Posted to News on 6th Aug 2007, 18:39
B&R launches compact, dynamic, reliable servo motors
A system's dynamics can generally be characterised on the basis of two values: the available motor torque and the moment of inertia for the power transmission system. The latter of the two consists of the moment of inertia of both the motor and the load and is an important measurement of the system's dynamics; a lower moment of inertia means higher dynamic properties for the system. In combination with the ACOPOS drive system, B&R's 8LSA series servo motors offer high-performance dynamics, precision and dependability.
The use of 19-bit encoders as standard ensures consistent movements and accurate positioning; 25-bit encoders are available for meeting the highest demands. Both variants are also available as multi-turn encoders. This means that inconvenient homing procedures and additional sensors are no longer necessary. The absolute encoder functions without a battery and is therefore totally maintenance free. The result is a highly dependable system that uses permanent-magnet-excited servo motors in which the only parts subject to wear are the bearings.
Dimensioning of the bearings therefore plays a decisive role in the reliability and longevity of the motors, hence the bearings in the 8LSA servo motors are sufficiently dimensioned and packed with high-quality synthetic lubricant. For unusually high demands, such as those that occur in belt drives, the motors are also available with reinforced bearings to withstand high radial forces.
Temperature monitoring
The temperature levels in the motor are monitored with two independently functioning systems. A linear temperature sensor is located in the motor winding to send the temperature, measured to the nearest degree, to the higher-level inverter. A second device integrated in the inverter calculates a virtual motor temperature from the process data. This combination of data ensures all-round protection of the motor windings.
All relevant mechanical and electrical information and data is stored in the encoder used for the 8LSA servo motors. This means that the user does not have to make any settings on the servo drive in the field. As soon as the encoder is connected to the servo drive and the power is applied to the electronics, the motor is automatically identified. The motor sends its rated parameters and limit parameters to the servo drive. The drive then automatically determines the current limits and current control parameters required for optimal control of the motor. This function also saves a considerable amount of work when commissioning the motor.
All B&R servo motors were designed for international use and, in addition to CE conformity, also carry the corresponding UL certification.
Broadoak, Southgate Park
Bakewell Road
PE2 6YS
UNITED KINGDOM
+44 (0)1733 371320
