Processing Technique and Tool Selection for Automotive Constant Velocity Joint Components
Introduction
Today, many cars utilize front-wheel drive, where the gearbox and drive axle are integrated to connect the wheels and transmission via two half shafts, propelling the vehicle.
Due to the frequent changes in the relative positions of the wheels and gearbox, along with variations in the angles between the output and input ends, a universal joint mechanism is required for adjustment, commonly referred to as a constant velocity joint (CV joint).
About Automotive CV Joints
Automotive CV joints, also known as CV cage-style joints, are a type of constant velocity joint, with another type being the CV cross-style joint. They are crucial components in the transmission system of cars, responsible for transferring power from the engine's gearbox to the two front wheels, enabling high-speed vehicle operation. CV joints are divided into inner and outer CV joints, with the inner joint connecting to the transmission differential and the outer joint connecting to the wheels. During power delivery and vehicle turning, the outer joint primarily functions.
Composition of CV Joints
Automotive CV joints typically consist of a bell-shaped housing, tripod bearings or steel balls, dust cover, retaining ring, and lubricating grease.
The outer CV joint comprises the following components:
1. Bell-shaped housing 2. Inner race 3. Retaining cage 4. Steel balls 5. Dust cover 6. Retaining ring 7. Lubricating grease
The inner CV joint comprises the following components:
1. Bell-shaped housing 2. Tripod bearings or steel balls (the main difference lies here) 3. Dust cover 4. Retaining ring 5. Lubricating grease
CV Joint Machining Process
The machining challenge with CV joints mainly lies in the hard machining of the inner race and bell-shaped housing (outer race) after heat treatment.
The following are the tools used in the machining process, with the majority being welded CBN tools.
While some may consider the use of indexable inserts, the design of these tools needs to consider the characteristics of the CV joint's race track shape, such as elliptical, gothic, or spherical, as well as factors like contact angle, clearance, and similarity, making indexable inserts not the optimal choice, considering mold costs and tool batch issues.
The current solution involves cutting, welding, and grinding PCBN inserts to meet tool design requirements, with PCBN tools exhibiting excellent performance in machining hard materials after heat treatment.
Machining the inner race involves strong interrupted cutting conditions, demanding high-impact resistance from CBN tools.
MoreSuperHard provides customized tool solutions, providing strong support for the smooth progress of customer production.
If you are facing similar processing problems, welcome to learn more about CBN inserts. MoreSuperHard will customize the most suitable tool for you.
