Crossed cylindrical roller bearing is one kind of bearing whose rollers are square crossing arranged between outer ring and inner ring. The rollers contact the raceway in linearity, so this bearing has better rigidity and less elastic strain. At the same time, this bearing can carry radial load, axial load and moment load simultaneously. They are especially suitable for high rigidity and high running accuracy applications.
The dimension of the inner and outer rings is a minimum to miniaturization, especially extremely thin type is close to the limit of small size, and high rigidity, so it is optimal for applications such as joints and swiveling units of industrial robots, swiveling tables of machining centers, rotary units of manipulators, precision rotary tables, medical instrument, measuring instruments, IC manufacturing machines, and etc..

2.What is a crossed roller slewing bearings

Among the crossed roller slewing bearings, cylindrical rollers are arranged perpendicular to each other through spacers on a V-shaped groove rolling surface at 90 degree, so the crossed roller bearing could bear multi-direction loads, such as radial load, axial load and moment load. Miniaturized inner ring and outer rings’ size, the extremely thin form nearly close to small size. And it has high rigidity, so it very reasonable for joints of industrial robots and rotary parts, rotary of mechanism center, mechanism rotary arm, precision rotary table, medical equipment, calculators, IC manufacturing equipment and other equipment.

Due to perpentical crossed cylindrical rollers has isolation spacers, prevent cylindrical tilt and cylindrical rollers friction, reduced the rotation torque. Othewise, compared with steel plate holder, there will be no edge stress concentration or locking of the rollers. At the same time, inner ring or outer ring is two-part structure, the clearnace of the crossed roller slewing bearings could be adjusted, even if preload is applied, it also could rotate highly precision and steady.

The application of high precision crossed roller slewing bearings

1. Machine tool : turret indexing、index plate、loader.
2. Robot : rotation、joint drive parts.
3. Semi-conductor manufacturing equipment : handling robot、examination platform.
4. LCD manufacturing equipment: handling robot、inspection platform、photosensitive application roller drive.
5. Printer : photosensitive application roller drive.

   Crossed roller slewing bearings

   High precission and capacity to support loads in all directions.

   Very specific features to adapt to high precision applications

   Renogear cross roller bearings feature high rigidity and high rotational precision. Since it has cylindrical rollers arranged orthogonally, it can support loads in all directions.

   This bearing is widely used in rotating parts that require compaction, high rigidity, and precision at rotating.

   3.High rotating precision and load crossed roller slewing bearing

   Renogear produces cross roller bearings with a very compact structure. The rolling surface has linear contact, so the elastic displacement based on the bearing load is extremely minimal, and furthermore, it is capable of bearing complicated loads in all directions (radial, axial and moment) and at the same time.

   Crossed-roller bearings are bearings for high-precision applications whose dimensions conform to ISO dimension series 18 as per DIN 616. They comprise outer rings, inner rings, rolling elements and plastic spacers. The outer ring is split and is held together by three retaining rings.

   Due to the X arrangement of the cylindrical rollers, these bearings can support axial forces from both directions as well as radial forces, tilting moment loads and any combination of loads by means of a single bearing position. As a result, designs involving two bearing positions can be reduced to a single bearing position. Crossed roller bearings are very rigid, have high running accuracy and are supplied with normal clearance, low clearance or preload. The bearing outer rings are easily fixed to the adjacent construction using clamping rings.

   A slewing bearing or slew[ing] ring (also called a turntable bearing) is a rotational rolling-element bearing that typically supports a heavy but slow-turning or slowly-oscillating loads in combination (axial, radial and moment loads), often a horizontal platform such as a conventional crane, a swing yarder, or the wind-facing platform of a horizontal-axis (yaw) windmill. In other orientations (e.g. a horizontal axis of rotation) they are used in materials handling grapples, forklift attachments, welding turnover jigs and so on.

   Compared to a “normal” ball bearing the rings are quite wide and usually have holes drilled in them to provide fixation to a structure. Seals can be provided between the rings to protect the rolling elements. Compared to other rolling-element bearings, slewing bearings are relatively thin section and require that the structure to which they are bolted is stiff enough so that under load predefined limits of distortion are not exceeded.

   Slewing rings range in size from as little as 100mm diameter to well over 15 000mm (often segmented at this size for easy transport and handling); for example the bearings on the Falkirk Wheel are 4 meters diameter and fit over a 3.5 meter axle. Slewing bearings are often made with gear teeth integral with the inner or outer race (or both in rare cases) used to drive the platform relative to the base (for example in winches).

   Slewing bearing designs range from single row ball or roller style, through double row ball or roller, triple row roller, combined (1 roller/ 1 ball) or wore guided raceways – each design having its own special characteristics and application. Old designs can have split rings to allow tight control on preload during assembly.

   As for other bearings that reciprocate, rather than rotating continuously, lubrication can be difficult. The oil wedge built up in a continuously rotating bearing is disrupted by the stop start motion of slewing. Instead, a hydrostatic bearing with pumped oil flow may be used.