Products

SBR Round Rail Series

SBR Open Linear Bearing Carriages travel along continuously supported round shafts. The opening beneath each bearing clears the shaft support, allowing the carriage to move while the rail remains supported along its length.

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Description

One shaft size, two carriage lengths

The choice between UU and LUU changes more than the space occupied by the block. Guangyuan's SBR chart lists standard and extended versions with different mounting lengths and load ratings.

For a 20 mm shaft, SBR20UU measures 50 mm long and has a published dynamic rating of 882 N. SBR20LUU extends to 96 mm, with a dynamic rating of 1,764 N. Both retain a 48 mm housing width, but their longitudinal mounting-hole spacing changes from 35 to 70 mm. The extended version therefore needs a different attachment footprint on the moving plate.

Selected dimensions and ratings from the product chart:

Model	Shaft Ø (mm)	Width W (mm)	Length L (mm)	Dynamic C (N)	Static C₀ (N)
SBR16UU	16	45	45	774	1,180
SBR16LUU	16	45	85	1,548	2,360
SBR20UU	20	48	50	882	1,370
SBR20LUU	20	48	96	1,764	2,740
SBR25UU	25	60	65	980	1,570
SBR25LUU	25	60	130	1,960	3,140

These are catalog bearing ratings, not allowable payloads for a complete table. Block spacing, load direction and overhanging tooling also affect the assembly.

Why the bearing is open underneath

A closed ball bushing would collide with the support beneath a continuously supported shaft. SBR uses an open bearing insert and a corresponding opening through the housing. The balls contact the exposed shaft surface while the support passes through the opening.

This arrangement lets the shaft transfer load into the machine bed along the rail instead of spanning freely between two end brackets. The benefit is particularly relevant as travel length increases and shaft bending becomes more significant.

The catalog identifies open inserts such as LM16UU-OP and LM20UU-OP in the standard blocks. Their recirculating balls provide the running contact; the surrounding housing connects the bearing to the moving component. SBR Open Linear Bearing Carriages must therefore be matched to the supported shaft profile as well as its diameter.

Can Guangyuan prepare rails for a specified machine length?

Yes. Guangyuan offers cut-to-length supply and production from drawings or samples. Specify the finished rail length separately from the carriage model and quantity: cutting the rail does not alter the standard UU or LUU block dimensions.

We build to customer drawings under OEM/ODM, and accept orders as small as a single piece for standard sizes.