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Cam Positioners

Cam Positioners detect angles of rotation by means of absolute encoders and give output signals according to the preset ON and OFF angles (Cam program).

Overview Features
Principles Classifications
Engineering Data Further Information

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Operating Principle

As shown in the following diagram, sin θ and cos θ voltage is applied to the two sets of fixed windings, S1-S3 and S2-S4, respectively, that are mechanically 90° out of phase. Observing the sin (θ - α) voltage induced in the rotating winding R1-R2 makes the Resolver a kind of rotating transformer that detects angles.


If the fixed winding is locked in position completely in phase with fixed winding S1-S3 (energized by sin θ voltage) for example, then sin θ voltage will be induced in R1-R2. When the rotating winding starts rotating, sin (θ - α) voltage will be induced in R1-R2 because of the cos θ voltage of the SR2-S4 winding that is 90° out of phase with the S1-S3 winding. (See the figure below.)


Allowable Thrust and Radial Forces

Thrust and radial forces represent the maximum vertical and horizontal forces applied to a shaft. The magnitude of these forces is proportionally related to the service life of the product (i.e., the mechanical service life of the bearings).


Origin Compensation

When a Resolver is linked to a mechanical system, the Resolver origin can be easily adjusted to match the machine origin if they are not the same. The process of aligning the two origins is called origin compensation.