Title:
DRIVE UNIT AND ELECTRICALLY ASSISTED BICYCLE
Document Type and Number:
WIPO Patent Application WO/2019/163695
Kind Code:
A1
Abstract:
Provided is a drive unit of an electrically assisted bicycle with which it is possible to comparatively reduce the diameter of a portion of a crankshaft 7a that fits with an input transmission body 28 to which a torque sensor 31 is attached, while the diameter of a part of the crankshaft 7a that links to and fits with a crank arm 7b is set to a dimension whereby sufficient linking strength can be achieved. The drive unit has the crankshaft 7a to which input drive force from pedals is transmitted via the crank arm 7b, and the input transmission body 28 which is fitted with the outer periphery of the crankshaft 7a via uneven parts 7c, 28b and on the outer periphery of which a strain-generating part of the torque sensor 31 is formed. A radial direction difference A1, which is the difference between the outside diameter of the location in the crankshaft 7a where the crank arm 7b is fitted and the outside diameter of the location where the input transmission body 28 is fitted, is less than a radial direction difference B1, which is the difference between the recessed part and the protruding part in the uneven part 28b formed in the inner surface of the location in the input transmission body 28 where the crankshaft 7a is fitted.
Inventors:
KAWAKAMI MASAFUMI
Application Number:
PCT/JP2019/005775
Publication Date:
August 29, 2019
Filing Date:
February 18, 2019
Export Citation:
Assignee:
PANASONIC IP MAN CO LTD (JP)
International Classes:
B62M6/55
Foreign References:
| JP2017019446A | 2017-01-26 | |||
| JP2017218104A | 2017-12-14 | |||
| JP2017197130A | 2017-11-02 |
Attorney, Agent or Firm:
MORIMOTO INT'L PATENT OFFICE (JP)
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