It's easy to be enamored with the latest technological innovations, but as designs get more complicated they can also become more failure prone. Many consumer products, it seems, last only as long as the warranty, and the same often holds in the industrial arena as well.
The Motion Control Group of Numatics Inc., Avon, Ohio, is bucking this trend with a new line of slides, rotary actuators, and grippers. The focus is on solid, durable designs that can be easily modified to meet special requirements.
For example, among the company's 23 new products is the SPS Series power slide. While the general industry trend in slides has been toward roller-bearing technology, the SPS instead relies on a T-slot plainbearing design.
T-slots aren't new, admits Jeff Schneid, the division manager, but they exemplify "proven, workhorse technology." Rollers might run with lower friction, but that's usually not a significant factor in most power-slide applications. Dirt and debris are more pressing concerns because rollers are more susceptible to contamination, while slides are selfcleaning and have higher load capacities. The simple design means there is less to go wrong, which often equates to less downtime.
The SPS slide has an aluminum-bronze alloy construction with a heavy cross section that is said to offer superior loadbearing capabilities throughout the stroke compared with roller slides. The pneumatically powered units are available with strokes ranging from 0.5 to 2 in. and provide thrust forces of 15 to 44 lb at 100 psi. Fine adjustments can be made to the extend stroke through the tooling plate, and the retract stroke is adjusted from the unit's backside. The parts have a standard footprint, for seamless changeout and retrofit.
Other products being introduced include:
Power slides. PBS Series power slides are designed for applications where space is at a minimum. An internal cylinder in the carriage assembly reduces overall length. The carriage is supported by four recirculating linear ball bearings and two hardened guide shafts. Cylinder bores range from 0.75 to 1.25 in., and the units develop from 31 to 100 lb of thrust.
Grippers. WBG Series parallel grippers use four independent pistons to open and close the jaws. Rack-and-pinion units synchronize jaw motion, which are independent from force rods and support rods. The products are made of high-strength aluminum for a high gripping force to weight ratio. Gripping force is 60 lb at 100-psi air pressure, with a 0.75-in. stroke,±0.001 in. repeatability, and an actuation time of 0.3 sec.
Rotary actuators. The LR series rotary actuators feature a low-profile rack-and-pinion design. Two independent pistons drive the racks against the pinion to rotate the platform. Bearings on each side of the pinion shaft support the rotary platform and handle high dynamic loads. Payloads range from 1 to 15 lb and torque output from 6.5 to 126 lb-in. Repeatability is 0.018° or less, maximum rotation is 190°, and maximum speed to turn 180° is from 0.3 to 0.4 sec, depending on the unit.
Other new products include six-finger grippers, four different series of parallel grippers, feed escapements, and a rotary manifold that transfers pressurized air through fixed ports to rotating parts on a rotary platform. The components are designed for specialty machine builders and system integrators, with two-day delivery standard. For more information, visit www.numatics.com