Automatic Speed Transmission Ratio of Linear Actuator

The linear actuator is a device which converts the rotational motion of the motor in to the linear motion through the lead screw. The linear actuator is used with the fixed ratio. The actuator is used with fixed transmission ratio application. The gear is fixed and it cannot be varied. The field application of the actuator is stamping machine. So, it has limitations of not using the actuator for the different weights. The variable weight and variable speed can be achieved by designing the actuator with the different gear ratio. The transmission ratio is the ratio between the driven and the drive. The different transmission ratio can be achieved by using freewheel at the shaft of the motor. The drive is fixed and is connected to the lead screw.The automatic shifting of the gears is done by measuring the load using the load cell. The load cell gives the output in kilograms. The value of the load is used to shift the gears. The shifting is carried out using the pulse given the PMDC motor by the chopper circuit. So depending on the load the gear position is decided. If the value of the load is less, then the gear position has the less transmission ratio. If the load is high, then the gear position has high transmission ratio. So the actuator will have the low speed and high torque for the heavier loads and the high speed and the low torque can be achieved for the lighter loads.