Methods and systems are provided for rear axle having a wet bath. In one example, a system comprises a pump configured to spin in a first direction to flow lubricant to a cooler and a second direction to entrain the lubricant with gas.

A transmission (1) for a motor vehicle (2) includes a transmission housing (3) with an interior space (4) and an oil sump (6). At least one rotating transmission component (5a) is arranged in the interior space (4) of the transmission housing (3). At least one compensating tank (7) is configured for collecting oil from the interior space (4). The compensating tank (7) is fluidically connected to the oil sump (6) via at least one return (8). The particular return (8) delivers a predefined flow back into the oil sump (6) as a function of a power throughput of the transmission (1).

Various implementations described herein are directed to a lubrication system for a gearbox of an aircraft. A lubrication line is coupled to a plurality of jets and/or orifices to provide lubrication to one or more components of the gearbox. A check valve is placed within the lubrication line in a location upstream from the plurality of jets and/or orifices.

Disclosed is a driving system having an oil circulation structure in which churned oil is collected in a housing and in which the collected oil is efficiently distributed to driving structures, which include a motor and a speed reducer, thereby smoothly cooling and lubricating the respective driving structures. In addition, it is possible to adjust the level of the oil depending on whether the driving structures are in a low-load state or a high-load state, thereby improving lubrication and cooling performance.

A cooling system differential oil contained in the housing of a differential for a vehicle. The differential includes a housing containing a first portion of differential oil. A tank contains a second portion of differential oil. An inlet passage is provided through which differential oil flows from the housing to the tank. An outlet passage is provided through which differential oil flows from the tank to the housing. A valve is disposed in the outlet passage that has a closed position preventing differential oil from flowing through the outlet passage. The valve has an open position in which differential oil is permitted to flow from the tank to the housing in response to the temperature of the differential oil in the housing exceeding a predetermined temperature.

A transfer structure for a vehicle which retains a stable amount of lubricant in a coupling chamber and maintains a cooling effect for a coupling by agitation of the lubricant irrespective of an inclination of a vehicle in a front-rear direction. The transfer structure includes a gear chamber housing first and second gears meshing with each other; a coupling chamber housing a coupling provided coaxially with the first gear; an introduction path which introduces a lubricant in the gear chamber into the coupling chamber; and a return path through which the lubricant in the coupling chamber is returned to the gear chamber. The return path is inclined downward toward the gear chamber from an opening that opens in a lower part of an intermediate part of the coupling chamber in a vehicle front-rear direction to an oil discharge hole that opens in the gear chamber.

A fluid sump for accommodating a lubricating fluid and transmission housing for a vehicle comprising such a fluid sump. The fluid sump may comprise a first compartment for collecting the lubricating fluid, a second compartment in which the lubricating fluid can be brought in contact with a rotating member, and an intermediate compartment having a first opening for introducing the lubricating fluid from the first compartment into the intermediate compartment, a second opening for introducing the lubricating fluid from the intermediate compartment into the second compartment, and a floating element. In one or more examples, the first opening can be opened and closed by the floating element, and the first compartment, the intermediate compartment and the second compartment are provided with ambient pressure.

A hydraulic fluid expansion tank is located inside a housing of a drive device. The expansion tank comprises a siphon tube in communication with a sump located within the drive device and also comprises a vent opening in communication with a vent of the drive device that is in communication with atmospheric pressure. The fluid expansion tank is positioned and restrained within the drive device without the use of fasteners.

An oil management system for a vehicle includes a differential housing, a transmission housing, a lubricant tank, a suction line, a lubricant pump, and an air suction pump. The transmission housing is connected to the differential housing in an air-tight manner, and a lubricant through-passage is defined between the transmission housing and the differential housing. The lubricant tank is provided in the differential housing and has a lubricant suction opening in a lower region. The lubricant pump conveys lubricant from the lubricant tank through the suction line and conducts the lubricant to the lubrication points in the differential housing and the transmission housing. The air suction pump pumps air from the lubricant tank into the transmission housing so that an excess air pressure is maintained in the transmission housing.

A vehicle system includes a vehicle component with a component temperature sensor, and a fluid circuit in fluid communication with the component and with a fluid temperature sensor. A controller is in communication with the component sensor and the fluid sensor. The controller is configured to, in response to a temperature difference between the component sensor and the fluid sensor being greater than a predetermined threshold value, output a flag or a diagnostic code indicative of a fluid level in the fluid circuit. A vehicle diagnostic method and a vehicle are also provided.