RHPBSB045100SUHP3Ball Screw Support Bearing 45 x 100 x 20 mm 60 Degree Contact Angle Universally Ground Heavy Preload

Product Description

What this part is

An RHP BSB045100SUHP3 ball screw support bearing, 45 mm bore, 100 mm outside diameter, 20 mm wide, ground as a universal single at heavy preload. Ball screw support bearings are a family of their own, built to take the axial thrust of a screw with very little radial duty.

Decoding the designation

In the RHP scheme BSB is the ball screw support series, 045100 gives the 45 mm bore and 100 mm outside diameter, SU marks the ring faces as universally ground and H is heavy preload. The carton also carries 45TAC100, the NSK number for the same bearing, which fixes the contact angle at 60°.

What these specs mean in practice

A 60° contact angle is far steeper than the 15° to 40° range of ordinary angular contact bearings. It puts almost the whole load path along the shaft axis, which gives very high axial stiffness and thrust capacity and very little radial capacity — exactly the duty a ball screw end support has, where the screw carries the feed force and a separate location takes the radial load. Heavy preload adds axial stiffness, which is what keeps positioning error and backlash-like deflection down on a feed axis.

Quantity and configuration

1 Pc. A single universally ground bearing, open on both faces. Ring faces are ground so any two pieces of the same designation mount back-to-back, face-to-face or in tandem and reach the specified heavy preload with the rings clamped solid.

Thrust direction

A single-row bearing of this type carries thrust in one direction only. A screw that is driven and braked in both directions uses a back-to-back pair, or a tandem stack per direction where the thrust is large.

Fitting notes

The high shoulder on the outer ring sets the mounting orientation, identified by the etched face marking. The rings clamp solid between the housing shoulder and the screw-end nut, so the squareness of both faces sets the achieved axial runout of the screw end.

Interchange guidance

Direct equivalents are the NSK 45TAC100 in the same universal-single, heavy-preload form, the FAG 7602045TVP and the NTN 45BST100, all 60° screw support bearings on the same 45 x 100 x 20 mm section. An ordinary 7209 or 7309 angular contact bearing is not a substitute: the shallower angle changes axial stiffness and thrust capacity even where the envelope is close. Light and medium preload versions of the same number are separate parts.