JP2024090826A - Vehicle drive device - Google Patents

Abstract

[Problem] To prevent an increase in size of a vehicle drive device, while suppressing adhesion of foreign matter such as dust generated by operation of a parking lock mechanism to electrical components such as a rotating electric machine. [Solution] A parking lock mechanism 6 includes a parking gear 6G that rotates integrally with a target rotating body, which is a rotating body constituting a power transmission mechanism 3 or a differential gear mechanism 5, and an engagement mechanism 6K that restricts rotation of the parking gear 6G by engaging with the parking gear 6G, and the parking gear 6G is disposed adjacent to a first axial side L1 relative to a coil end portion 11e. A cover member 2 that covers a portion of the coil end portion 11e facing the engagement mechanism 6K is disposed on a second axial side L2 relative to the parking gear 6G. [Selected Figure] Figure 1

Description

The present invention relates to a vehicle drive device.

International Publication No. 2022/074994 discloses a vehicle drive device (1) including a rotating electric machine (2), a planetary gear type reducer (4), and a differential gear mechanism (5) that distributes the power transmitted from the rotating electric machine (2) and the reducer (4) to a pair of wheels on the same axis (the symbols in parentheses in the background art are those of the reference document). This vehicle drive device (1) further includes a parking lock mechanism (3) for stopping the rotation of the wheels. A sun gear (41), which is an input gear of the planetary gear type reducer (4), is fixed to the radial outside of the rotor shaft arranged radially inside the rotor (21) of the rotating electric machine (2). In addition, a parking gear (30) that constitutes the parking lock mechanism (3) is fixed between the rotor (21) and the sun gear (41) to the radial outside of the rotor shaft. The rotor (21), parking gear (30), and sun gear (41) rotate together, and the rotation transmitted to the wheels is stopped by stopping the rotation of the parking gear (30) with a locking member.

International Publication No. 2022/074994

The parking lock mechanism (3) locks the parking gear (30) by the operation of the vehicle occupant. Generally, the parking lock mechanism (3) is activated when the occupant stops the vehicle and the wheels are not rotating, so the parking gear (30) is not rotating when the parking lock mechanism (3) is activated. However, there are cases where the occupant activates the parking lock mechanism (3) before the vehicle stops, in which case the locking member comes into contact with the rotating parking lock mechanism (3). Even when the parking gear (30) is stopped, dust such as metal powder may be generated due to contact between the parking gear (30) and the locking member, but such dust is more likely to be generated when the parking gear (30) is rotating. As described above, the parking gear (30) is disposed between the sun gear (41) and the rotor (21) of the reducer (4) along the rotation axis. A stator (25) equipped with a coil is disposed radially outside the rotor (21), and if dust reaches the coil, it may damage the coil's insulating coating or cause the attached dust to short-circuit the coil. In the vehicle drive device (1) disclosed in the above document, a case opening (120) is formed between the parking gear (30) and the rotating electric machine (1), and it cannot be said that the possibility of such dust reaching the coil is sufficiently eliminated.

In light of the above background, it is desirable to prevent the vehicle drive device from becoming larger, while suppressing the adhesion of foreign matter such as dust generated by the operation of the parking lock mechanism to electrical components such as rotating electrical machines.

In view of the above, a vehicle drive device includes a rotating electric machine having a rotor and a stator, a pair of output members each of which is drivingly connected to a wheel, a differential gear mechanism that distributes the torque of the rotating electric machine to the pair of output members, a power transmission mechanism that transmits power between the rotor and the differential gear mechanism, and a parking lock mechanism that restricts the rotation of the pair of output members, and is a vehicle drive device in which the rotating electric machine and the differential gear mechanism are arranged coaxially, and the stator includes a stator core and a coil wound around the stator core, and the direction along the rotation axis of the rotor is defined as the axial direction, one side of the axial direction is defined as the axial first side, and the axial The other side of the direction is the second axial side, and the coil has a coil end portion that protrudes from the stator core to the first axial side, and the parking lock mechanism has a parking gear that rotates integrally with a target rotating body that is a rotating body that constitutes the power transmission mechanism or the differential gear mechanism, and an engagement mechanism that restricts the rotation of the parking gear by engaging with the parking gear, the parking gear is disposed adjacent to the first axial side of the coil end portion, and a cover member that covers a portion of the coil end portion that faces the engagement mechanism is disposed on the second axial side of the parking gear.

According to this configuration, even if foreign matter such as metal powder generated by the parking lock mechanism scatters toward the coil end portion, the cover member arranged between the engagement mechanism of the parking lock mechanism and the coil end portion can prevent the foreign matter from adhering to the coil end portion. Therefore, the possibility that the insulation performance of the coil end portion will be reduced due to the foreign matter can be reduced. In a vehicle drive device in which a rotating electric machine and a differential gear mechanism are arranged on the same axis, it is required to reduce the axial dimension, so each component is often arranged close to each other in the axial direction. For this reason, the space in which the parking lock mechanism can be arranged is also limited, and the axial separation distance between the parking lock mechanism and the coil end portion of the rotating electric machine is often short. According to this configuration, even if the parking lock mechanism is arranged close to the coil end portion, the influence of foreign matter such as metal powder can be appropriately reduced. In other words, according to this configuration, it is possible to prevent the vehicle drive device from becoming larger, while suppressing the adhesion of foreign matter such as dust generated by the operation of the parking lock mechanism to electrical components such as the rotating electric machine.

Further features and advantages of the vehicle drive system will become apparent from the following description of exemplary, non-limiting embodiments, which are illustrated in the drawings.

Cross-sectional view of a vehicle drive device Skeleton diagram of a vehicle drive system Schematic control block diagram of a vehicle drive device FIG. 2 is a view of the rotating electric machine from a first axial side to a second axial side with the cover member attached. FIG. 2 is a view of the rotating electric machine from the first axial side to the second axial side with the cover member and the parking gear attached. FIG. FIG. 2 is a view of the cover member when viewed from the rotating electric machine side (second axial side) in a state in which the cover member is mounted on a vehicle. FIG. 4 is an enlarged side view showing a schematic relationship between the parking lock mechanism, the cover member, and the coil end portion. FIG. 4 is an enlarged side view showing a schematic relationship between a cover member and a coil end portion. FIG. 1 is a skeleton diagram showing another example of the configuration of a vehicle drive device;

Hereinafter, an embodiment of a vehicle drive device will be described with reference to the drawings. In this specification, "driving connection" refers to a state in which two rotating elements are connected so as to be able to transmit a driving force, including a state in which the two rotating elements are connected so as to rotate integrally, or a state in which the two rotating elements are connected so as to be able to transmit a driving force via one or more transmission members. Such transmission members include various members that transmit rotation at the same speed or at a variable speed, such as shafts, gear mechanisms, belts, chains, etc. In addition, the transmission members may also include engagement devices that selectively transmit rotation and driving force, such as friction engagement devices and meshing engagement devices. However, when referring to each rotating element of a planetary gear mechanism, "driving connection" refers to a state in which multiple rotating elements in the planetary gear mechanism are connected to each other without passing through other rotating elements. In addition, in this specification, "rotating integrally" refers to rotating integrally regardless of whether they are separable or not. That is, multiple components that rotate together may be integrally formed from the same material, or may be made of separate materials and integrated by welding, spline connection, etc. In addition, in this specification, with regard to the arrangement of two elements, "overlapping when viewed from a specific direction" means that when a virtual line parallel to the line of sight is moved in each direction perpendicular to the virtual line, there is at least a portion of an area where the virtual line intersects both of the two elements.

As shown in the cross-sectional view of FIG. 1 and the skeleton diagram of FIG. 2, the vehicle drive device 100 of this embodiment includes a rotating electric machine 1 having a rotor 12 and a stator 11, a pair of output members (such as a spline engagement portion 59 described later) each of which is drivingly connected to a wheel W, a differential gear mechanism 5 that distributes the torque of the rotating electric machine 1 to the pair of output members, a power transmission mechanism (a reduction gear 3) that transmits power between the rotor 12 and the differential gear mechanism 5, and a parking lock mechanism 6 for restricting the rotation of the pair of output members. The rotating electric machine 1, the reduction gear 3, the differential gear mechanism 5, and the parking gear 6G and the engagement mechanism 6K that constitute the parking lock mechanism 6 as described later are housed in a housing chamber E formed in the case 9.

The rotating electric machine 1 and the differential gear mechanism 5 are arranged on the same axis, and in this embodiment, the power transmission mechanism is configured as a planetary gear type fixed speed ratio reducer 3, and the rotating electric machine 1, the differential gear mechanism 5, and the reducer 3 (power transmission mechanism) are arranged on the same axis. The reducer 3 is not limited to a planetary gear mechanism, and may be configured as a reducer using a counter gear mechanism with multiple rotating shafts. In this case, at least the rotating electric machine 1 and the differential gear mechanism 5 are arranged on the same axis. Furthermore, the power transmission mechanism is not limited to a fixed speed reduction ratio reducer 3, and may be a transmission member such as a speed increaser with a fixed speed increase ratio, a stepped transmission that can achieve multiple speed ratios, or a transmission shaft that does not require gear shifting.

As shown in FIG. 2, a pair of wheels W are drivingly connected to a pair of drive shafts DS. The pair of wheels W includes a first wheel W1 and a second wheel W2, and the pair of drive shafts DS includes a first drive shaft DS1 and a second drive shaft DS2. The first wheel W1 is drivingly connected to the first drive shaft DS1, and the second wheel W2 is drivingly connected to the second drive shaft DS2.

In the following description, the direction along the rotation axis of the rotor 12 is referred to as the "axial direction L". One side of the axial direction L is referred to as the "axial first side L1", and the other side of the axial direction L is referred to as the "axial second side L2". In this embodiment, the rotating electric machine 1, the reduction gear 3, and the differential gear mechanism 5 are arranged coaxially in the order described from the axial second side L2 to the axial first side L1. Therefore, the axial second side L2 is the side on which the rotating electric machine 1 is arranged relative to the reduction gear 3, and the axial first side L1 is the side on which the differential gear mechanism 5 is arranged relative to the reduction gear 3. The vehicle drive device 100 of this embodiment has a single-shaft configuration, and the axis (rotation axis X) on which the rotating electric machine 1, the reduction gear 3, and the differential gear mechanism 5 are arranged is the rotation axis X of the vehicle drive device 100, and is also the rotation axis X of the rotating electric machine 1, the reduction gear 3, and the differential gear mechanism 5. The direction perpendicular to the rotation axis X of the rotor 12 is referred to as the "radial direction R". In the radial direction R, the side of the rotation axis X of the rotor 12 is referred to as the "radial inner side R1," and the opposite side is referred to as the "radial outer side R2." In addition, the direction along the vertical direction when the vehicle drive device 100 is mounted on the vehicle is referred to as the "up-down direction V" (see Figures 4 to 7, etc.). In the up-down direction V, the upper side is referred to as the upper side V1, and the lower side is referred to as the lower side V2. When the vehicle drive device 100 is mounted horizontally on the vehicle, one direction of the radial direction R coincides with the up-down direction V.

As shown in FIG. 1, the case 9 comprises a first case member 91 and a second case member 92 which are the core storage members of the storage chamber E, and a third case member 93 which is a cover member. The first case member 91 is a member which generally houses the rotating electric machine 1 therein, and the second case member 92 is a member which generally houses the gear mechanism (the reduction gear 3 and the differential gear mechanism 5) therein. The first case member 91 is a cylindrical member, and the second case member 92 is a bottomed cylindrical member, with a through hole formed in the bottom of the bottomed cylindrical member through which the second drive shaft DS2 passes. The third case member 93 is a lid-like member in which a through hole through which the first drive shaft DS1 passes is formed. The end of the first axial side L1 of the first case member 91 abuts against the end of the second axial side L2 of the second case member 92, and the end of the second axial side L2 of the first case member 91 abuts against the end of the first axial side L1 of the third case member 93, forming a storage chamber E in the space surrounded by the first case member 91, the second case member 92, and the third case member 93.

The rotating electric machine 1 functions as a drive source for the pair of wheels W. The rotating electric machine 1 is electrically connected to a DC power source 80 (see FIG. 3) that is composed of an electric storage device such as a battery or a capacitor, and has a function as a motor (electric motor) that receives a supply of electric power to generate motive power, and a function as a generator (electric power generator) that receives a supply of motive power to generate electric power. The rotating electric machine 1 generates driving force by running using the electric power stored in the DC power source 80, and also generates electricity using the driving force transmitted from the pair of wheels W to charge the DC power source 80.

As shown in Figs. 1 and 2, the stator 11 of the rotating electric machine 1 has a cylindrical stator core 11a. The stator core 11a is fixed to the case 9 (here, the first case member 91). The rotor 12 of the rotating electric machine 1 has a cylindrical rotor core 12a. The rotor core 12a is connected to the rotor shaft 13 so as to rotate integrally with the rotor shaft 13, and is supported by the case 9 so as to be rotatable relative to the stator core 11a. In this embodiment, the rotating electric machine 1 is an inner rotor type rotating electric machine. The rotor core 12a is disposed radially inward R1 relative to the stator core 11a, and the rotor shaft 13 is disposed radially inward R1 relative to the rotor core 12a.

The rotating electric machine 1 is a rotating field type rotating electric machine. Stator coil 11b is wound around stator core 11a, and coil end portions 11e are formed protruding on both sides of stator core 11a in the axial direction L. When distinguishing between the two coil end portions 11e, the coil end portion 11e located on the first axial side L1 is referred to as the first coil end portion e1, and the coil end portion 11e located on the second axial side L2 is referred to as the second coil end portion e2. In addition, although not shown, permanent magnets are arranged in rotor core 12a.

As shown in FIG. 3, the vehicle drive device 100 is controlled by a vehicle control device 200 mounted on the vehicle. Here, the vehicle control device 200 is exemplified by a drive system control device 201 that controls the entire vehicle drive device 100, and a rotating electric machine control device 202 that controls the rotating electric machine 1. The form shown in FIG. 3 is an exemplary and conceptual block diagram, and does not limit the physical configuration (circuit configuration) of the actual control device.

The rotating electric machine 1 is driven and controlled by the rotating electric machine control device 202 based on the target torque of the rotating electric machine 1, which is set according to a command from the drive system control device 201 that controls the vehicle drive device 100. The rotating electric machine control device 202 drives and controls the rotating electric machine 1 via an inverter INV configured with multiple switching elements. The inverter INV is connected between the DC power source 80 and the rotating electric machine 1 (stator coil 11b) and converts power between DC and multiple phases of AC. The rotating electric machine control device 202 controls the switching of the inverter INV to drive and control the rotating electric machine 1. Here, an example is shown in which the rotating electric machine 1 is a three-phase AC type, and the inverter INV converts power between DC and three-phase AC. The DC power source 80 and the inverter INV correspond to the power source of the rotating electric machine 1.

The rotating electric machine control device 202 performs current feedback control based on the rotational position of the rotor 12 (magnetic pole position of the permanent magnet), the rotational speed of the rotor 12, and the current flowing through the stator coil 11b of each of the three phases, to drive and control the rotating electric machine 1 via the inverter INV. The rotational position and rotational speed of the rotor 12 are detected by a rotation sensor 81 such as a resolver. Naturally, the rotation sensor 81 is not limited to a resolver, and may be configured by combining a rotational speed sensor such as an encoder with a magnetic sensor that detects the magnetic pole position, and does not prevent it from being in other forms. The current flowing through the stator coil 11b is detected by a current sensor 82. The current sensor 82 is, for example, a non-contact type current sensor installed near the power line 14 that connects the inverter INV and the stator coil 11b of the rotating electric machine 1.

The stator coil 11b generates heat when a current flows through it. For this reason, oil for cooling is sprinkled on the coil end portion 11e. Oil is stored in the bottom of the case 9 to cool the stator coil 11b, lubricate the rotating members such as various gears provided in the rotating electric machine 1, the reduction gear 3, the differential gear mechanism 5, etc., and lubricate the bearings that rotatably support these rotating members. The oil stored in the bottom is guided to an oil passage formed in the upper part of the case 9 by an oil pump (not shown) located outside the case 9 through an oil passage, and is supplied to the parts to be cooled and lubricated, such as the stator coil 11b, the gears, and the bearings. This oil pump is preferably driven by a drive source (e.g., a pump motor) different from the rotating electric machine 1, which is the drive source of the wheels W, and circulates the oil in the storage chamber E in the case 9.

As shown in FIG. 1, in this embodiment, the rotor shaft 13 is formed in a cylindrical shape coaxial with the rotor core 12a. A sun gear SG of a planetary gear mechanism constituting the reduction gear 3 is arranged on the outer periphery side of the rotor shaft 13 on the first axial side L1 relative to the rotor 12 so as to rotate integrally with the rotor shaft 13. In this embodiment, the sun gear SG is formed integrally with the rotor shaft 13. The rotor shaft 13 and the sun gear SG may be made of the same member, or may be made of separate members and joined by welding or the like. The sun gear SG is an input element of the reduction gear 3.

The differential gear mechanism 5 is a bevel gear type differential gear mechanism. The differential gear mechanism includes a pinion gear 51 and a side gear 52, both of which are bevel gears. The pinion gear 51 is supported by a differential case 50 as a differential support member and is rotatably supported by a pinion shaft 55 arranged to extend along the radial direction R. The pinion shaft 55 rotates integrally with the differential case 50, and the pinion gear 51 is configured to be rotatable (spin) around the pinion shaft 55 and rotatable (revolve) around the rotation axis X of the differential case 50. The differential case 50 houses the pinion gear 51, the side gear 52, and the pinion shaft 55 inside.

In this embodiment, the multiple pinion shafts 55 are arranged radially around the rotation axis of the differential case 50 (for example, four pinion shafts 55 are arranged in a cross shape when viewed in the axial direction L). A pinion gear 51 is attached to each of the multiple pinion shafts 55.

The side gear 52 includes a first side gear 53 and a second side gear 54, and is arranged as a pair spaced apart in the axial direction L. The first side gear 53 and the second side gear 54 mesh with each of the multiple pinion gears 51. The first side gear 53 and the second side gear 54 are arranged to rotate around the rotation axis X of the differential case 50.

As shown in Figs. 1 and 2, in this embodiment, the first side gear 53 is connected to a connecting shaft J extending along the axial direction L. The connecting shaft J is connected to rotate integrally with the first drive shaft DS1, which is drivingly connected to the first wheel W1. Therefore, the first side gear 53 is drivingly connected to the first wheel W1 via the connecting shaft J. The connecting shaft J is arranged to penetrate the radial inner side R1 in the axial direction L with respect to the rotating electric machine 1, the rotor shaft 13, and the reduction gear 3. In addition, the second side gear 54 is connected to rotate integrally with the second drive shaft DS2, which is drivingly connected to the second wheel W2.

The first drive shaft DS1, the second drive shaft DS2, the connecting shaft J, the first side gear 53, and the second side gear 54, which are drivingly connected to the wheels W and rotate integrally with the wheels W, can all be considered to be rotating members corresponding to the output members. The side gear 52 (first side gear 53, second side gear 54) can also be considered to be the differential gear mechanism 5 and the output member. The first side gear 53 and the second side gear 54 each have a gear portion that meshes with the pinion gear 51 and a spline engagement portion 59 that is connected to the connecting shaft J or the second drive shaft DS2. When considered functionally, the gear portion corresponds to the rotating member included in the differential gear mechanism 5, and the spline engagement portion 59 corresponds to the output member.

The reducer 3 is configured as a planetary gear mechanism with an input element that rotates integrally with the rotor shaft 13, a fixed element fixed to the case 9, an output element that rotates integrally with the differential input element (differential case 50), and a planetary gear PG. This planetary gear mechanism is a composite planetary gear mechanism with one sun gear SG, two ring gears (first ring gear RG1, second ring gear RG2), a planetary gear PG with two gear portions (first gear portion G1, second gear portion G2) that rotate integrally, and a carrier CR that rotatably supports the planetary gear PG.

The sun gear SG is connected to the rotor 12 so as to rotate integrally with the rotor 12. The first ring gear RG1 is fixed to the case 9. The second ring gear RG2 is disposed on the side of the differential gear mechanism 5 with respect to the first ring gear RG1, and is connected to rotate integrally with the differential input element. The planetary gear PG includes a first gear portion G1 that meshes with the sun gear SG and the first ring gear RG1, and a second gear portion G2 that rotates integrally with the first gear portion G1 and meshes with the second ring gear RG2. In this embodiment, the second gear portion G2 is formed to have a smaller diameter than the first gear portion G1. In this embodiment, the planetary gear PG is formed of the same material. However, the two materials may be integrated by welding or the like. In this embodiment, the sun gear SG is the input element, the first ring gear RG1 is the fixed element, and the second ring gear RG2 is the output element. The carrier CR is not connected to any rotating or fixed elements.

The parking lock mechanism 6 is provided to restrict the rotation of the pair of output members. In this embodiment, the parking lock mechanism 6 restricts the rotation of the pair of output members via the reduction gear 3 and the differential gear mechanism 5 by restricting the rotation of the rotor shaft 13 that rotates integrally with the sun gear SG. As shown in Figs. 1 and 2, the parking lock mechanism 6 includes a parking gear 6G and an engagement mechanism 6K that selectively engages with the parking gear 6G to restrict the rotation of the parking gear 6G. Below, the description will be made with reference to Fig. 5, which is a view of the rotating electric machine 1 from the axial first side L1 to the axial second side L2 with the parking gear 6G attached. As shown in Fig. 5, the parking gear 6G is arranged so as to overlap the coil end portion 11e when viewed in the axial direction.

The parking gear 6G is connected to the rotor shaft 13 so as to rotate integrally with the rotor shaft 13. In this embodiment, as shown in FIG. 1, the parking gear 6G and the rotor shaft 13 are engaged in a state in which relative rotation is restricted by spline engagement. In other words, the parking gear 6G is engaged in a state in which it cannot rotate relative to the rotor shaft 13. As shown in FIG. 5, an engagement portion 61 is formed on the parking gear 6G, and the rotation of the parking gear 6G is restricted by selectively engaging the parking pole 63 (engagement protrusion) of the engagement mechanism 6K with this engagement portion 61. By restricting the rotation of the parking gear 6G, the rotation of the rotor shaft 13 is also restricted, the rotation of the reduction gear 3 and the differential gear mechanism 5 is also restricted, and the rotation of the output member is also restricted.

As described above, in this embodiment, the input element in the reduction gear 3 is the sun gear SG, which rotates integrally with the rotor shaft 13. Therefore, it can also be said that the parking gear 6G rotates integrally with the rotating body that constitutes the reduction gear 3. The rotor shaft 13 and the sun gear SG are rotating bodies that rotate integrally with the parking gear 6G, and can be said to be target rotating bodies that are subject to regulation by the parking lock mechanism 6.

The parking lock mechanism 6 only needs to be able to restrict the rotation of the output member. Therefore, the target rotating body, which is the rotating body to be restricted by the parking lock mechanism 6, may be a rotating body that rotates in conjunction with the output member without being separated from the output member by an engagement device or the like. The target rotating body may be the rotor shaft 13 or the sun gear SG, as well as the side gear 52 of the differential gear mechanism 5 or the drive shaft DS. The target rotating body may also be another rotating body constituting the differential gear mechanism 5, such as the differential case 50, or another rotating body constituting the reducer 3, such as the second ring gear RG2. In other words, the parking lock mechanism 6 only needs to be configured with a parking gear 6G that rotates integrally with the target rotating body, which is the rotating body constituting the reducer 3 or the differential gear mechanism 5, and an engagement mechanism 6K that engages with the parking gear 6G to restrict the rotation of the parking gear 6G.

The parking lock mechanism 6 includes a parking actuator 6A such as an electric motor, as shown in FIG. 3, in addition to a parking gear 6G and an engagement mechanism 6K. The engagement mechanism 6K includes a parking pole 63 that selectively engages with an engagement portion 61 (gear teeth) of the parking gear 6G, a parking rod 65 driven by the parking actuator 6A, and a transmission mechanism 64 (see FIG. 5). The transmission mechanism 64 includes a cam mechanism and a link mechanism, and transmits power from the parking actuator 6A from the parking rod 65 to the parking pole 63. The parking pole 63 is configured to be able to change its position between an engagement position where it engages with the engagement portion 61 of the parking gear 6G and a non-engagement position where it is not engaged with the engagement portion 61 of the parking gear 6G.

The parking lock mechanism 6 locks the parking gear 6G by the operation of the vehicle occupant. Of course, this does not prevent the execution of control to automatically lock the parking gear 6G when the vehicle is stopped. In any case, the parking lock mechanism 6 generally operates when the wheels W are not rotating, so the parking gear 6G is not rotating when the parking lock mechanism 6 is activated. However, there are cases where the occupant activates the parking lock mechanism 6 before the vehicle is stopped, in which case the parking pole 63, which is the locking member, comes into contact with the rotating parking gear 6G. Even when the parking gear 6G is stopped, dust such as metal powder may be generated due to contact between the parking gear 6G and the parking pole 63, but such dust is more likely to be generated when the parking gear 6G is rotating.

In this embodiment, the parking gear 6G is disposed between the sun gear SG of the reducer 3 and the rotor 12 along the rotation axis X. A stator 11 having a stator coil 11b is disposed on the radially outer side R2 of the rotor 12, and the coil end portion 11e protrudes toward the parking gear 6G. As shown in FIG. 1 and FIG. 2, the parking gear 6G is disposed adjacent to the first axial side L1 with respect to the first coil end portion e1, which is the coil end portion 11e disposed on the first axial side L1. If dust reaches the coil end portion 11e, it may damage the insulating coating of the stator coil 11b, or the attached dust may cause a short circuit of the stator coil 11b.

For this reason, in this embodiment, as shown in Figures 1, 5, etc., a cover member 2 that covers the portion of the coil end portion 11e facing the engagement mechanism 6K is arranged on the second axial side L2 with respect to the parking gear 6G. As a result, even if foreign matter such as metal powder generated by the parking lock mechanism 6 is scattered toward the coil end portion 11e, the cover member 2 arranged between the engagement mechanism 6K of the parking lock mechanism 6 and the coil end portion 11e can prevent the foreign matter from adhering to the coil end portion 11e. Therefore, it is possible to reduce the possibility that the insulation performance of the coil end portion 11e will be reduced due to the foreign matter.

In the vehicle drive device 100 in which the rotating electric machine 1 and the differential gear mechanism 5 are arranged coaxially as in this embodiment, the dimensions in the axial direction L must be reduced, and therefore the components are often arranged close to each other in the axial direction L. This limits the space in which the parking lock mechanism 6 can be arranged, and often shortens the axial distance L between the parking lock mechanism 6 and the coil end portion 11e of the rotating electric machine 1. As shown in FIG. 1, this embodiment can appropriately reduce the effects of foreign matter such as metal powder even when the parking lock mechanism 6 is arranged close to the coil end portion 11e. Therefore, it is possible to prevent the vehicle drive device 100 from becoming larger, while suppressing the adhesion of foreign matter such as dust generated by the operation of the parking lock mechanism 6 to electrical components such as the rotating electric machine 1.

Figure 4 is a view of the rotating electric machine 1 from the first axial side L1 toward the second axial side L2 with the cover member 2 attached. As shown in Figure 4, one of the two coil end portions 11e, in this embodiment, the first coil end portion e1 located on the side where the power line 14 is wired from the outside of the case 9 as shown in Figure 1, is provided with a power line connection portion 16 which is a connection portion between the stator coil 11b and the power line 14 that electrically connects the stator coil 11b and the power source (inverter INV). As shown in Figure 4, the power line connection portion 16 and the engagement mechanism 6K are arranged so as not to overlap in the axial view. The cover member 2 is formed so as to cover the portion of the coil end portion 11e that overlaps with the engagement mechanism 6K in the axial view and to open the portion that overlaps with the power line connection portion 16 in the axial view.

The power line connection portion 16 is likely to protrude in the axial direction L from the coil end portion 11e because it connects the coil (stator coil 11b) and the power line 14. On the other hand, the portion of the coil end portion 11e other than the power line connection portion 16 is likely to be configured to suppress protrusion in the axial direction L. With this configuration, the cover member 2 can cover the range necessary to protect the coil end portion 11e from foreign matter generated by the parking lock mechanism 6 while not covering the power line connection portion 16, which is the portion of the coil end portion 11e that is likely to protrude in the axial direction L. Therefore, while appropriately protecting the coil end portion 11e, the cover member 2 can be appropriately positioned by utilizing the gap in the axial direction L between the coil end portion 11e and the parking gear 6G in the circumferential area where the power line connection portion 16 is not present. Therefore, the expansion of the axial direction L dimension of the vehicle drive device 100 due to the placement of the cover member 2 can be kept small.

As described above, the cover member 2 is provided so that dust generated by contact between the engagement mechanism 6K and the parking gear 6G does not adhere to the coil end portion 11e. Therefore, it is preferable that the range covering the coil end portion 11e is set based on the circumferential position of the engagement mechanism 6K, more specifically, based on the circumferential position of the parking pole 63. For example, as shown in FIG. 4, it is preferable that the cover member 2 is formed and arranged so as to cover a predetermined range in the circumferential direction based on the circumferential position of the parking pole 63 (circumferential reference position A0). As one aspect, it is preferable that the cover member 2 is formed and arranged so as to cover the coil end portion 11e in a range (coverage range A) of about 90 degrees to 180 degrees in the circumferential direction centered on the circumferential reference position A0. It is preferable that the coverage range A is set to a range that covers the entire range into which foreign matter such as dust generated by contact between the engagement mechanism 6K and the parking gear 6G scatters.

In FIG. 4, a range of 120 degrees is illustrated as the coverage range A. At the lower side V2 of the vertical direction V, the end of the cover member 2 is approximately aligned with the end of the coverage range A, but at the upper side V1 of the vertical direction V, the cover member 2 extends further in the circumferential direction than the end of the coverage range A. In this way, the coverage range A may be different between the clockwise range in the circumferential direction from the circumferential reference position A0 and the counterclockwise range in the circumferential direction.

In addition, dust generated by contact between the engagement mechanism 6K and the parking gear 6G scatters generally along the axial direction L from the first axial side L1 to the second axial side L2. Therefore, as in this embodiment, it is preferable that the cover member 2 is arranged to cover the direction in which foreign matter moves from the point where the engagement mechanism 6K and the parking gear 6G contact each other toward the coil end portion 11e.

In this embodiment, as shown in FIG. 4, a configuration in which the cover member 2 is arranged to cover a portion of the circumferential direction of the coil end portion 11e when viewed in the axial direction is illustrated. However, this does not prevent a configuration in which the cover member 2 is arranged to cover the entire circumferential area of the coil end portion 11e when viewed in the axial direction.

Figure 6 is a perspective view showing an example of the cover member 2, and Figure 7 is a plan view of the cover member 2 as viewed from the rotating electric machine 1 side (second axial side L2) in a vehicle-mounted state. As shown in Figure 6, the cover member 2 has a cover body portion 20 that faces the coil end portion 11e in the axial direction L to protect the coil end portion 11e, and an attachment portion 25 that attaches the cover member 2 to the case 9. In this embodiment, an example is shown in which a total of two attachment portions 25 are provided, one each on the upper side V1 and the lower side V2 of the cover member 2 in a vehicle-mounted state. However, three or more attachment portions 25 may be provided. Of course, as long as the cover member 2 can be stably fixed to the case 9, the number of attachment portions 25 may be one.

The cover body portion 20 is a portion that overlaps with the coil end portion 11e in an axial view. As shown in Figs. 4 to 7, the cover body portion 20 includes a first cover portion 21, a second cover portion 22, and a third cover portion 23. As shown in Figs. 4 and 5, the first cover portion 21, the second cover portion 22, and the third cover portion 23 overlap with the coil end portion 11e in an axial view. As will be described later with reference to Figs. 8 and 9, the first cover portion 21, the second cover portion 22, and the third cover portion 23 do not overlap with the coil end portion 11e in a radial view.

The mounting portion 25 for fixing the cover member 2 to the case 9 is disposed radially outward R2 with respect to the cover body portion 20. Therefore, the mounting portion 25 does not need to overlap with the coil end portion 11e when viewed in the axial direction. In this embodiment, as with the cover body portion 20, a form in which the mounting portion 25 does not overlap with the coil end portion 11e when viewed in the radial direction is illustrated as an example, but the mounting portion 25 may overlap with the coil end portion 11e when viewed in the radial direction.

As shown in Figs. 6 and 7, the cover member 2 has an oil inlet 26h connected to an oil supply unit (not shown) provided in the case 9, an oil outlet 28h through which oil is discharged, and a connecting oil passage 27p connecting the oil inlet 26h and the oil outlet 28h. As shown in Fig. 6, an inlet forming portion 26 and an outlet forming portion 28 are formed so as to protrude in the axial direction L from the cover main body portion 20. The inlet forming portion 26 and the outlet forming portion 28 are disposed radially outward R2 with respect to the cover main body portion 20, similar to the mounting portion 25, and do not overlap with the coil end portion 11e in the axial view. On the other hand, the inlet forming portion 26 and the outlet forming portion 28 protruding in the axial direction L overlap with the coil end portion 11e in the radial view.

The oil inlet 26h is formed to open in the axial direction L at the end of the inlet forming part 26 opposite the cover body part 20 (the end in the axial direction L when mounted on the vehicle), and is connected to an oil supply part (not shown) provided on the case 9. The end of the outlet forming part 28 opposite the cover body part 20 (the end in the axial direction L when mounted on the vehicle) is closed, and a plurality of openings that become the oil outlet 28h are formed on the lower side V2 of the outlet forming part 28 in the mounted state. In this embodiment, a form in which a plurality of openings are formed as the oil outlet 28h is exemplified, but a single opening may also be used. As described above, the outlet forming part 28 overlaps with the coil end part 11e when viewed in the radial direction, and the oil outlet 28h overlaps with the coil end part 11e when viewed in the radial direction.

As shown in FIG. 7, the cover member 2 is also provided with an oil passage forming portion 27 that connects the inlet forming portion 26 and the outlet forming portion 28. The oil passage forming portion 27 is formed with a connecting oil passage 27p that connects the oil inlet 26h and the oil outlet 28h. Oil supplied to the oil inlet 26h from an oil supply portion (not shown) provided in the case 9 is guided to the oil outlet 28h via the connecting oil passage 27p.

As shown in Figures 4, 6, and 7, the portion of the cover member 2 that is disposed above the coil end portion 11e V1 when the cover member 2 is mounted on the vehicle is referred to as the upper arrangement portion 29. In this embodiment, the upper arrangement portion 29 includes a part of the first cover portion 21, one mounting portion 25, a part of the oil passage forming portion 27, and the outlet forming portion 28. That is, the oil outlet 28h formed in the outlet forming portion 28 is provided in the upper arrangement portion 29. Therefore, by dripping oil from the oil outlet 28h, the oil can be supplied to the coil end portion 11e and the stator coil 11b can be cooled.

The stator 11, which is a non-rotating member, is fixed to the case 9, and the coil (stator coil 11b) is fixed to the stator 11. The engagement mechanism 6K is also attached to the case 9 that houses it. By attaching the cover member 2 to the case 9, the cover member 2 can be positioned appropriately with respect to the engagement mechanism 6K and the coil end portion 11e. Furthermore, with this configuration, cooling oil can be efficiently supplied to the coil end portion 11e using the cover member 2 that is positioned close to the coil end portion 11e.

Here, as shown in FIG. 4, the area of the coil end portion 11e other than the area where the power line connection portion 16 is provided is the general area 11g. In other words, the general area 11g corresponds to the range in which it is suitable to provide the cover member 2 without opening the coil end portion 11e when viewed in the axial direction. There are multiple directions in which the conductor extends when the stator coil 11b is wound, and the extension direction of the conductor differs depending on the winding in which the conductor extends along the circumferential direction, the winding in which the conductor extends in the circumferential direction and also in the radial direction, the winding in which the conductor extends in the radial direction, and the like. Due to these differences in winding, the amount of protrusion of the stator coil 11b in the axial direction L at the coil end portion 11e may not be constant. For example, in the power line connection portion 16, the amount of protrusion of the stator coil 11b in the axial direction L tends to be large. In addition, even in the case of winding that extends in the radial direction, it may become necessary to extend the conductor across the conductor wound in the circumferential direction, and the amount of protrusion in the axial direction L may be large.

Therefore, even in the general region 11g of the coil end portion 11e, unevenness in the axial direction L may be formed according to the arrangement of the conductor wires constituting the stator coil 11b due to differences in the winding method of the stator coil 11b. Here, the portion protruding in the axial direction L in a direction relatively away from the stator core 11a is called the convex portion 11p, and the portion located relatively closer to the stator core 11a and retreating from the convex portion 11p is called the concave portion 11c. At a position facing the concave portion 11c along the axial direction L, other members can be arranged to a position closer to the stator 11 (stator core 11a) while maintaining a distance from the stator coil 11b, compared to a position facing the convex portion 11p along the axial direction L. For example, the shape of the cover member 2, specifically the shape of the cover main body portion 20, can also be made uneven according to the uneven shape of the coil end portion 11e. Figure 6 and other figures show an example of a cover member 2 formed in such an uneven shape.

As described above, the engagement mechanism 6K is disposed adjacent to the coil end portion 11e in the axial direction L. Among the members constituting the engagement mechanism 6K, the member disposed at a position overlapping the coil end portion 11e in the axial direction and disposed closest to the stator 11 (in this embodiment, the second axial side L2) is regarded as the specific member. In this embodiment, as shown in Figs. 4, 5, and 8, the support body 66 supporting the pressing member that presses the parking pole 63 (engagement protrusion) by the power transmitted from the parking actuator 6A corresponds to the specific member. As shown in Fig. 8, the support body 66 as the specific member is disposed at a position overlapping with the recess 11c (the side of the stator 11, in this embodiment, the recess 11c recessed to the second axial side L2) in the general region 11g in the axial direction. The cover member 2 is formed so that the portion corresponding to the recess 11c is recessed to the second axial side L2 in the vehicle mounted state. In this embodiment, the second cover portion 22 corresponds to the portion corresponding to the recess 11c in the cover member 2. It can be said that the first cover part 21 and the third cover part 23 correspond to the parts of the cover member 2 that correspond to the protrusion 11p.

With this configuration, the members constituting the engagement mechanism 6K are positioned according to the unevenness in the coil end portion 11e, and the cover member 2 having a shape corresponding to the unevenness is positioned between the coil end portion 11e and the engagement mechanism 6K. Therefore, the cover member 2 can be positioned while ensuring a gap in the axial direction L between the cover member 2 and the engagement mechanism 6K. Therefore, the cover member 2 can be appropriately positioned, while minimizing the increase in the axial direction L dimension of the vehicle drive device 100 caused by the placement of the cover member 2.

Regardless of the unevenness of the coil end portion 11e in the axial direction L, as shown in FIG. 9, the cover member 2 (specifically, the cover body portion 20) is positioned so as not to overlap the coil end portion 11e when viewed in the radial direction.

That is, the cover member 2 covers the axial L side of the coil end portion 11e, but does not cover the radial R side (circumferential side) of the coil end portion 11e. Therefore, it is easier to reduce the size of the cover member 2 in the radial direction R compared to when the cover member 2 is shaped to cover the outer peripheral surface of the coil end portion 11e, and it is easier to avoid the dimensions of the vehicle drive device 100 expanding in the radial direction R due to the placement of the cover member 2.

In the above, as shown in Figures 1 and 2, the parking gear 6G is arranged between the rotating electric machine 1 and the axial direction L of the reduction gear 3. However, as shown in Figure 10, the parking gear 6G may be arranged to rotate integrally with the rotor shaft 13 on the opposite side of the reduction gear 3 with respect to the rotating electric machine 1. In this case, the coil end portion 11e to be protected by the cover member 2 is the second coil end portion e2.

In FIG. 10, in order to make the relationship in the axial direction L between the rotating electric machine 1, the parking lock mechanism 6, and the cover member 2 the same, the first axial side L1 and the second axial side L2 are swapped in comparison with FIG. 1 and FIG. 2. That is, in the embodiment illustrated in FIG. 10, the rotating electric machine 1, the reduction gear 3, and the differential gear mechanism 5 are arranged coaxially in the order shown from the second axial side L2 toward the first axial side L1. Therefore, the second axial side L2 is the side on which the rotating electric machine 1 is arranged relative to the reduction gear 3, and the first axial side L1 is the side on which the differential gear mechanism 5 is arranged relative to the reduction gear 3.

As shown in FIG. 10, the stator 11 includes a stator core 11a and a stator coil 11b wound around the stator core 11a. The stator coil 11b includes a coil end portion 11e (second coil end portion e2) that protrudes toward the first axial side L1 relative to the stator core 11a. The parking gear 6G is disposed adjacent to the first axial side L1 relative to the coil end portion 11e (second coil end portion e2). The cover member 2 that covers the portion of the coil end portion 11e (second coil end portion e2) that faces the engagement mechanism 6K is disposed on the second axial side L2 relative to the parking gear 6G.

Note that, in FIG. 10, as in the embodiment described above with reference to FIG. 1 and FIG. 2, an embodiment in which the parking gear 6G is connected to the rotor shaft 13 so as to rotate integrally therewith is illustrated. In other words, FIG. 10 also illustrates an embodiment in which the target rotating bodies are the rotor 12, the rotor shaft 13, the sun gear SG, etc. However, for example, the parking gear 6G may be connected to the connecting shaft J so as to rotate integrally therewith.

1: rotating electric machine, 2: cover member, 3: reducer (power transmission mechanism), 5: differential gear mechanism, 6: parking lock mechanism, 6G: parking gear, 6K: engagement mechanism, 9: case, 11: stator, 11a: stator core, 11b: stator coil (coil), 11c: recess, 11e: coil end portion, 11g: general area, 12: rotor, 14: power line, 16: power line connection portion, 20: cover main body portion, 22: second cover portion (portion of cover member corresponding to recess), 25: mounting portion, 26h: oil inlet, 27p: connecting oil passage, 28h: oil outlet, 29: upper arrangement portion, 52: side gear ( output member), 53: first side gear (output member), 54: second side gear (output member), 59: spline engagement portion (output member), 64: transmission mechanism, 66: support (specific member), 80: DC power source (power source), 100: vehicle drive device, DS: drive shaft (output member), DS1: first drive shaft (output member), DS2: second drive shaft (output member), INV: inverter (power source), J: connecting shaft (output member), L: axial direction, L1: first axial side, L2: second axial side, R: radial direction, R2: radial outer side (radial outer side), V1: upper side, W: wheel, X: rotation axis

Claims (5)

A rotating electric machine including a rotor and a stator;
A pair of output members each drivingly connected to a wheel;
a differential gear mechanism that distributes torque of the rotary electric machine to the pair of output members;
a power transmission mechanism for transmitting power between the rotor and the differential gear mechanism;
a parking lock mechanism for restricting rotation of the pair of output members,
A vehicle drive device in which the rotating electric machine and the differential gear mechanism are coaxially arranged,
The stator includes a stator core and a coil wound around the stator core.
A direction along the rotation axis of the rotor is defined as an axial direction, one side in the axial direction is defined as an axial first side, and the other side in the axial direction is defined as an axial second side,
The coil includes a coil end portion protruding toward the first side in the axial direction with respect to the stator core,
the parking lock mechanism includes a parking gear that rotates integrally with a target rotating body that is a rotating body constituting the power transmission mechanism or the differential gear mechanism, and an engagement mechanism that restricts rotation of the parking gear by engaging with the parking gear,
the parking gear is disposed adjacent to the coil end portion on the first axial side,
A cover member that covers a portion of the coil end portion that faces the engagement mechanism is disposed on the second axial side relative to the parking gear. a power line connection portion that is a connection portion between the coil and a power line that electrically connects the coil and a power source is provided at the coil end portion,
the power line connection portion and the engagement mechanism are arranged so as not to overlap each other when viewed in the axial direction,
The vehicle drive device according to claim 1 , wherein the cover member is formed to cover a portion of the coil end portion that overlaps with the engagement mechanism when viewed in the axial direction, and to open a portion that overlaps with the power line connection portion when viewed in the axial direction. A region of the coil end portion other than the region where the power line connection portion is provided is defined as a general region,
The general region is provided with projections and recesses in the axial direction in accordance with the arrangement of the conductor wires constituting the coil,
Among the members constituting the engagement mechanism, a member that is arranged at a position overlapping with the coil end portion as viewed in the axial direction and that is arranged closest to the second axial direction side is defined as a specific member,
the specific member is disposed at a position overlapping a recess recessed toward the second axial direction in the general region when viewed in the axial direction,
The vehicle drive device according to claim 2 , wherein the cover member is formed in a shape recessed toward the second axial direction at a portion corresponding to the recess. A direction perpendicular to the rotation axis of the rotor is defined as a radial direction,
The vehicle drive device according to claim 1 , wherein the cover member is disposed so as not to overlap with the coil end portion when viewed in the radial direction along the radial direction. a case that accommodates the rotating electric machine, the differential gear mechanism, the power transmission mechanism, the parking gear, and the engagement mechanism,
A direction perpendicular to the rotation axis of the rotor is defined as a radial direction,
The cover member is
a cover main body portion that overlaps with the coil end portion as viewed in the axial direction;
an attachment portion disposed radially outward from the cover body portion and attached to the case;
an oil inlet connected to an oil supply unit provided in the case;
an oil outlet through which oil is discharged;
A connecting oil passage connecting the oil inlet and the oil outlet;
an upper arrangement portion that is arranged above the coil end portion when the motor is mounted on a vehicle,
The vehicle drive device according to claim 1 , wherein the oil discharge port is provided in the upper arrangement portion.

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