like.

[0059] Figure 5 is a cross-sectional view of a plane passing through the second axis C2 and the Y direction, Figure 2 An enlarged view of the Q6 portion (a cross-sectional view through the output shaft accommodation chamber S3). Figure 6 It is a side view schematically showing the vehicle drive device 100 of the present embodiment as viewed from the A2 side. Figure 7 This is a perspective view schematically showing the vehicle drive device 100 of this embodiment as viewed from the A2 side. Figure 6 as well as Figure 7 In order to clarify the state in the transmission mechanism accommodation chamber S2, the differential cover member 202 is omitted from the illustration.

[0060] In addition, as described above, the transmission mechanism storage chamber S2 and the output shaft storage chamber S3 overlap with the second axis C2 in a plan view and are adjacent in the axial direction. In addition, the transmission mechanism storage chamber S2 extends in the X direction in a manner to store the speed reduction mechanism 34 and the differential gear mechanism 5, so the transmission mechanism storage chamber S2 and the output shaft storage chamber S3 extend in an L shape in a plan view. Hereinafter, the portion of the transmission mechanism storage chamber S2 that stores the speed reduction mechanism 34 is also referred to as the "speed reduction mechanism storage chamber S21", and the portion that stores the differential gear mechanism 5 is also referred to as the "differential gear storage chamber S22".

[0061] The output shaft housing portion 23 extends along the extension direction (i.e., axial direction) of the first output member 61 and around the second axis C2. The output shaft housing portion 23 may be in the form of a peripheral wall portion that forms a space S33 (a space including the output shaft storage chamber S3) around the first output member 61. In this case, the space S33 (a space including the output shaft storage chamber S3) around the first output member 61 includes an annular space portion around the first output member 61 when viewed along the axial direction A. In addition, in this case, the output shaft housing portion 23 may extend radially outward (X direction X2 side) of the rotary electric machine 1, and also form a part of the motor housing portion 21.

[0062] In the present embodiment, the axial A2 side of the output shaft housing chamber S3 is connected to the transmission mechanism housing chamber S2 (particularly the differential gear housing chamber S22). In addition, an oil-lubricated object is arranged on the axial A1 side of the output shaft housing chamber S3. That is, the end of the axial A1 side of the output shaft housing chamber S3 is connected to the space S31 in which the oil-lubricated object is arranged. The space S31 can be formed by the motor cover component 201. In this case, the space S33 around the first output component 61 continuously forms the output shaft housing chamber S3 and the space S31 in the axial direction. In the present embodiment, the oil-lubricated object includes a bearing BR2 and an oil seal 700. The oil seal 700 is arranged at the A1 side end of the first output component 61 to oil-tightly seal the first output component 61 and the housing 2. In addition, in a modified example, the output shaft housing chamber S3 may be replaced with the space S31 in which the bearing BR2 and the oil seal 700 are arranged, and the end portion on the axial A1 side may include the space S31 (the space in which the bearing BR2 and the oil seal 700 are arranged). In this case, the space S33 around the first output member 61 is constituted by the output shaft housing chamber S3.

[0063] In this embodiment, the oil is not circulated in the vehicle drive device 100 by a so-called forced lubrication method using an oil pump (mechanical or electric oil pump), but by a lubrication method (natural lubrication method) in which the oil is lifted up by the rotation of the gears and lubricated. However, in a modified example, an oil pump may be used simultaneously for part of the lubrication.

[0064] Specifically, in the present embodiment, a lubrication method is adopted in which various lubrication objects are lifted up and lubricated by the rotation of the output gear 30 (so-called differential ring) of the differential gear mechanism 5 .

[0065] As described above, according to the present embodiment, in the vehicle drive device 100 , by adopting such a natural lubrication method, it is possible to achieve cost reduction and size reduction due to not using an oil pump.

[0066] On the other hand, in order to properly supply oil to the bearing BR2 and the oil seal 700 by natural lubrication, the necessity of increasing the oil level or setting additional components such as an oil collecting tank is likely to increase. In addition, in order to increase the oil level, the required amount of oil increases, resulting in increased costs.

[0067] Therefore, in the present embodiment, the surface 231 of the output shaft housing portion 23 (hereinafter also referred to as “the inner peripheral surface of the peripheral wall 231”) facing the first output member 61 is Figure 5 ) and the outer peripheral surface of the first output member 61 are configured to extend in the axial direction A1 side at a position lower than in the axial direction A2 side.

[0068] Specifically, the inner peripheral surface 231 of the peripheral wall includes an inclined surface that forms a step difference between the axial A1 side and the axial A2 side. Such an inclined surface can be achieved by making the inner diameter of the inner peripheral surface 231 of the peripheral wall (the inner diameter around the first axis C1) increase as it moves toward the axial A1 side. However, in other embodiments, a step may be formed instead of or in addition to the inclined surface. In this case, the step may also be formed in a manner that the inner diameter of the inner peripheral surface 231 of the peripheral wall (the inner diameter around the first axis C1) gradually increases as it moves toward the axial A1 side.

[0069] In addition, the outer peripheral surface of the first output member 61 also includes an inclined surface that forms a step difference between the axial A1 side and the axial A2 side. Such an inclined surface can be realized by making the outer diameter of the outer peripheral surface of the first output member 61 (the outer diameter around the first axis C1) increase toward the axial A1 side. In this case, the outer diameter of the outer peripheral surface of the first output member 61 can be a constant value relative to the inner diameter of the peripheral wall inner peripheral surface 231 at each position along the axial direction. However, in other embodiments, a step can be formed instead of or in addition to the inclined surface.

[0070] Such an inner peripheral surface 231 of the peripheral wall and the outer peripheral surface of the first output member 61 can have the following function, that is, by the action of gravity, the oil supplied from the axial direction A2 side by the rotation of the output gear 30 of the differential gear mechanism 5 can flow toward the axial direction A1 side at a relatively large flow rate along the inclined surface. Specifically, the oil supplied from the axial direction A2 side by the rotation of the output gear 30 of the differential gear mechanism 5 (see Figure 5 After falling on the surface of the first output member 61, the liquid flows along the surface of the first output member 61 toward the axial direction A1 side (refer to Figure 5 At this time, the inclination of the surface of the first output member 61 promotes the flow of oil to the axial direction A1 side. In addition, the oil supplied from the axial direction A2 side by the rotation of the output gear 30 of the differential gear mechanism 5 (refer to Figure 5The oil then flows along the surface of the inner peripheral surface 231 of the peripheral wall, which is facing upward, toward the axial direction A1 (see arrow R61). Figure 5 At this time, the inclination of the inner peripheral surface 231 of the peripheral wall promotes the flow of oil toward the axial direction A1. As a result, oil can be supplied at an appropriate flow rate to the A1 side end of the first output member 61 or the lubricated object (bearing BR2, oil seal 700) disposed near the end.

[0071] Thus, according to the present embodiment, the oil raised by the rotation of the output gear 30 of the differential gear mechanism 5 can be appropriately supplied to the lubricated object (bearing BR2, oil seal 700) without providing additional components such as an oil collecting tank. Therefore, it is possible to achieve miniaturization and cost reduction by natural lubrication, and it is possible to appropriately supply oil to the lubricated object (bearing BR2, oil seal 700) located at a relatively far position from the output gear 30 of the differential gear mechanism 5 in the axial direction.

[0072] However, in order to supply oil at an appropriate flow rate to the lubricated objects (bearing BR2, oil seal 700), it is useful to introduce the oil stirred up by the rotation of the output gear 30 of the differential gear mechanism 5 into the output shaft accommodation chamber S3 from the axial direction A2 side at an appropriate flow rate.

[0073] Therefore, in this embodiment, a portion of the transmission mechanism housing portion 22 located at the boundary with the output shaft housing portion 23 in the axial direction (hereinafter also referred to as “bearing support portion 223”) has a cavity portion S223 (see Figure 5 ). In addition, the bearing support portion 223 is a portion located around the bearing BR1 and supporting the bearing BR1. In this case, the cavity portion S223 can be formed radially outside the bearing BR1 and at a height where the oil lifted by the rotation of the output gear 30 of the differential gear mechanism 5 is applied. In addition, two or more cavity portions S223 can be provided around the bearing BR1, for example, directly above in the up-down direction (the 12 o'clock position) and at a position lower than directly above (for example, the 11 o'clock position).

[0074] By providing such a cavity portion S223, the oil stirred up by the rotation of the output gear 30 of the differential gear mechanism 5 can be introduced into the output shaft storage chamber S3 from the axial direction A2 side at an appropriate flow rate. In addition, the oil stirred up by the rotation of the output gear 30 of the differential gear mechanism 5 can be directly introduced into the cavity portion S223. Therefore, it can be introduced into the output shaft storage chamber S3 from the axial direction A2 side at an appropriate flow rate without providing additional components such as an oil collecting tank.

[0075] In this embodiment, the motor housing chamber S1 and the output shaft housing chamber S3 (see Figure 2 as well as Figure 5 ) and used for lubrication etc., is supplied through a return flow path 290 (see Figure 3 ) returns to the transmission mechanism storage chamber S2 (especially the differential gear storage chamber S22).

[0076] The A2 side end of the return flow path 290 opens to the differential gear housing chamber S22, and the A1 side end communicates with the output shaft housing chamber S3. The output shaft housing portion 23 may have an opening or cutout 99 (see FIG. 1 ) for ensuring communication between the output shaft housing chamber S3 and the return flow path 290. Figure 3 ). Thus, the oil can be efficiently introduced from the output shaft accommodation chamber S3 to the return flow path 290.

[0077] Next, the main reference Figure 6 The structure in the transmission mechanism accommodation chamber S2 among the oil path structures will be mainly described.

[0078] In the present embodiment, as described above, since the natural lubrication method is adopted, it is useful to return the oil used for lubricating various lubricated objects to the lower part of the differential gear storage chamber S22 (the oil reservoir for the output gear 30 to be immersed) relatively quickly. For example, in the case where the return flow path such as the above-mentioned return flow path 290 is opened in the reduction mechanism storage chamber S21 outside the differential gear storage chamber S22 in the transmission mechanism storage chamber S2, the oil returning to the lower part of the differential gear storage chamber S22 via the return flow path is likely to be insufficient. In this case, there is a concern that the oil temperature sensor is not immersed in the oil due to the driving state of the vehicle, and the internal air temperature is measured. In order to avoid the above-mentioned undesirable situation, although the overall oil volume can be increased, in this case, the cost increase caused by the increase in the oil volume and the increase in the stirring loss caused by the rise in the oil level in the quiet state (stirring loss of the output gear 30) may become a problem.

[0079] Therefore, in this embodiment, the return flow path 290 opens at the lower part (lower than the second axis C2) of the differential gear storage chamber S22 in the transmission mechanism storage chamber S2. At this time, the end of the return flow path 290 on the axial A2 side (the opening on the differential gear storage chamber S22 side) preferably overlaps with the output gear 30 when viewed along the axial direction. As a result, the oil used for lubricating various lubricating objects including the above-mentioned bearing BR2, oil seal 700, etc. can be relatively quickly returned to the lower part of the differential gear storage chamber S22 (the oil reservoir for the output gear 30 to be immersed).

[0080] In this embodiment, as described above, the flow path forming member 90 is provided on the radially outer side of the rotating electric machine 1. The radially inner side of the flow path forming member 90 is engaged with the stator core 12, and the radially outer side is sealed on both sides of the axial direction relative to the flow path forming surface 209 of the housing 2. That is, the flow path forming member 90 is provided to separate the space S11 (refer to FIG. 1 ) where the coil end 13 on the axial A2 side (in this embodiment, the coil end 13 on the lead side) in the motor housing chamber S1 is located. Figure 2 ), and the space S12 where the coil end 13 on the axial direction A1 side is located (refer to Figure 2 Therefore, the space S11 (refer to Figure 2 ), and the space S12 where the coil end 13 on the axial direction A1 side is located (refer to Figure 2 ) is not actually connected between the above-mentioned axial directions. Therefore, the oil sprayed toward each coil end 13 through the axial oil passage 15a of the rotor shaft 15 and the radial spray hole 15b of the rotor shaft 15 (the oil sprayed by the centrifugal force when the rotor rotates) cannot return to the transmission mechanism storage chamber S2 through only one return flow passage. Specifically, the oil sprayed toward the coil end 13 in the space S12 can be returned to the transmission mechanism storage chamber S2 through the connection between the space S12 and the output shaft storage chamber S3 (refer to Figure 2 ), and returns to the transmission mechanism storage chamber S2 (especially the differential gear storage chamber S22) through the above-mentioned return flow path 290. On the other hand, the oil injected into the coil end 13 in the space S11 cannot actually return to the transmission mechanism storage chamber S2 (especially the differential gear storage chamber S22) through the above-mentioned return flow path 290.

[0081] Therefore, in this embodiment, as a second return flow path, a return flow path 292 is provided to connect the space S11 with the transmission mechanism storage chamber S2. Specifically, the end of the return flow path 292 on the axial A1 side is connected to the space S11 of the motor storage chamber S1, and the end of the return flow path 292 on the axial A2 side is connected to the lower part of the transmission mechanism storage chamber S2. In this embodiment, the end of the return flow path 292 on the axial A2 side opens at the lower part of the speed reduction mechanism storage chamber S21 (lower than the first axis C1). At this time, the end of the return flow path 292 on the axial A2 side (the opening on the speed reduction mechanism storage chamber S21 side) is preferably opened at the lower side than the second axis C2. Thus, the oil used for cooling the coil end 13 in the above-mentioned space S11 can be returned to the lower part (the oil reservoir for the output gear 30 to be immersed) in the differential gear storage chamber S22 via the speed reduction mechanism storage chamber S21. In other words, a water cooling structure based on the flow path forming member 90 can be realized around the stator core 12, and the oil supplied into the motor housing chamber S1 can be efficiently returned to the lower part of the differential gear housing chamber S22 (the oil reservoir into which the output gear 30 is immersed).

[0082] In addition, in the present embodiment, the end portion of the return flow path 292 on the axial direction A2 side (the opening on the speed reduction mechanism accommodation chamber S21 side) is arranged in the oil collecting tank 920 in the speed reduction mechanism accommodation chamber S21.

[0083] like Figure 6 As shown, the oil collecting tank 920 extends radially outward of the axial wall portion 9201 around the speed reduction mechanism 34 in the speed reduction mechanism storage chamber S21, and has an inlet 921 at a position where the oil raised by the rotation of the output gear 30 can be captured. In addition, the oil collecting tank 920 has a discharge port 922 opened in the differential gear storage chamber S22 at the lower part. In this case, the end of the return flow path 292 on the axial A2 side (the opening on the speed reduction mechanism storage chamber S21 side) can also be set near the discharge port 922. As a result, the oil used for cooling the coil end 13 in the above-mentioned space S11 can be relatively quickly returned to the lower part of the differential gear storage chamber S22 (the oil reservoir for the output gear 30 to be immersed) through the lower part of the oil collecting tank 920. In addition, the oil collecting tank 920 can also be connected to the axial oil passage 15a of the rotor shaft 15 in a manner that supplies oil to the axial oil passage 15a of the rotor shaft 15.

[0084] In addition, in a modified example, the return flow path 292 may be connected to the return flow path 290. For example, the return flow path 292 may be formed as a flow path that connects the space S11 and the return flow path 290. In this case, the length of the return flow path as a whole can be reduced, and an efficient return flow path structure can be realized.

[0085] An oil temperature sensor 98 is provided at the lower part of the oil collecting tank 920 (at Figure 6 In this case, the oil temperature sensor 98 is disposed near the discharge port 922 of the oil collecting tank 920. Thus, even when the vehicle is running, the possibility of the oil temperature sensor 98 being above the oil level can be reduced, so the reliability of the sensor information from the oil temperature sensor 98 can be improved.

[0086] Thus, in this embodiment, as described above, the oil lifted by the rotation of the output gear 30 of the differential gear mechanism 5 is introduced from the transmission mechanism storage chamber S2 to the output shaft storage chamber S3 via the cavity portion S223 located above the second axis C2. Furthermore, after the oil flows downward due to gravity and lubricates the bearing BR2 and the like, it returns from the output shaft storage chamber S3 to the differential gear storage chamber S22 via the end of the return flow path 290 located below the second axis C2 (the end on the axial direction A2 side). Thus, the oil can be lifted again by the rotation of the output gear 30 of the differential gear mechanism 5.

[0087] In addition, the oil raised by the rotation of the output gear 30 of the differential gear mechanism 5 is introduced into the axial oil passage 15a of the rotor shaft 15 through the oil collecting tank 920, and is ejected from the ejection hole 15b to the coil end 13 of the rotary electric machine 1 as described above. Furthermore, the oil ejected to the coil end 13 in the space S12 of the motor housing chamber S1 returns from the space S12 to the transmission mechanism housing chamber S2 through the end of the return flow passage 290 (the end on the axial direction A2 side) located below the second axis C2. In addition, the oil ejected to the coil end 13 in the space S11 of the motor housing chamber S1 returns from the space S11 to the transmission mechanism housing chamber S2 through the end of the return flow passage 292 (the end on the axial direction A2 side) located below the second axis C2. The oil thus returned to the transmission mechanism housing chamber S2 returns to the differential gear housing chamber S22 from the discharge port 922 located below the second axis C2 in the oil collecting tank 920. Thereby, it is possible to lift up again by the rotation of the output gear 30 of the differential gear mechanism 5 .

[0088] Although each embodiment is described in detail above, it is not limited to a specific embodiment, and various modifications and changes can be made within the scope of the technical claims. In addition, all or a plurality of the structural components of the above-mentioned embodiments can also be combined.

[0089] For example, in the above embodiment, both the surface of the output shaft housing portion 23 (the inner peripheral surface 231 of the peripheral wall) facing the first output member 61 and the outer peripheral surface of the first output member 61 have inclined surfaces, but the present invention is not limited thereto. For example, only the inner peripheral surface 231 of the peripheral wall may have an inclined surface.

[0090] In addition, in the above embodiment, the output shaft housing portion 23 is in the form of a peripheral wall portion surrounding the first output member 61 in at least a portion of the axial direction of the first output member 61, but the present invention is not limited thereto. For example, the output shaft housing portion 23 may be opposed to only a portion of the periphery of the first output member 61, including the lower side.

[0091] Description of Reference Numerals

[0092] 100…vehicle drive device, 1…rotating electric machine (drive source), 2…housing, 22…transmission mechanism housing portion (gear housing portion), 23…output shaft housing portion (wall portion, peripheral wall portion), 231…inner peripheral surface of the peripheral wall (surface of the wall portion), 290…return flow path (connecting path), 34…reduction mechanism (transmission mechanism), 30…output gear (ring gear), 5…differential gear mechanism (transmission mechanism), 61…first output component (shaft component), 99…opening or notch, BR1…bearing (first bearing), BR2…bearing (second bearing), S223…cavity portion, S31…space (object configuration space), W…wheel.

Claims

1. A vehicle drive device, wherein: have: a transmission mechanism that transmits the driving force from the driving source to the wheels via the shaft member; and a housing that accommodates the transmission mechanism and at least a portion of the shaft member; The housing comprises: a gear housing portion that stores oil that can be stirred up by the rotation of the gears of the transmission mechanism; and a wall portion which delimits at least the lower side of the space around the shaft member and extends along the extending direction of the shaft member, The space around the shaft member has one side in the extending direction of the shaft member connected to the interior of the gear housing portion, and the other side includes an object arrangement space for lubricating an object arranged with oil or is connected to the object arrangement space. The oil stirred up by the rotation of the gear of the transmission mechanism is supplied to the lubricated object in the space around the shaft member, or is supplied to the lubricated object via the space around the shaft member.

2. The vehicle drive device according to claim 1, wherein: A surface of the wall portion facing the lower side of the shaft member or an outer peripheral surface of the shaft member on the other side in the extending direction of the shaft member is lower than a height of the one side.

3. The vehicle drive device according to claim 2, wherein: The surface of the wall portion or the outer peripheral surface of the shaft member includes an inclined surface or a step forming a step difference between the other side and the one side.

4. The vehicle drive device according to claim 1, wherein: The one side of the shaft member in the extending direction is supported by the housing via a first bearing. The housing has a hollow portion that allows a space around the shaft member to communicate with an interior of the gear housing portion, located radially outside the first bearing and above an axial center of the shaft member.

5. The vehicle drive device according to claim 1, wherein: The other side of the shaft member in the extending direction is supported by the housing via a second bearing. The object to be lubricated includes the second bearing.

6. The vehicle drive device according to claim 1, wherein: The housing has a communication path for returning the oil used for lubricating the lubricated object to the interior of the gear housing portion. The wall portion has a hole or a notch that allows the object placement space to communicate with the communication path.

7. The vehicle drive device according to claim 1, wherein: It also includes a rotating electric machine forming the above-mentioned drive source, The transmission mechanism includes a speed reduction mechanism and a differential gear mechanism. The housing accommodates the rotating electrical machine, the speed reduction mechanism, the differential gear mechanism, and the shaft member. The gear is the ring gear of the differential gear mechanism. The wall portion extends radially outward of the rotating electrical machine.

8. The vehicle drive device according to any one of claims 1 to 6, wherein: The wall portion has a peripheral wall portion that delimits a space around the shaft member over the entire circumference in at least a portion of the region in the extending direction of the shaft member. The inner diameter of the peripheral wall portion and the outer diameter of the shaft member increase from the one side toward the other side in the extending direction of the shaft member.

Images