Provided is a life evaluating device that evaluates the life of a lubricant in a machine including a motor and a transmission mechanism that is lubricated by the lubricant and transmits power of the motor to a movable unit. The life evaluating device includes a motor-heat-value calculating unit that calculates a motor heat value on the basis of a current value of the motor, a frictional-heat-value calculating unit that calculates a frictional heat value in the transmission mechanism on the basis of rotating speed of the motor and a coefficient of friction of the transmission mechanism, a lubricant-temperature estimating unit that estimates temperature of the lubricant on the basis of the calculated frictional heat value and the calculated motor heat value, and a life estimating unit that estimates the life of the lubricant on the basis of the estimated temperature of the lubricant.

Provided is a life evaluating device that evaluates the life of a lubricant in a machine including a motor and a transmission mechanism that is lubricated by the lubricant and transmits power of the motor to a movable unit. The life evaluating device includes a motor-heat-value calculating unit that calculates a motor heat value on the basis of a current value of the motor, a frictional-heat-value calculating unit that calculates a frictional heat value in the transmission mechanism on the basis of rotating speed of the motor and a coefficient of friction of the transmission mechanism, a lubricant-temperature estimating unit that estimates temperature of the lubricant on the basis of the calculated frictional heat value and the calculated motor heat value, and a life estimating unit that estimates the life of the lubricant on the basis of the estimated temperature of the lubricant.

A roll stand (1) includes a roll (3), in particular a backup roll, mounted via oil film bearings (2). Each oil film bearing (2) has a sealing system for sealing the oil film bearing (2) to prevent oil leakage and a coolant ingress. The oil film bearing (2) is integrated into an oil-circulating lubrication system (4), which is fluidically connected to the oil film bearing (2) via oil feed lines (5) and an oil discharge line (6). A first sensor (11) is arranged in the oil feed line (5) and a second sensor (12) is arranged in the oil discharge line (6). The two sensors (11, 12) are designed to determine the coolant content in the relevant oil volume flow.

A method involves directing lubricant to different consumers which are to be monitored via their lubricant. The lubricant is drained through drain lines connected to the consumers and directed to a tank. At least some the lubricant in the drain lines or the consumers is extracted into extraction lines. Flow from the extraction lines is selectively directed to a measurement device, which then measures a characteristic of the lubricant. A system for carrying out such a method is also provided, wherein the system includes a multiplexer for selectively directing flow from the extraction lines.

A method involves directing lubricant to different consumers which are to be monitored via their lubricant. The lubricant is drained through drain lines connected to the consumers and directed to a tank. At least some the lubricant in the drain lines or the consumers is extracted into extraction lines. Flow from the extraction lines is selectively directed to a measurement device, which then measures a characteristic of the lubricant. A system for carrying out such a method is also provided, wherein the system includes a multiplexer for selectively directing flow from the extraction lines.

A method of monitoring a sealing component of a gas turbine engine, comprising: collecting oil leaked from the component; detecting a volume of the collected oil upstream of an oil return path of the gas turbine engine; and signalling for inspection of the component when the volume of the collected oil exceeds a threshold volume. Also disclosed is an oil leakage monitoring system for a gas turbine engine, comprising: one or more sealing components to be lubricated by oil; a valve downstream of the one or more components and fluidly connected to an oil system; a reservoir downstream of the one or more components to collect oil, the reservoir upstream of the valve; and a volume measurement device configured to detect the oil collected in the reservoir, and to signal for inspection of the one or more components when the oil collected in the reservoir exceeds a threshold volume.

The magnetic chip detector system can have a first conductor member and a second conductor member both exposed to a liquid flow path and separated from one another by gap, each one of the conductor members having a magnetic field oriented into the liquid flow path, at least a first one of the magnetic fields being actively modifiable; an electrical energy source configured to induce a current circulation across the gap; and a meter configured to measure a response of the gap to the induced current circulation.

The magnetic chip detector system can have a first conductor member and a second conductor member both exposed to a liquid flow path and separated from one another by gap, each one of the conductor members having a magnetic field oriented into the liquid flow path, at least a first one of the magnetic fields being actively modifiable; an electrical energy source configured to induce a current circulation across the gap; and a meter configured to measure a response of the gap to the induced current circulation.

A method and a system for monitoring a mechanical system, the mechanical system including a lubrication system provided with a reservoir containing a lubricating liquid, with a lubrication circuit designed to lubricate the mechanical system, as well as with a particle detection device arranged in the lubrication circuit. The detection device makes it possible, in particular, to count the number of particles flowing through the lubrication circuit and/or the flow rate of the particles. Comparing that number or that flow rate with a first threshold makes it possible to determine a risk of damage affecting the mechanical system and to anticipate the maintenance or reinforced monitoring operations that possibly need to be performed.

A gearbox includes a housing including a lubricant reservoir, at least one gear system arranged in the housing, at least one lubricant delivery passage operable to direct a flow of lubricant from a lubricant reservoir onto the at least one gear system, at least one lubricant return passage operable to guide the flow of lubricant to the lubricant reservoir, and a lubricant-out sensor fluidically connected to the at least one lubricant return passage. The lubricant-out sensor is operable to detect a non-pressure based parameter of the lubricant.