Systems, methods and apparatus for adjusting the depth of a trench opened by a row unit of an agricultural planter. The row unit includes a trench depth adjustment assembly configured to modify the furrow depth. In one embodiment, the depth adjustment assembly may include a gear box having one or more gears which engage with a gear rack. The gear box may be pivotally connected to a depth adjustment body supporting a rocker that adjusts upward travel of gauge wheel arms. In another embodiment, the depth adjustment assembly may include a depth adjustment arm having a screw receiver that cooperates with a driven screw that adjusts the position of the depth adjustment arm acting on the gauge wheels to adjust trench depth.

A method of displacing rotors of an aircraft between a hover mode and an aircraft mode includes rotating a spindle drivingly connected to the rotors about a spindle axis to displace the rotors between the hover and aircraft modes until a component displaceable with the spindle abuts against a downstop of the aircraft and applies a load against the downstop. The method includes passively maintaining the component against the downstop to maintain the load applied against the downstop. An aircraft is also disclosed.

A linear actuator includes a motor, a screw mechanism, and a bearing. The motor includes a stator and a rotor rotatable relative to the stator. The rotor includes a rotor shaft element. The screw mechanism includes a screw element and a follower drivingly engaged with the screw element, with rotation of the screw element causing the follower to shift axially along the screw element. The elements are drivingly intercoupled. The bearing rotatably supports a first one of the elements. The first one of the elements provides support to a second one of the elements such that the bearing also rotatably supports the second one of the elements.

A three-rotational-degree-of-freedom connection mechanism required for a robot that can make motion similar to a human has a simple structure, and there is no restriction on motion within a movable range. The three-rotational-degree-of-freedom connection mechanism includes a joint connecting a second member rotatably to a first member with three rotational degrees of freedom including rotation around a torsion axis, three actuators each including variable length links having a variable length, and power sources for generating force changing the lengths of variable length links and three first-member-side link attaching units provided in first member and the second-member-side link attaching units provided on the second member such that variable length links having a twisted relationship with respect to a torsion axis exist in each state within a movable range of joint.

An agricultural planting system for controlling the depth of an opener device comprising: an agricultural planter; an opener device mounted on the agricultural planter for engaging the ground of a field; a gauge wheel mounted on the agricultural planter for rotating on the ground of the field; a GPS device coupled to the agricultural planter, the GPS device configured to determine a location of the agricultural planter in the field; and a controller in electrical communication with the agricultural planter and the GPS device, the controller having predetermined settings associated with a map of the field, the controller being configured to select a relative elevation of the opener device and the gauge wheel based at least in part on the location determined by the GPS device, and produce, based on the location, a signal for adjusting the depth of engagement into the ground of the opener device.

A linear actuator includes a motor, a screw mechanism, and a bearing. The motor includes a stator and a rotor rotatable relative to the stator. The rotor includes a rotor shaft element. The screw mechanism includes a screw element and a follower drivingly engaged with the screw element, with rotation of the screw element causing the follower to shift axially along the screw element. The elements are drivingly intercoupled. The bearing rotatably supports a first one of the elements. The first one of the elements provides support to a second one of the elements such that the bearing also rotatably supports the second one of the elements.

A power transmission system that is adapted to transmit forces from a motor to a component comprises an externally threaded shaft 551 that is rotatably attached to the motor, an internally threaded fastener that is movably attached to the externally threaded shaft, a first element, and a second element that is movably attached to the first element at a second joint and that is rigidly attached to the component at a third joint.

An electric actuator for a steering system is adapted to control an angle of steered wheels on a vehicle to adjust a direction of travel of the vehicle. The electric actuator includes a housing assembly, an electric motor, and an actuation unit. The housing assembly is arranged around the electric motor and the electric motor is coupled with the actuation unit and configured to cause an actuator rod of the actuation unit to move relative to the housing assembly.

A steering for a marine propulsion unit adjusts at least one of a required steering speed and a required steering torque such that the required steering speed and the required steering torque fall within an output region when the required steering speed and the required steering torque are outside the output region, sets a target steering angle according to the adjusted required steering speed and required steering torque, and sets the target steering angle according to a rotation angle of a steering wheel when the required steering speed and the required steering torque are within the output region.

A robot includes elbows connecting forearms rotatably to upper arms with two rotational degrees of freedom. The elbow includes: an elbow joint connecting the forearm and the upper arm with two rotational degrees of freedom; an elbow drive main link; an elbow drive auxiliary link; a forearm-side main link attaching unit attached with one end of the elbow drive main link with two rotational degrees of freedom, and provided in the forearm; an elbow-drive-main-link-side auxiliary link attaching unit attached with one end of the elbow drive auxiliary link with two rotational degrees of freedom, and provided on the elbow drive main link; and two linear actuators for moving two upper-arm-side link attaching units each attached with the other end of either the elbow drive main link or the elbow drive auxiliary link with two rotational degrees of freedom, and provided so as to be movable along the upper arm.