Abstract:
A transmission device for converting a torque from rotary to linear movement includes a rack having a plurality of teeth and a pinion having rollers which mesh with the teeth of the rack, with pressurization provided therebetween. The rack has an arcuate tooth flank diametrically greater than each of the rollers of the pinion. The rack also has a tooth face which has an approach profile progressively moving away from the path of contact of each of the rollers along which each of the rollers would otherwise engage with the tooth face. A plurality of each of the rollers of the pinion concurrently mesh with the corresponding teeth of the rack. Another embodiment converts a torque between rotary and linear movement and comprises a pinion having a plurality of teeth and a rack having a plurality of rollers to mesh with the teeth of the pinion. The device achieves reduced transmission resistance, a silent intermeshing movement with no substantial noise and vibration, as well as reduced wear on the teeth and rollers.
Abstract:
An improved chain drive mechanism having a closed loop of roller chain passing round the opposite sprocket wheels. The profile of each tooth formed on the circumference of the sprocket wheel is in conformity with the envelope curve traced by a roller when the roller moves with its center following an involute-trochoid curve. The involute-trochoid curve is determined by offsetting the roller pitch line a certain distance apart outside the contact pitch line, and by rotating the contact pitch line on the base circle of the sprocket wheel to allow a point on the roller pitch line to trace a curve. The certain distance is so determined that the roller pitch may be equal to the incremental arc length, which is determined by dividing the circumference of the base circle by the number of teeth.