Abstract: A driving force transmission device includes an input section and an output section with rotation axes nonparallel to each other to avoid backlash. A driving force transmission device (1) includes a first rotator (2), a second rotator (3), and spheres (5A, 5B, 5C). The first rotator (2) performs one of an input operation and an output operation of a driving force and includes a concave surface (7). The second rotator (3) performs the other of the input operation and the output operation of the driving force and includes a convex surface (13) fitted into the concave surface (7). The spheres (5A, 5B, 5C) are between the concave surface (7) and the convex surface (13). The concave surface (7) has holes (32A, 32B, 32C) in which the respective spheres (5A, 5B, 5C) are received. The convex (13) surface has a groove (29, 30) that receives parts of the spheres (5A, 5B, 5C) protruding from the holes (32A, 32B, 32C).

Abstract: A driving force transmission device includes an input section and an output section with rotation axes nonparallel to each other to avoid backlash. A driving force transmission device (1) includes a first rotator (2), a second rotator (3), and spheres (5A, 5B, 5C). The first rotator (2) performs one of an input operation and an output operation of a driving force and includes a concave surface (7). The second rotator (3) performs the other of the input operation and the output operation of the driving force and includes a convex surface (13) fitted into the concave surface (7). The spheres (5A, 5B, 5C) are between the concave surface (7) and the convex surface (13). The concave surface (7) has holes (32A, 32B, 32C) in which the respective spheres (5A, 5B, 5C) are received. The convex (13) surface has a groove (29, 30) that receives parts of the spheres (5A, 5B, 5C) protruding from the holes (32A, 32B, 32C).

Abstract: A pinion (1) including a pin gear allows easy engagement with or disengagement from a mating gear. The pinion (1) includes a plurality of pins (2) as teeth, and includes a first plate (4) and a second plate (5) described below. The first plate (4) interconnects first ends of the pins (2). The second plate (5) is spaced from the first plate (4) in the rotation axis direction of the pinion (1), and interconnects second ends of the pins (2). The second plate (5) has, on its outer peripheral edge, recesses (15, 16) each between two pins (2) adjacent circumferentially. The recesses (15, 16) recede inward from inner circumferential ends of the pins (2). The pinion (1) is moved axially for engagement with or disengagement from the rack (3). The pinion (1) increases flexibility at the time of engagement with or disengagement from a mating gear.

Abstract: In a bearing device 1 which is assembled to a pinion 3 of a rack-and-pinion type drive mechanism 2, the bearing device 1 has a plurality of needle rollers 13. A plurality of pin rollers 9 are supported by an inner surface cylindrically formed by the plurality of needle rollers 13. Each of the plurality of needle rollers 13 is held at both ends 13a, 13b in an axial direction R by a retainer cage 14, so as to prevent the needle rollers 13 from being skewed against the axial direction R.

Abstract: In a bearing device 1, a plurality of columnar needle rollers 13 are provided. A cage 14 is provided in which the needle rollers 13 are arranged in parallel with each other along an axial direction R of a pin roller 9, so that the needle rollers 13 form a cylindrical configuration around the pin roller 9. The cage 14 has oppositely placed two rings 17 and a plurality of bridge pieces 18 bridged between the two rings 17, and having the bridge pieces 18 to rotatably accommodate the needle rollers 13 in order to achieve higher performances.

Abstract: In a bearing device 1 which is assembled to a pinion 3 of a rack-and-pinion type drive mechanism 2, the bearing device 1 has a plurality of needle rollers 13. A plurality of pin rollers 9 are supported by an inner surface cylindrically formed by the plurality of needle rollers 13. Each of the plurality of needle rollers 13 is held at both ends 13a, 13b in an axial direction R by a retainer cage 14, so as to prevent the needle rollers 13 from being skewed against the axial direction R.

Abstract: In a self-lubricating transmission device 1, a compression helical spring 15 is provided to urge an impregnation metal 14 as an impregnation means so as to slidably contact the impregnation metal 14 with pin rollers 7. In combination with a rotational movement of a pinion 6, the pin rollers 7 slide on a lower surface 14d of the impregnation metal 14 to supply a lubrication oil W to the pin rollers 7 so as to automatically lubricate the pinion 6 evenly at the right time for an appropriate amount of the lubrication oil W. This obviates the lubrication oil W being wastefully used, while at the same time, making a lubrication work quick, labor-saving and user-friendly.

Abstract: In a rack extension jig device 9, a protracted direction E of tooth projections 12-14 and an elevational direction H of racks 7, 8 are placed in a coplanar position G. This makes it possible to positively engage the tooth projections 12-14 with the respective rack teeth 7, 8 and half tooth surfaces 7c, 8c so as to set a predetermined pitch interval T at a contact portion between the neighboring racks 7, 8 by only pushing the tooth projections 12, 13, 14 against roots 7d, 8d of the respective rack teeth 7, 8 in perpendicular to the roots 7d, 8d, thereby making a rack-adding work easy, quick and user-friendly.

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 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 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 (?) 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: 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: 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.