One object is to provide a speed reducer that can absorb or relieve an impact acting thereon. A speed reducer of the present invention includes: a speed reducing unit a housing that houses the speed reducing unit and a shock absorbing means that allows the speed reducing unit to move with respect to the housing in a direction of a rotary shaft of the speed reducing unit.

Disclosed is multimaterial 3D printing (MM3P) to fabricate centimeter-scale robots by utilizing soft materials to create soft joints to replace revolute joints and also soft links to replace rigid links. A three-spring rotational-prismatic rotational (RPR) model is developed to approximate the motion of soft joints or links, which is further utilized to numerically predict the motion of the leg mechanism with multiple soft joints and links. The accuracy of the proposed numerical method is validated with experimental results. A functional walking robot actuated by a single DC motor is demonstrated.

A mechanical device lubrication level control system operates within a mechanical housing having a sump cavity and a lubricant director, where the lubricant director is located at the bottom of the housing. A mechanical gear set is located in the sump cavity and a lube tank is located in the lubricant director. There is located within in lube tank either a motor with a pump or an expandable air bladder that is inflatable by an air source. For the lube tank having the motor with the pump, the pump controls the lubricant within the sump cavity. For the lube tank having the expandable air bladder, the air source controls the lubricant within the sump cavity.

A mechanical device lubrication level control system operates within a mechanical housing having a sump cavity and a lubricant director, where the lubricant director is located at the bottom of the housing. A mechanical gear set is located in the sump cavity and a lube tank is located in the lubricant director. There is located within in lube tank either a motor with a pump or an expandable air bladder that is inflatable by an air source. For the lube tank having the motor with the pump, the pump controls the lubricant within the sump cavity. For the lube tank having the expandable air bladder, the air source controls the lubricant within the sump cavity.

Device and method for providing rotational power using power transmission are disclosed. The device enables multi-dimensional and angle-agnostic displacement of the rotational power output with respect to the input location and transference of high-torque and high-speed rotational movement, while preserving maximal efficiency and quick response. The device is a transmission gear that comprises at least two gear-links in a multi-link articulated gear (MLAG). Each of the links comprising at least two gear wheels. The transmission gear further comprising a common axis adapted to allow the links to rotate freely with respect to each other about the common axis and thus to allow change of the angle between the at least two links and thereby to change the distance between the input shaft and the output shaft.

An involute gear is disclosed. A circular base has a surface that includes an inner region and an outer region. A gear tooth extends outward from the outer region of the surface. A shape of the gear tooth is defined by a varying cross-sectional involute profile. Starting from a first involute profile that is in a plane parallel to the surface of the circular base and extending outward from a center of the circular base, each location on the first involute profile is rotated about a corresponding axis while traversing a path defined by a corresponding imaginary ray extending from the center of the circular base to that location in the first involute profile. The corresponding axis is tangential to an imaginary circle that encompasses the inner region of the surface and is perpendicular to the corresponding imaginary ray.

A belt drive mechanism with gear back-up comprises a driving pulley to which a driving gear is attached, a driven pulley to which a driven gear is attached, a drive belt drivingly connected between the driving and driven pulleys, and a back-up gear disposed between the driving and driven gears. When the drive belt is engaged with the driving and driven pulleys, teeth of the back-up gear are spaced apart from teeth of the driving and driven gears, and at least a portion of the teeth of the back-up gear are interposed between the teeth of the driving and driven gears. Thus, in a normal state, the drive belt is driven by the driving pulley and drives the driven pulley. However, in case of belt failure, the back-up gear is driven by the driven gear attached to the driving pulley and drives the driven gear attached to the driven pulley instead of the drive belt.

A mechanical device lubrication level control system operates within a mechanical housing having a sump cavity and a lubricant director, where the lubricant director is located at the bottom of the housing. A mechanical gear set is located in the sump cavity and a lube tank is located in the lubricant director. There is located within in lube tank either a motor with a pump or an expandable air bladder that is inflatable by an air source. For the lube tank having the motor with the pump, the pump controls the lubricant within the sump cavity. For the lube tank having the expandable air bladder, the air source controls the lubricant within the sump cavity.

A mechanical device lubrication level control system operates within a mechanical housing having a sump cavity and a lubricant director, where the lubricant director is located at the bottom of the housing. A mechanical gear set is located in the sump cavity and a lube tank is located in the lubricant director. There is located within in lube tank either a motor with a pump or an expandable air bladder that is inflatable by an air source. For the lube tank having the motor with the pump, the pump controls the lubricant within the sump cavity. For the lube tank having the expandable air bladder, the air source controls the lubricant within the sump cavity.

A bicycle hub assembly comprises a hub axle, a hub shell, and a sprocket support body. The sprocket support body includes a tubular part, a first sprocket engaging tooth, and a second sprocket engaging tooth. The tubular part includes an outer peripheral surface and an attachment portion. The first sprocket engaging tooth includes a first radially outer surface provided radially outward of the outer peripheral surface. The second sprocket engaging tooth includes a second radially outer surface and a third radially outer surface. The third radially outer surface is provided radially outward of the outer peripheral surface and radially inward of the second radially outer surface. A first distance is defined from the outer peripheral surface to the first radially outer surface. A second distance is defined from the outer peripheral surface to the third radially outer surface. The second distance is shorter than the first distance.