Name: bicycle torque and moment about an axis
Uploaded: 2023-09-22T11:49:21.000Z
Duration: 1 min 28 s
Channel: JoVE

自転車に乗ってペダルに力を加えてホイールを回すサイクリストを考えてみましょう。ペダルに力が加わると、取り付けられたチェーンがホイールの歯車に力を加えます。ホイールは車軸を中心に回転するため、回転軸はホイールを通過します。
軸に沿った力のモーメントは、力によってオブジェクトが特定の点または軸を中心に回転する量を測定します。
この場合、ホイールは x-z 平面の y 軸を中心に回転します。ここで、モーメントアーム、または回転軸と力の作用線との間の垂直距離が歯車の半径です。
したがって、y軸の周りの力のモーメントはFrsinθに等しくなります。
力は接線方向であるため、力ベクトルと半径の間の角度は 90 度です。
自転車では、力のモーメントに車軸の角速度を掛けて、車輪の回転によって生成される力を得ることができます。

<ol>
	<li>ヒベラー、RC(2016)。エンジニアリングメカニクス \u2012 静力学と力学。ニュージャージー州ホーボーケン:ピアソンプレンティスホール。145ページ。</li>
</ol>

軸周りの力のモーメント：スカラー

Moment of a Force About an Axis: Scalar

軸周りの力のモーメントは、物体の回転運動を特定の点や軸周りで決定するのに役立つ、力学における重要な概念です。力のモーメントはスカラー解析を用いて計算することができます。この解析では、回転軸と力の作用線との垂直距離、または単にモーメント腕を考慮します。

力のモーメントの概念をよく理解するために、自転車に乗るサイクリストの例を考えてみましょう。サイクリストがペダルに力を加えると、連結されたチェーンが車輪の軸に力を加え、それによって回転します。ここでは、回転軸は車輪の軸を通り、モーメント腕は車輪の軸の半径です。この場合、回転軸周りの力のモーメントは以下のように表されます：

<img alt="Equation 1" src="/files/ftp_upload/14258/14258_Equation_1v2.svg" style="text-align: center; height: 13px;" />

ここで、Fは加えられる力、rは軸の半径、θは力のベクトルと半径の間の角度です。力は接線方向に働くため、力のベクトルと半径の間の角度は90度です。

<p自転車では、力のモーメントに車輪の回転速度をかけることで、車輪の回転によって生み出される力を得ることができます。力のモーメントは、自転車、自動車、航空機などのさまざまな構造や機械の設計において重要であり、安定性と安全性を確保する役割を果たしています。

軸の周りの力のモーメントは、特定の点の周りのオブジェクトの回転運動を決定するのに役立つ力学の重要な概念です。

Education

JoVE Core

Mechanical Engineering

機械工学

Unit 1

ユニット1

Force System Resultants

力の系の合力

KEY TERMS AND CONCEPTS

主要用語と概念

bicycle torque and moment about an axis

The moment of a force about an axis describes how a force can make an object turn around a fixed line. In scalar analysis, the moment is found from the perpendicular distance between the axis of rotation and the line of action of the force. That distance is called the moment arm.

A bicycle gives a clear example of this idea. When the cyclist pushes on the pedal, the chain applies a force to the wheel’s axle and makes it rotate. The axis of rotation passes through the axle, and the moment arm is the axle radius.

For this case, the moment of force about the axis depends on the force, the radius, and the angle between the force vector and the radius. Because the force is tangential, that angle is 90 degrees. The moment of force can also be multiplied by the angular velocity of the axle to find the power produced by the wheel rotation.

This concept is important in the design of bicycles, automobiles, and aircraft. Engineers use it to help maintain stability and safety in these machines and structures.

Bicycle Torque and Moment About an Axis

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Learn how the moment of a force about an axis is found with scalar analysis, using a bicycle axle example and its link to rotational power.

Bicycle Torque and Moment About an Axis | JoVE K12

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mechanical engineering

Bicycle Torque and Moment About an Axis

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