Electric motor driven vehicle and power unit thereof

• US 5,222,572 A
• Filed: 12/31/1991
• Issued: 06/29/1993
• Est. Priority Date: 07/13/1989
• Status: Expired due to Term

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Ohzeki, Takashi, Kawashima, Yoshinori, Motodate, Shoji, Suzuki, Hideaki, Yamagiwa, Toshio, Uruno, Hiroshi
• Primary Examiner(s): Focarino, Margaret A.
• Assistant Examiner(s): Hurley, Kevin
• Application Number:
  US07/814,818
• Time in Patent Office: 546 Days
• Field of Search: 180/220, 180/221, 180/219, 180/205, 180/206, 180/227, 180/228, 180/229, 180/230, 180/231, 180/65.2, 180/65.1, 180/65.6, 180/65.7
• US Class Current: 180/220
• CPC Class Codes: B60L 15/2054 by controlling transmissions or clutches
• CPC Class Codes: B60L 2200/12 Bikes
• CPC Class Codes: B60L 2220/50 Structural details of electrical machines
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/461 Speed
• CPC Class Codes: B60L 2240/507 Operating parameters
• CPC Class Codes: B62K 2202/00 Motorised scooters
• CPC Class Codes: B62K 2204/00 Adaptations for driving cycles by electric motor
• CPC Class Codes: B62M 7/04 below the frame
• CPC Class Codes: B62M 7/12 with the engine beside or within the driven wheel
• CPC Class Codes: B62M 9/08 involving eccentrically- mounted or elliptically-shaped driving or driven wheel; with expansible driving or driven wheel
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

The invention relates to an electric motor driven vehicle having a driving unit assembled with a motor and transmission mechanism. In order to avoid a load in a low rotational state of the motor, the transmission mechanism is connected with the motor and driving wheel within a range of predetermined rotational numbers in which the motor approaches the vicinity of maximum efficiency. Accordingly, motor driving is possible from the start, and because of the small electric power and the low heat generating quantity, cruising distance is extended and the apparatus is consequently made to be compact and of light weight. The transmission is provided with an automatic starting clutch and an automatic transmission, and when a belt type stepless speed change transmission is used as the automatic transmission, operation of the motor near the vicinity of maximum efficiency can always be maintained in the usual speed change range. The driving unit can be constructed compactly as a power unit of swing type. Further, an advantageous cooling mechanism of the motor and a wiring structure of an electric power supply cord are disclosed herein.

Claims

1. A drive system for an electric motor driven vehicle comprising:

an electric motor;

a driving wheel;

a speed change transmission for transmitting the rotation of said electric motor to said driving wheel to run the vehicle, said speed change transmission maintaining motor speed within a range preselected to be within a desired percentage of maximum motor efficiency; and

an automatic clutch, disposed between said electric motor and said driving wheel, for functioning as a starting clutch.

2. The drive system of claim 1, wherein said speed change transmission varies between two ratios, a maximum ratio and a minimum ratio, which maintains a proper rational speed of said electric motor such that said electric motor operates at substantially maximum efficiency of a 100% duty factor between said two ratios.

3. The drive system of claim 1, wherein said speed change transmission varies between two ratios, a maximum ratio and a minimum ratio, and a duty factor during normal transmission is established at a predetermined value less than 100% so as to be obtained within an excessive output corresponding to at least an incremental amount of running resistance at said maximum ratio.

4. The drive system of claim 1, wherein the drive system is contained entirely in a unitary housing within a recess formed on an external side surface of said driving wheel.

5. The drive system of claim 1 further comprising:

a final reducing gear operatively coupled between said driving wheel of the electric motor driven vehicle and said speed change transmission for rotating said driving wheel; and

a single unitary housing containing said electric motor, said final reducing gear, and said speed change transmission.

6. The drive system of claim 5, wherein a rotary shaft of said electric motor drives said speed change transmission, said said stepless speed change transmission including a driving pulley comprising:

a first movable face slidably supported in an axial direction upon said rotary shaft;

a first fixed face formed on an end of said rotary shaft away from said electric motor;

a ramp plate fixed to said rotary shaft at a position between said electric motor and said first movable face; and

centrifugal force weight, in slidable contact directly between said first movable face and said ramp plate, movable in a radial direction towards and away from said rotary shaft to vary a distance said first movable face is supported along said rotary shaft from said first fixed face to respectively decrease and increase a torque of said electric motor.

7. The drive system of claim 6, said speed change transmission further comprising:

an input shaft, operatively coupled to and rotating said final reducing gear, in response to rotation of said rotary shaft;

a driven pulley comprising

a second movable face slidably supported in axial direction upon said input shaft, and

a second fixed face rotatably supported to said input shaft intermediate said final reducing gear and said second movable face; and

an automatic force clutch, operating as a braking clutch, operatively connected to said input shaft at a first established rotational speed,

said automatic clutch coupling a power of said driving pulley to said input shaft at a second established rotational speed, which is greater than said first established rotational speed.

8. The drive system of claim 6, said speed change transmission further comprising:

an input shaft operatively coupled to and rotating said final reducing gear in response to rotation of said rotary shaft; and

a driven pulley comprising

a second fixed face rotatably supported to an end of said input shaft away from said final reducing gear, and

a second movable face slidably supported in an axial direction upon said input intermediate said electric motor and said second fixed face.

9. The drive system of claim 8, said speed change transmission further comprising:

an automatic force clutch, operating as a braking clutch, operatively coupled to said input shaft and said driven pulley at a first established rotational speed,

said automatic clutch coupling a power of said driving pulley to said input shaft at a second established rotational speed, which is greater than said first established rotational speed,

said automatic clutch and said automatic force clutch operatively coupled to said second movable face.

10. The drive system of claim 5, wherein said desired percentage is 80% of operational maximum efficiency of said electric motor.

11. The drive system of claim 5, wherein the electric motor driven vehicle is an electric bicycle.

12. The drive system of claim 5, wherein said electric motor operates at 60% duty factor to ensure excessive output against running resistance.

13. The drive system of claim 1, further including, means for operating said speed change transmission in a high revolution zone of said electric motor than a peak output revolution of said motor.

14. An electric motor driven bicycle comprising:

a vehicle body including front, central, and rear frame portions extending along a longitudinal axis of said vehicle body and a drive wheel, having a drive wheel axis, coupled to said rear frame portion substantially planar to said longitudinal axis;

an electric motor, fixably mounted to said rear frame portion along a first side of said longitudinal axis and coupled to an external control means and battery supply, for driving a rotary shaft; and

drive means, contained in a single unitary housing pivotally connected to said rear frame portion along a second side of said longitudinal axis opposite that of said first side and operatively connected to said drive wheel, for driving said drive wheel, said drive means comprising

a final reducing gear, operatively coupled to said drive wheel, for rotating said drive wheel, and

a belt type stepless speed change transmission, operatively coupling said rotary shaft to said final reducing gear, for rotatably driving said final reducing gear.

15. The electric motor driven bicycle of claim 14, said electric motor fixably mounted to said rear frame portion so as to be mounted stationary above said drive wheel axis.

16. The electric motor driven bicycle of claim 14, said electric motor fixably mounted to said rear frame portion so as to be mounted stationary above said drive wheel axis.

17. An electric motor driven bicycle comprising:

a vehicle body including front, central, and rear frame portions and a drive wheel, having a drive wheel axis, coupled to said rear frame portion; and

a drive system contained in a single unitary housing coupled to said central frame portion by a plate connector, said rear frame portion by a spring member, and said drive wheel, said drive system comprising

an electric motor, coupled to external control means and battery supply, driving a rotary shaft,

a final reducing gear operatively coupled to and rotating a drive wheel of the electric motor driven bicycle, and

a stepless speed change transmission, operatively coupling said rotary shaft to and driving said final reducing gear,

said drive means implemented so that said electric motor is positioned above said drive wheel axis, and

said battery supply being housed within a battery housing space located under a step floor of said central frame portion to lower the center of gravity of the electric motor driven bicycle, said battery supply accessible through said step floor which is a lid of said battery housing space.

18. The electric motor driven bicycle of claim 17, said battery housing space is a box which is coupled to said central frame portion substantially planar to a longitudinal axis of said central frame portion and at a height substantially equal to said drive wheel axis.

19. The electric motor driven bicycle of claim 18, further comprising control means housing under a seat above said rear frame portion.

20. An electric motor driven bicycle comprising:

a vehicle body including front, central, and rear frame portions and a drive wheel, having a drive wheel axis, coupled to said rear frame portion;

a drive system contained in a single unitary housing, coupled to said central frame portion and said drive wheel, comprising

an electric motor, coupled to an external control means and battery supply, driving a rotary shaft,

a final reducing gear operatively coupled to and rotating a drive wheel of the electric motor driven bicycle, and

a belt type stepless speed change transmission, operatively coupling said rotary shaft to and driving said final reducing gear; and

a magnetically shielded user utilizable vehicle storage compartment.

21. The electric motor driven bicycle of claim 20, said magnetically shielded user utilizable vehicle storage compartment is located beneath a seat above said rear frame portion.

22. The electric motor driven bicycle of claim 21, further comprising a battery housing connected to said central frame portion substantially planar to a longitudinal axis of said central frame portion and at a height substantially equal to said drive wheel axis.

23. An electric motor driven bicycle comprising:

a vehicle body including front, central, and rear frame portions extending along a longitudinal axis of said vehicle body and a drive wheel, having a drive wheel axis, coupled to said rear frame portion substantially planar to said longitudinal axis;

an electric motor, fixably mounted to said rear frame portion along a first side of said longitudinal axis and coupled to an external control means and battery supply, for driving a rotary shaft; and

drive means, contained in a single unitary housing pivotally connected to said rear frame portion along a second side of said longitudinal axis opposite that of said first side and operatively connected to said drive wheel, for driving said drive wheel, said drive means comprising

a final reducing gear, operatively coupled to said drive wheel, for rotating said drive wheel, and

a stepless speed change transmission, operatively coupling said rotary shaft to said final reducing gear, for rotatably driving said final reducing gear,

said rear frame being pivotally coupled to said single unitary housing through a pair of supporting swing arms along said second side and being coupled to a support plate of said electric motor along said first side, said pair of supporting swing arms being pivotable along a central axis of said rotary shaft.

24. A drive system for an electric motor vehicle comprising:

an electric motor;

a driving wheel;

a speed change transmission for an electric motor vehicle comprising;

an electric motor;

a driving wheel;

a speed change transmission for transmitting the rotation of said electric motor to said driving wheel to run the vehicle, said speed change transmission maintaining motor speed within a range preselected to be within a desired percentage of maximum motor efficiency; and

a centrifugal clutch located between said electric motor and speed change transmission.

25. The drive system of claim 24, further comprising:

a transmission, which transmits power of the electric motor to the driving wheel;

said centrifugal clutch, directly fixed to said rotary shaft of the electric motor, being engaged when the rotational speed of the electric motor reaches an established rotating speed in the lower speed, thereby transmitting the driving power of the motor to the transmission.

26. The drive system of claim 25, wherein said transmission is a stepless transmission which reduces the rotation speed.