Movement Ratio
Machines and movement ratio (velocity ratio).
A machine is a device that can change the magnitude and line of action of a force.
Examples are
- pulley systems
- gear systems
- screw-jacks
A simple machine amplifies the input force (effort) to a larger output force (load).
Movement Ratio
The movement ratio (or velocity ratio) of a machine is defined as the ratio of the distance moved by the effort to the distance moved by the load. Movement ratio can be expressed as
Mr = se / sl
= velocity ratio (1)
where
Mr = movement ratio
se = distance moved by the effort (m, ft)
sl = distance moved by the load (m, ft)
Machine Efficiency
The efficiency of a simple machine is defined as the ratio of the force ratio to the movement ratio and can be expressed as
μ = Fr / Mr (2)
where
μ = machine efficiency
Fr = force ratio
Related Topics
-
Dynamics
Motion of bodies and the action of forces in producing or changing their motion - velocity and acceleration, forces and torque. -
Mechanics
The relationships between forces, acceleration, displacement, vectors, motion, momentum, energy of objects and more.
Related Documents
-
Conn-Rod Mechanism
The connecting rod mechanism. -
Force Ratio
The force ratio is the load force versus the effort force. -
Motors - Speed vs. Pulley Diameter
Pulley (Sheave) selection charts for motors ranging 850 - 3450 rpm. -
Pulleys
Pulleys, blocks and tackles. -
Ratios and Proportions
The relative values between quantities - ratios and proportions. -
Screw Jack - Effort Force vs. Load
Screw jacks and effort forces. -
Toggle Joint
A toggle joint mechanism can be used to multiply force.
