Nexen Roller Pinion System -- A White Paper

Competitive market pressures are pushing machine builders to design machines that are faster, more precise, and require less maintenance so they are more productive for their end users. In pursuit of these goals, more servo controlled linear drive systems are being employed. Linear drives are based several common technologies like ball screws, rack and pinion, belt drives, and linear motors. Each of these technologies have their strengths and weaknesses making none of them ideal for all applications due to short comings like 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. To address these linear drive systems limitations Nexen introduced the Roller Pinion System, a new, patented linear drive concept that combines the best attributes of the existing technologies while eliminating most of their shortcomings. The Nexen Roller Pinion System (RPS) takes the traditional rack and pinion concept and advances it by replacing spur gear teeth with bearing supported rollers that engage a unique rack tooth profile. The 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.