Industrial Motors
When it comes to industrial motors, there are many different types. Some are geared to specific applications, such as cranes and hoists that lift heavy loads through chains or ropes. Other motors are designed to power machinery like mills, crushers and cable cars. While these motors perform different tasks, they all have one thing in common: They use slip rings to transfer electricity from a stationary component to a rotating one.
In simple terms, a slip ring is an electrical connection that uses a stationary graphite brush that rubs against a rotating metal ring to transmit power or signals from the stationary to the rotating part of the machine. The electrical current passes from the stationary brush through the rotating ring and back to the stationary component, which then completes the circuit.
A slip ring motor has two main components: a fixed stator that has windings that function as electromagnets, and a rotor that spins within the stator. The rotor gets its rotational force from electromagnetic induction, which occurs when the rotor’s magnetic field interacts with the electric current passing through the rotor coils.
The difference between a slip ring motor and other AC induction motors is that the rotor windings of a slip ring motor have more turns than those of other motors, which results in a higher induced voltage and current. A motor with a high induced voltage produces more torque, especially when it is starting up. A secondary resistance starter, which consists of a contactor to switch the stator and a series of resistors to provide a controlled resistance profile, is used to reduce the induced current and voltage during start-up. The resistors are sized to dissipate the power required to accelerate the rotor to full speed.
Industrial Motors – What Are Slip Ring Motors?
Because of their superior start-up performance, slip ring motors are widely used in applications such as elevators, cranes, and hoists. The motors also have other advantages, such as a higher torque at rated speed and a lower operating current than other AC induction motors. However, despite their advantages, slip ring motors still require maintenance, and they may need to be replaced when worn down.
CG provides a wide range of slip ring motors for a variety of applications. These include abrasion-resistant and temperature-resistant designs, along with various sizes, current and voltage capacities and mechanical properties. Some are also waterproof and suitable for outdoor use, while others are thickly insulated to ensure stability in harsh environments.
To avoid electrical shorting, it is important to choose a good quality slip ring that can withstand high voltages and speeds. Typically, these motors are built with a steel frame for added strength and rigidity. They can also be insulated with epoxy resin and feature a high degree of corrosion resistance. Some are also manufactured using a special technique that allows for more effective brazing and heat dissipation. In addition, the slip rings are precision molded for increased stiffness and better resistance to vibration.