UJ cross or Universal Joint Cross or Cross is a device used alongside with rotating shafts like drive/ propeller shafts to maintain uniform rotating motion between them by coupling the metal rods and allowing the shafts to move flexibly in angular direction both upwards, downwards and sideways. The purpose of a UJ cross is high torque transmission/ transfer in limited space. Here is a simple youtube video to show how UJ cross helps in achieving this :
Below you can see some photos of applications of UJ Cross in vehicles. UJ cross is used in almost all vehicles – trucks, rotavator, cars, machinery etc.
Here you can see to connect two moving shafts, UJ cross is used so that appropriate rotating motion can be maintained between the rotating parts.
Some important parts of a OEM type UJ cross are:-
- Cross/ Spider – This is the main structure which is fitted inside the shaft.
- 4 grease/ grease less Roller Bearing – This is the cover which encompases the other parts and is attached to the cross/ spider
- Seal – Inside the roller bearing case, are the oil seal & dust cover seal which ensure proper play and gap between the other parts
- Needle Roller – Needle type robber helps in circular movements of the rotating shafts.
- Thrust Washer – ensures proper distance and play
- Circlip/ Snap Ring – 4 rings are attached to each roller bearing case for proper attaching to the shaft.
Source : GMB