不同轉速下發電式自行車訓練台發電與踩踏功率之效益

THE EFFICIENCY OF ELECTRICAL / BIKE POWER TRANSMISSION IN DIFFERENT CADENCES ON BIKE TRAINER WITH GENERATOR

前言：「綠能」概念應用於運動器材的開發越來越被重視，例如：自行車訓練台結合發電機。本研究目的在比較不同轉速下發電式自行車訓練台發電與踩踏功率之效益。方法：6位年輕男性為本研究受試者，在發電式訓練台以隨機次序進行四種迴轉數（60、75、90、105 rpm）以及三種齒輪比（50/21T、50/16T、50/12T）的自行車踩踏測試。踩踏功率計與發電式訓練台裝置於自行車後輪，並以發電機產生之電力通過負載時的電壓與電阻計算電功率，再比較各種測試情況下的發電效益。結果：速度與踩踏功率、電功率間皆有高度相關性。在所有齒輪比下105 rpm的發電效益皆顯著高於60 rpm。另外，在50/12T齒輪比下105 rpm的發電效益顯著高於75 rpm，且90rpm的發電效益也顯著高於60 rpm。結論：發電功率會隨著速度增加而變大。發電效益在高和中齒輪比時由低到中轉速時增加不明顯，但在低齒輪比時轉速對發電效益之影響較大。

Introduction: More and more “Green Power” concepts have been applied to the development of sport equipments， ex. the bike trainer combined with power generator. Therefore， the purpose of this study was to determine the efficiency of electrical / bike power transmission in different cadences on bike trainer with generator. Methods: Six young male were recruited as subjects and performed on the bike trainer with generator with 60， 75， 90 105 rpm cadences and 50/21T， 50/16T， 50/12T gear transmissions by a random sequence. The power meter and the bike trainer were attached on the rear wheel， and the electrical power was calculated by the voltage and resistance of load connected to the generator. Results: There were significantly high correlations among speed， bike and electrical powers. In all gear transmissions， the efficiency of power transmission on 105 rpm was significantly higher than 60 rpm. In 50/12T gear transmissions， the efficiency of power transmission on 105 rpm was significantly higher than 75 rpm， and 90 rpm was also significantly higher than 60 rpm. Conclusions: The electrical power has increased by speed. The change of power transmission efficiency was obvious from low to high cadences in the higher gear transmission， but the effect of cadence would become higher in lower gear transmission.