EC/ECT PLA Catalogue - Thomson - #101

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Precision Linear Actuators www.danahermotion.com 101 Glossary Pr – Sp Protection Class The protection class refers to the environmental rating of the enclosure. The first digit applies to airborne contaminants and the second digit to water/moisture. IP54: protected from dust and splashing water from any direction. IP65: dust tight and protected against low pressure water jets from any direction. Repeatability Repeatability is the ability for a positioning system to return to a location when approaching from the same distance, at the same speed and deceleration rate. Some of the factors that affect the repatability are the angular repeatability of the motor, drive and motion control system, system friction and changes in load, speed and deceleration. Resolution Resolution is the smallest move increment that the system can perform. Some of the factors that affect the resolution are the angular repeatability of the motor, drive and motion control system, system friction, the drive train reduction, the type and lead of the lead screw and changes in load, speed and deceleration. Resolver A resolver is basically a type of rotary electrical transformer used for measuring degrees of rotation and are commonly used on AC servo motors as a feedback device to control the commutation of the motor windings. The resolver is mounted to the end of motor shaft and when the motor rotates the resolver will transmit the position and direction of the rotor to the servo drive which then can control the motor. Most servo drives for AC servo motors on the market today can convert the resolver signal in to a pulse train (encoder signal simulation) which can be used by a motion control to determine and control the position of the motor. Also see “Encoder”, “Servo Drive”, “Servo Motor” and “Motion Control”. RoHS Compliance The RoHS directive stands for “the restriction of the use of certain hazardous substances in electrical and electronic equipment”. This directive bans the placing on the EU market of new electrical and electronic equipment containing more than agreed levels of lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyl (PBB) and polybrominated diphenyl ether (PBDE) flame retardants. All precicion linear actuators, controls and accessories sold in the EU are RoHS compliant. Service and Maintenance Precision liner actuators only need to be lubricated. The intervall between the lubrications depends on the how frequent and hard the actuator works. The lubrication of the entire actuator is done at one single point. No other service or maintenance is required. Servo Drive A servo drive is an electrical device which controls the commutation of a servo motor. Different types of servo motors require different types of drives. To be able to run the system as a servo system there must also be a motion control which give the commands to the servo drive and some kind of feedback (encoder, potentiometer, etc) to the control so that it can determine and adjust the speed and the position of the motor (closed loop feedback). Some servo drives has built in motion controls. Also see “Servo Motor”, Brushless AC Servo Motor” and “Controls”. Servo Motor A servo motor is a motor that works with a feedback device in a closed loop configuration controlled by a motion control. Any type of motor can in principal work as a servo motor but normally when speaking about servo motors you refer to motors that are specially designed to work in servo systems. Also see “Servo Drive”, Brushless AC Servo Motor” and “Controls”. Side Loads See “Extension Tube Side Loads”. Sizing and Selection This catalog can give you an overview of what Danaher Motion can offer you and an indication of which products that may suit your application. But in order to get the best solution for your it is neccessary to know your specific application and to carry out detailed sizing and selection calculations. Please contact customer service for further help. Speed Rating The speed versus load diagrams on each product page show the maximum allowed speed at any given dynamic load ranging from no load to maximum allowed dynamic load. For some actuators however, the critical speed limit can be a limiting factor for the maximum allowed speed if the extension tube extends beyond a certain point. Also see “Load Rating” “Forces” and “Critical Speed Limit”.