JP2005008143A - Electric driving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small-sized electric driving device capable of obtaining sufficient speed reduction ratio. <P>SOLUTION: The electric driving device includes independent motors provided on both sides of an engine on the front wheel side of an FR vehicle. That is, each motor corresponds to left and right wheels. Furthermore, a retarder transmitting the rotation of the motors to the drive shaft of each wheel is provided. Herein, the retarder can be installed even in a narrow space since it is arranged coaxially with the rotation shafts of the motors and the drive shafts of the wheels. Furthermore, the retarder can be miniaturized since it is constructed of a stepped pinion type planetary gear, and it is suitably attached to the vicinity of the engine with many spatial restrictions. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electric drive device mounted on a vehicle.

  There is known an electric drive device that includes a motor and a speed reducer and is mounted on a hybrid vehicle or a 4WD vehicle. As an example of such an electric drive device, there is an electric drive device including a differential device connected to left and right wheels via an axle, and an electric motor that transmits power to the axle via the differential device. It is described in Patent Document 1. In this electric drive device, the output shaft of the electric motor is formed in a hollow shape, the axle is passed through the inside, and the electric motor is arranged on the same axis as the axle, thereby reducing the size of the device.

  The electric drive for driving the wheels needs to be placed near the axle, but there is not enough space around the engine and the rear of the vehicle due to the structure, and the freedom to design and design the electric drive There are often restrictions. For example, since an engine mount, an intake and exhaust manifold, a steering shaft, and the like are disposed around the engine, it is desired to reduce the size of the electric drive device as much as possible. However, due to such restrictions, there is a problem that it is difficult to obtain a sufficiently large reduction ratio of the speed reducer constituting the electric drive device.

  Patent Document 2 discloses a motor with a speed reducer in which the speed reducer is a planetary gear and is arranged coaxially with the motor. Patent Documents 3 and 4 describe an in-wheel motor with a speed reducer in which the speed reducer is a planetary gear and is arranged coaxially with the motor. Also, Patent Documents 5 and 6 describe examples of lubrication techniques in a motor with a reduction gear using planetary gears.

JP-A-11-240347 JP 2003-127680 A JP 2001-32888 A Japanese Patent Publication No. 6-26932 JP 2001-173762 A JP 2000-46157 A

  This invention is made | formed in view of the above point, and makes it a subject to provide the electric drive device which can obtain a sufficient reduction ratio with a small size.

  In one aspect of the present invention, the electric drive device includes an electric motor that is provided on both sides of the engine and that operates independently of each other, and a reduction gear that transmits rotation of the electric motor to a wheel. It is arranged coaxially with the rotating shaft of the electric motor and the drive shaft of the wheel, and the speed reducer includes a stepped pinion type planetary gear.

  Said electric drive device is provided with the independent electric motor provided in the both sides of an engine in the front-wheel side of FR vehicle, for example. That is, each electric motor corresponds to the left and right wheels. In addition, a speed reducer that transmits the rotation of the electric motor to each wheel is provided. Here, since the speed reducer is arranged coaxially with the rotating shaft and wheels of the electric motor, it can be mounted in a narrow space. Further, since the speed reducer is composed of a stepped pinion type planetary gear, it can be reduced in size and is suitable for mounting in the vicinity of an engine having many space restrictions. Preferably, the electric motor is disposed on the front side of the vehicle from the engine mount of the engine.

  In one aspect of the electric drive device, the speed reducer includes a sun gear coupled to a rotation shaft of the motor, a stepped pinion gear that meshes with the sun gear, a gear that meshes with the stepped pinion gear, and the speed reducer. A fixed ring gear and a carrier portion that rotatably holds the stepped pinion gear and is coupled to the wheel may be provided. With this configuration, one ring gear and the other sun gear of the pair of planetary gears constituting the speed reducer can be omitted, so that the speed reducer can be reduced in size and weight.

  In another aspect of the electric drive device described above, the speed reducer can rotate the first sun gear coupled to the rotation shaft of the electric motor, the stepped pinion gear meshing with the sun gear, and the stepped pinion gear. A carrier portion that is held and fixed to the speed reducer, and a second sun gear that meshes with the stepped pinion gear and that is connected to a wheel of the vehicle. With this configuration, both the ring gears of the pair of planetary gears constituting the speed reducer can be omitted, so that the speed reducer can be reduced in size and weight.

  In another aspect of the electric drive device described above, a rectifying ring that covers an outer periphery of the stepped pinion gear can be provided. This rectifying ring is preferably fixed to the carrier part. In the structure in which the ring gear is omitted, the main flow of the lubricating oil generated by the rotation of the planetary carrier is prevented from rotating by the reverse rotation of the pinion gear. The turbulent flow can be confined in the rectifying ring so that the main flow of the lubricating oil is not affected.

  Another aspect of the above-described electric drive device includes a lubricating oil tank attached to the speed reducer, and the rectifying ring includes a lifting member for lifting the lubricating oil to the tank on the outer periphery thereof. Can do. The lifting member can be provided on the outer periphery of the rectifying ring, or can be provided on the side surface of the rectifying ring on the electric motor side. When the ring gear does not exist on the outer periphery of the planetary gear constituting the speed reducer, the ability to lift up the lubricating oil to the tank is reduced, so that the rectifying ring is provided with a lifting member so that it acts as a lifting ring. As a result, the lubricating oil can be effectively lifted into the tank. The drag resistance of the rotor in the electric motor can be reduced.

  In another aspect of the electric drive device described above, the rotating shaft of the electric motor has a hollow structure that functions as an oil passage for lubricating oil. Further, the rotating shaft of the electric motor can be provided with a notch for ejecting internal lubricating oil by a centrifugal force of rotation. Further, the electric drive device may include a lubricating oil tank attached to the speed reducer, and an oil passage that guides the lubricating oil in the tank into the rotating shaft of the electric motor. Thus, the lubricating oil is guided from the tank into the rotating shaft of the electric motor in the electric motor and the speed reducer. Since the rotating shaft of the electric motor rotates at high speed, the lubricating oil can be supplied to each part in the electric motor and the speed reducer by using the centrifugal force for lubrication.

  In another aspect of the electric drive device described above, the speed reducer includes a lubricating oil holding portion that holds the lubricating oil ejected from the notch and sends it to the stepped pinion gear, and the lubricating oil holding portion includes: The carrier portion, the plate-like member provided on the carrier bearing, and the film structure provided on the carrier portion. Further, the carrier portion may have a tapered portion at an inlet portion of the lubricating oil to the stepped pinion gear in the lubricating oil holding portion.

  In this aspect, the lubricating oil ejected from the rotating shaft of the electric motor is supplied to the stepped pinion gear through the lubricating oil holding part. The lubricating oil holding part restricts the moving direction of the lubricating oil to the stepped pinion direction by the plate-like part provided on the carrier bearing and the film structure provided on the carrier part. Further, a tapered portion is formed at the inlet portion of the lubricating oil to the stepped pinion gear so that the lubricating oil can easily enter. Thereby, it becomes possible to supply lubricating oil efficiently to a stepped pinion gear.

  Preferred embodiments of the present invention will be described below with reference to the drawings.

[Basic configuration of vehicle]
First, a basic configuration of the vehicle 100 according to the present embodiment will be described. In addition, the vehicle 100 according to the present embodiment is an application of the present invention to an FR vehicle (engine front and rear wheel drive system) of 4WD (four wheel drive) specification. However, the application of the present invention is not limited to this, and can also be applied to general FR vehicles and FF vehicles (engine front wheel drive system). Further, since this vehicle is premised on a known 4WD FR vehicle, description of 4WD is omitted.

  FIG. 1 shows a configuration of a vehicle 100 including a drive unit 8 according to the present invention. FIG. 1 shows a plan view of the vehicle 100. As shown in FIG. 1, the vehicle 100 mainly includes an engine 1, a torque converter 2, a transmission 3, a propeller shaft 4, a differential gear 5, drive shafts 6 and 9, a rear wheel 7, and a front wheel 10. And a drive unit 8, an engine mount 11, and auxiliary machinery 12.

  The engine 1 is an internal combustion engine that generates power by exploding an air-fuel mixture in a combustion chamber. The reciprocating motion of the piston due to the combustion of the air-fuel mixture in the combustion chamber is converted into the rotational motion of the crankshaft (not shown) via the connecting rod (not shown). The crankshaft transmits power to the rear wheel 7 via the torque converter 2, the transmission 3, the propeller shaft 4, the differential gear 5, and the drive shaft 6.

  The torque converter 2 is provided between the engine 1 and the transmission 3. The torque converter 2 uses a working fluid such as oil to function as a clutch for intermittently transmitting the rotational torque output from the engine 1 to the transmission 3 and to transmit the rotational torque to the transmission 3 by increasing the rotational torque. It has the function to do.

  The transmission 3 is provided between the torque converter 2 and the propeller shaft 4 and has a plurality of gears (planetary gears) corresponding to each of the four forward speeds (first to fourth speeds) and the first reverse speed. Have The transmission 3 operates a hydraulic control device (not shown) based on a command signal from the ECU, thereby performing a shift operation from a low speed to a high speed (shift up) or a shift from a high speed to a low speed (shift down). )I do.

  The propeller shaft 4 is a propulsion shaft that is provided between the transmission 3 and the differential gear 5 and transmits the driving force obtained from the engine 1 to the rear wheel 7 side.

  The differential gear 5 is composed of a combination of a plurality of bevel gears, and is a gear that adjusts the rotational speeds of the inner and outer wheels when the vehicle rotates. Specifically, when the vehicle 100 travels on a straight road, the differential gear 5 rotates the left and right front wheels at the same speed. On the other hand, when the vehicle 100 makes a turning motion, a difference between the rotational speeds of the left and right front wheels is generated. Therefore, the differential gear 5 adjusts the rotational speeds thereof to enable a smooth turning motion.

  The drive shaft 6 is an axle that is rotatably connected to the left and right rear wheels 7. The drive shaft 6 is rotated by a driving force from the engine 1 and transmits power to the rear wheel 7.

  The drive unit 8 includes, for example, a permanent magnet type synchronous motor that converts electrical energy into mechanical energy, and is provided at a position for driving the left and right front wheels.

  The drive shaft 9 is an axle that is rotatably connected to the left and right front wheels 10 independently on the left and right. The drive shafts 9 are output shafts of the left and right drive units 8, respectively, and are given drive force independently from each drive unit 8. That is, the left and right front wheels 10 are driven independently by the left and right drive units 8. By making the left and right wheel drive units independent (not connected) in this way, the entire drive unit can be miniaturized, and mounting on the front wheel side of FR vehicles with particularly large space constraints becomes easy.

  The engine mount 11 is a member that connects the vehicle body and the engine 1 and is provided in the engine room. Examples of the auxiliary machines 12 include an air conditioner compressor.

[First embodiment]
Next, the structure of the drive unit 8 according to the first embodiment will be described with reference to FIG.

(First example of gear train)
FIG. 2A schematically shows the internal structure of the drive unit 8. The drive unit 8 includes a motor unit 20 and a speed reduction unit 40, and is connected to a drive shaft 9 that is an output shaft.

  The motor unit 20 includes a stator 21, a rotor 22, and a rotor shaft 23. The stator 21 is obtained by winding a coil wire around mild steel or the like, and receives a power supply from the outside to change the magnetic field every moment. The rotor 22 rotates as the magnetic field of the stator 21 changes. The rotation of the rotor 22 is extracted by the rotor shaft 23 and transmitted to the speed reduction unit 40.

  The speed reduction unit 40 is configured by a gear train in which a first planetary gear 41 and a second planetary gear 42 are combined. FIG. 2B schematically shows the configuration of the first example of the gear train. As shown in the figure, the gear train of the speed reduction unit 40 is configured by a combination of a first planetary gear 41 and a second planetary gear 42. Basically, the first planetary gear 41 includes a sun gear 41S, a pinion gear that revolves while rotating around the sun gear, a ring gear 41R that rotates on the outer periphery thereof, and a planetary carrier 41C that rotatably holds the pinion gear. Similarly, the second planetary gear 42 includes a sun gear 42S, a pinion gear, a planetary carrier 42C, and a ring gear 42R.

  In the gear train of this embodiment, first, the output from the motor unit 20 is given to the sun gear 41S of the first planetary gear 41 via the rotor shaft 23. The planetary carrier 41C of the first planetary gear 41 is connected to the planetary carrier 42C of the second planetary gear 42, and the ring gear 42R of the second planetary gear 42 is fixed to the casing of the speed reduction unit 40, for example. The planetary carrier 42C of the second planetary gear 42 is connected to the drive shaft 9, and the output after deceleration is taken out from the drive shaft 9.

  As can be seen from FIG. 2B, in this gear train, the ring gear 41R of the first planetary gear 41 and the sun gear 42S of the second planetary gear 42 do not contribute to the rotation and can be omitted (shown by broken lines). ). Thereby, the reduction part 40 can be reduced in weight and size.

  What is configured in this manner is the gear train inside the speed reduction unit 40 of FIG. In FIG. 2A and the following description, the planetary carriers 41C and 42C of the first and second planetary gears 41 and 42 connected to each other will be referred to as a “connected carrier portion 44”. A stepped pinion gear 45 is used at the connecting portion between the planetary carriers 41C and 42C. The “stepped pinion gear” is a pinion gear formed by integrally molding two pinion gears having different diameters on the same axis. An example of the outer shape of the stepped pinion gear 45 is shown in FIG. 3A, and its structure is schematically shown in FIG. In this embodiment, as schematically shown in FIGS. 3A and 3B, the stepped pinion gear 45 is formed by integrally forming a pinion gear portion 41p on the first planetary gear 41 side and a second planetary gear 42p portion. The diameter of the pinion gear 41p portion on the first planetary gear 41 side is larger than the diameter of the pinion gear portion 42p on the second planetary gear 42 side. As shown in FIGS. 2A and 2B, the pinion gear portion 41 p on the first planetary gear 41 side of the stepped pinion gear 45 meshes with the sun gear 41 </ b> S of the first planetary gear 41. Further, the pinion gear portion 42p on the second planetary gear 42 side of the stepped pinion gear 45 meshes with the ring gear 42R of the second planetary gear 42.

  With the above configuration, the rotation of the motor unit 20 is transmitted to the sun gear 41S of the first planetary gear 42 via the rotor shaft 23. The rotation of the sun gear 41S is transmitted to the stepped pinion gear 45. The ring gear 42R of the second planetary gear 42 is fixed, and the rotation of the stepped pinion gear 45 is transmitted to the drive shaft 9 as the rotation of the connecting carrier portion 44 integrated with the stepped pinion gear 45 and output.

(Second example of gear train)
Next, another example of the gear train provided in the speed reduction unit 40 will be described. FIG. 4 schematically shows the structure of another example of a gear train using two planetary gears. This gear train is also constituted by a combination of the first planetary gear 41 and the second planetary gear 42. Similar to the example shown in FIG. 2, the stepped pinion gear 45 is used, and the connecting carrier portion 44 that holds the stepped pinion gear 45 rotatably is fixed. The output from the motor unit 20 is given to the sun gear 41S of the first planetary gear 41. The connection carrier portion 44 is fixed, and the rotation of the sun gear 41S is transmitted to the sun gear 42S of the second planetary gear 42 via the stepped pinion gear 45, and the rotation after deceleration is output from the drive shaft 9 connected to the sun gear 42S. The In this example, since the connecting carrier portion 44 is fixed and the sun gear 42S of the second planetary gear 42 is used as an output, both the ring gears of the first and second planetary gears 41 and 42 can be omitted. As a result, the size of the gear train itself can be reduced and the weight can be reduced. In particular, in this example, compared to the first example of the gear train shown in FIG. 2, the ring gear can be omitted for both the first and second planetary gears, so that the outer shape of the speed reduction unit 40 can be further downsized. Therefore, it is particularly suitable for mounting on the front wheel side of an FR vehicle, for example, where an arrangement space such as a steering shaft is required.

  As described above, in the drive unit of the present invention, since the motor unit 20 and the speed reduction unit 40 are arranged coaxially, the drive shaft and the axle shaft pass through, so that they are arranged on an axle having a relatively large space. It becomes possible to do. Further, by disposing the heavy motor portion on the center side of the vehicle and disposing the speed reduction portion on the wheel side, it is possible to reduce the size of the mounting portion of the drive device for the vehicle. Furthermore, by using a gear train that uses a stepped pinion type planetary gear, it is possible to obtain a desired high reduction ratio while reducing the size and weight of the entire reduction part. In the first and second examples of the gear train, a reduction ratio of about 8 can be realized.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG. 2nd Example is related with the method of controlling the flow of the lubricating oil in the deceleration part 40 in the drive unit 8 which uses the 1st example of the gear train in the above-mentioned 1st Example.

  Generally, in the case of adopting a structure in which a ring gear rotates in a transmission using a planetary gear, a circulating flow of lubricating oil is constituted by the ring gear having the largest diameter. That is, a large number of teeth provided on the outer periphery of the ring gear play a role of scooping up the lubricating oil accumulated in the transmission from the bottom to the top, and the effect of circulating the lubricating oil in the transmission can be obtained.

  In this regard, in the first example of the gear train described above, since the ring gear 41R on the first planetary gear 41 side is omitted, the above-described circulation effect of the lubricating oil by the ring gear cannot be obtained on the first planetary gear 41 side. The main flow of the lubricating oil in the speed reduction part 40 is basically formed by the rotation of the connecting carrier part 44. However, the pinion gear portion 41p on the first planetary gear 41 side of the stepped pinion gear 45 revolves while rotating on the outer periphery of the sun gear 41S in the direction opposite to that of the sun gear 41S. For this reason, the rotation of the pinion gear portion 41p disturbs the main flow of the lubricating oil formed by the rotation of the carrier connecting portion 44 (hereinafter referred to as “lubricating oil turbulence”), and the lubricating oil. The problem that the agitation resistance increases may arise.

  From the above viewpoint, in the second embodiment, in order to remove the influence of the turbulent flow of the lubricating oil caused by the rotation of the stepped pinion gear 45 on the main flow of the lubricating oil in the speed reduction unit 40, a rectifying ring is used. Provide.

  FIG. 5A schematically shows the internal structure of the drive unit 8 including the rectifying ring 50, and FIG. 5B shows an example of the shape of the rectifying ring 50. The rectifying ring 50 is disposed so as to accommodate the sun gear 41S and the pinion gear portion 41p of the first planetary gear 41 therein. Therefore, the inner peripheral surface 51 of the rectifying ring 50 functions as a rectifying surface that prevents the turbulent flow of the lubricating oil from escaping outside the rectifying ring 50. Further, the side surface 52 (the left side surface of FIG. 5B) of the rectifying ring 50 is used as a fixing surface for fixing the rectifying ring 50 to the connection carrier portion 44 as shown in FIG. 5A.

  As shown in FIG. 5A, the rectifying ring 50 is fixed to the connection carrier portion 44 so as to cover the outer periphery of the sun gear 41 </ b> S and the pinion gear portion 41 p of the first planetary gear 41, and the rotation of the connection carrier portion 44. Rotate with. Accordingly, the pinion gear portion 41p of the stepped pinion gear 45 revolves while rotating around the outer periphery of the sun gear 41S in the rectifying ring 50, and the turbulent flow of the lubricating oil generated by the pinion gear portion 41p is retained in the rectifying ring 50, It is possible to prevent the main flow of the lubricating oil generated outside the 50 from being affected. Thereby, it becomes possible to smooth the lubrication inside the deceleration part 40. FIG.

[Third embodiment]
Next, a third embodiment of the present invention will be described. This embodiment relates to a structure for circulating lubricating oil in the drive unit 8 adopting the first example of the gear train in the first embodiment. In the configuration in which the motor unit 20 and the speed reduction unit 40 are coaxially arranged as in the drive unit 8 of the present invention, when the lubricating oil circulates in the motor unit 20 and the speed reduction unit 40, the level of the lubricating oil is the motor of the motor. If the gap is higher than the gap, there is a problem that the drag resistance of the motor increases.

  Specifically, in the drive unit 8 in which the motor unit 20 and the speed reduction unit 40 are provided coaxially as shown in FIG. 6, the level of lubricating oil when the motor unit 20 is not operating (hereinafter referred to as “static”). L2 is higher than the level of lubricating oil (hereinafter referred to as “dynamic oil bath level”) L1 while the motor unit 20 is operating. In the state of the static oil bath level L2, the gap G between the stator 21 and the rotor 22 (hereinafter referred to as “motor gap”) is lower than the static oil bath level L2, and the rotor 22 is partially in the lubricating oil. Will be immersed. For this reason, drag resistance at the time of rotation of the rotor 22 (resistance when the rotor 22 rotates against the lubricating oil) increases, and there is a problem that the operating efficiency of the motor decreases.

  For this reason, it is required to lower the dynamic oil bath level by moving the lubricating oil to an oil tank provided in the upper part of the speed reduction unit 40 or the like by some method during the operation of the motor.

  In this respect, the drive unit 8 of the present invention does not include the ring gear on the first planetary gear 41 side as described above, and the pinion gear portion 41p exists on the outermost periphery, so that it is difficult to move the lubricating oil to the upper oil tank. . This point will be described in detail with reference to FIG. For example, when the helical gear 210 is present in the gear train of the speed reducer, as schematically shown in FIG. 7A, the lubricating oil is easily lifted up by the oil tank 212 provided on the top of the speed reducer due to the rotation of the helical gear 210. Become. On the other hand, as schematically shown in FIG. 7 (b), when there is no ring gear on the outermost periphery as in the first example of the gear train described above and a pinion gear 214 is present instead, the lubricating oil is sufficiently raised. The pinion gear 214 rotates in the reverse direction to the sun gear, so that the main flow of the lubricating oil is weakened.

  Therefore, in the present embodiment, the scraping ring 55 for lubricating oil is fixed to the connecting carrier portion 44 and the lubricating oil is guided to the oil tank 60 provided on the upper portion of the speed reducing portion 40. Specifically, as shown in FIG. 6, a rectifying ring 50 is provided on the connecting carrier portion 44 in the same manner as in the second embodiment, and a plurality of blade-type scraping members 54 are provided on the outer periphery of the rectifying ring 50. It was. That is, the rectifying ring 50 according to the second embodiment provided with a plurality of lifting members 54 is used as the lifting ring 55. As a result, the scraping ring 55 rotates according to the rotation of the connecting carrier portion 44, and the scraping member 54 moves the lubricating oil to the oil tank 60 provided on the upper portion of the speed reduction portion 40, thereby reducing the drag resistance of the rotor 22. Let

  FIG. 8 shows an example of the raking ring 55. FIG. 8A shows a scraping ring 55a in which a scraping member 54 is provided on the side surface of the rectifying ring 50 in a circumferential shape, and corresponds to the one illustrated in FIG. On the other hand, FIG. 8B shows a scraping ring 55b in which a plurality of scraping members 54 are provided circumferentially on the outer peripheral surface of the rectifying ring 50 as another example.

  In addition, which structure is adopted as the scraping ring 55 is determined in consideration of the size of the motor unit 20 and the speed reduction unit 40 constituting the drive unit 8. For example, in the example shown in FIG. 6, the diameter of the rectifying ring 50 constituting the lifting ring 55 is equal to the diameter of the motor unit 20, and therefore, the lifting ring 55 a shown in FIG. On the other hand, when the diameter of the motor unit 20 is larger than the diameter of the rectifying ring 50, the position of the rotor 22 is relatively lowered, and the static oil bath level L2 itself is lowered. In that case, as shown in FIG. 8B, a scraping ring 55b having a scraping member 54 provided on the outer periphery of the rectifying ring 50 is used, so that the lubricating oil can be lifted from below. Is preferred.

  As described above, in this embodiment, the oil tank 60 is provided above the motor unit 20 and the speed reduction unit 40, and the lifting ring 55 is fixed to the connecting carrier unit 44 of the gear train. As the connecting carrier portion 44 rotates, the scraping member 54 lifts the lubricating oil at the bottom of the speed reduction portion 40 and moves it to the oil tank 60, thereby reducing the dynamic oil bath level L2 and dragging the rotor 22. Resistance can be reduced. Further, by providing a plurality of scraping members 54 on the rectifying ring 50 in the second embodiment to form the scraping ring 55, the influence of the turbulent flow of lubricating oil generated by the pinion gear portion 41p as in the second embodiment. The effect of removing can also be obtained.

[Fourth embodiment]
Next, a fourth embodiment of the present invention will be described. The fourth embodiment relates to a lubricating oil circulation method in the drive unit 8. In the present embodiment, the gear train in the speed reduction unit 40 may be the first example or the second example described in the first embodiment.

  As in the present invention, in a drive unit including a motor part and a speed reduction part, it is difficult to supply lubricating oil to a bearing for a rotor shaft of the motor part or a pinion of the speed reduction part using a planetary gear. For this reason, a method using a dedicated oil pump is also known, but there are problems such as an increase in the size of the entire drive device and an increase in cost.

  In this embodiment, a method of supplying lubricating oil to each part in the motor part and in the speed reducing part by using the centrifugal force generated by the rotation of the rotor shaft is adopted without providing a dedicated oil pump.

  FIG. 10 schematically shows the configuration of the drive unit 8 that employs the lubrication method according to this embodiment. The basic configurations of the motor unit 20 and the speed reduction unit 40 are the same as those in the first to third embodiments. As illustrated, an oil tank 60 is provided in the drive unit 8 so as to straddle the motor unit 20 and the speed reduction unit 40. A hole 61 is provided at the end of the oil tank 60, and an oil passage 62 is provided so as to penetrate the hole 61 in the vertical direction. The oil passage 62 extends in the vertical direction from the height of the rotor shaft 23 to the height of the oil tank 60. Further, the rotor shaft 23 is hollow, and the lubricating oil can pass therethrough.

  Around the rotor shaft 23, bearings 70 and 71 for the rotor shaft 23 are provided. Further, a planetary carrier bearing 72 is provided in the speed reduction portion 40. These bearings are subject to lubrication.

  Next, the lubricating oil circulation path will be described. The lubricating oil accumulated in the oil tank 60 moves from the hole 61 through the oil passage 62 into the hollow rotor shaft 23 by gravity. The rotor shaft 23 is provided with a notch 80 at a position corresponding to the bearing 70, and a notch 81 is also provided in the vicinity of the bearings 71 and 72. The lubricating oil that has reached the hollow rotor shaft 23 through the oil passage 62 is ejected to the outside from the notches 80 and 81 due to the centrifugal force generated by the high-speed rotation of the rotor shaft. The lubricating oil ejected from the notch 80 lubricates the rotor shaft bearing 70. Further, the lubricating oil ejected from the notch 81 is guided in the direction of the stepped pinion gear 45 of the speed reduction unit 40 according to the broken line arrow. Thus, the rotor shaft bearing 71, the planetary carrier bearing 72, and the stepped pinion 45 are lubricated. Lubricating oil ejected from the notch 81 is used for lubricating the stepped pinion 45 and the like, and then accumulates at the bottom of the speed reduction unit 40, and the scraping ring 55 supplies it to the oil tank 60. Thus, lubrication in the motor unit and the speed reduction unit is performed.

  As described above, according to the present embodiment, the lubricating oil in the drive unit 8 is collected in the upper oil tank 60 by the lifting ring 55, and is guided from there to the hollow rotor shaft 23 using gravity. Then, using the centrifugal force of the rotor shaft 23 that rotates at the highest speed, lubrication is performed by ejecting lubricating oil from a notch provided in the rotor shaft 23 to a necessary portion. Therefore, since the lubricating oil is supplied to the necessary part by utilizing the centrifugal force generated by the rotation of the rotor shaft during the operation of the motor unit, a dedicated oil pump or the like is not required, and the lubrication can be performed effectively at a low cost. .

[Fifth embodiment]
Next, a fifth embodiment of the present invention will be described. The fifth embodiment relates to a structure for effectively supplying lubricating oil to the pinion gear when the lubricating oil circulation structure in the fourth embodiment is used.

  FIG. 9 shows a cross-sectional view of the stepped pinion gear 45 portion from the end of the hollow rotor shaft 23 on the speed reduction unit 40 side. As shown in the drawing, a pinion shaft 48 passes through the center portion of the stepped pinion gear 45. The pinion shaft 48 has a hollow structure, and lubricating oil can flow through the internal oil passage 48a. The stepped pinion gear 45 is rotatably held by the connecting carrier portion 44. A scraping ring 55 is provided so as to cover the first pinion gear portion 41p of the stepped pinion gear 45, and a scraping member 54 is provided on a side surface of the scraping ring 55.

  The lubricating oil that has moved to the right in the drawing in the hollow rotor shaft 23 is sent from the notch 81 to the lubricating oil holding portion 94 in the upper drawing in the drawing by the centrifugal force generated by the rotation of the rotor shaft 23. The lubricating oil holding part 94 is mainly formed by the inner wall 49a of the casing 49 of the speed reduction part 40, the planetary carrier bearing 72, the connection carrier part 44, and the end face 45a of the pinion gear part 41p of the stepped pinion gear 45. The lubricating oil moves through the lubricating oil retaining portion 94 upward along the broken line arrow 90 in the drawing, and moves to the oil passage 48 a inside the pinion shaft 48 through the introduction oil passage 91 provided in the connection carrier portion 44. . Then, through a notch 48 b provided in the pinion shaft 48, the pinion shaft 48 enters the gap 93 between the pinion shaft through hole of the stepped pinion gear 45 and lubricates when the pinion shaft 48 rotates.

  In the lubricating oil holding part 94, a film structure 92 is formed on the connection carrier part 44 substantially in parallel with the end face 45 a of the stepped pinion gear 45. The film structure 92 is continuously formed in the circumferential direction of the connection carrier portion 44. The membrane structure 92 can be integrally formed with the connection carrier portion 44 using the same metal material as the connection carrier portion 44. The membrane structure 92 guides the lubricating oil that has entered the lubricating oil holding portion 94 along the broken arrow 90 in the direction of the upper introduction oil passage 91, and the lubricating oil that has entered the lubricating oil holding portion 94 is stepped. It suppresses flowing out to the end surface 45a side of the pinion gear 45. As a result, most of the lubricating oil that has entered the lubricating oil holding portion 94 can be used for lubricating the stepped pinion gear 45.

  The planetary carrier bearing 72 includes a Z plate 72a on the left end face in the drawing. The Z plate 72 a prevents the lubricating oil supplied into the bearing 72 from flowing out in the left direction in the figure, and efficiently guides the lubricating oil that has entered the lubricating oil holding portion 94 to the introduction oil passage 91. That is, the lubricating oil holding part 94 suppresses the flow of the lubricating oil to the left side in the figure by the Z plate 72a of the bearing 72 and suppresses the flow of the lubricating oil to the right side in the figure by the membrane structure 92, thereby The lubricating oil ejected from the nozzle 23 is guided in the direction of the upper introduced oil passage 91.

  Furthermore, in this embodiment, the shape of the connecting carrier portion 44 in the vicinity of the inlet of the introduction oil passage 91 is tapered toward the inlet of the introduction oil passage 91, so that the lubricating oil is guided more smoothly to the introduction oil passage 91. To be configured. The shape of this part is schematically shown in FIG. FIGS. 11A and 11B show examples of the shape of the connecting carrier portion 44 in the vicinity of the inlet 99 to the introduction oil passage 91. 11 (a) and 11 (b) correspond to the cross section taken along the cutting plane XX in FIG.

  FIG. 11A shows an example in which the vicinity 99 of the inlet of the connecting carrier portion 44 to the introduction oil passage 91 is formed to have a curved contour, and FIG. 11B shows a linear contour. An example is shown. In any case, the lubricating oil introduced from the inside of the rotor shaft 23 to the lubricating oil holding portion 94 moves in the direction of the arrow due to the centrifugal force of the rotor shaft 23 and smoothly passes through the vicinity of the inlet 99 formed in a tapered shape. Are introduced into the oil passage 91 and supplied to the oil passage 48 a in the pinion shaft 48.

  As described above, in this embodiment, the membrane structure 92 is provided in the connecting carrier portion 44 and the Z plate 72a is provided in the planetary carrier bearing 72, so that the lubricating oil entering the lubricating oil holding portion 94 from the rotor shaft 23 is wasted. Without guiding to the direction of the introduction oil passage 91. Further, the lubricating oil is smoothly introduced into the introduction oil passage 91 by forming the vicinity region 99 of the inlet to the introduction oil passage 91 of the lubricant holding portion 94 in a tapered shape. Thus, the lubricating oil introduced into the lubricating oil holding part 94 by centrifugal force can be effectively used for lubricating the stepped pinion gear 45.

  As described above, in the electric drive device of the above embodiment, the motor unit and the speed reduction unit are arranged coaxially and substantially on the axle, so that the drive shaft and the axle shaft pass therethrough, so that there is a relatively large space. It becomes possible to arrange | position on a certain axle shaft. Further, by disposing the heavy motor portion on the center side of the vehicle and disposing the speed reduction portion on the wheel side, it is possible to reduce the size of the mounting portion of the drive device for the vehicle. Furthermore, by using a gear train that uses a stepped pinion type planetary gear, it is possible to obtain a desired high reduction ratio while reducing the size and weight of the entire reduction part.

  In the example of the vehicle 100 shown in FIG. 1, the electric drive device according to the first to fifth embodiments described above is provided on the front wheel side of the FR vehicle, but conversely, it may be provided on the rear wheel side of the FF vehicle. Is possible.

[Sixth embodiment]
Next, a sixth embodiment of the present invention will be described. In the above first to fifth embodiments, the electric drive device of the present invention is applied to the drive unit shown in FIG. 1, but in the sixth embodiment, the electric drive device of the present invention is an in-wheel type. It is the example comprised as a drive unit.

  FIG. 12A shows a schematic configuration of the drive unit 108 according to the sixth embodiment. As shown, the drive unit 108 is incorporated within the wheel. Similar to the above-described embodiment, the drive unit 108 mainly includes a motor unit 110 and a speed reduction unit 112. Here, the motor unit 110 and the speed reduction unit 112 can be basically configured similarly to the motor unit 20 and the speed reduction unit 40 according to the first to fifth embodiments. FIG. 12A shows the configuration of the speed reduction unit 112 that employs the first example of the gear train, as in FIG. 2A.

  As shown in FIG. 12A, the motor unit 110 is accommodated in the rim 131 of the wheel 130. An output shaft 109 of the drive unit 108 is coupled to the rim 131 via a hub bearing 126. A brake unit 120 is provided on the outer periphery of the motor unit 110. The brake unit 120 is configured by disposing a disk 111 coupled to a rim 131 of a wheel 130 between a pair of brake pads 121 coupled to a case of the motor unit 110.

The drive unit 108 is suspended from a body (not shown) by a suspension device. An upper arm 114 fixed to a body (not shown) and a lower arm 116 fixed to a subframe (not shown) are coupled to the case of the speed reduction unit 112. In the above configuration, the rotor shaft 123 in the motor unit 110 is connected to the case. The rotation is transmitted to the sun gear 141S of the speed reduction unit 112 and further transmitted to the connection carrier unit 144 via the stepped pinion gear 145. The rotation of the connecting carrier portion 144 is transmitted to the output shaft 109 and is transmitted to the rim 131 of the wheel 130 via the hub bearing 126. Thus, the rotation of the wheel 130 is obtained by the rotation of the rotor 122 in the motor unit 110.

  The in-wheel type drive unit 108 shown in FIG. 12A has a structure in which the motor unit 110 larger than the speed reduction unit 112 is accommodated inside the wheel 130, and therefore the portion of the drive unit 108 located outside the wheel 130 is made small. can do. Since the drive unit 108 is suspended from the body by the suspension device, the shock absorber of the suspension device can be provided close to the drive unit 108 by reducing the portion located outside the wheel 130. There are advantages such as miniaturization.

  FIG. 12B shows another example of the in-wheel type drive unit. Contrary to the drive unit 108 in FIG. 12A, the drive unit 128 is configured by providing the speed reduction unit 112 inside the wheel 130 and providing the motor unit 110 outside thereof. The suspension structure on the body by the wheel 130, the brake unit 120, and the suspension device is basically the same as the example of FIG.

  The rotation of the rotor 122 of the motor unit 110 is transmitted to the sun gear 141S of the gear train of the reduction unit 112, the stepped pinion gear 145, the connection carrier unit 144, and the output shaft 109. The rotation of the output shaft 109 is transmitted to the rim 131 of the wheel 130 via the hub bearing 126. Thus, rotation of the wheel 130 is obtained by rotation of the rotor 122.

  In the in-wheel type drive unit 128 shown in FIG. 12B, the brake unit 120 is provided in the vicinity of the outer periphery of the speed reduction unit 112 instead of the motor unit 110. Therefore, there is an advantage that heat generated by the brake unit 120 is not easily transmitted to the motor unit 110.

  Further, in the in-wheel type drive unit according to the present embodiment, a rectifying ring and a scraping ring for lubricating oil can be provided as in the second and third embodiments. FIG. 13 shows an example in which a rectifying ring 150 and a lifting member 154 are provided for the in-wheel type drive unit 108 shown in FIG. As shown in the figure, a rectifying ring 150 is provided on the connecting carrier part 144 in the speed reducing part 112, and a rake member 154 for lubricating oil is provided on the rectifying ring 150 so as to function as a rake ring. The rake member 154 rakes up the lubricating oil to the oil tank 160 as the connecting carrier portion 144 rotates. Thereby, lubrication in the motor part 110 and the deceleration part 112 can be performed smoothly.

It is a figure which shows the structure of the vehicle carrying the electric drive device by this invention. It is a figure which shows the 1st example of the gear train which comprises the deceleration part of a drive unit. It is a figure which shows the structure of a stepped pinion gear. It is a figure which shows the 2nd example of the gear train which comprises the deceleration part of a drive unit. It is a figure which shows the example of a structure of the drive unit concerning 2nd Example, and a rectification | straightening ring. It is a figure which shows the structure of the drive unit concerning 3rd Example. It is a figure explaining the state in which the lubricating oil was lifted up by the gear which comprises a deceleration part. It is a figure which shows the example of a raking ring. It is a figure which shows the structure of the drive unit concerning 4th Example. It is sectional drawing which shows the structure of the pinion gear vicinity of the drive unit concerning 5th Example. It is a figure which shows typically the structure of the lubricating oil holding | maintenance part shown in FIG. It is a figure which shows the structure of the in-wheel type drive unit concerning 6th Example. It is a figure which shows the structural example of the in-wheel type drive unit which provided the rectification | straightening ring and the scraping member of lubricating oil.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 8 Drive unit 20 Motor part 21 Stator 22 Rotor 23 Motor shaft 40 Reduction part 44 Connection carrier part 45 Stepped pinion gear 47 Drive shaft 50 Rectification ring 55 Lifting ring 60 Oil tank 94 Lubricant holding part

Claims (14)

An electric motor provided on both sides of the engine and operating independently;
A speed reducer for transmitting rotation of the electric motor to wheels,
The speed reducer is disposed coaxially with the rotating shaft of the electric motor and the wheel,
The speed reducer includes a stepped pinion type planetary gear.   The electric drive device according to claim 1, wherein the electric motor is disposed on a front side of a vehicle with respect to an engine mount of the engine. The speed reducer is
A sun gear coupled to the rotating shaft of the motor;
A stepped pinion gear meshing with the sun gear;
A ring gear meshing with the stepped pinion gear and fixed to the speed reducer;
The electric drive device according to claim 1, further comprising: a carrier unit rotatably holding the stepped pinion gear and coupled to the wheel. The speed reducer is
A first sun gear coupled to the rotating shaft of the electric motor;
A stepped pinion gear meshing with the sun gear;
A carrier part rotatably holding the stepped pinion gear and fixed to the speed reducer;
2. The electric drive device according to claim 1, further comprising: a second sun gear that meshes with the stepped pinion gear and is connected to a wheel of the vehicle.   The electric drive device according to claim 3, further comprising a rectifying ring that covers an outer periphery of the stepped pinion gear.   The electric drive device according to claim 5, wherein the rectifying ring is fixed to the carrier portion. Comprising a tank of lubricating oil attached to the speed reducer;
The electric drive device according to claim 5 or 6, wherein the rectifying ring includes a scraping member for scraping lubricating oil to the tank on an outer periphery thereof.   The electric drive device according to claim 7, wherein the lifting member is provided on an outer periphery of the rectifying ring.   The electric drive device according to claim 7, wherein the lifting member is provided on a side surface of the rectifying ring on the electric motor side.   The electric drive device according to claim 1, wherein the rotating shaft of the electric motor has a hollow structure that functions as an oil passage for lubricating oil.   The electric drive device according to claim 10, wherein the rotating shaft of the electric motor includes a notch for ejecting internal lubricating oil by a centrifugal force of rotation.   12. The electric motor according to claim 10, further comprising: a lubricating oil tank attached to the speed reducer; and an oil passage that guides the lubricating oil in the tank into the rotating shaft of the electric motor. Drive device. The speed reducer has a lubricating oil holding part for holding the lubricating oil ejected from the notch and sending it to the stepped pinion gear,
The said lubricating oil holding | maintenance part is comprised by the said carrier part, the plate-shaped member provided in the bearing for said carriers, and the film | membrane structure provided in the said carrier part, It is characterized by the above-mentioned. Electric drive device. The electric drive device according to claim 13, wherein the carrier portion has a tapered portion at an inlet portion of the lubricating oil to the stepped pinion gear in the lubricating oil holding portion.

Images