A compound of the formula (2) ##STR00001##
wherein R.sup.3 is a hydrocarbon group having 12 or 14 carbon atoms which is mainly composed of any one of 1-methylundecyl, 1-ethyldecyl, 1-dodecyl, 1-methyltridecyl, 1-ethyldodecyl and 1-tetradecyl, and 30 to 40 mole % of the total benzylic carbons of R.sup.3 being quaternary, R.sup.4 is a branched hydrocarbon group having 16 to 20 carbon atoms, 42 to 100 mole % of the total benzylic carbons of each R.sup.3 and R.sup.4 being quaternary, m and n are each a real number of 1.0m2.0, 1.0n2.0 and 2.0m+n3.0.

A planetary gear device includes: a first internal gear and a second internal gear, a first external gear which meshes with the first internal gear, a second external gear which meshes with the second internal gear, and an eccentric body which circumferentially moves the first external gear and the second external gear. The first external gear and the second external gear each independently have external teeth and are connected to each other to integrally rotate with each other, the first internal gear and the second internal gear each independently have internal teeth, one of the first internal gear and the second internal gear is connected to a stationary side, and the other thereof is connected to an output side, and each of the first internal gear and the second internal gear has internal teeth which are constituted by a support body, and a rotating body rotatable to the support body.

A tribological system, comprising a main body and a sandwich lubrication, in which the sandwich lubrication includes a binder-free solid lubricant layer comprising a solid lubricant, and a lubricant layer comprising a lubricant. The binder-free solid lubricant layer and the lubricant layer are present as separate layers on the main body and wherein the mass ratio of solid lubricant to lubricant is at most 0.05:1.

A tribological system, including a main body and a sandwich lubrication, wherein the sandwich lubrication includes a binder-free solid lubricant layer including a solid lubricant, and a lubricant layer including a lubricant. The binder-free solid lubricant layer and the lubricant layer are present as separate layers on the main body and the mass ratio of solid lubricant to lubricant is at most 0.05:1. The solid lubricant includes polytetrafluoroethylene (PTFE), metal sulfide, graphite, graphene, boron nitride (hexagonal), calcium phosphate, silicate, layered silicate, or mixtures thereof.

Examples of the ester oil include diester oils such as dibutyl sebacate, dioctyl sebacate, di-2-ethylhexyl sebacate, dioctyl adipate, diisodecyl adipate, ditridecyl adipate, ditridecyl phthalate, and methyl acetyl ricinolate; aromatic ester oils such as trioctyl trimellitate, tridecyl trimellitate, and tetraoctyl pyromellitate; polyol ester oils such as trimethylolpropane caprylate, trimethylolpropane pelargonate, pentaerythritol-2-ethylhexanoate, and pentaerythritol pelargonate; carbonate oil; complex ester oil which is an oligoester of polyhydric alcohol and mixed fatty acid including dibasic acid and monobasic acid; etc.

A sealing apparatus includes: an annular reinforcement ring around an axis; and an annular elastic body part around the axis, which is attached to the reinforcement ring and is formed of an elastic body. The elastic body part has: a side lip, an intermediate lip, and a grease lip. A grease as a lubricant is applied to respective inner peripheral side surfaces of the side lip, the intermediate lip, and the grease lip. A thickener of the grease includes no urea-based thickener. In a usage state of the sealing apparatus, a cross sectional area of an inter-lip space enclosed by the side lip, the intermediate lip, and a hub ring is equal to or greater than 3.5 mm.sup.2.

A power system includes an electric motor for driving a left wheel and a right wheel of a vehicle, an electric motor control device for controlling the electric motor, a transmission disposed on a power transmission path between the electric motor, the left and right wheels, a differential device for distributing output decelerated by the transmission to the left and right wheels, a case which accommodates the electric motor, the transmission, and the differential device, a left axle of which one end is connected to the differential device and the other end extends from the case to be connected to the left wheel, and a right axle of which one end is connected to the differential device and the other end extends from the case to be connected to the right wheel. A conductive rotation allowing member having conductivity is provided between the differential device and the case.

An assembly providing a bearing, a lubricant and a contamination sensor for determining a level of contamination in the lubricant. The sensor includes an EM wave generator for generating an EM signal, and an EM sensing element arranged in contact with the lubricant. The EM sensing element receives the generated EM signal and transmits an output signal whose properties are responsive to real and imaginary parts of a complex relative permittivity of the lubricant. The output signal is received by an EM measuring device that measures first and second parameters of the output signal, which are respectively representative of the real and imaginary parts of the complex relative permittivity. The EM measuring device determines a level of water contamination in the lubricant, based on the measured first parameter alone and determines a level of metal particle contamination in the grease, based on the measured first and second parameters.

A rolling bearing arrangement having a first and a second raceway element, and rolling bodies being arranged between the two raceway elements so that the two raceway elements are rotatable against each other in the manner of a rolling bearing, a space between the raceway elements in which the rolling bodies are rolling off comprising a lubricating grease, at least one sensor element for sensing temperature, at a specific point of the rolling bearing, particularly in the space, and for sensing speed of the rolling bearing and a unit receiving the sensed temperature and speed, calculating from the profiles of the sensed temperature over time and from the speed over time via a calculated energy imposed on the grease a used and/or remaining period of the grease life-time.

The present disclosure provides a formulated conductive grease for an associated bearing that can be used in a drive system, such as a variable frequency drive system for motors having a formulation sufficient to reduce the voltage build up that causes damaging electric discharge machining (EDM) on rotational bearing supported surfaces, such as inner and outer races, while still maintaining a grease composition suitable for bearing long life at operational temperatures. The higher conductivity of the inventive grease results in lowering of the threshold voltage of pulse discharges, which consequently decreases the energy release in each pulse and the resulting bearing temperatures, avoiding bearing damage. The disclosure further provides a bearing lifetime prediction model given typical discharge conditions from both Si and SiC inverters using a bearing state of health (SOH) metric.