One of the differences between radial ball bearings and recirculating ball linear guides has historically been that radial bearings typically use a cage to separate the balls and control their movement, whereas profiled rail guides did not. But in the early 2000’s, manufacturers of profiled rail bearings began introducing versions with ball cages (also referred […]
Ball + roller guides
Linear motion trends in slides: Robotics and mobile designs lead the charge
Demand for simple-to-install and pre-integrated linear-slide systems continues unabated … especially in applications only recently automated. Here’s the perspective of Matt Mowry, North American market manager for drylin products at igus: “We’ve supplied fully assembled and customized linear-slide tables … complete with motors and accessories. We’ve also supplied custom-extruded linear profiles and bearing liners to […]
Follow these four tips when using L10 life to size linear bearings
The well-known bearing life equation, often referred to as L10 life, is a fundamental element in the sizing and selection of recirculating linear bearings. Through statistical analysis and real-world testing, the L10 life equation can predict, with 90 percent reliability, the life that a recirculating bearing can be expected to achieve. But even this universally […]
Rotary ball splines ensure sub-millimeter accuracy
The NB rotary ball spline has a cylindrical nut that rolls on the ball spline shaft. Rotary ball splines can be used for both rotational motion and linear motion, providing sub-millimeter accuracy every time. Popular applications include SCARA robots, the vertical shaft of assembly equipment, automatic tool changers, and loaders. A ball spline’s forte is […]
Profiled rail accuracy: When accuracy class doesn’t tell the whole story
You’ve chosen a profiled rail and bearing for a high-precision application — machining, cutting, or metrology, for example. The bearing (aka carriage, or runner block) has good load capacity and rigidity, so it should provide long life and low deflection. But when you integrate the assembly into your application, you notice that the system doesn’t […]
Selecting shafts for linear bearings: two things you need to know
In a round shaft linear bearing system, the shaft acts as the inner raceway of the bearing and plays a significant role in the wear and life of the system. Both recirculating and plain linear bearings as well as track-roller wheel-based linear bearings can use a wide variety of shaft materials, depending on the application […]
SKF LLT profile rail guides designed to suit a wide range of applications
SKF LLT profile rail guides from SKF Motion Technologies, Inc. have been uniquely designed to deliver smooth running performance, high precision and accuracy, and long service life with minimal maintenance for a wide range of linear guiding applications. LLT guides have the ball circuits placed in an X-arrangement, which optimizes load sharing in all four […]
How raceway geometry affects profiled rail guide performance
In the context of profiled rail guides with recirculating balls, the raceway geometry defines how the load-carrying balls are positioned relative to the raceways of the rail and the bearing (aka “carriage” or “slide”). The two most common raceway geometries are referred to as circular arc and Gothic arch, but some manufacturers have adopted a […]
Beam deflection equations for linear systems
When a linear guide, such as a round shaft or profiled rail, deflects or sags, the bearings that travel along the guide experience edge loading (a higher load concentrated at the ends of the bearing), which can cause rough, irregular movement, increased wear, and reduced bearing life. And when a linear guide is incorporated into […]
THK expands manufacturing plants and automated processes in response to LM guide demand
THK is taking major steps to meet the growing worldwide demand for linear motion products. In fact, as the world leader in linear motion guides, THK has recently invested over a half-billion dollars in new brick and mortar facilities that will increase floor space for their global manufacturing operations to just under 10.5 million square […]
