JP2013056573A - In-wheel motor drive unit for electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized compact in-wheel type motor drive unit for an electric vehicle provided with a parking brake function.SOLUTION: A plurality of engagement holes 71a made of long holes of circular arc shape are formed at equal intervals on two circles of different diameters the centers of which are the rotation axis of the rotor 13 of an electric motor 10 that rotationally drives the hub wheel 45 for wheel drive, with a motor case 11 having a pair of solenoids 72a, 72b in correspondence with the respective two circles, while, when the electric vehicle is parked, the pair of the solenoids 72a, 72b are put in operation, with at least the plunger 73 of one of the solenoids being engaged with the engagement hole for the control of the rotor 13.

Description

  The present invention relates to a motor drive device for an in-wheel electric vehicle that drives wheels of a vehicle.

  FIG. 1 schematically shows an in-wheel electric vehicle. In this electric vehicle, a motor drive device A using an electric motor as a drive source is housed inside a pair of left and right rear wheels 1 as drive wheels, and each of the pair of rear wheels 1 is independently provided by the motor drive device A. To drive.

  As an in-wheel motor drive device A employed in the in-wheel electric vehicle as described above, one described in Patent Document 1 has been conventionally known. In the in-wheel motor drive device described in Patent Document 1, the rotation output from the rotor shaft of the electric motor is decelerated by the reduction mechanism and output to the hub wheel, and the rotation of the hub wheel is transmitted to the wheel. I have to.

  Here, in the motor drive device described in Patent Document 1, since the braking mechanism is arranged at the end of the wheel opposite to the wheel, the electric motor is arranged close to the wheel of the wheel. Therefore, the support structure for the electric motor can be simplified.

  In addition, since the braking mechanism brakes the rotor shaft on the driving side with a small torque, not on the output side that has been decelerated, a small-sized braking mechanism can be adopted, and the motor driving device can be downsized. It has the feature that can be aimed at.

JP 2000-52788 A

  By the way, although the in-wheel motor drive device described in Patent Document 1 has a braking mechanism, the braking mechanism is a service brake for driving that applies a braking force when the vehicle travels. There is nothing listed.

  Here, in the in-wheel motor drive device, downsizing is required because it is attached to a wheel, and there is a concern about the upsizing by adding a parking brake function for parking, and a compact and compact in-wheel motor with a parking brake function. A drive is required.

  An object of the present invention is to provide a motor drive device for a small and compact in-wheel electric vehicle provided with a parking brake function.

  In order to solve the above-mentioned problems, in the present invention, a stationary stator incorporated in a motor case, an electric motor having a rotor rotatable in the stator, and the electric motor is rotationally driven, and the rotation is performed. In an in-wheel motor drive device for an electric vehicle having a wheel wheel driving hub wheel for transmitting to a drive wheel, a parking brake device is provided between the rotor and the motor case, and the brake device is a rotor. A plurality of engagement holes are provided at equal intervals on two circles having different diameters centered on the rotation axis of the motor case, and the motor case has one of the plurality of engagement holes arranged on the same circle. A pair of solenoids having plungers that can be inserted is provided corresponding to each of the two circles, and at least one of the solenoids is activated when the pair of solenoids is operated. As the maytansinoid the plunger is inserted into one of a plurality of engaging holes on the corresponding circle is the employing the configuration to restrict the relative positional relationship between the formation position and a pair of solenoids of the engaging hole.

  In the in-wheel motor drive device configured as described above, each of the pair of solenoids is operated when the electric vehicle is parked. The plunger is advanced by the operation of the pair of solenoids, and the plunger of at least one solenoid is inserted into one of a plurality of engagement holes on the corresponding circle, and the rotor is braked by the engagement of the engagement holes and the plunger. The electric vehicle is held in a stopped state.

  In the in-wheel motor drive device, since the parking brake device brakes the rotor on the drive side with a small torque, the brake device is a simple device for engaging the solenoid plunger with the engagement hole formed in the rotor. The configuration can be small. Therefore, an in-wheel motor drive device with a compact parking brake function having a small axial length can be obtained.

  Here, the in-wheel motor drive device may be configured to directly transmit the rotation of the rotor of the electric motor to the hub wheel, or a reduction mechanism is provided between the rotor of the electric motor and the hub wheel. The rotation of the rotor may be decelerated and transmitted to the hub wheel.

  By adopting a planetary gear type reduction mechanism as the reduction mechanism and disposing the planetary gear type reduction mechanism inside the rotor, a compact in-wheel motor drive device for an electric vehicle having an axial length can be obtained. it can.

  In the in-wheel motor drive device according to the present invention, the engagement hole can be an arc-shaped long hole. When an arc-shaped long hole is used as an engagement hole, a plurality of engagement holes are formed between adjacent engagement holes at intervals slightly smaller than the outer diameter of the plunger, and a plurality of holes formed on the outer circle are formed. The engagement holes formed on the inner circle and the plurality of engagement holes formed on the inner circle are shifted by a half pitch position in the circumferential direction, and both ends of the engagement holes on the inner circle are the ends of the engagement holes on the outer circle. Indexing when forming a plurality of engagement holes on the outer circle with a relative mounting angle of a pair of solenoids, with the circumferential length of the lap portion being equal to or greater than the outer diameter of the plunger. By setting the integral multiple of the angle, the plunger of at least one solenoid can be reliably inserted into one of the plurality of engagement holes on the corresponding circle when the pair of solenoids are operated.

  Here, when the rotor has a side plate, a cylindrical portion may be provided on the side surface of the side plate, and a plurality of engagement holes may be provided in an inward flange formed at the open end of the cylindrical portion.

  When a self-holding solenoid is used as the solenoid, the plunger is held in the inserted state even when the solenoid is energized with the plunger engaged in the engagement hole, and power is consumed. Can be suppressed, and economic efficiency can be improved.

  In the in-wheel motor drive device for an electric vehicle according to the present invention, a plurality of engagement holes are provided at equal intervals on two circles having different diameters around the rotation axis of the rotor. A pair of solenoids having plungers that can be inserted into one of a plurality of engagement holes arranged on a circle are provided, and the plungers of at least one solenoid are moved into one of the plurality of engagement holes by actuation of the pair of solenoids. Since the brake function for parking can be added to the in-wheel motor drive device with a simple configuration with a small number of parts, a small and compact in-wheel motor drive device with a parking brake can be obtained. be able to.

Schematic diagram of an electric vehicle The front view which shows embodiment of the in-wheel motor drive device which concerns on this invention 2 is a longitudinal sectional view of the in-wheel motor drive device shown in FIG. Sectional drawing which shows the electric motor and deceleration mechanism part of FIG. Sectional drawing which shows the wheel bearing part of FIG. Sectional view along line VI-VI in FIG. (I) and (II) are sectional views showing the braking state of the rotor Sectional drawing which shows other embodiment of the in-wheel motor drive device which concerns on this invention

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 2 to 7 show an embodiment of an in-wheel motor drive device for an electric vehicle according to the present invention. As shown in FIG. 2, an in-wheel motor drive device A is provided inside the wheel 2 in the drive wheel 1.

  As shown in FIG. 3, the in-wheel motor drive device A transmits the electric motor 10, a speed reduction mechanism 60 that decelerates and outputs the rotation of the electric motor 10, and the rotation from the speed reduction mechanism 60 to the drive wheel 1. And a wheel bearing 40 that rotatably supports the drive axle 30.

  As shown in FIG. 4, the electric motor 10 includes a motor case 11, a stator 12 incorporated inside the motor case 11, and a rotor 13 incorporated inside the stator 12.

  The motor case 11 includes a case main body 14 having an end plate 15 and a cover 16 that closes an opening at one end of the case main body 14. The cover 16 is a cylinder that is fitted into the opening end of the case main body 14. The cylindrical portion 16a and the fitting surface of the case main body 14 are sealed by incorporating a seal ring 17.

  The rotor 13 is provided with a cylindrical portion 13b on the outer periphery of the disc portion 13a, a flange portion 13c provided at one end portion of the outer periphery of the cylindrical portion 13b, and a side plate 13d attached to the other end portion of the cylindrical portion 13b. The permanent magnet 13e provided on the outer periphery of the cylindrical portion 13b is sandwiched from both sides, and is rotated in the stator 12 by energizing the coil 12a of the stator 12.

  A boss portion 13f is formed at the center of the disc portion 13a of the rotor 13, and the rotor shaft 18 is inserted into the boss portion 13f. The rotor shaft 18 is prevented from rotating around the rotor 13 by the key 19 and rotates together with the rotor 13.

  The end plate 15 of the motor case 11 is formed with a cylindrical bulging portion 20 that enters the inside of the rotor 13, and the boss portion 13 f is inserted into an insertion hole 21 formed at the center of the bulging portion 20. The space between the boss portion 13f and the insertion hole 21 is sealed by a seal member 22 incorporated between the outer diameter surface of the boss portion 13f and the inner diameter surface of the insertion hole 21.

  As shown in FIG. 3, the drive axle 30 is disposed on the outer end side of the rotor shaft 18 and is disposed coaxially with the rotor shaft 18. As shown in FIG. 4, the drive axle 30 has an insertion hole 31 formed at an end facing the rotor shaft 18, and an outer end portion of the rotor shaft 18 by a pair of bearings 32 incorporated in the insertion hole 31. Is supported rotatably.

  As shown in FIG. 5, the wheel bearing 40 that rotatably supports the drive axle 30 includes a bearing outer ring 41 and an inner member 42 incorporated inside thereof. A vehicle body mounting flange 43 is formed on the outer diameter surface of the bearing outer ring 41. The vehicle body mounting flange 43 is abutted against the outer surface of the end plate 15 of the motor case 11, and is tightened by a bolt 44 screwed into the end plate 15. The motor case 11 is attached.

  The inner member 42 includes a hub wheel 45 and a bearing inner ring 46 provided on an inner side end portion of the hub wheel 45, and the bearing inner ring 46 is a small-diameter shaft formed at the inner side end portion of the hub wheel 45. It is fitted to the part 45a. Each of the hub wheel 45 and the bearing inner ring 46 is rotatably supported by a rolling element 47 incorporated between the bearing outer ring 41 and the seal member 48 incorporated on the outer side of the rolling element 47. And both end openings of the bearing space formed at the opposite end portions of the inner member 42 are closed.

  The hub wheel 45 is provided with a wheel mounting flange 49 on the outer periphery of the outer end of the outer ring 41 of the bearing outer ring 41, and a nut 51 is screwed to each of the plurality of bolts 50 provided on the wheel mounting flange 49. The brake rotor 54 that forms a service brake and the wheel 2 of the drive wheel 1 are attached to the wheel attachment flange 49 by engaging the nut 51.

  The drive axle 30 is inserted inside the hub wheel 45 and is prevented from rotating on the hub wheel 45 by engagement by the serrations 52. By attaching the wheel bearing 40 that supports the drive axle 30 to the end plate 15, the opening of the bulging portion 20 provided in the end plate 15 is closed to form a sealed space 53 on the inside. A speed reduction mechanism 60 is incorporated therein.

  As shown in FIG. 4, the speed reduction mechanism 60 includes a sun gear 61 provided at the shaft end of the rotor shaft 18, an internal gear 62 fitted and fixed to the inner diameter surface of the bulging portion 20, and its internal teeth. The planetary gear 63 includes planetary gears 63 that mesh with the inner teeth on the inner periphery of the gear 62 and the outer teeth on the outer periphery of the sun gear 61, and the planetary gear 63 is an inner side end of the drive axle 30. Is supported so as to be rotatable about a gear shaft 65 supported by a disc-shaped carrier portion 64 provided on the outer periphery of the outer periphery of the outer periphery of the gear.

  As shown in FIGS. 3, 4, and 6, a parking brake device 70 is provided on the cover 16 that closes one end opening of the case body 14 in the electric motor 10.

  The brake device 70 is provided with a plurality of engagement holes 71 a and 71 b at equal intervals on two circles having different diameters around the rotor shaft 18 of the rotor 13, and the cover 16 has a plurality of holes arranged on the same circle. A pair of solenoids 72a and 72b having plungers 73 that can be inserted into one of the engagement holes 71 is provided corresponding to each of the two circles, and at least when the pair of solenoids 72a and 72b is operated. The rotor 13 is braked by the engagement of the plunger 73 and the engagement holes 71a and 71b so that the plunger of one solenoid is inserted into one of the plurality of engagement holes on the corresponding circle.

  Here, as shown in FIG. 6, each of the engagement holes 71a and 71b is an arc-shaped long hole, and the engagement hole 71a arranged on the outer circle and the engagement arranged on the inner circle. The joint hole 71b is formed with an interval slightly smaller than the outer diameter of the plunger 73 between the adjacent engagement holes 71a.

  In addition, the plurality of engagement holes 71a arranged on the outer circle of the rotor 13 and the engagement holes 71b arranged on the inner circle are shifted from each other by a half pitch position in the circumferential direction, and are formed on the inner circle. Both ends of 71b overlap with both ends of the engagement hole 71a on the outer circle in the radial direction, and when the circumferential length of the wrap is L and the outer diameter D of the plunger 73, the relationship of L> D is established. Has been.

  Furthermore, if the relative mounting angle of the pair of solenoids 72a and 72b is α, and the index angle when forming the plurality of engaging holes 71a on the outer circle is β, the mounting angle α is an integral multiple of the index angle β. It is said that.

  As described above, by regulating the mutual relationship between the engagement holes 71a and 71b and the interval between the engagement holes adjacent in the circumferential direction and the relative positional relationship between the pair of solenoids 72a and 72b, the pair of solenoids 72a and 72b At the time of operation of 72b, as shown in FIG. 6 and FIGS. 7 (I) and (II), the plunger 73 of at least one solenoid is surely inserted into one of the plurality of engagement holes 71a and 71b on the corresponding circle. Can be inserted.

  Here, FIG. 6 shows a state in which the plunger 73 of the solenoid 72a arranged on the outer circle is inserted into one engagement hole 71a on the outer circle. FIG. 7 (I) shows a state in which the plunger 73 of the solenoid 72b arranged on the inner circle is inserted into one engagement hole 71b on the inner circle, and FIG. A state is shown in which the plungers 73 of the pair of solenoids 72a and 72b are inserted into one engagement hole 71a on the outer circle and one engagement hole 71b on the inner circle.

  The in-wheel motor drive device for an electric vehicle shown in the embodiment has the above-described structure, and when the vehicle travels, the rotor 13 is rotated by energizing the coil 12a of the stator 12 forming the electric motor 10. The rotation of the rotor shaft 18 that rotates with the wheel 13 is transmitted from the hub wheel 45 to the wheel 2 to rotate the drive wheel 1.

  When the vehicle is parked, the pair of solenoids 72a and 72b are operated simultaneously. By the operation of the solenoids 72a and 72b, as shown in FIGS. 6 and 7 (I) and (II), the plunger 73 of at least one solenoid is inserted into the plurality of engagement holes 71a and 71b on the corresponding circle. Then, the rotor 13 is braked by the engagement of the plunger 73 with the engagement holes 71a and 71b.

  Thus, since the rotor 13 can be held in a stopped state by operating the parking brake device 70, it is not necessary to depress the brake pedal of the service brake and maintain the depressed state during parking. .

  Here, when a self-holding solenoid is adopted as the solenoids 72a and 72b, the plunger 73 is inserted even when the solenoid 73 is engaged with the engagement holes 71a and 71b and the solenoid is turned off. Since it is held in a state, power consumption can be suppressed and economic efficiency can be improved.

  When parking on a slope, the rotational torque of the vehicle is applied from the drive wheel 1 to the plunger 73 engaged with the engagement holes 71a and 71b, making it difficult to disengage the plunger 73.

  At this time, there is a circumferential clearance between the planetary gear 63 and the internal gear 62 of the planetary gear type reduction mechanism 60 and the motor case 11, and the rotor 13 can rotate within the clearance, so that the solenoid When the rotor 13 of the electric motor 10 is rotated forward or backward by two signals of a release signal of 72a and 72b and a brake signal of depressing the brake pedal of the service brake, torque is lost momentarily. The plunger 73 comes out of 71a, 71b, and the lock of the rotor 13 can be easily released.

  Further, when the parking brake device 70 is operated, a radial load from the vehicle body weight acts on the plunger 73 via the rotor 13. The force is small on a flat road. However, on a steep slope where the inclination angle is θ, the weight of the vehicle body × sin θ / reduction ratio is applied to the plunger 73.

  At this time, when the radial load applied to the plunger 73 is received by the solenoid body supported by the motor case 11, the operation of the solenoids 72a and 72b is hindered.

  In order to prevent the occurrence of such inconvenience, in FIG. 3 and FIG. 4, the motor case 11 is provided with a slide bearing 75 that slidably supports the plungers 73 of the solenoids 72a and 72b, and the slide bearing 75 receives a radial load. I am doing so.

  The sliding bearing 75 may be made of a sintered alloy, or may be made of a synthetic resin.

  In FIG. 3, a plurality of engagement holes 71 a and 71 b are provided in the disk portion 13 a of the rotor 13, but as shown in FIG. 8, a cylindrical portion 76 is formed on the side surface of the side plate 13 d in the rotor 13, A plurality of engagement holes 71 a and 71 b may be provided in an inward flange 77 formed at the open end of the cylindrical portion 76.

  In the embodiment, the rotation of the rotor shaft 18 is decelerated by the speed reduction mechanism 60 and transmitted to the drive axle 30. However, the drive axle 30 and the speed reduction mechanism 60 are omitted, and the rotation of the rotor shaft is performed by the hub wheel. 45 may be directly transmitted.

DESCRIPTION OF SYMBOLS 1 Drive wheel 10 Electric motor 11 Motor case 12 Stator 13 Rotor 16 Cover 45 Hub wheel 60 Reduction mechanism 70 Brake device 71a Engagement hole 71b Engagement hole 72a Solenoid 72b Solenoid 73 Plunger 75 Slide bearing 76 Cylindrical part 77 Inward flange

Claims (10)

An electric motor having a fixedly arranged stator incorporated in a motor case and a rotor rotatable in the stator, and a wheel wheel driving wheel that is driven to rotate by the electric motor and transmits the rotation to a driving wheel. In an in-wheel motor drive device for an electric vehicle,
A brake device for parking is provided between the rotor and the motor case, and the brake device is provided with a plurality of engagement holes at equal intervals on two circles having different diameters around the rotation axis of the rotor. The motor case is provided with a pair of solenoids having plungers that can be inserted into one of a plurality of engagement holes arranged on the same circle, corresponding to each of the two circles. When the solenoid is operated, the position of the engagement hole and the relative positional relationship between the pair of solenoids are regulated so that the plunger of at least one solenoid is inserted into one of the plurality of engagement holes on the corresponding circle. An in-wheel motor drive device for an electric vehicle characterized by the above.   The in-wheel motor drive device for electric vehicles of Claim 1 with which the deceleration mechanism which decelerates the rotation of the said rotor and transmits to a hub wheel between the said electric motor and the said hub wheel was provided.   The in-wheel motor drive device for electric vehicles according to claim 2 in which said reduction gear mechanism consists of a planetary gear type, and the planetary gear type reduction mechanism is arranged inside said rotor.   The in-wheel motor drive device for electric vehicles according to any one of claims 1 to 3 in which said engagement hole consists of an arc-like long hole by which both ends of a peripheral direction were made into an arc surface.   5. The rotor according to claim 1, wherein the rotor has a side plate, a cylindrical portion is provided on a side surface of the side plate, and the plurality of engagement holes are provided in an inward flange formed at an opening end of the cylindrical portion. An in-wheel motor drive device for an electric vehicle according to any one of the items.   The in-wheel motor drive device for an electric vehicle according to any one of claims 1 to 5, wherein the solenoid is a self-holding solenoid.   The rotor is unlocked by pulling out the plunger from the engagement hole by rotating the rotor of the electric motor forward or backward by two signals of a release signal of the solenoid and a brake signal of depressing a brake pedal of the service brake. The in-wheel motor drive device for electric vehicles of 6.   The in-wheel motor drive device for electric vehicles in any one of Claim 1 thru | or 7 which provided the sliding bearing which supports the plunger of the said solenoid slidably in the said motor case.   The in-wheel motor drive device for electric vehicles according to claim 8 in which said slide bearing consists of sintered alloy.   The in-wheel motor drive device for electric vehicles according to claim 8 in which said slide bearing consists of synthetic resin.

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