Image Credit: Electromate | Isotech, inc. | Berg W.M., Inc.
Ball slides are sometimes referred to as ball and rod bearing assemblies, or ball bearing slides. Ball slide stages are simply ball slides coupled with a drive mechanism. The result is a very smooth linear motion, accurately controlled by rotation of the drive mechanism.
Ball slides use a bearing system composed of two rows of balls on both sides of the base. Each row is contained between four rods. These two rows of balls are preloaded to eliminate play. As the carriage moves, the balls roll along the rods. Ball slides provide smooth, accurate, low friction motion. They are typically very reliable, and because there is no direct sliding contact between the base and carriage, they do not require regular lubrication.
Important specifications for ball slides include the base length, base height, carriage length, carriage width, and top height. Larger dimension devices can handle greater loads, although size is often a limiting factor since the slide has to fit into the housing or drive system. Other important specifications include dynamic load carrying capacity and maximum linear velocity or speed.
Ball slides are available with a number of additional features that help them perform their duties with greater functionality.
Way covers and bellows - Way covers, which are sometimes referred to simply as bellows, cover the rails / guides for protection from dust and dirt.
Wipers and scrapers - Wipers or scrapers for cleaning the surface of the rails / guides while in service. This is a very valuable feature if the ball slides are to be used in dusty or otherwise compromised environments.
Stackability - Stackability means that the slides may be stacked (one on top of another) to provide linear motion in more than one axis.
Double carriages - Double carriages have two sliding platforms for additional work or carrying capacity.
Locking mechanism - Lockable ball slides have a brake assembly for slowing or stopping the linear motion, or a lock for maintaining the carriage in a specific position.
Specific Ratings & Standards
Some ball slides carry specific ratings, which state that they are approved for specific applications. Two of the most common ratings are cleanroom certified and vacuum rated. Cleanroom certified ball slides meet or exceed the requirements needed for use in cleanroom environments. Cleanroom requirements are typically specified in orders of magnitude of 1, 10, 100, 1000, 10,000, relating the particles per million and defining the particle size. Vacuum rated ball slides are designed to withstand the rigors of working within vacuum chambers.
Additional standards for ball slides can be found at the IHS standards store.
Related Products & Services
Crossed Roller Slides
Crossed roller slides are simple linear motion devices that consist of a stationary base and a moving carriage. The rollers are crossed at a 90° angle in an alternating fashion and are enclosed in the rails, which have a machined V-shaped groove to support the rollers.
Dovetail slides are linear motion devices that allow motion and positioning along a linear axis.
Linear Slides and Linear Stages
Linear slides are simple linear motion devices composed of a stationary base and a moving carriage. Linear stages are slides with a drive mechanism that provide controlled, precise positioning along a linear axis.