Linear bushings, also known as ball bushings, are linear bearings that ride on a hardened, round shaft to provide linear guidance with low friction. The first linear bushing designs were patented in 1945 and became commercially available in the 1950’s. Until the introduction of profiled rail linear guides in the 1970’s, linear bushings served as the […]
Linear actuators: Pneumatic or electric?
Updated May 2018 || Electrons or air molecules? That’s not a question you hear very often, but it’s one that engineers and designers wrestle with when developing a new machine or process. That’s because a wide range of linear actuators, especially rod-type versions, are available either electrically driven or pneumatically driven. The choice of which […]
Transmitting torque with keyed shafts
Power transmission between two rotating components requires a secure connection between the shaft of the driving component, and the hub of the mating part. One way to ensure torque transmission without slipping is by using a keyed connection. For most automation applications (motors, gearboxes, pulleys, etc.), a parallel key, also known as a straight key, with […]
Five things to consider in vertical applications
Mounting orientation is one of the core considerations when sizing and selecting a linear actuator. Depending on the type of linear guides used, some actuators can support higher downward or lift-off loads than side loads, or can handle pitch and yaw moments better than roll moments—all important factors when evaluating an actuator for vertical duty. […]
The basics of air bearings
Bearings are often thought of as mechanical rolling or sliding elements, but linear (or rotary) bearings can also use a thin film of pressurized air to support a load. With no mechanical elements to generate friction or heat, air bearings are ideal for applications that require extremely high precision and stiffness. Pressure generation and air delivery […]
What is linear motor commutation?
The process of linear motor commutation is not well understood and is often glossed over, but it has a significant effect on performance. Motor force (torque in a rotary motor) is proportional to the magnitudes of the magnetic fields of the magnet track (stator in a rotary motor) and forcer (rotor in a rotary motor), multiplied […]
Parker announces North American production of high moment rodless linear actuator series
Now manufactured in the USA, the HMR attains greatly improved lead times and new customization options. Parker’s Electromechanical Automation Division, a leading supplier of motion control technology, is pleased to announce the domestic manufacturing for the complete line of High Moment Rodless (HMR) electromechanical linear actuators. “This move will serve to greatly improve product lead times […]
Ball rail systems: twice the service life and high travel accuracy
The patented entry zone of the new BSHP ball runner blocks from Rexroth improves travel accuracy and work piece quality while greatly increasing load capacities and service life. These runner blocks are available in most sizes, versions, and accuracy classes. BSHP ball runner blocks are 100% interchangeable into existing profiled rail applications using the same […]
How encoder resolution is determined
Resolution is a fundamental specification and one of the most important factors when selecting an encoder. For linear encoders, resolution designates the number of measuring units per distance (inch or millimeter), whereas for rotary encoders, it refers to the number of measuring units per revolution (also called pulses per revolution, or PPR) or per degree of […]
New miniature lead screws
Helix Linear Technologies today unveiled its Ultra Miniature lead screw product line. Helix designed the new range of lead screws for applications that demand micron level positioning and impressively small envelopes. Helix is matching these new screws with their proprietary internally lubricated anti-backlash nut designs to produce a precision lead screw assembly with zero backlash […]