Drive unit, electrically assisted vehicle having the drive unit, and method of assembling the drive unit

Patent metadata

Field	Value
Publication number	US-10855147-B2
Application number	US-201816058020-A
Country	US
Kind code	B2
Filing date	Aug 8, 2018
Priority date	Aug 9, 2017
Publication date	Dec 1, 2020
Grant date	Dec 1, 2020

Abstract

A drive unit for an electrically assisted vehicle includes an electric motor, an electronic circuit board including a control circuit that controls rotation of the electric motor, a holder that covers an entirety or a portion of the electronic circuit board and is fixed to the electronic circuit board, and a housing that accommodates the electric motor, the electronic circuit board, and the holder, such that the electronic circuit board is at a deeper position than the holder. A position of the holder on the electronic circuit board is fixed by tabs. The holder and the electronic circuit board are fixed to the housing by fasteners extending through first holes in the electronic circuit board and second holes in the holder.

First claim

What is claimed is:

1. A drive unit for an electrically assisted vehicle, the drive unit comprising:
an electric motor;
an electronic circuit board having mounted thereon a control circuit that controls rotation of the electric motor;
a holder that covers an entirety or a portion of the electronic circuit board and is fixed to the electronic circuit board; and
a housing that accommodates the electric motor, the electronic circuit board, and the holder, such that the electronic circuit board is accommodated at a deeper position than the holder; wherein
the electronic circuit board includes a first hole;
the holder includes a second hole and at least two tabs;
a position of the holder on the electronic circuit board is fixed by the at least two tabs; and
the electronic circuit board and the holder are fixed to the housing by a fastener extending through the first hole and the second hole.

2. The drive unit of claim 1 , wherein, when the holder is fixed to the electronic circuit board, the first hole and the second hole oppose each other.

3. The drive unit of claim 2 , wherein
the housing includes a third hole;
when the holder is fixed to the electronic circuit board and the holder, and the electronic circuit board and the holder are inserted in the housing, the first hole and the third hole oppose each other; and
the electronic circuit board is fixed to the housing as a result of the fastener passing through the first hole and into the third hole.

4. The drive unit of claim 3 , wherein
the fastener includes a screw; and
the third hole is a female screw hole.

5. The drive unit of claim 1 , wherein
the second hole in the holder defines a recess along an outer periphery of the holder; and
when the holder is fixed to the electronic circuit board, a predetermined space is provided between the first hole and the outer periphery where the recess is located.

6. The drive unit of claim 5 , wherein the predetermined space is wider than a space that causes interference between the recess and a head of the screw.

7. The drive unit of claim 4 , wherein the second hole in the holder includes a screw guide with a tapered shape.

8. The drive unit of claim 1 , wherein the holder covers a region of the electronic circuit board in a vicinity of or adjacent to the first hole.

9. The drive unit of claim 1 , wherein
the holder further includes an insertion guide on an outer periphery of the holder; and
the insertion guide extends along an inner wall of the housing and in a depth direction of the housing.

10. The drive unit of claim 9 , wherein
an outer edge of the electronic circuit board is spaced apart from a surface of the inner wall of the housing; and
the insertion guide is disposed between the outer edge of the electronic circuit board and the inner wall surface of the housing.

11. The drive unit of claim 1 , wherein
the electronic circuit board further includes at least one wiring line which is electrically connected to the electric motor;
the holder further includes a harness guide on an outer periphery of the holder; and
when the holder is fixed to the electronic circuit board and the holder and the electronic circuit board are inserted in the housing, the at least one wiring line is pushed into and maintained in the housing by the harness guide.

12. The drive unit of claim 11 , wherein
the harness guide includes a first guide and a second guide which are connected to each other;
the first guide extends along an inner wall of the housing and in a depth direction of the housing;
the second guide is connected to the first guide at a predetermined position thereof, and extends in a direction which is perpendicular or substantially perpendicular to the depth direction; and
with the second guide, the harness guide keeps the at least one wiring line in the housing.

13. The drive unit of claim 12 , further comprising a crank shaft; wherein
the electronic circuit board and the holder are each C-shaped or substantially C-shaped, and surround the crank shaft with the crank shaft being in a center thereof; and
the second guide of the harness guide extends in a direction which is perpendicular or substantially perpendicular to the depth direction of the housing and which extends toward the crank shaft.

14. An electrically assisted vehicle comprising:
a plurality of wheels;
the drive unit of claim 1 ; and
a motive power transmission that transmits a driving power generated by the electric motor of the drive unit to at least one of the plurality of wheels.

15. A method of assembling a drive unit for an electrically assisted vehicle, the method comprising:
providing a housing;
providing an electronic circuit board having mounted thereon a control circuit that controls rotation of an electric motor that drives the electrically assisted vehicle, the electronic circuit board including a first hole;
providing a holder including at least two tabs and a second hole;
using the at least two tabs to fix a position of the holder on the electronic circuit board so that the holder covers an entirety or a portion of the electronic circuit board;
inserting the electronic circuit board into the housing while pressing on the holder, so that the electronic circuit board is accommodated at a deeper position than the holder; and
fixing the electronic circuit board and the holder to the housing by passing a fastener through the first hole and the second hole.

Assignees

• Yamaha Motor Co Ltd

Inventors

• Usami Tomohiro

Classifications

• B62M6/45 Primary

  Control or actuating devices therefor · CPC title

• H05K5/006

  characterized by features for holding the PCB within the housing · CPC title

• H02K11/33 Primary

  Drive circuits, e.g. power electronics (H02K11/38 takes precedence) · CPC title

• B62M6/80 Primary

  Accessories, e.g. power sources; Arrangements thereof · CPC title

• B62M6/55

  power-driven at crank shafts parts · CPC title