Rotary Limit Switches

A rotary limit switch is a rotary limit switch that follows shaft revolutions through a gear reducer connected to the drive shaft and operates its internal switches with its cams at set positions. It is used in the hoisting, travel and bridge movements of cranes and hoists to determine the upper-lower or forward-reverse stopping points based on shaft revolutions. The category includes EMAS VT series rotary limit switches in gear ratios of 1/25, 1/50, 1/75, 1/100, 1/150, 1/200 and 1/300, with 2, 3 or 4 switches (2CO, 3CO, 4CO) and 20° or 60° cams. Select the rotary limit switch by the gear ratio that covers the total shaft revolutions of the movement to be monitored, the number of switches equal to the number of points to be stopped or slowed, the cam angle, and the shaft connection type. As the denominator of the ratio grows (for example 1/300), more drive shaft revolutions correspond to one revolution of the cam shaft, and a longer travel distance can be monitored. A rotary limit switch is not an encoder that provides position as a continuous signal; it only opens and closes contacts at the set positions.

Products

How to choose Rotary Limit Switches

A rotary limit switch is a rotary limit switch that follows shaft revolutions through a gear reducer connected to the drive shaft and operates its internal switches with its cams at set positions. It is used in the hoisting, travel and bridge movements of cranes and hoists to determine the upper-lower or forward-reverse stopping points based on shaft revolutions.

  • Separate sensing, motion control, logic processing and operator interface requirements.
  • Select signal type, supply voltage, communication protocol and I/O count for the machine network.
  • Verify housing size, sensing distance and PNP/NPN output polarity against the PLC input card.

Frequently asked questions

What is Rotary Limit Switches and where is it used?

A rotary limit switch is a rotary limit switch that follows shaft revolutions through a gear reducer connected to the drive shaft and operates its internal switches with its cams at set positions. It is used in the hoisting, travel and bridge movements of cranes and hoists to determine the upper-lower or forward-reverse stopping points based on shaft revolutions.

What should I compare when choosing Rotary Limit Switches?

Select the rotary limit switch by the gear ratio that covers the total shaft revolutions of the movement to be monitored, the number of switches equal to the number of points to be stopped or slowed, the cam angle, and the shaft connection type.

Where can I find technical details for Rotary Limit Switches products?

A rotary limit switch is not an encoder that provides position as a continuous signal; it only opens and closes contacts at the set positions.

Rotary Limit Switches Selection Guide: Technical Criteria and Engineering Practice