Elongated thin strip stock is blanked to form interlocking laminas for electric motor or generator rotors or stators at successive blanking stations. At a final assembly station the laminas are stacked and pressed into interlocking relationship. In response to an operator input a predetermined number of reversals, or half turns about the stack axis of the previously stacked lamina are provided in order to compensate for nonuniform strip thickness to obtain a rotor or stator of substantially uniform height. Alternatively the thickness of the strip stock is gauged at transversely spaced points on the strip to determine cross feed thickness variation in the strip whereupon the stacked laminas are automatically provided with a number of reversals about the stack axis in response to a thickness differential that would result in a parallelism error in the stack that exceeds a predetermined amount. Rotor conductor slots are formed in the stacked laminas and are skewed to the stack axis by providing arcuate indexing of each lamina relative to the next preceding lamina in the stack by an arcuate increment that is automatically determined in response to operator entered inputs relative to the stack height, the skew angle, nominal lamina thickness and skew direction.
RELATED APPLICATION
This is a continuation of copending application Ser. No. 853,207, filed Apr. 17, 1986 and now U.S. Pat. No. 4,738,020 granted Apr. 19, 1988 which in turn is divisional application of my copending application Ser. No. 06/478,692, filed Mar. 25, 1983 now U.S. Pat. No. 4,619,028 and entitled "APPARATUS FOR MANUFACTURE OF LAMINATED PARTS."
A stator for a fractional horsepower motor has a mounting hole of reduced dimensions for fixing the position of motor mounting brackets which support a rotor. The configuration of the mounting holes increase the area where magnetic flux may pass. One configuration reduces the depth of the mounting hole to one or two laminates of each side of the stator. Another configuration is an elongated hole which lies in the direction of the magnetic flux. Each laminate may have a tang which interlocks with tangs on other laminates when the laminated stack is squeezed together in a punch press.
A progressive stamping die assembly apparatus and method in which strip stock material advances in a first direction through the apparatus and substantially simultaneously with the strip stock movement, a transversely moveable die station moves in opposite second and third directions substantially perpendicular to the first direction to one of a plurality of predetermined positions.
A dual action indexing system and method for relatively rotating a lamina and a partial lamina stack in a progressive die assembly. The dual action indexing system includes a mechanical indexer such as a roller gear cam which provides a large indexed rotational movement to correct for thickness inconsistencies in the laminas and a relatively small and fast servo motor to provide a small indexed rotational movement to provide a desired skew angle. The rotational movements of the mechanical indexer and servo motor are combined by a phase adjuster. The combined rotational movement is used to rotate a choke barrel into which the laminas are punched to form a lamina stack. The operation of the servo motor is regulated by a controller and may thereby be conveniently and rapidly adjusted.
A progressive stamping die assembly apparatus and method in which strip stock material advances in a first direction through the apparatus and substantially simultaneously with the strip stock movement, a transversely moveable die station moves in opposite second and third directions substantially perpendicular to the first direction to one of a plurality of predetermined positions.
An indexing system for a die assembly for manufacturing a stack of laminae from sheet stock material in a punch press, the stack having a desired stack height and a skew angle, the stock material having a nominal thickness. The indexing system includes indexing means for producing a first indexing input movement in response to movement of the punch press, a motor for producing a second indexing input movement in response to a control signal, and differential means for combining the first and second indexing input movements into an indexing output movement and having first and second input means for respectively receiving the first and second indexing input movements. The first input means is coupled to the indexing means, and the second input means is coupled to the motor. The differential means also has output means for transmitting the indexing output movement; a rotatable choke barrel in which laminae are received and stacked. The choke barrel is rotationally coupled to the output means, and is rotated in accordance with the indexing output movement. Cyclical inertial loads imparted by the choke barrel are absorbed within the motor.
