214 & 224 WHEEL-TYPE EXCAVATORS Flexible Coupling Caterpillar

Flexible Coupling
1.1. Assembly

Fig. WH 116

The essential component of the coupling is the flexible section, a molded part of heavy duty Hytrel. The metal parts are placed only in this flexible part.

The metal parts to be screwed axially are secured against the flat surface of the flywheel while those to be screwed radially are screwed on the cylindrical hub. Force flows from the flywheel via the axially mounted metal parts to the flexible section and from there via the radially mounted segments to the cylindrical drive hub which is located on the pump shaft.

The coupling is fitted with a clamping hub so that it can be fixed absolutely snugly on the shaft of the hydraulic pump. Assembly is straightforward, since the flexible part of the coupling can be stretched and motor and pump are simply connected.


1. Mount the radial segments on the hub and tighten bolts (1) to 220 N·m. If the segments are already mounted on delivery, they should not be removed again.

2. Push the hub onto pump shaft as far as possible and fix with the two locking screws (2). Tightening torque = 90 N·m.

3. Bolt the axial segments together with the flexible section to the flywheel and tighten bolts to 220 N·m.

4. Attach pump assembly to coupling.


1. Take care when tightening the bolts (1) that the segments are properly seated (Fig. a wrong, Fig. b right). Apply a little grease to the bolt heads before mounting in order to reduce friction between the bolt heads and segments.

2. Use only the "Inbus Plus" bolts supplied, with a colored compound (e.g. blue) on the thread. This compound contains microcapsulated adhesive which cements the bolt in the thread and helps prevent loosening.

The curing time of this adhesive after tightening is approximately 4-5 hours at room temperature (20°C) for an adequate effect. Do not operate coupling beforehand. The adhesive is fully cured after 24 hours. Higher temperatures accelerate hardening, e.g. at 70°C (heat with hot air blower) the curing time is only 15 minutes.

"Inbus Plus" is temperature resistant from -80 to +90°C and the bolts can be used at most 3 more times. Should for some reason or other these "Inbus Plus" bolts not be available, the threaded holes and the bolts must be carefully degreased and securely cemented with a different, reliable adhesive, e.g. "Loctite". Lock washers, or suchlike are not permissible.