Driving device for motor for drive wheel of vehicle

• US 9,712,090 B2
• Filed: 09/16/2016
• Issued: 07/18/2017
• Est. Priority Date: 02/25/2011
• Status: Active Grant

• Current Assignee: NTN Corporation
• Original Assignee: NTN Corporation
• Inventors: Kanda, Takeshi, Yamada, Hiroyuki, Okada, Koichi
• Primary Examiner(s): Cuevas, Pedro J
• Application Number:
  US15/267,777
• Publication Number:
  US 20170005599A1
• Time in Patent Office: 305 Days
• Field of Search: 290 45, 318139, 318801
• CPC Class Codes: B60K 17/356 having fluid or electric motor, for driving one or more wheels disposition of motor in, or adjacent to, traction wheel B60K7/00
• CPC Class Codes: B60K 2007/0038 the motor moving together with the wheel axle
• CPC Class Codes: B60K 2007/0092 the motor axle being coaxial to the wheel axle
• CPC Class Codes: B60K 7/0007 the motor being electric
• CPC Class Codes: B60L 15/007 Physical arrangements or structures of drive train converters specially adapted for the propulsion motors of electric vehicles
• CPC Class Codes: B60L 15/08 using pulses
• CPC Class Codes: B60L 2210/14 Boost converters
• CPC Class Codes: B60L 2210/44 Current source inverters
• CPC Class Codes: B60L 2220/44 Wheel Hub motors, i.e. integrated in the wheel hub
• CPC Class Codes: B60L 2220/46 Wheel motors, i.e. motor connected to only one wheel
• CPC Class Codes: B60Y 2400/61 Arrangements of controllers for electric machines, e.g. inverters
• CPC Class Codes: H02K 11/33 Drive circuits, e.g. power electronics H02K11/38 takes precedence
• CPC Class Codes: H02K 9/00 Arrangements for cooling or ventilating channels or ducts in parts of the magnetic circuit H02K1/20, H02K1/32; channels or ducts in or between conductors H02K3/22, H02K3/24
• CPC Class Codes: H02M 1/008 Plural converter units for generating at two or more independent and non-parallel outputs, e.g. systems with plural point of load switching regulators
• CPC Class Codes: H02M 3/1584 with a plurality of power processing stages connected in parallel
• CPC Class Codes: H02M 7/003 Constructional details, e.g. physical layout, assembly, wiring or busbar connections
• CPC Class Codes: H02P 27/08 with pulse width modulation
• CPC Class Codes: H02P 5/00 Arrangements specially adapted for regulating or controlling the speed or torque of two or more electric motors H02P6/04, H02P8/40 take precedence
• CPC Class Codes: H02P 5/74 controlling two or more ac dynamo-electric motors H02P5/46, H02P5/60 take precedence
• CPC Class Codes: H02P 6/04 Arrangements for controlling or regulating the speed or torque of more than one motor H02P6/10 takes precedence
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility

Abstract

A driving device for motors for drive wheels of a vehicle includes a plurality of in-wheel motor assemblies and motor drivers. The motor drivers include a smoothing circuit, an inverter unit to convert the direct current power, inputted through the smoothing circuit, into a three phase alternating current power, an inverter control unit for controlling the inverter unit, and a cooler for cooling the inverter unit. The plurality of the motor drivers are disposed within a single common casing and the plurality of the motor drivers share the smoothing circuit. The inverter control unit of the plurality of the motor drivers is of a control type capable of driving the driving element of the inverter unit according to the PWM scheme and the plurality of the motor drivers have equal cycles of PWM relative to each other and are configured to displace ON and OFF timings of the driving element.

Claims

1. A driving device for motors for drive wheels of a vehicle, comprising:

a plurality of in-wheel motor assemblies incorporated in at least two of a plurality of drive wheels of the vehicle; and

a plurality of motor drivers for controlling the respective in-wheel motor assemblies, the motor drivers including a smoothing circuit that includes a smoothing capacitor and is configured to smooth a direct current power supplied from a battery unit, an inverter unit that includes a plurality of driving elements each configured to perform switching operation and is configured to convert the direct current power, inputted through the smoothing circuit, into a three phase alternating current power through an intermittent operation of the driving elements, and an inverter control unit for controlling the inverter unit and a cooler for cooling the inverter unit;

wherein the plurality of the motor drivers are disposed within a single common casing and, the plurality of the motor drivers share the smoothing circuit which is a component part of those motor drivers, and

wherein the inverter control unit of the plurality of the motor drivers is of a control type capable of driving the driving element of the inverter unit according to the PWM scheme and the plurality of the motor drivers have equal cycles of PWM relative to each other and are configured to displace an ON and OFF timings of the driving element.

2. The driving device for motors for drive wheels as claimed in claim 1, wherein each of the inverter control units includes a calculator having a function of determining ON and OFF timings of the driving element in the inverter unit to thereby control torque or rotational speed of the motor in the in-wheel motor assembly, and a pre-driver circuit configured to control ON and OFF of the driving element in the inverter unit, and

wherein the plurality of the inverter control units share the calculator in the inverter control unit.

3. The driving device for motors for drive wheels as claimed in claim 1, wherein the plurality of the motor drivers displace the ON timings so that the center of an ON timing of the driving element of each of the motor drivers comes to have an equal interval by dividing the PWM cycle by the number of the motor drivers.

4. The driving device for motors for drive wheels as claimed in claim 1, wherein the plurality of the motor drivers displace the ON timings so that the start point of the ON timing of the driving element of the inverter unit of each of the motor drivers comes to have an equal interval by dividing the PWM cycle by the number of the motor drivers.

5. The driving device for motors for drive wheels as claimed in claim 1, wherein the motor drivers displace the ON and OFF timings of the driving element of the inverter unit an angle of 90°

relative to each other in terms of the PWM cycle.

6. The driving device for motors for drive wheels as claimed in claim 1, wherein each of the motor drivers comprises a booster unit for boosting a power supply voltage from an power source, the booster unit including a booster control section, a driving element, a reactor and a rectifier;

and

wherein the plurality of the motor drivers are integrated together so that the inverter control units and the booster control sections of the booster units are at least partially shared among the plurality of the motor drivers.

7. The driving device for motors for drive wheels as claimed in claim 6, wherein each of the inverter control units includes a first calculator having a function of determining ON and OFF timings of the driving element in the inverter unit to thereby control torque or rotational speed of the motor in the in-wheel motor assembly, the first calculator being shared by the plurality of the inverter control units, and

wherein the booster control section includes a second calculator, and the first calculator of the inverter control unit and the second calculator of the booster control section are shared so that the inverter control unit and the booster control section are integrated together.

8. The driving device for motors for drive wheels as claimed in claim 7, wherein the booster unit includes a plurality of driving elements and a plurality of reactors for one booster control section.

9. The driving device for motors for drive wheels as claimed in claim 8, wherein the booster control section of the booster unit drives a plurality of driving elements according to the PWM scheme and render PWM cycles of the plurality of the driving elements to be equal to each other to displace the ON and OFF timings of each of those driving elements.

10. The driving device for motors for drive wheels as claimed in claim 9, wherein the booster control section f the booster unit displaces the ON and OFF timings so that the center of the ON and OFF timings of each of the driving element comes to have an equal interval by dividing the PWM cycle by the number of the driving elements.

11. The driving device for motors for drive wheels as claimed in claim 9, wherein the booster control section or the booster unit displaces the ON and OFF timings so that the start point of the ON and OFF timings of each of the driving element comes to have an equal interval by dividing the PWM cycle by the number of the driving elements.

12. The driving device for motors for drive wheels as claimed in claim 8, wherein the booster control section of the booster unit controls so that the ON timings of all of the plurality of the driving elements will not overlap.

13. The driving device for motors for drive wheels as claimed in claim 8, wherein the booster control section of the booster unit changes the PWM cycle of the plurality of the driving elements.

14. The driving device for motors for drive wheels as claimed in claim 13, wherein the booster control section of the booster unit drives all of the plurality of the driving elements at cycles equal to each other.

15. The driving device for motors for drive wheels as claimed in claim 13, wherein the booster control section of the booster unit renders the PWM cycle to be variable with a proportion of ON and OFF timings of PWM being fixed.

16. The driving device for motors for drive wheels as claimed in claim 15, wherein the booster control section of the booster unit settles the proportion of ON timing of PWM of the plurality of the driving elements to an interval obtained by dividing the PWM cycle by the number of the plurality of the driving elements to thereby displace the ON timings so that the ON timings of each of the driving elements will not overlap.

17. The driving device for motors for drive wheels as claimed in claim 15, wherein the booster control section of the booster unit settles the proportion of OFF timing of PWM of the plurality of the driving elements to an interval obtained by dividing the PWM cycle by the number of the plurality of the driving elements to thereby displace the OFF timings so that the OFF timings of each of the driving elements will not overlap.

18. The driving device for motors for drive wheels as claimed in claim 7, further comprising a bypass path for supplying an electric current with the reactor being bypassed.