A linear stage assembly comprising a nut having a wall defining a bore which has a nut helical thread which includes: a crest, a root, and a flank between the crest and root; a screw having a screw helical thread about an exterior which includes: a crest, a root, and a flank between the crest and the root; wherein the nut and the screw are in a mating relationship so that the nut flank and the screw flank are in contact with one another defining a contact interface which imposes a frictional force that is sufficiently small to allow generally longitudinal movement in response to an actuation load of the screw or the nut relative to the other and sufficiently large to prevent back drive of the screw or the nut relative to the other after the actuation load is removed and in response to an opposing reaction force.

A linear motion guide device has a high rigidity, a good linear motion guiding accuracy, and as little rattling as possible. The linear motion guide device prevents sand, water or other contaminants from entering its actuator main body, and features low maintenance requirement. A linear motion member of the linear motion guide device includes a plurality of axially divided segments. Each of these segments supports a plurality of guided members which make contact with two, mutually paired, guide surfaces of a housing. A preload can be applied between the guide surfaces and the guided member. The housing has a sealed structure, with a pressure inside the housing higher than an external pressure, for preventing external sand and water from entering the housing.

A linear motion guide device has a high rigidity, a good linear motion guiding accuracy, and as little rattling as possible. The linear motion guide device prevents sand, water or other contaminants from entering its actuator main body, and features low maintenance requirement. A linear motion member of the linear motion guide device includes is constituted by a plurality of axially divided segments. Each of these segments supports a plurality of guided members which make contact with two, mutually paired, guide surfaces of a housing. A preload can be applied between the guide surfaces and the guided member. The housing has a sealed structure, with a pressure inside the housing higher than an external pressure, for preventing external sand and water from entering the housing.

A micro-movement subassembly as a precise driving screw for angle adjustment, comprising a shank, a turnbuckle, and a central cylindrical shaft. The subassembly is precise for linear displacement, good orientation, stable and reliable adjustment, which can be used for a variety of precision-oriented precision micro-angle adjustment of the drive screw.

An apparatus for opening and closing a deck lid of a vehicle body includes a jack-screw type drive unit having two elongated relatively rotatable drive elements which are threadably engaged for bi-directional displacement. An electric motor engages the rotatable drive element. A first mounting device pivotally connects the rotatable drive element to a relatively fixed point on the vehicle. A second mounting device pivotally connects the non-rotatable drive element to the deck lid, or vice versa. The motor is energized to affect bi-directional control of the drive unit while enabling low back-drive effort. A concentric spring counters loading due to the weight of the deck lid.

A ball screw device includes a screw shaft, a nut, a ball train including a plurality of main balls, and a plurality of coil springs disposed in the ball train. The nut moves from a first axial side to a second axial side while an axial force is applied to the nut by rotation of the screw shaft. The plurality of coil springs are more densely arranged on the first axial side than on the second axial side in the ball train.

A marine drive includes an internal combustion engine that drives a propulsor into rotation to effect a thrust, and a transmission that shifts amongst a forward gear for a forward thrust, a reverse gear for a reverse thrust, and a neutral state for a zero thrust. The marine drive further includes a shift rod rotatable about its own axis to shift the transmission amongst forward, reverse, and neutral, and an actuator. The actuator includes an actuator motor that rotates an output shaft and a gear shaft that effectuates rotation of a shift rod. The output shaft is connected to a gear shaft through a first gearset such that rotation of the output shaft causes the rotation of the gear shaft, and the gear shaft is connected to the shift rod through a planetary gearset such that rotation of the gear shaft causes the rotation of the shift rod.

A marine drive includes an internal combustion engine that drives a propulsor into rotation to effect a thrust, and a transmission that shifts amongst a forward gear for a forward thrust, a reverse gear for a reverse thrust, and a neutral state for a zero thrust. The marine drive further includes a shift rod rotatable about its own axis to shift the transmission amongst forward, reverse, and neutral, and an actuator. The actuator includes an actuator motor that rotates an output shaft and a gear shaft that effectuates rotation of a shift rod. The output shaft is connected to a gear shaft through a first gearset such that rotation of the output shaft causes the rotation of the gear shaft, and the gear shaft is connected to the shift rod through a planetary gearset such that rotation of the gear shaft causes the rotation of the shift rod.

In a power-transmitting mechanism with rolling-element bearing according to the present invention, an inner ring has plural inner ring members disposed in series in an axial direction, an outer ring has plural outer ring members respectively cooperating with the plural inner ring members. Plural rolling elements are disposed between the cooperating inner ring members and outer ring members. A retainer has plural partitions retaining the plural rolling elements at predetermined intervals in the circumferential direction such that rolling elements disposed between one pair of cooperating inner ring and outer ring members and rolling elements disposed between another pair of cooperating inner ring and outer ring members orbit the corresponding inner ring members in a synchronized manner, and a connector connecting the plural partitions such that the plural partitions integrally rotate around an axis.

A river or tidal turbine for generating a minimum predetermined value of electricity from river current received at a harnessing module comprises a harnessing module, a control module and a generating module. Han's principle is that harnessed power from a river or tidal turbine must exceed a predetermined value of control power used by the turbine. Minimum power is lost in a three variable closed mechanical control system. The three variable closed mechanical system comprises a Hummingbird control assembly of first and second spur/helical gear assemblies which may be preferably mechanically simplified. The Hummingbird control, a control motor and a generator among other components may be mounted on a floating platform for delivery of constant power at constant frequency given sufficient input from a waterwheel harnessing module driven by river current flow in at least one direction. A tidal embodiment may comprise a moveable hatch for permitting the waterwheel to turn in foe same rotational direction regardless of direction of water current flow.