A door opening and closing device for vehicles of the present invention includes: a motor drive mechanism; a first housing that accommodates the motor drive mechanism; a spindle drive mechanism connected to the motor drive mechanism; and a second housing that is arranged coaxially with the first housing and relatively moves with respect to the first housing by the spindle drive mechanism. The spindle drive mechanism includes: a spindle connected to the motor drive mechanism; a spindle nut screwed with the spindle; a push rod fixed so as not to rotate relative to the spindle nut and provided with a protrusion on its outer periphery; and a guide tube in which a guide groove guiding the protrusion of the push rod in an axial direction is formed.

An indexed drive system (10) for mechanised tools, in particular an electric toothbrush, for selectively imparting various drive modes to a pair of concentrically-arranged drive shafts (12, 14) thereby imparting various brushing modes to the head (H) of the mechanised tool, in particular an electric toothbrush.

The present invention is characterized to include a cylindrical cam that is provided to correspond to a moving path and possesses an engaging groove, the moving path moving in an uncoupled state with each of a plurality of carriers to which an object to be conveyed is respectively installed and the plurality of carriers being in states where a set of a plurality of first carriers and a set of a plurality of second carriers are alternately lined up, and a drive source that drives the cylindrical cam, wherein a first cylindrical cam and a second cylindrical cam, as the cylindrical cam, are respectively provided to correspond to a predetermined position in the moving path, the first cylindrical cam possessing an engaging groove with which only the first carriers are engageable and the second cylindrical cam possessing an engaging groove with which only the second carriers are engageable, a first drive source that drives the first cylindrical cam and a second drive source that drives the second cylindrical cam are included as the drive source, the engaging grooves of the first cylindrical cam and the second cylindrical cam are helical grooves that possess a first groove part and a second groove part, the second groove part being continuous with the first groove part, being positioned on a downstream side in a conveying direction with respect to the first groove part and having a pitch different from the pitch of the first groove part, and the second cylindrical cam rotates to move the second carrier that reached the first groove part when an interval of the first carriers is changed by the set of the plurality of the first carriers moving past the first groove part to reach the second groove part by a rotation of the first cylindrical cam.

Disclosed is an actuator capable of imparting a linear, rotary, or combined roto-linear force. In one embodiment, the actuator has a rotor and a stator, each having helical grooves with a thrust ball occupying the grooves. A nose piece is situated at the end of the actuator and can be attached to other equipment. The actuator is electrically controlled and can be used in applications requiring high forces or other specialized environments.

A backlash-free spindle nut is disclosed with a thread that can be meshed with a spindle. The spindle nut has a first nut part with a first internal thread and a second nut part with a second internal thread that can be twisted in relation to the first nut part. To generate a preload between the first nut part and the second nut part, the spindle nut has an elastic element. The preload can be adjusted through relative twisting between the first nut part and the second nut part. The elastic element can work between the first nut part and a secure intermediate part, whereby relative twisting between the first nut part and the second nut part can be locked by locking a relative twisting position between the second nut part and the intermediate part.

A motor system including: a cylindrical body; a converter configured to convert a two-directional rotation into a one-directional rotation; a rotatable shaft configured to be (a) disposed inside of the cylindrical body, (b) rotatable in both a counterclockwise direction and a clockwise direction, and (c) coupled to a drill bit through the converter; a driving piston configured to be coupled to the rotatable shaft and configured to divide the cylindrical body into a first chamber and a second chamber; and a flow piston configured to change flow direction of the fluid within the cylindrical body to drive the driving piston, wherein the driving piston is configured to be driven by the fluid via a pressure difference to move in a forward direction and in a reverse direction.

An apparatus for boring a wellbore, including a bit body having a first end, an inner cavity, and a second end. The first end is connected to a workstring that is configured to deliver a rotational force to the bit body. The inner cavity contains a profile having a first radial cam surface. The second end includes a working face containing a cutting member. The apparatus also includes a pilot bit rotatively connected within the inner cavity. A second radial cam surface is contained on a first end of the pilot bit. The first and second radial cam surfaces are operatively configured to deliver a hammering force. A second end of the pilot bit may include an engaging surface configured to engage a formation surrounding the wellbore. The bit body rotates relative to the pilot bit.

An apparatus for boring a wellbore, including a bit body having a first end, an inner cavity, and a second end. The first end is connected to a workstring that is configured to deliver a rotational force to the bit body. The inner cavity contains a profile having a first radial cam surface. The second end includes a working face containing a cutting member. The apparatus also includes a pilot bit rotatively connected within the inner cavity. A second radial cam surface is contained on a first end of the pilot bit. The first and second radial cam surfaces are operatively configured to deliver a hammering force. A second end of the pilot bit may include an engaging surface configured to engage a formation surrounding the wellbore. The bit body rotates relative to the pilot bit.

A screw (20) assembly for an actuator (10) is described comprising: a screw (20); a nut (22) threaded on said screw (20), such that rotation of said screw (20) causes axial movement of said nut (22); a stop located at an end of said screw (20) and defining an axial limit of said nut (22); a first feature located on said nut (22); and a second feature located on said stop; wherein said first and second features are configured to cooperate with one another substantially upon contact of said nut (22) with said stop so as to indicate an amount of free movement between said nut (22) and said screw (20).

In one embodiment, an actuator has a roller, a helical track, and at least one track follower. The roller has a cylindrical body that has a first end, a second end that is offset from the first end along a central axis, and a cylindrical outer surface that extends from the first end to the second end. The helical track is disposed around the cylindrical outer surface in a helical pattern. The at least one track follower can be attached to a load, and rides along the helical track when the roller is rotated about the central axis so as to translate the load along an axial direction that is substantially parallel to the central axis. In some embodiments, the roller has an internal motor that is disposed within the cylindrical body.