A circular wave drive system is provided. In one aspect, the circular wave drive includes a compliant input ring gear having an inner surface having internal input ring gear teeth; an input cycloidal disc having an outer surface having external input cycloidal disc gear teeth oriented on the outer surface, and wherein the external input cycloidal disc gear teeth at least partially engage the internal input ring gear teeth; a compliant primary drive gear having an outer surface having external primary drive gear teeth; an eccentric motion generator including an eccentric portion and a non-eccentric portion and wherein a centerline of the eccentric portion and the non-eccentric portion are offset from one another; and an output cycloidal disc having an inner surface with internal output cycloidal disc teeth, and wherein the internal output cycloidal disc teeth at least partially engage the external primary drive gear teeth.

A speed reducer includes an outer tubular member, internal tooth pins, oscillating gears and a carrier block. The outer tubular member has pin grooves on an inner circumferential surface thereof. The internal tooth pins are rotatably placed in the pin grooves. The oscillating gears have external teeth smaller in number than the pin grooves, and the oscillating gears are oscillatorily rotatable with the external teeth engaging with the internal tooth pins. The carrier block is cooperatively connected to the oscillating gears such that the oscillating gears are allowed to oscillatorily rotate relative to the carrier block and restricted from rotating on own axis relative to the carrier block. A displacement restricting member configured to restrict the internal tooth pins from being displaced inwardly in a radial direction of the outer tubular member is disposed between the outer peripheries of the oscillating gears adjacent to each other.

An electric actuator includes a motor, a speed reduction mechanism, and a bearing fixed to a motor shaft having an eccentric axis portion. The speed reduction mechanism has: an externally toothed gear, an internally toothed gear, a facing member arranged facing the externally toothed gear, and column members arranged to protrude from one member of the facing member and the externally toothed gear toward the other member and surround the motor axis. The other member has hole portions arranged to surround the motor axis. The column members are inserted into the hole portions respectively, and support the externally toothed gear to be swingable around the motor axis via an inner side surface of each of the hole portions. At least one of the column members is attached to the one member in a manner of being rotatable around a central axis of the at least one column member.

An electric actuator includes a motor, a speed reduction mechanism, and a bearing fixed to a motor shaft having an eccentric axis portion. The speed reduction mechanism has: an externally toothed gear, an internally toothed gear, a facing member arranged facing the externally toothed gear, and column members arranged to protrude from one member of the facing member and the externally toothed gear toward the other member and surround the motor axis. The other member has hole portions arranged to surround the motor axis. The column members are inserted into the hole portions respectively, and support the externally toothed gear to be swingable around the motor axis via an inner side surface of each of the hole portions. At least one of the column members is attached to the one member in a manner of being rotatable around a central axis of the at least one column member.

A speed reducer with a falling-off prevention feature according to an aspect of the disclosure includes: a speed reducer for decelerating rotation from a drive source that generates a rotational force and outputting the decelerated rotation, the speed reducer being mounted to a robot; and a coupling member for coupling the speed reducer to the robot. The coupling member maintains coupling between the speed reducer and the robot irrespective of displacement of the speed reducer relative to the robot.

A speed reducer with a falling-off prevention feature according to an aspect of the disclosure includes: a speed reducer for decelerating rotation from a drive source that generates a rotational force and outputting the decelerated rotation, the speed reducer being mounted to a robot; and a coupling member for coupling the speed reducer to the robot. The coupling member maintains coupling between the speed reducer and the robot irrespective of displacement of the speed reducer relative to the robot.

A measuring device with a crankshaft and a load cell for determining a radial force acting on the crankshaft having a receiving sleeve for receiving a bearing ring and a fastening ring for attaching the load cell in a transmission housing. Axial support areas are provided on the fastening ring for axially supporting the outer ring of the first bearing. Moreover, measuring regions for receiving radial forces of the receiving sleeve are provided which connect the receiving sleeve with the fastening ring. Strain sensors are attached to at least two of the measuring regions. An evaluation electronics is connected to the strain sensors.

A gear device includes an outer cylinder; an internal member at least partially housed in the outer cylinder and configured to rotate relative to the outer cylinder about a predetermined rotation axis; a first main bearing fitted into an annular space formed between the outer cylinder and the internal member; and a second main bearing fitted into the annular space and configured to define the rotation axis in cooperation with the first main bearing. A distance between a first intersection where a load action line of the first main bearing intersects with the rotation axis and a second intersection where a load action line of the second main bearing intersects with the rotation axis is set to fall within a range expressed by a predetermined inequality expression.

A gear device includes an outer cylinder; an internal member at least partially housed in the outer cylinder and configured to rotate relative to the outer cylinder about a predetermined rotation axis; a first main bearing fitted into an annular space formed between the outer cylinder and the internal member; and a second main bearing fitted into the annular space and configured to define the rotation axis in cooperation with the first main bearing. A distance between a first intersection where a load action line of the first main bearing intersects with the rotation axis and a second intersection where a load action line of the second main bearing intersects with the rotation axis is set to fall within a range expressed by a predetermined inequality expression.

This unit-type strain wave gearing is provided with a cross-roller bearing that supports an internally toothed gear and an externally toothed gear in a relatively rotatable manner, wherein a meshing portion between the two gears is lubricated by a grease. In the outer circumference of the externally toothed gear, a gap is formed which communicates with the meshing portion and a raceway groove of the cross-roller bearing. A portion of the grease pressed out from the meshing portion to the gap flows out through a through-hole formed in the internally toothed gear, and flows back to the meshing portion. The grease can be suppressed from leaking to the outside of the unit from an oil seal of the cross-roller bearing.