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:
In a rolling ball type two-stage low speed changer device 1, empirical formulas are obtained as a relationship between number of first, second, third and fourth lobes z1, z2, z3, z4 of a hypo based groove 6 (8) and an epi-based groove 7 (9). The relationship is represented by z1>z2, z3>z4, z1−z2=2, z3−z4=2 and z3=n×z2×½ (n: integer), and enables to a precise and smooth rotational transmission without inviting differential slippage and incurring an irregular rotation and uneven torque transmission on an output shaft 16 within the practical usage, and reducing a thickness dimension to render a whole structure compact, achieving a high transmission efficiency without inviting a backlash, and attaining a high torque transmission with low noise.
Abstract:
In a gearless differential speed reducer, first and second discs are provided in a manner to oppose each other, and a plurality of semi-spherical recesses circumferentially are provided on the opposing surface of the first disc along a certain pitch circle. A groove provided on the opposing surface of the second disc, the groove defined as a cycloidal-based curve running along a pitch circle. A rollable ball is provided to be placed at each of the semi-spherical recess and the groove. The balls are adapted to roll within the recess, and at the same time, roll along the groove when a rotational movement is transmitted to the second disc to impart the second disc with a nutational movement. A rectifier member provided to pick up a rotational movement from the nutational movement of the second disc.
Abstract:
Among six follower balls (5) aligned on the input shaft (7), the two balls (5) situated on one end side (A) always engage tightly with one engagement surface (10a), while the other two balls (5) situated on the other end side (B) always engage tightly with the other engagement surface (10b). This regulates the movement of the balls (5) against the engagement surface (10a, 10b) of the cammed streak portions (10) so as to eliminate a backlash played between the balls (5) and the cammed streak portions (10). This makes it possible to prevent the meshing noise from being induced so as to implement a low noise operation. With the point-to-point contact maintained between the cammed streak portions (10) and the balls (5), it is possible to reduce a friction therebetween, thereby improving a torque transmissibility against the follower wheel (4) to insure a smooth rotational movement with a higher precision.
Abstract:
In a ball-rolling type torque transmission device, an outer race groove an inner race groove are provided between the eccentric rotation disc and the input shaft, the output shaft or a first stationary member within the housing, the outer race groove being defined along a hypocycloidal curve having N+2 lobes, while the inner race groove defined along an epicycloidal curve having N lobes. Rollable balls are placed to position at N+1 points between the inner race groove and the outer race groove. A rectifying member is provided between the eccentric rotation disc and the input shaft, the output shaft or a second stationary member within the housing to rectify a movement of the eccentric rotation disc by cancelling an eccentric component of the eccentric rotation disc. A geometrical relationship between L1, L2, R1 and R2 being defined as follows: L1/L2=R1/R2 where L1 is a wavelength of one lobe of the outer race groove along which each of the balls rolls, L2 is a wavelength of one lobe of the inner race groove along which each of the balls rolls, R1 is a distance from a center of each of the balls to a first line formed by connecting points in which each of the balls inscribes the inner race groove, and R2 is a distance from a center of each of the balls to a second line formed by connecting points in which each of the balls inscribes the outer race groove.
Abstract:
In a roller type transmission device 1, an array 11 of transmission pin rollers is press fit circularly into an inner side surface 10a of a stationary ring 10, and an array 18 of controllable pin rollers is press fit circularly into an inner side surface 13c of a rotational ring 13. To pin rollers 11a, 18a, employed are high precision cylindrical rollers or needle rollers which are usually used for a roller bearing or the like. Such is the structure that the array 11 of transmission pin rollers and the array 18 of controllable pin rollers work as inner teeth to make a backlash phenomenon minimum, rendering a pitch distance precise between the pin rollers, maintaining a uniform tooth profile with a high precision, equalizing a surface roughness and improving a meshing precision between the pin rollers 11a, 18a and the teeth 7a, 8a.
Abstract:
In a roller type transmission device 1, an array 11 of transmission pin rollers is press fit circularly into an inner side surface 10a of a stationary ring 10, and an array 18 of controllable pin rollers is press fit circularly into an inner side surface 13c of a rotational ring 13. To pin rollers 11a, 18a, employed are high precision cylindrical rollers or needle rollers which are usually used for a roller bearing or the like. Such is the structure that the array 11 of transmission pin rollers and the array 18 of controllable pin rollers work as inner teeth to make a backlash phenomenon minimum, rendering a pitch distance precise between the pin rollers, maintaining a uniform tooth profile with a high precision, equalizing a surface roughness and improving a meshing precision between the pin rollers 11a, 18a and the teeth 7a, 8a.
Abstract:
In a worm-rack type transmission device (1) a curved side portion (6) is provided on rack teeth (2a) of a linear rack (2) in a manner to form a part of an ellipsoidal surface (E) and twisted by a changing rate (θ) of a torsional manner a toothed streak (5) of a worm wheel (3). The worm wheel (3) brings the toothed streak (5) into engagement with the curved side portion (6) in a line-to-line contact, enabling to a self-locking property and strengthening a transmission power to insure a high transmission efficiency with a least friction loss so as effectuate a linear drive for an extended distance travel with a high precision.
Abstract:
In an intermittent torque transmission device, an input shaft is provided to have a cylindrical cam face. An output shaft has a wheel provided in a manner to intersect the input shaft. A plurality of recesses are provided on an upper surface of the wheel along a predetermined base circle. A cam groove is provided on the cylindrical cam face of the input shaft. A spherical ball is rotatably provided in each of the recesses of the wheel while engaging against the cam groove so as to intermittently rotate the wheel of the output shaft in association with the rotational movement of the input shaft.
Abstract:
Gearless differential speed reducer comprising a first disc secured to a casing, a second rotary disc arranged to face the first disc, sinuous grooves provided with the facing sides of discs, the sinuous shapes of which are epicycloid and hypocycloid curves determined along a certain pitch circle, spherical balls provided between the discs to position into the grooves, and an eccentric shaft connected to the rotary disc through a bearing. Rotational movement of the eccentric shaft allows the rotary disc to rotate around one end of the shaft, while going along the pitch circle, since the balls rolls along the sinuous grooves. A single rotation of the shaft permits the rotary disc to travel by the length equivalent to that of two lobes of the grooves, yielding speed reduction ratio as a formula of 2/N(N+2) when the groove of the first disc counts its number of lobes as N.