Linear drives are based on several common technologies such as ball screws, rack and pinions, belt drives, and linear motors. Each of these have strengths and weaknesses making none ideal for all applications. Some shortcomings include backlash, low rigidity, cumulative error, thermal creep, limited length, low speeds, low-force capability, vibration, noise, particle emissions, high maintenance, low life, and high cost. The roller pinion system (RPS) is one way to address the limitations of traditional linear drives. The RPS linear-drive concept combines the best attributes of existing technologies while eliminating most of their shortcomings.

The roller-pinion system is similar to a traditional rack and pinion but replaces spur-gear teeth with bearing-supported rollers that engage a rack tooth profile. Bearing-supported rollers eliminate the sliding friction of traditional rack and pinion with smooth rolling friction that give a 99% efficient rotary-to-linear-motion conversion.

An RPS runs at speeds up to 11 m/sec (36.1 fps). Only linear motors are faster. Even at these speeds, the low-friction design generates minimal heat and wear on components.

The RPS rack uses a modular concept with only two standard factory lengths per size that are joined to create runs of any length. Full lengths are about 1 m and half-lengths about 0.5 m depending on tooth pitch. Shorter rack segments can be made by cutting the rack.

Because of the smooth way rollers engage the rack teeth the RPS generates low noise and vibration. It does not generate noise caused by tooth slap or recirculating balls in other linear drives. The system is whisper quiet at low speeds and less than 75 db at full speed. Typically, the guiding system, servomotor, and reducer generate more noise than the RPS. Less noise and vibration is always a plus because it reduces inaccuracy in precision sensors and encoders and creates a better working environment for personnel who may have to work nearby.

The pinion consists of 10 or 12 bearing-supported rollers, sealed and lubricated for life, making them maintenance free. The rack requires lubrication with a high-performance light grease at installation and then every six months or 2 million pinion revolutions. In special applications an RPS can run lubrication free as long as the speed is less than 30 m/min. Other mechanical linear drive systems require more frequent lubrication or maintenance.

Because lubrication requirements are low or nonexistent, the RPS has low particle emissions making it ideal for applications such as clean rooms, coating operations, and pharmaceutical production. Even with little maintenance the RPS provides 60,000,000 pinion revolutions of life at its rated performance. That's 9.6 to 28.8 million meters (3.2 to 95.5 million ft) when properly installed and maintained. RPS's will operate beyond this point with diminishing accuracy.

No lubrication is also beneficial in dirty applications such as cutting, milling, and routing. Contaminants are less likely to stick to the rack.