BOSCH REXROTH
R151735020

Ball screw assembly with front lube unit

Characteristic features

Equipped with Rexroth’s functionally reliable, series-made front lube unit, a ball screw assembly can attain an exceptionally long travel life without relubrication. Thanks to intensive development work and thorough testing under realistic conditions, the use of front lube units combined with prelubricated nuts enables you to achieve lifelong, optimal lubrication of Rexroth precision ball screw assemblies.

From its built-in oil reservoir, the front lube unit delivers the precise amount of oil required to replenish the used amounts of oil in the soap matrix of the grease. The oil is applied directly to the raceway of the ball screws via the low-friction point-contact zone of the open-pored foam. This optimized delivery minimizes lubricant consumption and allows you to achieve lifelong lubrication.

Ecologically sound

The front lube unit ideally combines eco-friendliness with cost-efficiency. It minimizes oil consumption and keeps the surroundings clean. This protects the environment.

Lubrication concept

This logo indicates that the Rexroth ball screw assembly with prelubed nut and front lube unit are lubed for life.

Note: The front lube unit is not suitable for use with driven nuts.

Lifelong lubrication

The effective life of the Rexroth front lube unit matches the service life curve of the ball screw assembly. When operated within the recommended load limits, a ball screw assembly equipped with a front lube Unit will require no relubrication, thanks to the optimal delivery of lubricant. Based on our extensive tests, the lubrication performance of the front lube unit can now be reliably predicted for the first time. With the front lube unit form Rexroth, a ball screw assembly will operate safely for five years long or for 300 million revolutions without relubrication.

Structural design of front lube units

1) Seal

2) Housing and cover – material: special plastic

3) Open-pored foam

4) Ring nut

5) Intermediate ring

6) Recirculation cap

7) Ball nut

8) Ball screw

Contact zone of the open-pored foam

Front lube unit

The front lube unit (VSE) has been designed for the long-term, maintenance-free operation of the ball screw assembly. It is attached to the nut and delivers lube oil continuously to the rolling elements. For travel up to 300 million revolutions without relubrication.

The front lube unit can be combined with the following nut types:

Lifelong lubrication

Results confirmed by our extensive tests:

1) Life-time lubrication: For axial loads of 15-35% of the dynamic load rating C, the nut is lubed for life.

2) Maintenance-free up to 300 x 106 revolutions: For axial loads of < 15% of the dynamic load rating C, the ball screw assembly requires no maintenance for up to 300 million revolutions.

3) Relubrication required: After 300 million revolutions, the nut should be relubricated as usual. The front lube unit does not have to be removed from the nut.

a) Normal operating load

n = revolutions

%C = relative load