The raceway profile describes the geometry of the contact surfaces on which rolling elements such as balls or rollers roll. It is a key design feature of ball screws, rolling bearings, and linear guides, as it significantly influences force transmission, friction, load capacity, stiffness, and service life.
The career profile has a direct impact on several key characteristics:
- the contact area between the rolling elements and the raceway,
- the surface pressure, and wear,
- efficiency and smooth operation,
- the stiffness and load-bearing capacity of the system,
- the contact angle and, consequently, the load distribution.
An optimally designed raceway profile ensures even load distribution and reduces local stress peaks. This makes a significant contribution to reliable and long-lasting operation.
Different raceway profiles are used depending on the application:
- Circular arc profile: Commonly used in ball screws. The raceway radius is slightly larger than the ball radius, creating a defined contact zone.
- Gothic profile: Consists of two intersecting circular arcs and enables favorable load distribution as well as increased stiffness.
- V-shaped profile: Less commonly used in lead screws and is more often used in guide systems when precise positioning is required.
The raceway profile is also of great importance for operation and service life:
- A profile that is too small results in high surface pressure and increased wear
- A profile that is too large can impair guidance and reduce stiffness
- An optimally designed profile offers a balanced combination of load-carrying capacity, accuracy, and service life
The raceway profile is therefore precisely tailored to the ball diameter, contact angle, and preload. In ball screws, this affects, among other things, the dynamic load rating, preload options, noise and vibration characteristics, and suitability for precision or heavy-duty applications.