Intermittent Duty Rotary Solenoids

Intermittent duty rotary solenoids convert axial motion into rotary stroke and are rated for on-off applications at less than 100% duty cycles. Like other types of solenoids, they convert electrical energy into mechanical power. Many intermittent duty rotary solenoids consist of a plunger and small ball bearings that ride on an inclined plane. Electrical current is supplied to a coil that is wound tightly enough to limit the current drain and sized large enough to provide for adequate heat dissipation. The resulting magnetic field draws the plunger from its unpowered, extended position to a seated position against a backstop or pole piece. Because the linear force on the plunger is nonlinear with position, the force is relatively high immediately adjacent to the seated position and declines rapidly with increased distance from the seated position. Intermittent duty rotary solenoids are considerably small than continuous duty devices and provide less pull-and-hold strength. For rotary solenoids that are capable of both intermittent and continuous duty, force ratings vary widely by duty cycle.

Performance specifications for intermittent duty rotary solenoids include direction, maximum rotary stroke, axial stroke, response time, power rating, starting torque, and holding torque. Direction indicates whether the energized rotation is clockwise or counterclockwise when viewed from the armature flange end. Maximum rotary stroke is the full rotary travel in angular units. Axial stroke is the full axial travel during rotary actuation in distance units. Response time is the time required to move full-stroke under no-load conditions. Power rating is the input power for a specified winding at a specified voltage. For DC-powered solenoids, power rating is measured in watts (W) For AC-powered solenoids, power rating is expressed in volt-amps (VA). Starting torque is measured in the de-energized or fully extended position. Holding stroke is measured at the energized or fully seated position.   

Intermittent duty rotary solenoids vary in terms of power inputs and special features. DC-powered devices are rated for 3 VDC, 6 VDC, 12 VDC, or 24 VDC inputs. AC-powered devices are rated for 24 VAC, 115 VAC, or 230 VAC inputs. In terms of features, some intermittent duty rotary solenoids include internal drive electronics to regulate power, speed, range, or other motion control parameters. Other devices include an integral encoder or variable position control. Torsion springs are sometimes used to hold the plunger in the extended position when the solenoid is unpowered. Hermetically sealed and intrinsically safe (IS) devices are commonly available. Intermittent duty rotary solenoids that are UL-approved meet published standards for safety from Underwriters Laboratories (UL).

Pages: 1 - 3 of 78