What are the different types of servo motors?

Servo motors are an integral component found in a diverse range of applications. From robotics right the way to textile production, servo motors are a beneficial component. There are many different types of servo motors, however, so we’ve elaborated on these below for your convenience. Find out what is a servo motor and in further detail about servo motor control in this useful Matara blog.

What is a servo motor?

Servo motors are electromechanical devices that convert electrical signals into controlled mechanical motion. They’re used for many motion control applications where the precise servo motor control of accuracy, torque and speed is a necessity. These actuators usually consist of a suitable motor, gearbox, position sensor and a controller.

They are typically used for:

• Robotics: Actuating joints in robots for precise movement and manipulation.
• CNC machines: Controlling tool position and trajectory in machining operations.
• Industrial automation: Positioning and control of conveyors, assembly lines, and other machinery.
• Medical devices: Positioning surgical instruments and other medical equipment.

The different types of servo motor

There are many different types of servo motors. However, they’re split into two distinctive categories – DC and AC motors. There are many types of motors within these, which we will detail below.

DC servo motors

DC motors are operated using a DC (direct current) power supply, meaning that the electric current only flows in one direction. Their servo motor control is operated in a very simple manner, with the speed of the motor being directly proportional to the voltage supplied. As a result, these are typically used in simpler, lower-cost applications.

Series motor

Series servo motors are used to provide a high starting torque and draw a large current. The drawback of this motor is that they have less effective speed regulation in comparison to other motor types. You can flip the field voltage using split series field winding to achieve turnaround.

Split series motor

A split series motor can function as an individually energised field-controlled motor. They have a split-field rate with partial or fractional kilowatts and have a common curve for torque and speed, unlike a series motor. This curve represents the rapid reduction of torque in connection with higher speeds, as well as a high stall torque. This provides excellent damping capabilities.

AC servo motors

AC motors are powered through an alternating current (AC), which means that the direction of the electrical current alternates. The speed of these motors is controlled by the frequency of the voltage and the number of magnetic poles. You can find AC servo motors everywhere from automated applications to robotics. They’re typically more commonplace due to their efficiency, dependability and accuracy.

Positional rotation servo motor

Positional rotation servo motors have a shaft output capable of a 180-degree variation. This motor includes several physical stops in the gear, allowing for the protection of the rotational sensor and stopping with movement precision.

Continuous rotation servo motor

A continuous rotation servo motor functions similarly to a positional rotation servo motor, though has no restrictions on its rotational spatial range. The servo’s input is directly linked to the output speed and direction. As a result, there are no limits to movement for both clockwise and anticlockwise directions.

Linear servo motor

A linear servo motor functions similarly to a positional rotation servo motor. The difference between these two types of servo motors however is that this type of motor features extra gears and a rack and pinion mechanism, allowing it to move forwards and backwards in a linear direction.

Servo motors at Matara

At Matara, we’re proud to stock servo motors from Yaskawa. Yaskawa is a highly regarded servo motor manufacturer, known for their groundbreaking motion control, software and robotics supplies across the globe. We supply AC servo motors, known for their high-performance capabilities.

The standard options that Matara UK deals with are AC servo motors, with two main models we supply:

• SGM7J Series 400V – The SGM7J Series can run at 200V 1-phase or 3-phase. They are medium inertia, high-speed motors designed to be lightweight and have a compact footprint. It has an integrated 24-bit encoder resolution, keeping industry-leading positional accuracy with torque ratings up to 2.39N-m at 3000 RPM.

• SGM7A Series 200V – The SGM7A Series motor is a 400V 3-phase motor that is highly efficient and has an integrated 24-bit high-resolution encoder. This range is designed for low inertia, high-speed applications, however, this range is extremely versatile and lends itself well to a wide variety of applications. Offering a wide operating window, the SGM7A is just as capable of operating at high load/slow speed as it is at a low load/high speed

These models come with a range of benefits that pose an advantage over many other motors:

• They are 20% more compact in size, meaning they are easier to fit in more applications.
• They can withstand ambient temperatures from 0c to 40c (with derating, possible usage from 40c and 60c.)
• They can be used with certain Servo pack models.

Linear servo motors at Matara

We hope you now know what a servo motor is, about servo motor control and all about the different types of servo motors in much greater depth after this article.

Matara is a supplier of quality servo motors and many other types of pneumatic actuators. With over three decades of experience, we’ve got a solid background in supplying the UK market with linear automation products and components. Whether you’re looking to set up a new system from scratch or are looking to simply upgrade your existing application, you can find all of the market-leading components you need with us.

To find out more about the linear servo motors available at Matara, contact us today at +44(0) 1684 850000 or email us at sales@matarauk.co.uk.