Though final control elements such as actuators, ball screws, cylinders and positioners aren’t the sexiest parts of machine automation, they nonetheless are the crucial nuts and bolts of motion control systems that keep things moving.
However, like most essential components and devices, not much changes in the way of new and exciting technological innovations from year to year. Products that offer optional mounting configurations, multiple axes, the lure of improved productivity and accelerated speeds at lower costs are introduced as new to the marketplace. However, a closer look reveals not much new when it comes to operating motors and drives.
Despite this trend, the North American market for motion control components and products was estimated at a whopping $81 billion, including more than $50 billion for MRO use and nearly $31 billion in purchases by industrial OEMs, according to statistics released in December 2005 by the Power Transmission Distributors Assn. (PTDA).
In 2005, U.S. manufacturers' sales of motion control components increased 9.6% compared to sales for 2004, according to the PTDA's Market Outlook Report. In December 2005, sales fell 9.1% from the previous month, and decreased 2.1% compared to December 2004. Compared to November, sales of mounted bearings, standard industrial motors, variable speed drives and shaft couplings increased. Sales of unmounted bearings, positioning systems/linear motion products, gear products, mechanical drive systems and other PT products, and clutches and brakes decreased.
Statistics provided by the report show year-to-date orders of motion control components from U.S. manufacturers grew 11.2% compared to 2004. December orders were down 9.1% over November and decreased 0.7% compared to December 2004.
Research provided by Frost & Sullivan says a growing price competition among manufacturers in the North American motion control components markets "spurs end users to increasingly base purchasing decisions on cost alone." In a bid to keep expenses at a minimum, many manufacturers are "trying to increase the number of production process that can be completed by factory automation, thereby driving demand for motion control products," the report claims.
The Power Transmission Group says suppliers are under pressure to continue offering competitively priced new technology products. "Technical expertise, understanding of customer demands across a wide range of applications, and an emphasis on improving performance are vital for manufacturers to compete effectively in this market sector," the report states.
DGEA cantilever electric linear actuator comes in two mounting configurations in sizes 18, 25, and 40 mm. The motor is mounted parallel to the actuator with the integrated right-angle gearbox, eliminating obstructions and installation space. It has speeds to 3 m/sec, repeatability of ±0.05 mm, and stroke lengths to 1,000 mm.
RCP2-RSW robo cylinder is IP65-rated, 45-mm wide, with a load capacity of 40 kg (horizontal)/19 kg (vertical). RCP2-RMW is 64 mm wide with a load capacity of 55 kg (horizontal)/26kg (vertical). Both have strokes 50-300 mm, speeds can be changed during slider/rod movement, and positioning repeatability is ±0.02 mm.
Higher Ground Speed
Long-lead ball screws integrate a nut rotating inside the bearings and along the fixed screw shaft. It has linear speeds to 110 m/min, angular contact bearings directly mounted on the nut and preloaded in an "O" configuration, a fixed screw shaft for simplified mounting, two all-metal seals to protect the support bearings and nut from contaminants, and brush wipers mounted in the ball screw in standard configuration for additional protection.
SKF Linear Motion & Precision Technologies
UBT controller can be configured for merge, divert or transfer mode through a serial port, plugs into the line where needed and can interface directly with DeviceNet. ZoneLink serial interface card allows distributed controllers to communicate with each other and configure and monitor a zero pressure accumulation conveyor line.
Linear actuator system has positioning accuracy below 12 µm for high-end machine building applications. Constant, high rigidity is achieved over the complete travel distance. Applications include the printing, packaging, food processing, machining and medical industries.
Alpha Gear Drives
Perform Under Pressure
PowerMax tie-rod type hydraulic cylinders have heat-treated shafts and precision machined pistons and caps for extended cylinder life. Series PML cylinders provide working pressure to 2,500 psi, Series PMH cylinders to 3000 psi. It has a ductile iron rod clevis threaded 360° for a full contact area, and a positive set screw locking device helps the cylinders withstand continuous high loads.