Have you ever wondered what constant-velocity joints are? What is their purpose and use? If you are keen to know about them then this article is certainly for you.
Constant-velocity joints are popularly called CV joints. They help in transmission of power by the drive shaft through some variable angle. This happens at a steady rotational speed and there is no appreciable rise in friction. They are generally used in all-wheel drive and front-wheel drive cars. The rear-wheel drive cars having independent rear suspension commonly utilize CV joints. You will find them at the rear-axle halfshafts ends and on propshafts. You will find their use in Audi Quattros for four half axles and also on front-to-rear propeller shaft.
These joints get the rubber boot – CV gaiter protection. The splits and cracks in boot will cause corrosion in the joint. The joint would require a replacement if it is not soon removed, cleaned, greased, besides fitting the new boot.
The Rzeppa joint contains the spherical inner having 6 grooves. It consists of a similar outer shell that is enveloping it. One ball is guided by each groove. There is an input shaft that fits in a gear’s center. This gear is star shaped and nests inside the circular cage.
Although it is a spherical cage but the ends are open. There are typically six openings in it around perimeter. The gear and cage fit into the grooved cup. Six big steel balls are placed in cup grooves. These joints can accommodate large angle changes when there is turning of front wheels using a steering system.
Some Rzeppa joints permit articulation of 45-48 degrees, while some provide 52 degrees. The driveshaft outboard end uses a little different unit. The driveshaft end is splined. It fits into an outer joint and a circlip is used for keeping it in place.