LEW Specification
LEW – Cross roller bearing/ground raceways
Product type
- 4 race rings with ground raceways
- Plastic cage with rollers
- Franke bearing elements of the type LEW are suitable for medium rotary speeds and accuracies. They impress with their smooth running, high stiffness and compact installation space. The crosswise arranged rollers absorb the same high loads from all directions. Bearing elements type LEW are robust and insensitive to shocks and vibrations.
Characteristics
- Maximum possible integration capacity
- High stiffness
- Greatest possible flexibility of preload, runability and diameter ranges
- Bearing elements type LEW consist of two inner and two outer races and a plastic cage with rollers. The race rings are split in one place to compensate for temperature expansion factors. They have balancing properties in demanding types of stress. LEW are usually installed without backlash. Depending on the requirements, the preload can be adjusted individually. For tuning methods see “Technical Information”
Diameter Range
- Infinitely variable from 400 to 1200 mm
Mating structure
The built-in bearing element determines the load capacity of the overall construction. The enclosing construction can therefore consist of alternative materials such as steel, aluminum, plastic. Planarity and concentricity (see diagram below) are largely defined by the enclosing parts. Increased manufacturing accuracy can further improve these values.
Constructive Example
Technical Details
| Material | Race rings: 67SiCr5, rollers: 100Cr6, cage: PA12 |
|---|---|
| Temperature in use | –30 °C bis +80 °C, briefly up to +100 °C |
| Circumferential speed | Max. 4 m/s |
| Lubrication | Shell Gadus S3 V220 |
| Lubrication schedule | See “Technical information” |
| Tolerances | See “Technical Information” |
Please find additional information on bearing selection, calculation, mounting and setting in‘Technical information’.
LEW Drawing
Loadings
Rotational resistance
The rotational resistance indicates the preload on the bearing assembly. It is dependent on the respective type and the race ring diameter. The values indicated in the diagram are standard values and can be aligned individually.
Radial and axial runout accuracy
The running accuracies indicated in the diagram are maximum values and may be improved by restricting the tolerances.
Please find additional information on bearing selection, calculation, mounting and setting in‘Technical information’.
Standard Cages
Strip cages for the LBK series
The band cage is segmented in the length required respectively and delivered fitted with balls and ready-to-use. The number of segments is dependent on the bearing diameter and the ball size. The band cage can also be created in one part for special applications.
Special Cages
Flat cages made of hard fabric, non-corrosive steel, brass.
It is mandatory to use a flat cage for temperatures exceeding 100 °C and with ball diameters larger than 20 mm. Special solutions, including complete non-corrosive properties or radiation resistance, are also possible.
Special cages in the form of band or prong-type cages are available for special requirements in terms of ambient conditions or mounting space.
Franke also delivers materials such as plastic, non-corrosive, brass and Teflon.
Washers
Larger bearings and bearing elements use washers to simplify adjustment between the separate inner and outer rings. The washers are made of non-corrosive sheet steel. It is sensible to include in the design specifications a theoretical initial gap of 0.5 mm for the adjustment.
Seals
By standard, the bearing assemblies are fitted with sleeve seals S120. Temperature: –30 °C to +80 °C (NBR).
Max. circumferential speed: 5 m/s.
The seals can be ordered by the meter in order to seal the construction (e.g. when using a bearing element). The joint is then bonded using adhesive agent Loctite 401®.
Call us for more information on 01772 780200
Advantages
Maximum design freedom, without compromising precision or load capacity.
Principle
4 Point ContactFreedom of Design
4 Point contact principle to take load from all directions. the rolling process does not take place directly between the rolling elements and the mating structure, but rather on special race rings, giving maximum freedom of design.
Compact
Minimal Mounting SpaceMinimal Mounting Space
Requiring only a small mounting space, the compact and highly resilient four-point geometry of Franke Bearings gives you maximum freedom of design, making an ideal design component for your application.
Material
Unlimited Material ChoiceUnlimited Material Choice
Franke lightweight aluminum bearings are 65% lighter than steel, offering substantial design freedom. Available in a wide range of materials, from aluminium, bronze ceramic, plastic, carbon, 3D printed and many more.
Bespoke
Built To Your ApplicationBuilt To Your Application
Available in sizes from 60 – 2000+ mm. 95% of our products are bespoke versions. Franke rotary solutions are always designed and built to fit your application. We work with you from concept, to prototype through to final testing.