A speed reduction device including a first internally meshing planetary gear mechanism and a second internally meshing planetary gear mechanism, including: a housing; an input shaft rotatably supported by the housing at its first shaft portion through a first bearing; a planetary gear member rotatably supported by an eccentric shaft portion of the input shaft through a second bearing; and an output shaft rotatably supported by a second shaft portion of the input shaft through a third bearing, wherein a distance in an axial direction between a first support position and a second support position is equal to a distance in the axial direction between the second support position and a third support position, and a distance in the axial direction between the second support position and an input-side meshing position is equal to a distance in the axial direction between the second support position and an output-side meshing position.

A speed reducer comprises a transmission shaft, an eccentric wheel, a first wheel assembly, a rotating wheel and a second wheel assembly. The first wheel assembly comprises a first wheel disc and at least one first roller. The at least one first roller is disposed on the inner wall of first wheel disc. The rotating wheel comprises a main body comprising an outer ring structure and a concave structure. The outer ring structure comprises at least one first tooth. The at least one first tooth is in contact with the corresponding first roller. At least one second roller is disposed within the concave structure. The second wheel assembly comprises a second wheel disc and at least one second tooth. The at least one second tooth is disposed on an outer periphery of the second wheel assembly. The at least one second tooth is in contact with the corresponding second roller.

A speed reducing device includes a motor and a speed reducing mechanism. The speed reducing mechanism includes at least one roller assembly, a cycloid disc, at least one fixing disc and a positioning assembly. The roller assembly is disposed within a rotor portion of the motor. While the roller assembly is rotated with the rotor portion, the roller assembly is eccentrically revolved. The roller assembly includes a wheel disc and at least one roller. The cycloid disc includes a main body and at least one cycloid tooth structure. The cycloid tooth structure is protruded from an outer periphery of the main body and in contact with the corresponding roller. While the roller assembly is eccentrically revolved, the at least one cycloid tooth structure is pushed against the corresponding roller, so that the cycloid disc is correspondingly rotated.

A pinion cage for supporting at least one spiral gear planet wheel in a spiral gear planetary gear train for an adjustment device for adjusting two structural components which can be adjusted relative to one another, wherein the spiral gear planet wheel comprises a planet wheel axle which comprises a first axial section extending over the spiral gear planet wheel and comprises a second axial section extending over the spiral gear planet wheel, and the pinion cage comprises a tubular base body which defines a pinion cage axis, at least one perforation arranged in the base body and penetrating through it, a first support section starting from the perforation, a second support section starting from the perforation, wherein the first and the second support sections are constructed for rotatably receiving the first and the second axial sections and are arranged in such a manner that the planet wheel axle runs in a twisted manner to the pinion cage axis if the axial sections are received in the support sections, and the pinion cage comprises a first fixing means connected to the base body for fixing the first axial section in the base body and a spiral gear planetary gear train with such a pinion cage and to an engine transmission unit with such a spiral gear planetary gear train.

A pinion cage for supporting at least one spiral gear planet wheel in a spiral gear planetary gear train for an adjustment device for adjusting two structural components which can be adjusted relative to one another, wherein the spiral gear planet wheel comprises a planet wheel axle which comprises a first axial section extending over the spiral gear planet wheel and comprises a second axial section extending over the spiral gear planet wheel, and the pinion cage comprises a tubular base body which defines a pinion cage axis, at least one perforation arranged in the base body and penetrating through it, a first support section starting from the perforation, a second support section starting from the perforation, wherein the first and the second support sections are constructed for rotatably receiving the first and the second axial sections and are arranged in such a manner that the planet wheel axle runs in a twisted manner to the pinion cage axis if the axial sections are received in the support sections, and the pinion cage comprises a first fixing means connected to the base body for fixing the first axial section in the base body and a spiral gear planetary gear train with such a pinion cage and to an engine transmission unit with such a spiral gear planetary gear train.

A reduction assembly, attachable to a torque limiting device, comprising a drive shaft having an input segment, an eccentric segment, and an output segment, wherein the input segment and the output segment each have a centerline running along a same first axis, and wherein the eccentric segment has a center line running along a second axis, the second axis being parallel to the first axis and positioned a first distance away from the first axis. The assembly further comprising a disk assembly having a disk with a body, a plurality of lobes positioned concentrically on the body, and an opening extending through the body, the opening configured to slidably engage the eccentric segment of the drive shaft. The assembly further comprising a disk receptacle configured to engage with the disk, the receptacle having a floor and a wall with a plurality of protrusions extending from the wall, wherein the number of the plurality of protrusions is equal to one more than the number of the plurality of lobes on the disk.

A reduction assembly, attachable to a torque limiting device, comprising a drive shaft having an input segment, an eccentric segment, and an output segment, wherein the input segment and the output segment each have a centerline running along a same first axis, and wherein the eccentric segment has a center line running along a second axis, the second axis being parallel to the first axis and positioned a first distance away from the first axis. The assembly further comprising a disk assembly having a disk with a body, a plurality of lobes positioned concentrically on the body, and an opening extending through the body, the opening configured to slidably engage the eccentric segment of the drive shaft. The assembly further comprising a disk receptacle configured to engage with the disk, the receptacle having a floor and a wall with a plurality of protrusions extending from the wall, wherein the number of the plurality of protrusions is equal to one more than the number of the plurality of lobes on the disk.

A roller screw mechanism is provided comprising a screw with an outer thread, and a nut disposed around and coaxially with the screw and comprising an inner thread; and with rollers that each have an outer thread and inserted between the screw and the nut, each roller having two ends each provided with an outer gear teeth, each outer gear teeth having, in cross-section, an outer diameter less than or equal to a root diameter of the outer thread of the rollers; and two synchronizing gear teeth disposed coaxially to the screw and in which the outer gear teeth of the rollers engage, wherein the outer gear teeth of the rollers have teeth with a flank having, in cross-section, a convex hypotrochoidal profile and the synchronizing gear teeth have teeth with a flank having, in cross-section, a hypotrochoidal or epitrochoidal profile.

The precessional gear transmission comprises a body, a satellite wheel with two bevel gear rings driven by a crankshaft in sphero-spatial motion around a fixed point, two central bevel wheels, one immobile fixed in the body and the other mobile mounted on a driven shaft. The teeth of the gear rings have a circular arc flank profile, those of the central bevel wheels are variable curvilinear. The configuration of the parameters of angles, the number of teeth, the ratio of the numbers of teeth of the mating wheels in the gears and the radius of the circular arc of the teeth profile of the gear rings determines the geometry and the kinematics of the contact of the teeth, the degree of frontal overlap, expressed by the number of simultaneously engaged pairs of teeth and defines the pressure angle between the mating flanks.

The precessional gear transmission comprises a body, a satellite wheel with two bevel gear rings driven by a crankshaft in sphero-spatial motion around a fixed point, two central bevel wheels, one immobile fixed in the body and the other mobile mounted on a driven shaft. The teeth of the gear rings have a circular arc flank profile, those of the central bevel wheels are variable curvilinear. The configuration of the parameters of angles, the number of teeth, the ratio of the numbers of teeth of the mating wheels in the gears and the radius of the circular arc of the teeth profile of the gear rings determines the geometry and the kinematics of the contact of the teeth, the degree of frontal overlap, expressed by the number of simultaneously engaged pairs of teeth and defines the pressure angle between the mating flanks.