Solar trackers that may be advantageously employed on sloped and/or variable terrain to rotate solar panels to track motion of the sun across the sky include bearing assemblies and other mechanical features configured to address mechanical challenges posed by the sloped and/or variable terrain that might otherwise prevent or complicate use of solar trackers on such terrain.

Solar trackers that may be advantageously employed on sloped and/or variable terrain to rotate solar panels to track motion of the sun across the sky include bearing assemblies and other mechanical features configured to address mechanical challenges posed by the sloped and/or variable terrain that might otherwise prevent or complicate use of solar trackers on such terrain.

An electromagnetic actuating device. The device includes an electromagnetic coil including a central recess extending in an axial direction, a cylindrical pole tube inserted into the central recess and provided with a magnetic separation point, an armature situated displaceably in the pole tube, the armature being movable by an actuation of the electromagnetic coil, the armature being mounted in the pole tube in a sleeve-shaped bearing foil inserted into the pole tube, the bearing foil including an inner side facing toward the armature and used as a sliding surface and an outer side facing toward the cylindrical pole tube. It is provided that the bearing foil is coated at least on the inner side using a first layer made of perfluoroalkoxy polymer. A manufacturing method for such an electromagnetic actuating device is also described.

Upset oilfield tubing or upset pump rods are protected from abrasive wear by non-metallic circumferential wear bands applied to the upset portions of the tubing or rods and/or at selected locations along non-upset portions of the tubing or rods between the upset ends. The wear bands may be formed from selected polymeric materials including thermal polyurethane, polyphthalamide PTFE blends, and polyether ether ketone (PEEK), injection-molded onto suitably prepared circumferential surfaces of the tubing or rods. The wear bands may incorporate stainless steel mesh or other reinforcing materials embedded in the injection-molded polymeric material.

A bearing system includes a first bearing, the first bearing being annular in shape and defining a ring aperture, the first bearing including a first surface and a second surface, a second bearing being substantially the same in construction to the first bearing, a first surface of the second bearing contacting a second surface of the first bearing, wherein each of the bearings is constructed of nylon MDS.

A length-adjustable steering shaft for a motor vehicle may include a hollow outer shaft with an unround inner cross section, in which an inner shaft is received in a torque-locked and axially movable manner. A profiled sleeve may be arranged between the inner shaft and the outer shaft, and the profiled sleeve may have a fastening portion connected to the inner shaft. The inner shaft may be configured at least in part as a hollow shaft that has an interior that is open towards the end that is inserted into the outer shaft. To reduce the outlay in terms of production and assembly, the fastening portion may extend from the end into the interior of the inner shaft and is connected to an inner surface of the interior.

A steer-by-wire steering system for a vehicle includes a rack moveable in an axial direction, the rack having a bushing engagement portion comprising an outer surface including a plurality of rack flat surfaces. The steering system also includes an anti-rotation bushing disposed proximate an outer surface of the rack at the bushing engagement portion of the rack, the anti-rotation bushing having a plurality of bushing flat surfaces, wherein the number of the plurality of rack flat surfaces and the number of the plurality of bushing flat surfaces is identical.

Bearings with visually distinct wear indicators are disclosed. An example bearing disclosed herein includes a movable portion, a race to receive the movable portion along a first surface to thereby permit movement of the movable portion within the race, and a liner disposed on the first surface of the race, the liner having a first layer and a second layer, the first layer disposed on top of the second layer, the first layer visually distinctive from the second layer.

The invention relates to an imide polymer-based solid film lubricant, a method for producing same, a sliding element comprising same and the use thereof. According to the method, difunctional or cyclized difunctional compounds and optionally functional fillers are added to a non-imidized or partly imidized polyamide acid prepolymer or an imidized short-chain blocked prepolymer in a solvent or solvent mixture and then, depending on the prepolymer, a polymerization reaction or an imidization reaction and in both cases a crosslinking reaction is carried out. The solid film lubricant comprises an imide polymer as the resin matrix and optionally functional fillers, the molecules of the imide polymer comprising groups (R.sub.1) of the difunctional compounds that additionally contribute to the crosslinking.

A resin material 16 for a sliding member contains a synthetic resin 18, graphite particles 20 dispersed in the synthetic resin 18, and a hard material 24. The synthetic resin 18 contains 5% or more by volume and 30% or less by volume of polytetrafluoroethylene (PTFE) 22. The graphite particles 20 have an average particle diameter of 0.5 μm or more and 5.0 μm or less and have a content of 1% or more by volume and 15% or less by volume in the synthetic resin 18.