Linear guides, when applied to industrial uses, require substantial load capacity. To withstand the dynamic and complex forces properly, linear guides need adequate load capacity in a variety of orientations. Such forces may originate from different sources such as the moving masses, force of gravity, modifications and oppositions to motion caused by cutting tools or other process requirements. Since it is difficult to locate the payload mass always in the ideal position directly over the linear guide wheel, cantilever and gantry configurations require a combination of radial and axial load capacity. Guide wheels contain two rows of angular contact ball bearings, which can accommodate forces in different directions.
Low cost linear guide wheel applications can consider such guide wheels for simplified load conditions. Radial wheels are the answer to requirements where the center of mass can be situated close to the centerline of the guide wheel. Accommodating the center of the moving mass close to the centerline of the guide wheel substantial axial load capacity is unnecessary since the load on the wheel is a radial load.
Therefore, it is wasteful to specify a linear guide wheel bearing designed with high axial load capacity where there are no axial loads.
Many industries consider radial wheels as a major innovation. These include the woodworking industry, where they utilize the product during the design of processing machinery as well as in the finished goods. Accomplishing reliably smooth motion in environments heavily contaminated with debris, such as in process and sawdust grit is now budget-friendly, especially because of rapid failure of traditional linear bearings.
Processing applications consider radial wheels as an ideal product. These include machine doors and guarding, material handling aids, assembly workstation tools, adjustable position jigs and fixtures, guided sawing, CNC engraving and many other production floor activities. Finished products such as adjustable furniture, heavy-duty drawer slide applications, motorized doors and windows, sliding wall panels and other multitude of other market-defining products use radial wheels as the design is well-suited for use in such products.
It is easy to install radial wheels on products or equipment. You need only simple hand tools and off-the-shelf fasteners. Their simplified and non-adjustable concentric centerline design allows them to be mounted without bushings as the through-hole geometry accommodates standard metric or inch fasteners. Low stiffness or compliant applications utilize them commonly. For example in free-hanging wall panels, where there are no rigid fit-up adjustments. However, alternate guide wheel products can accommodate implementation of rigid preloaded systems with simple mechanisms that are external to the guide wheel.
Radial wheels usually have a 90-degree V-groove on the perimeter and roll on matching 90-degree running surfaces. The linear guide truck may have the 90-degree surface in the traditional dual-V. Manufacturers offer the tracks with optional mounting holes in AISI grade carbon steel or stainless steel hardened or unhardened. Both material types have the same ball retainer cages, seal and grease. Typically, the ball cage is made of glass-reinforced nylon and the seal is made from nitrile butadiene rubber combined with stainless steel. The bearings are usually lubricated for life.