Linear Performance

Advanced linear motion technologies offer an effective option for applications that might traditionally utilize rotary motors, ballscrews and other mechanical motion devices. New linear motion devices typically offer effective ways to reduce friction, zero backlash capabilities and the ability to precisely control loads.

By selecting fully integrated products, machine designers can focus on the performance required by the application rather than detailed engineering issues. Because of the “systems” nature of linear motion applications, suppliers focus not only on the details of the motor technology, but also the actuators and mechanical design elements required to achieve effective control.

LINEAR STAGES ADDED TO MOTION CONTROL PORTFOLIO

Rockwell Automation is introducing a new line of linear stages for a wide range of load-carrying applications. The Allen-Bradley MP-Series integrated linear stages utilize familiar programming tools and offer seamless integration with other parts of the control system. Because the MP-Series integrated linear stages are available in both ballscrew and direct drive linear motor versions, machine designers can select a linear stage based purely on desired performance and not worry about the internal technology.

Features include rugged industrial design with IP30 environment protection rating, an exterior cable track that is easy to replace without device disassembly and operation without home and over-travel switches, improving reliability and reducing the need for additional wiring and programming time.

DOUBLE STACK EXTERNAL HYBRID LINEAR ACTUATOR

The 28000 series (Size 11) from Haydon Switch & Instrument is a double stack, external hybrid linear actuator. A rotating acme stainless-steel lead screw is incorporated into the motor's rotor. Shaft to lead screw couplers are not needed, simplifying the assembly.

The external linear actuator replaces four different components — a motor, coupler, lead screw and nut. The nut on the actuator uses the same thermoplastic as the rotor drive nut on non-captive and captive designs.

This double stack external hybrid linear actuator is available in resolutions ranging from 0.000125 inch (.003175 mm) per step to 0.002 inch (.0508 mm) per step and delivers thrusts of up to 30 lb (133N). A standard external linear has 4 inches of visible lead screw, but the lead screw length, termination and external nut design can be customized.

LINEAR MOTOR X-Y BASE

A ready-engineered linear stepper X-Y positioning base from Baldor uses a novel honeycomb-structured composite material used to reduce the cost of applying advanced linear motor technology. With prices starting from $7,000, the bases provide machinery builders with a highly competitive alternative to traditional solutions such as rotary motors and ballscrews or belts.

The new X-Y bases are available in a choice of seven standard sizes with square or rectangular working areas ranging from 375 x 375 to 750 x 1,500 mm. They are capable of move speeds of up to 1.5 m/sec at resolutions to 2.5 microns and with a repeatability of better than 2 microns. The units also offer friction-free mechanics with zero backlash and no wind-up.

The base's moving element, the forcer, floats on an air bearing and integrates two linear stepper motors mounted at right angles to each other to provide X and Y directional thrust.

NEW LINE OF LINEAR ACTUATORS

New PL linear actuators from Pacific Bearing provide a highly accurate system, high load capability and T-slots for easy mounting. Given the broad selection of ball screws available, the PL is targeting a wide range of applications where overall system accuracy is a high priority.

The unit's simple, precision-machined aluminum design allows for both easy installation and excellent durability. Its machined profile provides for flushed mounting on both sides and the base for ease of installation. A magnetic seal prevents contamination and allows the system to function in the most demanding food and beverage environments or the clean environments typically found in medical and pharmaceutical applications. By eliminating the belt drive gearboxes required by similar actuators, the PL series offers a lower overall system cost. Pre-loaded ball bearing rollers, guided by the company's patent-pending Integral V™ hardened steel raceways, create smooth, precision guidance.

LINEAR SHAFT MOTOR STAGE

The SCR100 stage from Nippon Pulse is a complete single-axis stage which integrates a slide guide, encoder and linear shaft motor. It offers a wide range of advantages for applications requiring high performance and accuracy. The linear shaft motor allows for higher resolution, speed and continuous force than a standard stepper or piezo servomotor.

The motor and non-contact optical linear encoders are self-contained inside the stage, making it a low-profile compact solution. Each SCR stage requires a servo driver to operate the stage. Any two SCR stages will bolt directly together to form a very stiff, compact X-Y assembly standard, without the need for adapter plates. Two SCR stages can be supplied as an X-Y stage to insure true orthogonal orientation between the two axes.

Key features include: the unit's moving magnet design, absence of any moving cables, a precision ground cross roller and built-in non-contact optical linear encoder, as well as sub-micron resolution.