This arrangement will not provide axial support to the ring in either direction, so the assembly machine must be fixtured to “back up” or axially locate the ring temporarily while the mating components are assembled. The Tolerance Ring will be subjected to all radial loading and should be selected with appropriate capacity.
This arrangement provides a groove in the housing for HV rings or a groove in the shaft for SV rings. These grooves capture the ring axially on both sides and simplify assembly. When the shoulder (stepped) diameter is held close to the nominal diameter, the following advantages occur:
This arrangement is similar to the centered arrangement at a lower cost. With the exception of piloting for alignment, this method may provide the advantages of the centred arrangement when the stepped diameter is held close to the nominal diameter of the mating component.
The “tops” of the corrugations (The I.D. on HV style rings or the O.D. on SV rings) are formed with a rounded contour, which assists as a lead-in edge during assembly. It is very important that the lead-in edge of the mating parts is contoured with a generous radius or a shallow (15°) chamfer. Sharp corners on the lead-in edge could dig in and mar the Tolerance Ring, sacrificing performance.
Best results of assembling mating parts are achieved by using an arbor press and fixturing the parts to hold them squarely in place during assembly. The fixture also needs to ensure that eccentricity during assembly is less than 10% of the nominal radial clearance. Except for very light duty rings, aligning the parts by hand and/or hammering the assembly together jeopardises alignment and performance. If misalignment occurs during assembly, there is a tendency for the lead-in edge of the mating part to flatten corrugations in one area of the Tolerance Ring.
When using the centred arrangement, a small radius (re) and adequate groove width should be used to ensure that the Tolerance Ring may be properly seated on the cylindrical surface, the groove needs to be deep enough to ensure the ring is not dislodged during assembly.