Embodiments of an electric linear actuator may include a roller screw assembly, an electric motor coupled to the roller screw assembly, and a linear transducer operatively coupled with the roller screw assembly. The motor may be configured to drive the roller screw assembly to extend and retract another component, such as a rod. In some embodiments, the linear transducer may be configured to detect a position of the rod. The roller screw assembly may be coupled directly to the motor via a gear coupling, with the motor disposed generally in axial alignment with the roller screw assembly. Other embodiments disclosed herein include a veneer lathe carriage with electric linear actuators and corresponding apparatuses, methods, and systems.

A linear drive actuator that includes a linear drive mechanism that includes a hollow, threaded roller screw shaft with a thrust bearing formed on one end and a roller screw nut mounted on the opposite end moves axially over the shaft when the shaft is rotated. Attached to the roller screw nut is a hollow extension tube that both extends into a main housing. The distal end of the extension tube extends through the end of the main housing and includes an end cap or a connector. The proximal end of the drive shaft connects to a drive axle on a multiple gear assembly. The multiple gear assembly is coupled to a dual motor assembly. Located adjacent to the dual motor assembly is a volume compensation housing that contains a moving piston that divides the housing lubricant holding chamber filled with a lubricating fluid and an air chamber that communicates with outside air. During operation, the lubricating flows into the motor assembly, the gear assembly, into the nut body and to the extension tube. The amount and direction of flow of lubricating fluid is controlled by the axial movement of the roller screw nut and extension tube to continuously lubricate and cool the actuator.

An anti-backlash device for preventing backlash derived from a moving load on a screw used in converting rotary motion into linear motion, the anti-backlash device comprising: a cylindrical pressure actuator integrally formed with a helical thread and axially mounted on the screw; a cradle integrally formed with a helical thread and internal cradle threads, the cradle being mounted exterior to and in mechanical contact with both the cylindrical pressure actuator and the screw, and a preloading means comprising a wave spring and a retainer mounted in the cradle.

The present disclosure relates to the technical field of aerial work platforms, in particular to a linear actuator with a contact type safety nut, and an aerial work platform. The linear actuator includes a central screw, a driving nut mechanism, and a safety nut mechanism. The central screw has a screw raceway. The safety nut mechanism includes a safety nut seat sleeved at the periphery of the central screw. Limit hole channels pointing to the central screw are arranged on the safety nut seat. An elastic buffer element is arranged in each of the limit hole channels. A safety ball is arranged between the elastic buffer element and the central screw. The contact type safety nut enables the linear actuator to always keep safety, stability, and no loss of accuracy in a conversion process that the safety nut mechanism gets involved to take effect while the driving nut mechanism fails.

A sliding table assembly includes a sliding seat unit slidably mounted to a base unit. Two auxiliary sliding seats are slidably mounted to the base unit and disposed on two sides of the sliding seat unit. A connection member is connected between the auxiliary sliding seats. Two roller sets are respectively mounted to the auxiliary sliding seats. Each roller set has rollers to roll on the base unit. A driving screw rod is coupled to the sliding seat unit and embraced by the auxiliary seats. When the sliding unit is moved by the driving screw rod, it pushes the auxiliary sliding seats to slide together therewith.

The present invention relates to a linear module. The linear module according to an example of the present invention comprises a base plate; a screw disposed on the base plate and arranged in the longitudinal direction of the base plate; a carrier block including a hollow part surrounding a portion of the screw; a carrier block rail disposed on one side of the carrier block and arranged in the longitudinal direction of the base plate; a long rail disposed on the base plate and arranged in the longitudinal direction of the base plate; and a roller guide disposed between the carrier block rail and the long rail and to reduce the frictional force between the carrier block rail and the long rail when the carrier block moves in the longitudinal direction of the base plate.

Described is a rotary mechanical transmission including a containment structure, a first rotary element, connected or connectable to a drive unit to define a mechanical power input unit and rotatable about an axis of rotation, a fixed guide, a second rotary element rotatable about the axis of rotation and defining a power output unit and an intermediate roto-translational element, extending along the axis of rotation and including a first threaded portion, coupled to the first rotary element, and a second threaded portion, coupled to the fixed guide. The intermediate element is also coupled with the second rotary element by a linear guide parallel to said axis of rotation. The first threaded portion and the second threaded portion have different pitches and are at least partly separated along the axis of rotation. The intermediate element is defined by a hollow body and the second rotary element is inserted inside the intermediate element.

An actuator for driving a rotatable component includes a first, rotating member comprising a screw and a second member comprising a nut threaded to said screw, wherein rotation of said first member causes axial movement of said first or second member. The component also includes a third member coupled to the second member, wherein axial movement of said first or second member causes axial movement of said third member and a fourth, rotating member coupled to said third member and connectable to said component. The system also includes a bearing system located between said third member and said fourth member, said bearing system configured to cause said fourth member to rotate upon said axial movement of said third member so as to drive said component.

Embodiments of an electric linear actuator may include a roller screw assembly, an electric motor coupled to the roller screw assembly, and a linear transducer operatively coupled with the roller screw assembly. The motor may be configured to drive the roller screw assembly to extend and retract another component, such as a rod. In some embodiments, the linear transducer may be configured to detect a position of the rod. The roller screw assembly may be coupled directly to the motor via a gear coupling, with the motor disposed generally in axial alignment with the roller screw assembly. Other embodiments disclosed herein include a veneer lathe carriage with electric linear actuators and corresponding apparatuses, methods, and systems.

An actuator for providing a thrust force over a determined travel, comprising a nut, a screw, a sleeve configured to surround the screw in an axial direction (X-X) of the screw, a plurality of rollers, the nut being configured to cooperate with the screw, the nut being secured to the rollers, which are free to rotate, the rollers being configured to each move in particular in the one of at least one helical guide or the sleeve, the screw being configured in order, when it is turned, to operate the actuator, to rotate the nut when it bears via the rollers on a profile of the helical guide and to thus advance in the axial direction (X-X) of the screw at greater or lesser speed along a slope of the profile of the helical guide. The actuator further comprises a motor configured to turn the screw. Successive values of the slope all along the profile or profiles of respectively the one or more helical guides ae adapted to ensure that the slope systematically compensates for at least one peak of the desired thrust force in order to carry out clipping of the maximum values of the thrust force such that the motor, the screw and the nut are dimensioned to a motor torque value corresponding to the value of the thrust force after clipping.