A hybrid propulsion system includes a heat engine configured to drive a heat engine shaft. An electric motor configured to drive a motor shaft. A transmission system is connected to receive rotational input power from each of the heat engine shaft and the motor shaft and to convert the rotation input power to output power. A first lubrication/coolant system is connected for circulating a first lubricant/coolant fluid through the heat engine. A second lubricant/coolant system in fluid isolation from the first lubrication/coolant system is connected for circulating a second lubricant/coolant fluid through the electric motor.

A lubrication system for a mechanical system, the lubrication system comprising a main tank, a reserve tank and a main lubrication circuit. The main lubrication circuit comprises, in particular, a pump drawing in the lubricating liquid from the main tank via a main suction point and a main suction pipe connecting the main suction point to the pump. The reserve tank is supplied with lubricating liquid either directly from the main tank or via the main lubrication circuit. The reserve tank is connected to the main suction pipe via an outlet pipe and the reserve tank is located above the main suction point so that the lubricating liquid flows through the outlet pipe to the main suction pipe by gravity.

A gear system includes at least one gear stage, a pump system and oil channels for circulating a first lubricant oil flow via first elements of the gear stage and a second lubricant oil flow via second elements of the gear stage, and an oil conditioning system for controlling temperatures of the first and second lubricant oil flows so that the temperatures of the first and second lubricant oil flows are different from each other and flow rates of the first and second lubricant oil flows are different from each other. Thus, it is possible to utilize for example the fact that bearings do not need as much oil flow as gear wheels but, on the other hand, lowering oil temperature of the bearings provides more advantages than lowering oil temperature of the gear wheels.

A hybrid propulsion system includes a heat engine configured to drive a heat engine shaft. An electric motor configured to drive a motor shaft. A transmission system is connected to receive rotational input power from each of the heat engine shaft and the motor shaft and to convert the rotation input power to output power. A first lubrication/coolant system is connected for circulating a first lubricant/coolant fluid through the heat engine. A second lubricant/coolant system in fluid isolation from the first lubrication/coolant system is connected for circulating a second lubricant/coolant fluid through the electric motor.

A negative-pressure balance system for a gearbox of a centrifugal compressor includes the gearbox, a hermetically-sealed low-level oil collecting tank and a U-shaped negative-pressure balance pipe. The gearbox is connected to a respirator, and the back pressure of the respirator is a local ambient atmospheric pressure. The bottom of the gearbox and the low-level oil collecting tank are connected by an oil conduit. An oil demister communicated with the low-level oil collecting tank is mounted at the top of the low-level oil collecting tank. The oil demister at least includes a ventilation device. The respirator is communicated with a front-end lubricating point in the gearbox. One end of the U-shaped negative-pressure balance pipe is communicated with the respirator, and the other end of the U-shaped negative-pressure balance pipe is communicated with a rear-end lubricating point in the gearbox.

An oil strainer is arranged between an oil pan configured to close a lower opening of a transmission case and a control valve body which is installed in the lower opening. The control valve body has a discharge hole of oil in a portion opposing the oil strainer. The oil strainer has an oil suction port in a portion opposing the oil pan, and has a rib projecting on the control valve body side on a surface of a portion opposing the control valve body. When seen from the oil pan side, the oil suction port and the discharge hole are provided so that positions are not matched from each other. When seen from the oil pan side, the rib is provided to cross a straight line passing through the oil suction port and the discharge hole in a region between the oil suction port and the discharge hole.

A bypass apparatus for lubricant in an unregulated pressurized gearbox including: a block including a lubricant inlet in fluid communication with a pressure relief valve, wherein the pressure relief valve diverts lubricant into the gearbox or into an oil filter, wherein lubricant is returned to the gearbox when the lubricant is cold and/or pressure at the pressure relief valve is high to reduce damage to the gearbox caused by high pressure during a cold start, and when the lubricant temperature increases and the pressure is reduced the pressure relief valve closes and lubricant enters the oil filter.

A panicle catcher for capturing entrained particles in a fluid is disclosed. The particle catcher can include an enclosure defining a flow channel between an inlet and an outlet. Trapping means may be incorporated into the particle catcher. Where provided, the trapping means can be arranged at or near the inlet to allow fluid comprising entrained particles to enter the flow channel through the inlet and to substantially prevent the fluid comprising entrained particles from exiting the flow channel through the inlet. Filtering means may also be incorporated into the particle catcher. Where provided, the filtering means can be arranged at or near the outlet to keep at least some a part of the entrained particles from exiting the flow channel through the outlet.

An epicyclic gear train includes a sun gear and planet gears mounted to a carrier and engaged to the sun gear. The planet gears and the carrier are rotatable about a center axis, and the carrier is engaged with a power output at a carrier-output engagement location. Ring gears are in meshed engagement with the planet gears. Planet gear bearings are disposed between one of the planet gears and the carrier. A lubrication interface is defined between each planet gear bearing and one of the planet gears. A bearing lubrication system includes a lubricant supply conduit extending between a conduit inlet at the carrier-output engagement location and conduit outlets at the lubrication interfaces of the planet gear bearings. A lubricant strainer is mounted about the conduit inlet at the carrier-output engagement location.

A hydrostatic transaxle includes: a casing; a hydraulic continuously variable transmission; and an oil filter that includes a filter body for filtering the hydraulic oil and a filter holding member configured to guide clean oil filtered in the filter body to a suction oil reservoir, in which the filter holding member includes a filter installation portion for installing the filter body, and a suction oil reservoir provided at a position different from the filter installation portion, and the filter installation portion and the suction oil reservoir are configured to be separable from each other and be couplable to each other to freely flow.