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Improved torque performance on liner actuators

An Inmoco product story

Edited by the Engineeringtalk editorial team Dec 24, 2001

Inmoco has extended the application capabilities of its Exlar GS range of integrated liner actuators with the introduction of the GSX Series, which provide 35% more continuous motor torque

Inmoco has extended the application capabilities of its Exlar GS range of integrated liner actuators with the introduction of the GSX Series, a range of actuators employing T-LAM, a new, segmented lamination stator design.

T-LAM enables 35% more continuous motor torque to be provided from the same frame sizes as existing GS series units, with no cost premium.

The improved torque performance (up to 11.41Nm) and efficiency of the GSX Series units are the result of a design harnessing the combination of high-density Neodymium iron boron magnets and the limited heat generation qualities inherent in the new T-LAM segmented stator design.

In particular, the elimination of end turns in the stator, and the use of thermally conductive potting removes the parts most susceptible to failure in a traditional stator.

The design also benefits from interface insulation against the high voltage and currents of today's servo drives, and from Class H insulation that complies with UL requirements.

Apart from their improved torque performance, the GSX Series actuators have the same dimensions and offer the same mechanical performance advantages as the traditional GS Series.

Both designs combine a brushless servo motor, an inverted roller screw and an encoder/resolver feedback source into a single compact assembly, which eliminates the cost and complexity of a systems engineering approach, as all elements for producing linear motion have been properly matched and designed into the actuator and tested for their efficiency.

The brushless servo design of the GSX series linear actuators allows them to be used in state-of-the art closed loop servo systems, where electronic control of positioning and velocity is required.

In these systems position feedback can be provided in a number of different forms to match customer specifications, including resolvers, encoders or internally mounted linear position feedback sensors.

The GSX series actuators employs an inverted roller screw mechanism to convert the rotary motion of the brushless motor into high speed, high thrust linear motion.

This mechanism has a lead accuracy of 25*m/300mm for high precision operation and can also be supplied with zero backlash.

The large contact area of the roller screw - due to the use of rollers rather than balls, allows high force characteristics while guaranteeing long life - 15 times the life of comparably sized ball screws is common - even in the most demanding repetitive applications.

In addition, the planetary design of the roller screw allows it to be accelerated at over 800mm/sec and rotated faster (up to 5,000 rpm) than comparably sized ball screws.

GSX series actuators offer additional benefits in the form of contamination protection.

In conventional rotary to linear devices the critical mechanisms are exposed to the environment and therefore require frequent inspection, cleaning and lubrication.

In contrast, all converting components in the GSX series actuator are mounted within the sealed motor housing, which is IP65 rated, (IP67 upon request).

The smooth extending rod allows the use of a bushing and seal arrangement, which prevents abrasive particles and other forms of contamination from entering the actuator's critical mechanisms.

This assures trouble-free operation even in the most severe environments.

Lubrication requirements for the GSX series actuators are minimal.

Designed to be lubricated with either grease or recirculated oil, they can be run for up to 10,000 hours between re-greasing.

Recirculated oil lubrication eliminates the need for lubrication maintenance altogether: an oil lubricated GS actuator will operate indefinitely with no servicing requirements.

The GSX actuators are available in a wide variety of stroke lengths, sizes, speeds and mounting configurations.

Inmoco can also supply custom actuators to fit special applications.

A wide range of optional features extends the capabilities of the GSX range these include: internal end switches, electric brakes, linear positioning sensors, backlash free followers and multiple mounting and rod end configurations.

GSX actuators are suitable for use in many demanding applications including, automatic tool changers, dispensing, wire guiding, chip and wafer handling, robot manipulation, testing, web guidance, indexing material cutting, tension control, volumetric pumps, simulation testing, automated assembly, injection moulding and riveting, joining and fastening.