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Servomotors are made for demanding applications

An Inmoco product story

Edited by the Engineeringtalk editorial team Dec 23, 2005

Three new ranges of DC brush servomotors provide the high levels of response and torque, accuracy and reliability required in demanding applications.

Servo system specialist Inmoco has introduced three ranges of DC brush servomotors that provide the high levels of response and torque, accuracy and reliability required in demanding applications such as robotics, machine tools, automatic handling, papermaking, plastic-film and foil processing, tension control and packaging machinery.

The three ranges are characterised by their compact size, highly dynamic performance and high levels of precision.

Key to this performance is the use of high-energy rare earth magnets, which reduce motor size, yet provide a very favourable power/weight ratio compared with conventional ferrite magnet or wound field motors.

In addition, as the motors are DC units, they offer reduced complexity and are therefore simpler and easier to wire-up and install.

The smallest of the motor series, the M4-200 is designed for applications in the range from 0.4 to 1.6Nm continuous torque and for speeds up to a maximum of 6000rev/min.

It is designed especially for robotics, machine tool and automatic handling equipment, as well as for mobile and general servo-drive applications where accuracy, reliability and high power/weight ratio are vitally important.

The maximum terminal voltage of the M4-200 servomotors has been kept to 90V, but very useful performance can be obtained at lower voltages, such as 48 or 60V: torque from the motors being maintained at reduced speeds.

The flexible design of the M4-200 motors provides the facility for mounting tachos, encoders, resolvers and other positional feed-back devices: this by means of a spigot at the nondriving end with a shaft extension.

A fail-safe brake can also be incorporated onto the motors for more critical applications, and there is also the facility for alternative power connection by MS connectors, cable, or flying leads.

The medium, M4-295, range of servomotors combines small size with exceptional dynamic performance.

The 40Nm peak torque of the M4-295 servomotors delivers ample power for fast, accurate positioning.

This is aided by low motor inertia, which enables theoretical acceleration of up to 25,000rad/s2 to be achieved.

In addition, with a speed range capability in excess of 20,000:1 one M4-295 motor can provide rapid traverse and feed rates for each machine axis, eliminating the complexity and compliance of multiple motors, clutches, and gear trains.

Moreover, the efficient servomotor design means that speeds as low as 6rev/h may be achieved in a positioning loop without cogging.

Underpinning this performance is the unique permanent-magnet structure of the M4-295 servomotors, which eliminates the commutation and thermal runaway problems commonly encountered in conventional ceramic-magnet motors.

Equipped with tachogenerators as a standard feature, the M4-295 DC servomotors are the ideal solution for providing precise motion control in machine tools, robotics, automatic handling, wiredrawing, paper, plastic-film and foil processing, tension controls and packaging machinery.

The largest servomotors in Inmoco's M4, DC range are the M4-420X.

These offer all the operating features and benefits of the M4-295 motors, but are higher-rated, both for power (2.6kW) and torque output.

The peak torque of 161Nm gives ample power for fast, accurate positioning, and the combination of the efficient permanent magnet design and low motor inertia delivers high levels of acceleration, up to a theoretical maximum of 6500rad/s2.

All of the servomotors making up the M4 ranges are supported by a wide range of options, including special shafts - including no keyways, oil seals, brakes, special sealing, special windings, brakes and thermostats.

In addition, the M4-200 servomotors can be offered with an encoder option, as an alternative to the standard tacho equipment.