Abstract: An apparatus comprises a wave generator configured to move water on a front side of the wave generator to generate a surfable wave and a displacer configured to move in synchronization with the wave generator, the displacer to displace water on a back side of the wave generator to compensate for water elevation changes on the back side of the wave generator that would occur in the absence of the displacer.

Abstract: A hopper valve for transferring particles from a supply container to a hopper, the hopper valve comprising a valve body coupled to the supply container, a fill tube moveably coupled to the valve body, and a foot member moveably coupled to the fill tube and configured to engage the hopper.

Abstract: A hopper valve for transferring particles from a supply container to a hopper, the hopper valve comprising a valve body coupled to the supply container, a fill tube moveably coupled to the valve body, and a foot member moveably coupled to the fill tube and configured to engage the hopper.

Abstract: A torque transfer coupling includes a shaft and a first second set of hydraulic devices. Each hydraulic device of the first set of hydraulic devices has a first end operably connected to a first end of the shaft, wherein the hydraulic devices of the first set of hydraulic devices are disposed about an axis of the shaft. Each hydraulic device of the second set of hydraulic devices has a first end operably connected to a second end of the shaft, and wherein the hydraulic devices of the second set of hydraulic devices are disposed about the axis of the shaft. Each hydraulic device can include a piston and cylinder assembly wherein extension and retraction of each piston of each hydraulic device is generally tangential to a portion of a circle encircling the shaft.

Abstract: One aspect of the invention is a test assembly comprising a prime mover, an actuator assembly and a torque transfer coupling. The actuator assembly has an end configured to be attached to a shaft of a portion of a test specimen such as a wind turbine assembly. The actuator assembly has a shaft supported for rotation by hydraulic bearings. The torque transfer coupling connects the primer mover to the actuator assembly.

Abstract: A system includes a support, an actuator and a swivel joint coupling the actuator to the support. The swivel joint includes a first base member, a second base member, and a spider positioned between the first and second base members. The spider includes a center support and first and second bearing support elements. Each bearing support element has an arcuate surfaces adapted to form joints with the first and second base members. In one embodiment, at least one shim element disposed is between at least one of the first and second bearing support elements and the center support.

Abstract: A torque transfer coupling includes a shaft and a first second set of hydraulic devices. Each hydraulic device of the first set of hydraulic devices has a first end operably connected to a first end of the shaft, wherein the hydraulic devices of the first set of hydraulic devices are disposed about an axis of the shaft. Each hydraulic device of the second set of hydraulic devices has a first end operably connected to a second end of the shaft, and wherein the hydraulic devices of the second set of hydraulic devices are disposed about the axis of the shaft. Each hydraulic device can include a piston and cylinder assembly wherein extension and retraction of each piston of each hydraulic device is generally tangential to a portion of a circle encircling the shaft.

Abstract: One aspect of the invention is a test assembly comprising a prime mover, an actuator assembly and a torque transfer coupling. The actuator assembly has an end configured to be attached to a shaft of a portion of a test specimen such as a wind turbine assembly. The actuator assembly has a shaft supported for rotation by hydraulic bearings. The torque transfer coupling connects the primer mover to the actuator assembly.

Abstract: A system includes a support, an actuator and a swivel joint coupling the actuator to the support. The swivel joint includes a first base member, a second base member, and a spider positioned between the first and second base members. The spider includes a center support and first and second bearing support elements. Each bearing support element has an arcuate surfaces adapted to form joints with the first and second base members. In one embodiment, at least one shim element disposed is between at least one of the first and second bearing support elements and the center support.

Abstract: A swivel joint is provided comprising a first base member, a second base member, and a spider positioned between the first and second base members. The spider includes a center support and first and second bearing support elements. Each bearing support element has an arcuate surfaces adapted to form joints with the first and second base members. In one embodiment, at least one shim element disposed is between at least one of the first and second bearing support elements and the center support.

Abstract: A swivel joint is provided comprising a first base member, a second base member, and a spider positioned between the first and second base members. The spider includes a center support and first and second bearing support elements. Each bearing support element has an arcuate surfaces adapted to form joints with the first and second base members. In one embodiment, at least one shim element disposed is between at least one of the first and second bearing support elements and the center support.

Abstract: A swivel joint according to the present invention includes first and second base members. A spider includes first and second arcuate surfaces which form joints with the first and second base members, respectively. Furthermore, the spider includes first and second pins both opposed from each other and third and fourth pins opposed from each other. A first mechanism is coupled to the spider and the first base member and is adapted to effect a force between the first arcuate surface and the first base member. Also, a second mechanism is coupled to the spider and the second base member and is adapted to effect a force between the second arcuate surface and the second base member.

Abstract: A friction stir welding spindle includes a support having a center bore. A spindle shaft is adapted to support a stir welding tool and extends within the bore. A bearing assembly allows simultaneous rotational and axial displacement of spindle shaft in the bore relative to the support. A sensing device is adapted to provide an output signal indicative of at least one of a force coincident with axial displacement of the spindle shaft and an axial position of the spindle shaft.

Abstract: A friction stir welding spindle includes a support having a center bore. A spindle shaft is adapted to support a stir welding tool and extends within the bore. A bearing assembly allows simultaneous rotational and axial displacement of spindle shaft in the bore relative to the support. A sensing device is adapted to provide an output signal indicative of at least one of a force coincident with axial displacement of the spindle shaft and an axial position of the spindle shaft.

Abstract: A swivel joint according to the present invention includes first and second base members. A spider includes first and second arcuate surfaces which form joints with the first and second base members, respectively. Furthermore, the spider includes first and second pins both opposed from each other and third and fourth pins opposed from each other. A first mechanism is coupled to the spider and the first base member and is adapted to effect a force between the first arcuate surface and the first base member. Also, a second mechanism is coupled to the spider and the second base member and is adapted to effect a force between the second arcuate surface and the second base member.

Abstract: A robotic vehicle capable of traveling over various terrain and traversing obstacles. In one embodiment, the vehicle includes a cylindrical body having two or more drive wheels coupled to the ends thereof. The wheels are selectively powered to propel the vehicle. The vehicle may further include a spring member which may be deflected to a first, stored position from a second, extended position. The spring member may be quickly released from the first, stored position such that it strikes the terrain with sufficient force to lift and propel the vehicle over or onto a proximate obstacle or object. Robotic vehicles of the present invention may also include one or more sensing devices operable to collect information. Electronics may further permit autonomous, semi-autonomous, and/or remote control of the vehicle. In still other embodiments, the robotic vehicle forms part of a multi-robot surveillance team.

Abstract: A rod end has a split clamp housing which supports a bearing for transferring motion or loading forces from an actuator to another part to be loaded. An adjustable stop for the clamp is used to adjust the backlash of the bearing used with the rod end to a desired level without causing distortion. A spherical washer set is used for transferring loads between the two clamp portions. The housing for the bearing is clamped against the spherical washer set at a preselected loading so that the bearing is able to rotate and swivel as needed, but backlash is removed.

Abstract: Table couplings for coupling hydraulic actuators to large shaking tables, such as earthquake simulator tables are preloaded under gaseous pressure to permit the couplings to be nontension carrying couplings, which in turn permits use of hydrostatic slip bearings between the side surfaces and the bottom surface of the table and the actuators. The hydrostatic bearings in turn reduce the need for swivels, links and yokes that carry both tension and compression. The use of compression only loading such as that permitted with the present device, also reduces the problem of making a satisfactory table foundation, because only compression loads are carried to the foundation rather than alternating tension-compression loads.