According to one aspect, a lubricant level sensing system for an actuator is provided. The lubricant level sensing system includes a pressure port in an outer housing of the actuator, a pressure sensor, and a pathway from the pressure port to the pressure sensor. The pathway establishes fluid communication between the pressure sensor and a free volume of an internal cavity of the outer housing relative to a lubricant level in the internal cavity such that the pressure sensor detects a pressure of the free volume used to derive the lubricant level.

A method for determining timing of oil filling for a ball screw can determine whether the oil film in a specific time period is sufficient, falling or insufficient, and then know the optimum timing of oil filling, by comparing the sum of the slope values within respective time periods with a predetermined value. The method is further capable of determining the timing of oil filling even when the rotation speed of the ball screw changes. The method includes a step of signal acquisition, a step of converting signal, a step of defining and saving eigenvalues, a step of calculating eigenvalues, and a step of determining oil filling.

An auxiliary power unit (APU) oil quantity indication system and method provides a stable and accurate oil quantity indication during startup, mission duration and shutdown. The system determines a gulp value at various stages of operation, which is combined with a raw oil quantity indication to provide an indicated oil quantity.

An auxiliary power unit (APU) oil quantity indication system and method provides a stable and accurate oil quantity indication during startup, mission duration and shutdown. The system determines a gulp value at various stages of operation, which is combined with a raw oil quantity indication to provide an indicated oil quantity.

Systems and methods are provided for remotely monitoring liquid lubricant levels for pump equipment. A system includes a reservoir to store lubricant and a lubrication gland to expose a shaft seal of the pump equipment to the lubricant. A feed line and a return line circulate the lubricant between the reservoir and the lubrication gland. A level sensor is configured to measure a fluid level in the reservoir. The level sensor uses a communication interface to transmit fluid level data a monitoring device mounted to the pump equipment. The monitoring device is configured to compare the fluid level data against stored alert thresholds and send, to a provider network, an alert signal when the fluid level data is below an alert threshold. If the fluid level data is not below an alert threshold, the monitoring device stores the fluid level data for periodic reporting.

According to one aspect, a lubricant level sensing system for an actuator is provided. The lubricant level sensing system includes a pressure port in an outer housing of the actuator, a pressure sensor, and a pathway from the pressure port to the pressure sensor. The pathway establishes fluid communication between the pressure sensor and a free volume of an internal cavity of the outer housing relative to a lubricant level in the internal cavity such that the pressure sensor detects a pressure of the free volume used to derive the lubricant level.

A linear transmission device with capability of real-time monitoring of an amount of a lubricant includes a long shaft, a moving part, a lubricating device and a detecting module. The lubricating device includes a shell and an oil containing unit. The shell is formed with a first accommodating space. The oil containing unit is disposed in the first accommodating space and configured to provide the lubricant to an outer surface of the long shaft. The detecting module includes a temperature sensing unit and a control unit. The temperature sensing unit is configured to detect a current temperature of the oil containing unit. The control unit is connected with the temperature sensing unit and configured to: receive the current temperature; calculate a remaining amount of the lubricant of the oil containing unit based on the current temperature and an oil releasing model; and output the remaining amount.

A machine lubrication system includes a bellows-type container filled with lubricant that connects to a support base of a pump of the lubrication system. The container includes a neck extending from a convex bottom surface of the container. The support base includes a concave mounting surface and a passageway in communication with an inlet of the pump. The neck sealingly attaches the container to the passageway with the bottom surface of the container on the mounting surface the support base.

A linear transmission device with capability of real-time monitoring of an amount of a lubricant includes a long shaft, a moving part, a lubricating device and a detecting module. The lubricating device includes a shell and an oil containing unit. The shell is formed with a first accommodating space. The oil containing unit is disposed in the first accommodating space and configured to provide the lubricant to an outer surface of the long shaft. The detecting module includes a temperature sensing unit and a control unit. The temperature sensing unit is configured to detect a current temperature of the oil containing unit. The control unit is connected with the temperature sensing unit and configured to: receive the current temperature; calculate a remaining amount of the lubricant of the oil containing unit based on the current temperature and an oil releasing model; and output the remaining amount.

A method for checking the oil level in a marine drive unit, where the drive unit is provided with an external oil filter, an oil level sensor adapted to determine an oil level in the drive unit, and an electronically controlled tilt means, comprising the steps of, initiating an oil level check, controlling the tilt means to tilt the drive unit to a plurality of different tilt angle positions, for each tilt angle position, determining if the oil level sensor detects the oil level in the drive unit, for each tilt angle position, registering the tilt angle of the drive unit and the signal from the oil level sensor, determining at which tilt angles the sensor detects the oil level, and in dependence of the determined tilt angle of the drive unit, determining if the oil level of the drive unit is within a predefined range.