One may use the soft and rigid cardan joints depending by the angle between the axes of the cardan shafts to be connected. In soft cardan joints, the angular displacement of the shafts occurs due to the deformation of the elastic elements. In rigid cardan joints, the angular displacement of the shafts occurs due to the deformation of the cardan joints of metal details. The rigid cardan joints are more popular in modern cars.
Types of universal joint in automobile
There are universal joints of unequal and equal angular velocities (by kinematics). All car drives use universal joints of unequal angular speeds, except for the drive of steered wheels. You can see cardan joint of unequal angular speeds below. The cardan joints of this type has been wide using.
Construction of Cardan Joints (Construction of Universal Joints)
a-c universal joints of unequal angular speeds; d and e – universal joints of equal angular speeds; 1 – cap; 2 – lock plate; 3 – bearing cup; 4- needles; 5 – felt seals; 6, 10, 24 and 28 – forks; 7 – safety valve; 8 – a cross; 9 – oiler; 11 – cardan shaft; 12 – reflector; 13 – spring-loaded oil seal; 14 – block ring; 15 and 16 – radial and mechanical seal seals; 17 – internal cam; 18 – central ball; 19 – external cam; 20 – driving balls; 21 – pin; 22 – joint pin; 23 – semiaxle; 25 and 27 – semi-cylindrical cams; 26 – central disk.
Universal Joints of unequal angular speeds consist of two steel forks 6 and 10 and the cross 8 which pivotally connects them. The cross is mounted in the ears of the forks on needle bearings (a).
The bearings, consisting of glasses 3 and needles 4, are put on the polished spikes of the cross 8 made of chrome steel and are fixed in the eyes of the forks 6 and 10 with retaining plates 2 with the covers 1 placed under them. The glands prevent the lubricant from flowing out of the bearings, which enters through butterdish 9 and channels in a crosspiece. A safety valve 7 serves to remove excess lubricant.
Another cardan joint with a needle bearing, in which rubber self-sliding glands 13 are used, and the bearing cups are fixed in the forks by snap rings 14, is shown in figure (b).
For more reliable protection of needle bearings from oil leakage, two oil seals are sometimes installed – radial and end (c).