1 Field of the Invention
The present invention relates to a soft start coupling device which allows a motor to accelerate a load in a controlled fashion and, more particularly, to a coupling device wherein the dynamic characteristic of the load acceleration is consistant regardless of the type of load or changes in the load being accelerated.
2 Description of the Prior Art
Smooth start and torque control of motors for driven applications has been recognized as a need by the industry. The most common method employed has been with mechanical devices such as clutches, transmissions, fluidics, etc. for most drive applications. Mechanical technology has its place in industry but the cost to performance ratio of these methods continues to be relatively high. Electrical methods have also been utilized in solid state reduced voltage starters and to a lesser degree, AC variable frequency drives. The electrical technology has satisfied the market need for soft start utilizing solid state reduced voltage starters however, the cost of this technology remains disproportionately high at the lower horse power level. This is due to the cost contribution of electrical applications which is dominated by the price of SCR's, firing circuits, heat sinks, packaging, terminations, and thermal issues.
One of the primary objects of the invention, therefore, is to provide a higher performance soft start coupling at a low cost.
A further object of the invention is to provide a highly reliable device which sits at the motor/load interface and transfers torque in a controlled, predictable, repeatable transition, regardless of the load characteristics.