By Circulation Method:
Internal Circulation: Balls circulate inside the nut through a deflector. This offers a compact design and a small nut outer diameter, but the deflector passage is complex and the ball capacity is relatively small.
External Circulation: Balls circulate outside the nut through a tube or end cap. This design is relatively simple, with a large ball capacity and slightly higher load capacity, but the nut’s radial dimensions are larger. The tube type is the most common.
By Preload Method:
Double Nut Preload: Two single nuts are preloaded using washers or springs. This provides easy adjustment and stable preload.
Single Nut Variable Lead Preload: The raceway lead is varied (increased or decreased) in the middle of the nut, creating an internal interference fit to achieve preload. This offers a compact design, but the preload is fixed and cannot be adjusted.
Single Nut Increased Ball Preload: Preload is achieved using balls slightly larger than the theoretical raceway size. The preload amount depends on the ball size.
By Application:
Positioning Type: Emphasizes high precision, high rigidity, low temperature rise, and high preload. Used in CNC machine tools, measuring equipment, etc.
Transmission Type: Emphasizes high load, long life, and cost-effectiveness. Used in injection molding machines, handling equipment, etc., with low or zero preload.