Conical pin

Basic parameters of large planetary roller ball screw:

Main parameters of external thread

1) Diameter D (major diameter) (d) - the idea of overlapping with the crown of inch screw thread the diameter on the circle also known as the size of the central roller

2) Nominal diameter (path) D1 (D1) - the upper diameter of the imaginary circle overlapped with the bottom of the British screw thread, which is used as the carrying diameter of the risk model in the carrying forward of the compressive strength

3) Pitch diameter D2 -- the diameter on the imaginary circle where the thickness of the internal tooth and the width of the tooth seam are the same in the radial model, similar to the mean diameter D2 ≈ 0.5 (D + D1) of the external thread

4) Pitch P -- the radial pitch between two points matched on the bus duct of the diameter circle by the adjacent two teeth

5) Lead (s) - the radial distance between two matching points on the bus duct on the radius circle of the adjacent two teeth on the same helix

6) Number of thread n - number of external thread helix, generally for the convenience of making n ≤ 4 pitch, lead, number of thread intermediate connection: S = NP

7) Helix rising angle ψ -- the intersection angle of the broken line of helix on the radius circle and the plan straight to the helix center line.

8) Thread angle α - Radial plan of external thread intersection angle of two sides of thread 9) thread diamond β - intersection angle of the side of external thread thread and the straight plan of thread center line. Symmetrical screw tooth

The main limits of various external threads (except for the external thread of rectangular frame) can be seen in relevant specifications - the nominal pressure limit is the external thread diameter, and the external thread is similar to the nominal diameter of water pipe.

The locking standard of screw type pair is: the rising angle of external thread of round center roller specification is lower than or equivalent to the internal friction angle of screw type pair.

The output power of the drive system of the screw type pair is: the ratio of the active work to the input work when the nut rotates for one cycle.

Defeat the force on the circle required by the radial force Q average speed rise