Page 7 of catalogue Precision rail guides of SKF Linearsysteme GmbH

Fig. 5
LWRE ACS

LWRE Crossed roller

LWRPM/ LWRPV Slide coating

LWR Crossed roller

LWRM/ LWRV Needle roller

may occur as a result of the unfavourable tribological conditions. Sliding rail guides are preferred in such circumstances. The coating material is based on PTFE and is bonded on to the unhardened LWRPM rail and then ground to the correct dimension. This wear-resistant material combination is characterised by its stickslip-free, vibration-damping running properties, at the same time offering excellent stiffness and emergency running properties. These guide rails are largely insensitive to contamination, coolants and Lubricants. Materials and precision The rails of the Modular Range guides are manufactured from tool steel 90 MnCrV 8 with a hardness of between 58 and 64 HRC. If required by the application, the rails can also be supplied in special stainless steel, e.g. X 90 CrMoV 18 in all standard dimensions. All rolling elements are made from carbon chromium steel 100 Cr 6 with a hardness of between 58 and 64 HRC. The parallelism of the raceways is divided into three classes. Class P10, with a maximum deviation of 10 μm per 1 000 mm length, meets most of the demands for normal machinery. Where greater precision is required, tolerance classes P5 and P2 are also available. The assortment is complemented by various accessories specially designed for the Modular Range of rail guides. These include end pieces with or without wipers as well as special attachment Screws.

LWR/LWRB Ball

LWR/LWRB series This basic series of the Modular Range covers a wide variety of rail guide applications for limited travel. Where low friction is essential, ball cage assemblies are recommended. If, on the other hand, high load carrying capacity is the chief requirement, robust crossed roller assemblies are to be preferred. The LWR series is manufactured in nine sizes based on rolling element dimensions. LWRE series For a given load carrying capacity, the dimensions of the LWRE series are significantly less than those of the corresponding member of the LWR series. Thus, for instance, an LWRE 6 guide with a cage length of 100 mm has a greater load carrying capacity than a standard LWR 12. The LWR 12 measures 58 x 28 mm whereas the LWRE 6 measures only 31 x 15 mm (Fig. 1).

LWRE ACS series All rails of the LWRE series are also available with ACS, a special system to prevent “cage-creep”. These rails are used where cage-creep occurs due to high acceleration, uneven preloading or load distribution as well as jerky running or directiondependent speeds of travel. LWRM/LWRV series These guides are used principally where high load carrying capacity is called for in combination with high stiffness, for instance on grinding Machines. This series is fitted with Needle roller and cage assemblies consisting of two rows of needle rollers at right angles to each other. LWRPM/LWRPV series Where extremely short strokes of high frequency occur, this special series with slide coating is an essential alternative to those with rolling element assemblies. In the case of balls or rollers subjected to high transverse acceleration, pitting of the tracks

7