CN2390808Y

CN2390808Y - Telescopic crank driving mechanism for bicycle

Info

Publication number: CN2390808Y
Application number: CN 99225236
Authority: CN
Inventors: 崔宝昌
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-10-08
Filing date: 1999-10-08
Publication date: 2000-08-09
Anticipated expiration: 2009-10-08

Abstract

The utility model discloses a telescopic crank driving mechanism for a bicycle. The utility model is characterized in that a sliding sleeve is fixed to the center of a chain wheel, and a crank is inserted in the sliding sleeve; an eccentric disc which is fixed to a bicycle frame and a chain disc form an eccentric structure, and the disc edge of the eccentric disc is provided with a planetary roller; the crank is pivoted with the planetary roller, and the front end of the crank is pivoted with a step tread plate; when moving, the step tread plate can rotate only along the circumference of the eccentric disk, the crank does reciprocation in the sliding sleeve, simultaneously, the lengths of the step tread plate and the chain wheel (a center shaft) can vary following the crank, i.e., the force moment is constantly varied, and therefore, the work is increased under the action of the same force or the usage of force is reduced under the same work condition so that the purpose of labour saving when a bicycle is ridden can be achieved.

Description

Bicycle retractable crank transmission device

The utility model relates to the improvement of transmission mechanism of bicycle, is furtherly to disclose a kind of bicycle retractable crank transmission device, belongs to the mechanical transmissioning technology field.

Conventional transmission mechanism of bicycle is directly to give chain drum with the power transmission by crank, drive cycle racing, because the length of crank is changeless for chain drum, be that moment is constant, so the same power institute work of human is the same, can't further accelerate the speed of bicycle with same power.

The purpose of this utility model aims to provide a kind of bicycle retractable crank transmission device, uses the speed that further improves bicycle with the same propulsive effort of conventional bicycle.

The purpose of this utility model is achieved in that on the axis of bicycle and is provided with sprocket wheel, sliding sleeve is fixed on the middle part of sprocket wheel, crank is inserted in the sliding sleeve, eccentric disk is fixed on the vehicle frame and constitutes eccentric structure with bicycle middle shaft, the dish edge of eccentric disk is provided with planetary roller, crank and planetary roller are coupling, and step tread plate is coupling at the front end of crank; When step tread plate moved in a circle, drive crank and planetary roller moved along the circular path of eccentric disk, and simultaneously, crank reciprocatingly slides in sliding sleeve, and orders about sprocket wheel and rotate around axis, drove cycle racing.

Good effect of the present utility model is: adopt eccentric chain drum structure, can only rotate along the eccentric disk circular path during step tread plate motion, make crank crank motion in sliding sleeve, the length of step tread plate and sprocket wheel (axis) constantly changes with crank, and promptly moment constantly changes, thereby under same power effect, acting increases, or do under the same merit condition, firmly reduce, promptly reach labour-saving purpose by bike.

Fig. 1 is the utility model structure principle chart.

Further specify the utility model below in conjunction with accompanying drawing:

In Fig. 1, chain drum 5 is fixed on the axis 8 of bicycle, is connected with trailing wheel by chain 7, and sliding sleeve 6 is that three roller structures triangular in shape connect, and be fixed on the center of chain drum 5, crank 3 is inserted in the sliding sleeve 6, and eccentric disk 4 is fixed on the bicycle rack, with sprocket wheel 5 (axis) center be that eccentric structure is arranged, the dish edge of eccentric disk 4 is a groove structure, satellite gear 2 is embedded in wherein, and the other end of crank 3 is coupling with satellite gear 2 and step tread plate 1 respectively, drives satellite gear 2 and moves in a circle along eccentric wheel 4; In implementation process, the eccentric throw of eccentric disk and axis is 75 millimeters.

Claims

1, a kind of bicycle retractable crank transmission device, be that chain drum (5) is fixed on the axis of bicycle, be connected with trailing wheel by chain (7), it is characterized in that: sliding sleeve (6) is fixed on the center of sprocket wheel (5), crank (3) is inserted in the sliding sleeve (6), and eccentric disk (4) is fixed on the vehicle frame and constitutes eccentric structure with chain drum (5), and the dish edge of eccentric disk (4) is provided with planetary roller (2), crank (3) is coupling with planetary roller (2), and step tread plate (1) is coupling at the front end of crank (3).

2, bicycle retractable crank transmission device according to claim 1 is characterized in that: above-mentioned sliding sleeve (6) is that three roller structures triangular in shape connect, and is fixed on the center of chain drum (5).