Throat diameter and center distance installation position detection device and method for double-envelope worm gear speed reducer

The invention discloses a throat diameter and center distance installation position detection device and method for a double-envelope worm gear speed reducer. The detection device comprises a measuring block for simulating the central position of a worm gear, a clamping spring, a dial indicator and a height gauge; the measuring block is a centering measuring block which is formed by equally cutting a worm gear finished product processed by the upper limit of the diameter tolerance of the worm gear tooth part through the center of the worm gear and serves as an actual worm center; a plane tangent to the center point of the worm gear is cut out on the side, opposite to the tooth part face of the worm gear, of the measuring block; a hole is formed in the measuring block, the center line of the hole perpendicularly intersects with the straight line where the plane is located, and the clamping spring is connected into the hole in a penetrating mode and clamps the measuring block to the worm. The detection method d