Linear Actuators

What is a Linear Actuator? 

An electric linear actuator is a device that converts rotational motion into linear motion – to produce push and pull movements.It consists of a motor, a gearbox and a spindle including a nut which the moving rod is attached.

This way it is possible to lift, adjust, tilt, push or pull heavy or hard-to-reach objects, simply by applying a voltage.

Mecvel Linear actuators offer quiet and clean movements with reliable accuracy. They are energy efficient and have a long lifetime with little or no maintenance.

A Linear actuator is easy to install compared to hydraulic or pneumatic systems as it takes up much less space and does not require pumps ,hoses or compressors.

What are the main factors to be considered in the sizing of a Linear Actuator?

What is the difference between Static Load and Dynamic Load?

Dynamic, working, or lifting load is the force that will be applied to the linear actuator while it is in motion. Static load, also called the holding load, is the force that will be applied to the linear actuator when it is not in motion.

In what direction can loads be applied to Linear Actuators?

Mecvel Linear actuators can be used in tension, compression or combination applications. Eccentric and side loads should be avoided. If in doubt please contact us on 01388 778400 to discuss

What is the duty cycle capability of a Linear Actuator?/h2>

Duty cycle rating for a linear actuator is generally expressed as a percentage of “on time” (the ratio of on time to total time) or as distance travelled over a period of time. AC actuators operate between no load and rated load with very little change in duty cycle. In DC models, duty cycle is approximately inversely proportional to load (percent of rated capacity).For further help on duty cycles please give us a call.

Is back-driving possible in electro-mechanical Linear Actuators?

Unless otherwise stated back-driving is possible in all electric linear actuators. Mecvel actuators that use a ball screw are normally fitted with an electrical brake (typically motor mounted) to prevent the load from back-driving the actuator. An acme screw actuator is considered self-locking, it may still back-drive if significant vibration and cyclic temperature variations are present. Mecvel acme screw or trapezoidal screw actuators are therefore considered to be self-locking.

What type of motors do the Linear Actuators use?

Mecvel Linear Actuators are available with AC or DC motor variants, however each range has preferred standard types and as a general rule smaller force actuators are DC , whilst high force actautors are AC.The AC Motors will be either 110-115v , 220-240 VAC 1-phase motors, 220-240/380-415VAC 3-phase motors (50/60Hz). For DC voltages, 12v,24v,36v and 48v are standard.

Can Linear Actuators have limit switches?

Mecvel Linear actuators can be supplied with limit switches. The type of limit switches available varies with each product range, these include electro-mechanical  F type these are integrated adjustable limit switches which consist of micro switches operated by a cam mounted inside a terminal box on the side of the actuator.

FCM type which are external adjustable magnetic proximity sensors mounted on the cover tube of the actuator and operate by a magnet fitted to the nut.

Please note If the limit switches are not set correctly the unit may be damaged during operation. Also the limit switches may require resetting if the return tube on the linear actuator is rotated manually, as this will change the limit switch setting.

Some Mecvel Actuators can be also be used with a current limiting device to switch off the motor when it is fully extended or retracted , please give us a call to discuss suitability.

What are the common issues in the failure of an Linear Actuator?

Improper loadings, failure to set limit switches correctly, excessive duty cycle and extreme environments may contribute to premature actuator failure.Please contact us if you need assistance in selection.