What is mechanical power transmission?
Mechanical power transmission is the transmission of mechanical energy (physical motion) from one component of a machine to another. Most machines require some form of mechanical power transmission. Common examples are electric razors, water pumps, turbines and automobiles.
In most cases, the rotational motion of the driving machine is transformed into the rotational motion of the driven machine. However, the speed, torque and direction of rotation may change.
In some cases, the rotary motion can be converted to translational (reciprocating) motion, depending on the functional requirements of the application. These changes can be made using linkages or other machine components.
Types of mechanical transmission:
Various machine components can transmit power between machine shafts. Mechanical power transmission technology includes several methods of transmitting power and speed:
- Shaft Couplings
- Chain drive
- Belt drive
- Electric screws(threaded rod)
The main function of a belt drive is to transmit power between two parallel shafts by means of a belt. Pulleys (also called belt pulleys) are mounted on these shafts and are free to move. The belts used are closed, so they have no beginning or end. If two pulleys have the same diameter, they will turn at the same speed.
However, the difference in axle diameters will result in faster or slower speeds. Belt drive pulleys usually turn in the same direction.
There are three types of belt drives: V-belt, toothed belt and smooth belt. Most drive systems are equipped with V-belts or toothed belts.
1- V-belt drive
A V-belt drive consists of two or more pulleys with V-shaped grooves on their outer surfaces. The V-belt is tensioned in these grooves and when the driving pulley moves, the V-belt moves the driven pulley.
Insufficient V-belt tension or worn V-grooves can cause the belt to slip. Slippage also occurs when the system fails. Multiple V-belts can be used together on pulleys to transmit more power.
2- Toothed belt drive
A timing belt drive consists of two or more pulleys with teeth molded into their outer surfaces to allow the belt to fit between the pulley teeth. Unlike V-belt drives, toothed belt drives have little clearance between the teeth, eliminating the risk of slippage. In addition, the efficiency of the toothed belt drive is higher than that of the V-belt drive.
A chain drive uses two "sprockets" connected by a chain, similar to a belt drive. This chain consists of a series of links aligned with a toothed sprocket. The shaft runs in parallel and all sprockets rotate in the same direction. Like toothed belt drives, chain drives do not slip and can transmit motion over longer distances.
Shaft couplings are used to connect two aligned drive components. They are used in a variety of industries, particularly mechanical drives, paper and graphics, and plastics manufacturing.
In addition to power transmission, shaft couplings have other functions:
- Shock and vibration absorption
- Compensation for misalignment and mechanical flexibility
- Ensuring high torsional rigidity
Transmission by gears
Gear drives are used to transmit torque and power from one shaft to another, so like other types of transmissions, they are often used to change the direction or angle of rotation. In addition, gear drives are used to increase or decrease the torque or speed range. This type of drive is equipped with input and output gears, also known as motor gears and output gears.
Like belt and chain drives, gear drives are non-slip.
Gear drives are often used when high power must be transmitted over short distances. When a small gear drives a large gear, it creates a large force. Conversely, when a large gear replaces a small gear, the power is reduced and the speed is increased.