Servo Motors

The basic definition for Servo Motors are automatic devices that use an error-correction routine to correct the motion of the Servo Motors. The general term servo can be applied to systems other than a Servo Motors that use a feedback mechanism such as an encoder or other feedback device to control the motion parameters. Typically when the term servo is used it applies to 'Servo Motors' but this term is also used as a general control term with the meaning of a feedback loop to position whatever the item is including a Servo Motors.

Servo Motors are different from other controlled motors in that they are controlled by a time-based derivative commonly referred to as the PID loop. The Servo Motors that are used to control position must be capable of changing the velocity of the output shaft because the time-based derivative, or the rate of change of position, is velocity.

There are two main types of Servo Motors - Rotary and Linear.

Rotary Servo Motors
Rotary Servo Motors are what most people think of when they think of Servo Motors. The three types of Servo Motors are: AC Servo Motors, Brush DC Servo Motors, and Brushless DC Servo Motors. The motion of rotary Servo Motors are often converted into linear motion by the use of a screw thread (ball screw or leadscrew), or with the use of belts and pulleys.

Rotary AC Servo Motors are the AC type motor that is used with a feedback device. These are typically only used in smaller application because a large AC Servo Motors is typically too inefficient when compared to its DC or Brushless counterparts.

linear servo motors
linear servo motors are a flattened out Servo Motors where the rotor is on the inside, and the coils are on the outside of a moveable u-channel. Both Servo Motors types are becoming more popular as Servo Motors prices continue to come down.

Servo Motors are considered one of the more expensive motors when compared to AC, Brushless, DC, Stepper, and other motor types. The reason for the expense of Servo Motors is the precision required to make Servo Motors and the expensive components that go along with Servo Motors. Generally speaking Servo Motors are intended to be a very precise positioning or speed control device. The motion should be smooth and very precise. To accomplish these features, Servo Motors are manufactured under very tight control parameters. Along with the cost of Servo Motors are the case, bearings, connectors, and feedback devices. The case is usually industrial grade, often sealed to achieve an IP65 rating or better. The bearings are high quality to make sure that the Servo Motors can run the speeds desired and can handle the appropriate axial and radial loads. The connectors are typically mil-style connectors that can be detached at the motor, but are very reliable and industrial grade. The Feedback devices are typically differential encoders and or resolvers. The devices are very expensive and add cost to Servo Motors.

There are two options for Servo Motors feedback controls, either a servo encoder or a servo resolver. A servo encoder and a servo resolver provide the same solution in many applications, but are vastly different. They are both used to sense speed, direction, and position of the Servo Motors output shaft.

The resolver on the Servo Motors use a second set of rotor and stator coils called the transformer to induce rotor voltages across an air gap. The resolver does not use any electronic components, therefore it's very robust with a high temperature range, and is inherently shock resistance due to its design. A resolver is mostly used in harsh environments.

The optical encoder on Servo Motors uses a rotating shutter to interrupt a beam of light across an air gap between a light source and a photodetector, over time the wear associated with the rotating shutter reduces the longevity and reliability of the encoder. The application will determine whether a resolver or an encoder is needed. Encoders are more accurate and are easier to implement so they should be the first choice for any application. The only reason to choose a resolver is if environmental and longevity requires it.

Anaheim Automation provides many different accessories for our Servo Motors. These accessories include a brake, encoder, connector, cable and a handheld interface unit.

The Servo Motors brake is a 24vdc system. These Servo Motors brakes are perfect for any holding applications. They are available on many Anaheim Automation Servo Motors, and are already attached to the rear of Servo Motors. The Servo Motors brakes have a low voltage design for applications that are susceptible to weak batter, brown out, or long wiring runs. When electric power is applied to the Servo Motors brake the armature is pulled by the electromagnet force in the magnet body assembly, which overcomes the spring action. This allows the friction disc to rotate freely. When electrical power is interrupted, the electromagnetic force is removed and the pressure spring mechanically forces the armature plate to clamp the friction disc between itself and the pressure plate. Anaheim Automation's Servo Motors are designed with a 2500 counts per revolution quadrature encoder, with a resolution of 10,000 pulses per revolution.

Anaheim Automation's Servo Motors come with all the necessary connectors to connect to another company's servo driver or an Anaheim Automation servo driver. These Servo Motors connectors can also be purchased separately if they are lost. Please refer to the user's guide for a specific part number.

Servo Motors cables can be made with the supplied Servo Motors connector, or can be purchased from Anaheim Automation. The Servo Motors cable comes with a standard length of 5M but can be adjusted to any length required.

The steam engine governor is considered the first powered feedback system that used a gain value so it is considered the first servo mechanism. The word Servo Motor comes from the French phrase "Le Servomoteur" or the "slave motor". The first known record of its use was by JJL Farcot in 1868 to describe steam engines and hydraulics for use in steering a ship.

Anaheim Automation provides many different accessories for our servo motor. These accessories include a brake, encoder, connector, cable and a handheld interface unit.

The servo motor brake is a 24vdc system. These servo motor brakes are perfect for any holding applications. They are available on any Anaheim Automation servo motor, and are already attached to the rear of the servo motor. The servo motor brakes have a low voltage design for applications that are susceptible to weak batter, brown out, or long wiring runs. When electric power is applied to the servo motor brake the armature is pulled by the electromagnet force in the magnet body assembly, which overcomes the spring action. This allows the friction disc to rotate freely. When electrical power is interrupted, the electromagnetic force is removed and the pressure spring mechanically forces the armature plate to clamp the friction disc between itself and the pressure plate.

Anaheim Automation's servo motor is designed with a 2500 counts per revolution quadrature encoder, with a resolution of 10,000 pulses per revolution.

Anaheim Automation's servo motor comes with all the necessary connectors to connect to another company's servo driver or an Anaheim Automation servo driver. These servo motor connectors can also be purchased separately if they are lost. Please refer to the user's guide for a specific part number.

Servo motor cables can be made with the supplied servo motor connector, or can be purchased from Anaheim Automation. The servo motor cable comes with a standard length of 5M but can be adjusted to any length required.

Anaheim Automation was established in 1966 as a manufacturer of "turnkey" motion control systems. Its' emphasis on R&D has insured the continued introduction of advanced motor driver/controller, such as the Servo Motors product line. Today, Anaheim Automation ranks among the leading manufacturers and distributor of motion control products, a position enhanced by its excellent reputation for quality products at competitive prices. The Servo Motors product line is no exception to the Company's goal.

Anaheim Automation offers a wide variety of standard and Servo Motors. Occasionally, OEM customers with mid to large quantity requirements prefer to have Servo Motors that are custom or modified to meet their exact design requirements. Sometimes the customization is as simple as shaft modification, brake, oil seal for an IP65 rating, mounting dimensions, wire colors, or label. Other times, a customer might require that Servo Motors meet an ideal specification such as, speed, torque, and/or voltage.
Engineers appreciate that Anaheim Automation's Servo Motors product line can answer their desire for creativity, flexibility and system efficiency. Buyers appreciate the simplicity of the "one-stop shop," and the cost savings of custom Servo Motors design, while engineers are pleased with Anaheim Automation's dedicated involvement in their specific servo motor system.

Anaheim Automation's standard Servo Motors product line is a cost-effective solution, in that they are known for their rugged construction and excellent performance. A considerable size of its sales growth has resulted from dedicated engineering, friendly customer service and professional application assistance, often surpassing the customer's expectations for fulfilling their custom requirements. While a good portion of Anaheim Automation's Servo Motors sales involves special, custom, or private-labeling requirements, the company takes pride in its standard stock base located in Anaheim, California, USA. To make customization of Servo Motors affordable, a minimum quantity and/or a Non-Recurring Engineering (NRE) fee is required. Contact the factory for details, should you require custom Servo Motors in your design.

All Sales for customized or modified Servo Motors are Non-Cancelable-Non-Returnable, and a NCNR Agreement must be signed by the customer, per each request. All Sales, including customized Servo Motors, are made pursuant to Anaheim Automation's standard Terms and Conditions, and are in lieu of any other expressed or implied terms, including but not limited to any implied warranties. Anaheim Automation's customers for the Servo Motors product line is diverse: companies operating or designing automated machinery or processes that involve food, cosmetics or medical packaging, labeling or tamper-evident requirements, cut-to-length applications, assembly, conveyor, material handling, robotics, special filming and projection effects, medical diagnostics, inspection and security devices, pump flow control, metal fabrication (CNC machinery), and equipment upgrades. Many OEM customers request that we "private-label" the Servo Motors, so that their customers stay loyal to them for servicing, replacements and repairs.

PLEASE NOTE: Technical assistance regarding its Servo Motors product line, as well as all the products manufactured or distributed by Anaheim Automation, is available at no charge. This assistance is offered to help the customer in choosing Anaheim Automation products for a specific application. However, any selection, quotation, or application suggestion for Servo Motors, or any other product, offered from Anaheim Automation's staff, its' representatives or distributors, are only to assist the customer. In all cases, determination of fitness of custom Servo Motors in a specific system design, is solely the customers' responsibility. While every effort is made to offer solid advice regarding the Servo Motors product line, as well as other motion control products, and to produce technical data and illustrations accurately, such advice and documents are for reference only, and subject to change without notice.

The following information is intended as a general guideline for the installation and mounting of Servo Motors. WARNING - Dangerous voltages capable of causing injury or death may be present in Servo Motors system. Use extreme caution when handling, testing, and adjusting during installation, set-up, tuning, and operation. It is very important that the wiring of Servo Motors be taken into consideration upon installation and mounting.

Subpanels installed inside the enclosure for mounting Servo Motors system components, must be a flat, rigid surface that will be free from shock, vibration, moisture, oil, vapors, or dust. Remember that the Servo Motors and amplifier will produce heat during work, therefore, heat dissipation should be considered in designing the system layout. Size the enclosure so as not to exceed the maximum ambient temperature rating. It is recommended that the servo amplifier be mounted in an upright position, providing adequate airflow. Servo Motors should be mounted in a stable fashion, secured tightly. NOTE: There should be a minimum of 10mm between the servo amplifier and any other devices mounted in the system/electric panel or cabinet. There should be at least 10mm space in the lateral direction and 50mm space in the longitudinal direction, between the servo motor amplifier and other electronic/electrical devices. For multi-axis systems, mount in the panel left to right according to power utilization (highest to lowest). If power utilization is unknown, mount from left to right based on Amp rating.

NOTE: in order to comply with UL and CE requirements, the servo motor amplifier must be grounded in a grounded conducive enclosure offering protection as defined in standard EN 60529 (IEC 529) to IP55 such that they are not accessible to the operator or unskilled person. As with any moving part in a system, Servo Motors should be kept out of the reach of the operator. A NEMA 4X enclosure exceeds those requirements providing protection to IP66. To improve the bond between the power rail and the subpanel, construct your subpanel out of a zinc-plated (paint-free) steel. Additionally, it is strongly recommended that the servo motor amplifier be protected against electrical noise interferences. Noise from signal wires can cause mechanical vibration and malfunctions.

The following environmental and safety considerations must be observed during all phases of operation, service and repair of Servo Motors system. Failure to comply with these precautions violates safety standards of design, manufacture and intended use of Servo Motors and amplifier. Please note that even a well-built servo motor products operated and installed improperly, can be hazardous. Precaution must be observed by the user with respect to the load and operating environment. The customer is ultimately responsible for the proper selection, installation, and operation of Servo Motors system.

The atmosphere in which Servo Motors are used must be conducive to good general practices of electrical/electronic equipment. Do not operate Servo Motors in the presence of flammable gases, dust, oil, vapor or moisture. For outdoor use, Servo Motors and the amplifier must be protected from the elements by an adequate cover, while still providing adequate air flow and cooling. Moisture may cause an electrical shock hazard and/or induce system breakdown. Due consideration should be given to the avoidance of liquids and vapors of any kind. Contact the factory should your application require specific IP ratings. It is wise to install Servo Motors and amplifier in an environment which is free from condensation, electrical noise, vibration and shock.

The following information is intended as a general guideline for wiring of the Anaheim Automation Servo Motors product line. Be aware that when you route power and signal wiring on a machine or system, radiated noise from the nearby relays, transformers, and other electronic devices can be induced into motor and encoder signals, input/output communications, and other sensitive low voltage signals. This can cause systems faults and communication errors. WARNING - Dangerous voltages capable of causing injury or death, may be present in the servo motor amplifier. Use extreme caution when handling, wiring, testing, and adjusting during installation, set-up, tuning, and operation. Don't make extreme adjustments or changes to the servo motor amplifier parameters, which can cause mechanical vibration and result in failure and/or loss. Once Servo Motors are wired, do not run the servo amplifier by switching On/Off the power supply directly. Frequent power On/Off switching will cause fast aging of the internal components in the servo amplifier, which will reduce the lifetime of servo motor system. It's required to use reference signals to control the running of the servo motor amplifier.

Strictly comply with the following rules:
- Route high-voltage power cables separately from low-voltage power cables.
-Segregate input power wiring and Servo Motors power cables from control wiring and motor feedback cables as they leave the servo amplifier. Maintain this separation throughout the wire run.
-Use shielded cable for power wiring and provide a grounded 360 degree clamp termination to the enclosure wall. Allow room on the sub-panel for wire bends.
- Make all cable routes as short as possible.
- Single point grounding is required when mounting the Servo Motors and servo amplifier, and grounding resistance should be lower than 100?.
- It's prohibited to apply power input noise filter between servo amplifier and Servo Motors.
Factory made cables are recommended for use in our Servo Motors and amplifier systems. These cables are purchased separately, and are designed to minimize EMI. These cables are recommended over customer-built cables to optimize system performance and to provide additional safety for the servo motor system and the user.

NOTE: Meeting CE Requirements for Servo Motors and amplifier system requires a ground system, and the method of grounding the ac line filter and the servo amplifier must match. Failure to do this renders the filter ineffective and may cause damage to the filter. For grounding and filter suggestions, please contact the factory.

WARNING - To avoid the possibility of electrical shock, perform all mounting and wiring of the servo motor and amplifier system prior to applying power. Once power is applied, connection terminals may have voltage present, even when the servo motor and amplifier are not in use.

Anaheim Automation's cost-effective Servo Motors product line is the wise choice for both OEM and user accounts. Anaheim Automation's customers for the Servo Motors product line is diverse: industrial companies operating or designing automated machinery or processes that involve food, cosmetics or medical packaging, labeling or tamper-evident requirements, cut-to-length applications, assembly, conveyor, material handling, robotics, special filming and projection effects, medical diagnostics, inspection and security devices, pump flow control, metal fabrication (CNC machinery), and equipment upgrades. Servo Motors are found in motion systems that require High torque, position, velocity and/or torque control.

Anaheim Automation also offers a Servo Motors product line that integrates matched Servo Motors, servo amplifier and controller in one unit. This design concept makes selection easy, thus reducing errors and wiring time. With friendly customer service and professional application assistance, Anaheim Automation often surpasses the customer's expectations for fulfilling the specific Servo Motors and amplifier requirements, as well as other motion control needs.

NOTE: Technical assistance regarding the Servo Motors product line is available at no charge. This assistance is offered to help the customer in choosing Anaheim Automation products for a specific application. However, any selection, quotation, or application suggestion for Servo Motors, or any other product, offered from Anaheim Automation's staff, its' representatives or distributors, are only to assist the customer. In all cases, determination of fitness of Servo Motors in a specific system application is solely the customers' responsibility. While every effort is made to offer solid advice regarding Servo Motors in a specific application, and to produce technical data and illustrations accurately, such advice and documents are for reference only, and subject to change without notice. Anaheim Automation is in no event responsible or liable for indirect or consequential damages resulting from the use or application of Servo Motors. Improper use of Servo Motors in an application can result in personal injury or death, property damage, and/or economic loss.