JPH0920280A - Motorized bicycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate mounting and demounting of an electric motor by apply ing a spline work on the tip of a shaft, in an electric motor with a reduction gear for a motorized bicycle. SOLUTION: Based on a signal outputted from a controller, the electric motor shaft 3 of an electric motor 2 is rotated, a spline machined on the tip of the shaft and a shape machined in the interior of a gear 4 are fitted in each other for fastening. A power transmitted to the gear 4 is transmitted to a clutch 12 through gears 5, 6, and 7 to drive a rear wheel as the number of revolutions is reduced. The size of the electric motor is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an auxiliary drive device for a bicycle equipped with an electric motor.

[0002]

2. Description of the Related Art An electric bicycle is known that detects a human-powered driving force and controls the increase / decrease of the driving force of an electric motor according to the detected increase / decrease of the driving force.

In order to secure a space for installing the electric motor, a bevel gear or the like is used by making the electric motor and the crankshaft orthogonal to each other, or embedded in a rear wheel.

[0004]

However, in the above-mentioned conventional configuration, the electric motor is equipped with a brush, and it is necessary to replace the electric motor depending on the life of the brush and the commutator for long-term use. In addition, even if it breaks down, it is difficult to disassemble the motor for replacement, and due to the tightness and adjustment of the incorporated parts, it cannot be repaired at any bicycle shop.

[0005]

In order to achieve this object, the electric motor-operated bicycle of the present invention is provided with a spline or serration process at the tip of the electric motor, and the electric motor can be removed only by removing the bolts attached to the outside. Is.

[0006]

With this configuration, the shaft tip of the electric motor is splined, the reduction gear is fitted, and the electric motor is attached to the gear BOX. When replacing the electric motor, the gear box can be replaced without disassembling.

Further, since the load applied to the tip of the shaft is received by the entire shaft due to the groove (spline) machined in the shaft, the thickness of the shaft can be made smaller and the motor can be made smaller, unlike the case where the shaft is partially processed like key machining. Can be achieved.

[0008]

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is an electric motor with a speed reducer, 2
Is an electric motor, 3 is a motor shaft tip, 4 is a gear a, 5 is a gear b, 6 is a gear c, 7 is a gear d, 8 is a bearing a, 9 is a bearing b, 10 is a bearing c, 11 is a bearing d, 12 Is composed of a clutch.

The operation of the electric motor with reduction gear constructed as above will be described with reference to FIG.

Based on a signal output from a controller (not shown), the electric motor shaft 3 of the electric motor 2 rotates and the spline formed on the shaft tip and the processed shape inside the gear 4 are fitted and fastened. The power transmitted to the gear 4 is transmitted to the clutch 12 via the gear 5, the gear 6, and the gear 7 while the rotation speed is being reduced, and drives the rear wheel.

The gear 4 is fixed by the bearing 10 embedded in the gear BOX, so that the gear 4 does not fall off even if the motor shaft 3 is removed.

The rotation speed of the electric motor is usually 3000 to 4000.
rpm and the reduction ratio in the gear box is 1/10 to 10
It is 1/20. Therefore, the reduction ratio of the first stage is 1/4 ~
1/6 is used, and the helical gear is used as the gear 4 for noise reduction. Further, by increasing the number of teeth of the sprocket used for the rear wheel of the bicycle, the reduction ratio can be reduced and the gear box can be downsized.

To replace the electric motor, the electric motor and the gear BO
It can be removed simply by removing the bolt that fastens X.

[0015]

As described above, according to the present invention, since the shaft tip of the electric motor is splined and the fitting process is performed on the gear of the reduction gear, the coupling can be detached. Therefore, repairing / replacement of the electric motor does not require disassembling the gear BOX, work can be smoothly performed, and replacement and repair can be easily performed even at a bicycle shop. In addition, since the coupling method that receives the load on the entire shaft and has little notch effect is effective for transmission of drive of the electric motor, it is possible to reduce the shaft diameter of the electric motor, downsizing the electric motor and reducing the cost of the electric motor. Can be achieved.

[Brief description of the drawings]

FIG. 1 is a sectional view of an electric motor with a speed reducer according to an embodiment of the present invention.

[Explanation of symbols]

 1 Electric motor with reduction gear 2 Electric motor 3 Electric motor shaft tip 4 Gear a 5 Gear b 6 Gear c 7 Gear d 8 Bearing a 9 Bearing b 10 Bearing c 11 Bearing d 12 Clutch

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masami Wada 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (2)

[Claims] 1. A motor and means for detecting a human driving force,
It is characterized in that it comprises control means for an electric motor according to the increase or decrease of the measured human driving force, the electric motor and the human driving force are independently separated, and a direct transmission means is provided to a driving wheel of a bicycle. Electric bicycle with auxiliary power. 2. The electric bicycle with auxiliary power according to claim 1, wherein serration and spline processing is applied to a shaft tip of the electric motor, and the electric motor and the reduction mechanism are transmitted by the processing.