Abstract: A three-dimensional tooth profile of internal teeth in a strain wave gearing is a basic internal-teeth tooth profile at an internal-teeth outer end, and is a reduced tooth profile, in which the basic internal-teeth tooth profile is proportionally reduced only in the lateral direction, at other tooth-trace-direction positions. A three-dimensional tooth profile of external teeth is a basic external-teeth tooth profile at an external-teeth outer end, and is an increased tooth profile, in which the basic external-teeth tooth profile is proportionally increased only in the lateral direction, at other tooth-trace-direction positions. Tooth cutting process becomes easier than when only the external teeth employ a three-dimensional tooth profile. Since the tooth profiles, which are proportionally reduced and increased only in the lateral direction along the tooth trace direction, are employed, it is further easier in tooth cutting process.

Abstract: A brake for a motor includes a fixed-side engaging plate fixed to a motor shaft; a movable-side engaging plate coaxially opposed to the fixed-side engaging plate along the direction of a center axis; and a self-holding type solenoid that moves, in the direction of the center axis, the movable-side engaging plate to a halt cancelation position separated from the fixed-side engaging plate and a halt position where engagement with the fixed-side engaging plate occurs. When the motor is halted, the solenoid is driven to move the movable-side engaging plate from the halt cancelation position to the halt position. The movable-side engaging plate which has reached the halt position is mechanically engaged with the fixed-side engaging plate, and the motor shaft is forcibly halted.

Abstract: A strain wave gearing includes an internally toothed gear integrated with an inner ring. A bolt hole is formed in the internally toothed gear. The bolt hole includes a bolt passage hole part, and a screw hole part extending in the direction of an axial line, continuously from the bolt passage hole part. The screw hole part, to which a bolt-fastening force is applied, is formed at a location away in the direction of the axial line from a location adjacent to a radially outer side of an internally toothed gear. Deformation, occurring during fastening of a bolt, at a portion in which the internally toothed gear is formed can be reduced, and adverse effects caused by the deformation such as a decrease in the accuracy of engagement or meshing of the internally toothed gear and an externally toothed gear can be inhibited.

Abstract: A strain wave gearing has three components and a temporary-fixing jig, three components being an internally toothed gear, a cup-shaped externally toothed gear, and a wave generator. The temporary-fixing jig is securely fastened to an output shaft fixed to the externally toothed gear by a temporary-fixing bolt and is securely fastened to an input shaft fixed to a cam plate of the wave generator by a temporary-fixing bolt. The temporary-fixing jig engages with the output shaft and the input shaft and maintains the three components in an assembled state. There is no need for an operation for adjusting the positions of the three components in an operation for attaching the strain wave gearing to a motor. After the strain wave gearing has been attached to the motor, the temporary-fixing jig is removed from the strain wave gearing, wherefore less space is required for installation.

Abstract: In a strain wave gearing, both of a pulley for transmitting rotation in a direction orthogonal to a rotation central axis and an output shaft are arranged on an axial-direction first side relative to a cup-shaped externally toothed gear. The input shaft, which transmits input rotation from the pulley to the wave generator, functions as a support shaft for both the pulley and the wave generator and is supported at both ends by the first and second bearings. A mechanism for transmitting rotation from the pulley to the wave generator, and a mechanism for supporting the rotation-transmitting mechanism, can be made compact, and support strength can also be ensured.

Abstract: A strain wave gearing has a lubricant sealing structure that prevents a lubricant from leaking to the outside through a gap portion between a hollow input shaft and an end plate. The lubricant sealing structure includes an oil-repellent surface formed on the surface portion facing the gap portion, an oil seal that seals the gap portion, and an oil film forming surface formed at a lip tip surface of the oil seal. The oil-repellent surface has a surface texture in which first fine grooves are formed in a predetermined pattern so that an oil-repellent effect can be obtained with respect to the lubricant. The oil film forming surface has a surface texture in which second fine grooves are formed in a predetermined pattern so that an oil film forming effect of a seal lip grease can be obtained.

Abstract: An exemplary encoder assembly includes a substrate, a first encoder, and a second encoder. The substrate has two or more position sensors, each position sensor being configured for detecting a rotary position of a shaft or other rotating element of a machine. The first encoder includes at least one first position sensor of the two or more position sensors. The at least one first position sensor is disposed on the substrate for off-axis alignment with the shaft or other rotating element of the machine. The second encoder includes a second position sensor of the two or more position sensors, the second position sensor being disposed on the substrate for on-axis or off-axis alignment with the shaft or other rotating element of the machine. Each position sensor is configured to detect different or common signal types, and a signal type of the second position sensor excludes optical signals.

Abstract: The flat strain wave gearing is provided with an axially arranged rigid gear, flexible gear and wave generator. The flexible gear forms a flat truncated cone shape, has a tooth formation portion connected via a bellows-shaped cross-sectional diaphragm to a rigid boss which is an output shaft linking part. The flat strain wave gearing can ensure axial flexibility of the tooth formation portion, and can enable teeth of the flexible gear to mesh favorably with teeth of the rigid gear in the axial direction in each position in the tooth trace direction. Local bias of the load torque in the meshing portion in the tooth formation portion can also be suppressed.

Abstract: A three-dimensional tooth profile of internal teeth in a strain wave gearing is a basic internal-teeth tooth profile at an internal-teeth outer end, and is a reduced tooth profile, in which the basic internal-teeth tooth profile is proportionally reduced only in the lateral direction, at other tooth-trace-direction positions. A three-dimensional tooth profile of external teeth is a basic external-teeth tooth profile at an external-teeth outer end, and is an increased tooth profile, in which the basic external-teeth tooth profile is proportionally increased only in the lateral direction, at other tooth-trace-direction positions. The tooth tip circle of an internal-teeth inner-end-side portion of the internal teeth is larger than that of other portions and does not interfere with the external teeth. The external teeth and the internal teeth mesh three-dimensionally, the teeth do not interfere at the internal-teeth inner-end side.

Abstract: A three-dimensional tooth profile of internal teeth in a strain wave gearing is a basic internal-teeth tooth profile at an internal-teeth outer end, and is a reduced tooth profile, in which the basic internal-teeth tooth profile is proportionally reduced only in the lateral direction, at other tooth-trace-direction positions. A three-dimensional tooth profile of external teeth is a basic external-teeth tooth profile at an external-teeth outer end, and is an increased tooth profile, in which the basic external-teeth tooth profile is proportionally increased only in the lateral direction, at other tooth-trace-direction positions. Tooth cutting process becomes easier than when only the external teeth employ a three-dimensional tooth profile. Since the tooth profiles, which are proportionally reduced and increased only in the lateral direction along the tooth trace direction, are employed, it is further easier in tooth cutting process.

Abstract: In this optical rotary encoder, detection tracks of a rotating disc are irradiated with detection light emitted from a light-emitting element. An optical signal obtained via slits in the detection tracks passes through a slit pattern in a fixed slit plate and is received by light-receiving surfaces of a light-receiving element. The slit pattern in the fixed slit plate is formed so as to fit into a range of an effective spot of the detection light. An LED or other light-emitting element that has a small effective spot diameter can be used, which is advantageous in terms of reducing costs and making the device more compact.

Abstract: A three-dimensional tooth profile of internal teeth in a strain wave gearing is a basic internal-teeth tooth profile at an internal-teeth outer end, and is a reduced tooth profile, in which the basic internal-teeth tooth profile is proportionally reduced only in the lateral direction, at other tooth-trace-direction positions. A three-dimensional tooth profile of external teeth is a basic external-teeth tooth profile at an external-teeth outer end, and is an increased tooth profile, in which the basic external-teeth tooth profile is proportionally increased only in the lateral direction, at other tooth-trace-direction positions. The tooth tip circle of an internal-teeth inner-end-side portion of the internal teeth is larger than that of other portions and does not interfere with the external teeth. The external teeth and the internal teeth mesh three-dimensionally, the teeth do not interfere at the internal-teeth inner-end side.

Abstract: In a gear skiving process method, a tooth-cutting process is performed on a surface to be cut of a workpiece using a first skiving cutter disposed at a first processing position on the surface to be cut and a second skiving cutter disposed at a second processing position set apart by 180° in a circumferential direction from the first processing position. Parts that are to be right tooth flanks of internal teeth to be created in the surface to be cut of the workpiece are cut mainly by the first skiving cutter. Additionally, parts that are to be left tooth flanks are cut mainly by the second skiving cutter. Conditions of the processing performed using the first and second skiving cutters can be controlled individually and teeth having a shape in which the left and right tooth flanks are different can be processed efficiently.

Abstract: A bearing unit is provided with a strain element for torque detection. The strain element is provided with a first annular part attached to a rotation-side member, a second annular part attached to a load-side member, and a plurality of ribs serving as strained parts linking the first annular part and the second annular part together. One of an inner race and an outer race is integrally formed on the first annular part of the strain element. Deformation, which occurs in the ribs of the strain element due to torque exerted on the rotation-side member from the load-side member, is detected by a strain gauge, etc., and converted to torque. The strain element for torque detection can be incorporated into a motor, a reducer, or another rotary propulsion unit without the need for a dedicated installation space and without the need for fastening fittings, etc.

Abstract: A planetary reduction gear using a helical gear is configured such that a rear-stage sun gear is rotatably supported by a device housing via a radial bearing on one side in the direction of a center axis, and is rotatably supported by a rear-stage planetary carrier via a thrust bearing on the other side. The rear-stage planetary carrier is rotatably supported by the device housing via a rear-stage carrier bearing. A preload is applied to the thrust bearing by a preload mechanism mounted to the rear-stage planetary carrier. Displacement of the rear-stage sun gear caused by a thrust force generated due to engagement with a rear-stage planetary gear can be suppressed, and an angle error between input rotation and output rotation can be suppressed.

Abstract: An externally toothed gear of a cup-type strain wave gearing has external teeth, the tooth profile of which gradually changes in the tooth-trace direction. The external teeth are formed with an external teeth portion capable of meshing with internal teeth of an internally toothed gear, a first external teeth extension portion and a second external teeth extension portion, in which the first and second external teeth extension portions do not mesh with the internal teeth. The second external teeth extension portion has a narrowing tapered tooth profile so that the second external teeth extension portion serves as a guide when the external teeth is inserted into the internal teeth. The work of assembling the externally toothed gear in the internally toothed gear is made easier.

Abstract: A speed ratio switching type strain wave gearing can switch the speed ratio of output rotation with respect to one input rotation into two states or multiple states with a simple configuration. The speed ratio switching type strain wave gearing includes first and second internally tooted gears, an externally toothed gear having first and second external teeth formed on the external peripheral surface thereof, a wave generator that causes the first and second external teeth to partially mesh with the first and second internally toothed gears, a clutch mechanism that can selectively switch the first and second internally toothed gears into a fixed state. Input rotation from the wave generator can be reduced in speed at a different speed ratio and derived from the externally toothed gear by selectively switching the first and second internally toothed gears into a fixed state.

Abstract: A speed ratio switching type strain wave gearing can switch the speed ratio of output rotation with respect to one input rotation into two states or multiple states with a simple configuration. The speed ratio switching type strain wave gearing includes first and second internally toothed gears, an externally toothed gear having first and second external teeth formed on the external peripheral surface thereof, a wave generator that causes the first and second external teeth to partially mesh with the first and second internally toothed gears, a clutch mechanism that can selectively switch the first and second internally toothed gears into a fixed state. Input rotation from the wave generator can be reduced in speed at a different speed ratio and derived from the externally toothed gear by selectively switching the first and second internally toothed gears into a fixed state.

Abstract: An outer-ring lubrication groove pattern formed in an outer-race raceway surface and an inner-race lubrication groove pattern formed in an inner-race raceway surface of a wave generator bearing of a strain wave gearing device are patterns in which linear lubrication grooves having very small widths and depths of several micrometers or less are arranged at fine pitches of several micrometers or less. The inner-race lubrication groove pattern includes a second groove pattern formed in long-axis-side inner-race raceway surface portions to hold the lubricant, and a first groove pattern formed in short-axis-side inner-race raceway surface portions to hold the lubricant and guide the lubricant to the second groove pattern. This configuration improves the contact state between balls and the inner-race and outer-race raceway surfaces of the wave generator bearing, thus reducing the coefficient of friction therebetween.

Abstract: A strain wave gearing has a wave generator provided with a plurality of rollers mounted between an ellipsoidal outer peripheral surface of a plug and an inner peripheral surface of an externally toothed gear. The plug is formed with recesses along the ellipsoidal outer peripheral surface. The recesses open in a first end surface of the plug facing toward a diaphragm of the externally toothed gear. The radial rigidity of the plug is relatively low in the side having the first end surface in the direction of a plug axis. When viewed along the direction of the plug axis, the respective rollers can be brought into linear contact with the inner peripheral surface of the externally toothed gear at positions on the long axis (Lmax) of the elliptically-flexed externally toothed gear, so as not to occur one-sided contact state.