A bearing inner race for a solar panel tracker positioning system includes a semi-circular shaped body having a first upper land and an oppositely facing second upper land. A first elongated aperture is positioned proximate to the first upper land and a second elongated aperture is positioned proximate to the second upper land. A first alignment ring is centered within the first elongated through aperture and a second alignment ring is centered within the second elongated through aperture. The bearing inner race also includes a ground stud integrally connected to the body in an as-cast condition of the body.

A solar tracker bearing assembly has a rotating element sandwiched between two mounting brackets and held together by fasteners. The rotating element includes an arc-shaped slot such that the rotating element can pivot against the fixed mounting brackets. Bearings may be positioned within the arc-shaped slot. The rotating element can be configured to accept toque tubes of various cross-sections.

Provided is a magnetic bearing device which allows easy initial adjustment and allows optimal bearing control to be performed by a simple algorithm without increasing a memory capacity of a controller. A pair of square multipliers and an adder acquire respective steady-state current values of a pair of electromagnets which attract a rotor shaft of a magnetic bearing not shown in opposite radial directions, square the respective steady-state current values, and add up the respective squared steady-state current values. Then, to optimally change respective currents in the electromagnets in accordance with a mounting posture of the magnetic bearing, a correction coefficient arithmetic operator calculates a correction gain instruction value acting on the electromagnets from the steady-state current values squared/added up. Then, a gain instruction value obtained by adding the correction gain instruction value to a fundamental gain of a control circuit for the electromagnets is input to a gain amplifier. The gain amplifier generates a corrected current instruction value on the basis of the gain instruction value and optimally controls the magnetic bearing.

A solar tracker bearing assembly has a rotating element sandwiched between two mounting brackets and held together by fasteners. The rotating element includes an arc-shaped slot such that the rotating element can pivot against the fixed mounting brackets. Bearings may be positioned within the arc-shaped slot. The rotating element can be configured to accept toque tubes of various cross-sections.