Magtrol

WB 23 and WB 27 – High-Speed Eddy-Current Dynamometers

Magtrol’s WB 23 and WB 27 Eddy-Current Dynamometers are designed for very high-speed motors and dental or surgical tool testing applications. By providing a braking torque that is proportional to the rotational speed, rated torque is reached at the rated speed. The Dynamometer features a low level of inertia, due to small rotor dimensions, and brake cooling is provided by air flow inside the dynamometer housing.

A PT temperature sensor continuously monitors the brake temperature and alarms the DSP 7000 Controller to stop the brake excitation current in order to protect the dynamometer from overheating. Torque is measured by a reaction torque transducer placed on the stator. The dynamometer has a torque measuring accuracy rating of ± 0.2 % full scale. The speed is measured by an optical sensor and a 2-PPR encoder. This sensor measures speeds between 10 000 rpm and 100 000 rpm with a full scale accuracy of ± 0.06 % (using a DSP 7000).

Features

• Torque: 80 mN·m and 150 mN·m
• Speed: up to 100 000 rpm
• Power: 250 W continuous; up to 500 W (WB 23) or 1 kW (WB 27) intermittent
• Low inertia
• Very low residual torque
• Stable and smooth braking torque
• Measuring system with air-bearing
• Data acquisition via DSP 7000 Controller and M-TEST Software
• Built-in electronics with Torque & Speed measurement

Operating Principles

The WB 23 and WB 27 Eddy-current Dynamometer provides full braking power at high speed. This type of brake has been specially designed to test motors rotating at speeds up to 100 000 rpm, with the braking torque dependent upon the rotation speed. Due to the 2-PPR encoder, the system is not designed to provide closed loop control below 10 000 rpm.

The dynamometer includes air bearings for minimizing friction and assuring the best possible torque reading accuracy. It is necessary to connect the air input through the air filtering and drying kit (included).