Swellable Ring Oil Leak Detection in Robot Gearbox Joints
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The aging of seals in robot gearbox joints leads to oil leakage into the motor, causing operational issues and safety risks, with existing solutions unable to detect oil leakage in the motor wrapped inside a joint.
Innovation Solution
An apparatus comprising a swellable ring arranged around the output shaft of the motor, which swells upon contacting oil to apply a radial force, detectable by a controller through torque changes or current variations, allowing for early detection of oil leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a seal is used to prevent oil leakage, then oil leakage is prevented, but the seal ages and fails over time leading to undetected oil leakage into the motor
Solution Approach 1:
The swellable ring is positioned in advance around the output shaft to intercept oil leakage before it enters the motor. When oil leaks past the aging seal, the swellable ring detects it immediately by swelling upon contact, providing early warning before the oil can contaminate the motor interior.
Solution Approach 2:
The swellable ring acts as an intermediary component between the sealed environment and the motor. It intercepts and detects oil leakage at the boundary, preventing direct contact between leaked oil and the motor, thereby extending detection time and preventing damage.
2Volume of moving object
If the motor is wrapped inside a joint, then the robot structure is compact, but oil leakage detection becomes difficult
Solution Approach 1:
The swellable ring performs self-detection by automatically swelling when it contacts leaked oil. This self-actuating mechanism eliminates the need for external sensors or complex detection systems, making the compact motor-wrapped structure compatible with reliable oil leakage detection.
Solution Approach 2:
The detection mechanism relies on parameter change - specifically, the change in volume and shape of the swellable ring when it absorbs oil. This physical parameter change provides a detectable signal (radial force, position change) that indicates oil leakage, solving the detection difficulty in compact configurations.
3Reliability
If maintenance is performed after oil leakage occurs, then the motor may already be damaged, but replacing the entire motor increases costs
Solution Approach 1:
The swellable ring provides preliminary detection of oil leakage before it can damage the motor. This early warning allows maintenance to be performed proactively by replacing only the seal, avoiding the need for expensive motor replacement that would occur if leakage went undetected until after motor damage.
4Difficulty of detecting and measuring
If a swellable ring is added to detect oil leakage, then detection capability is improved, but device complexity increases
Solution Approach 1:
The swellable ring is a passive, self-actuating component that detects oil leakage through its own physical response (swelling) rather than requiring external power, control systems, or complex sensing mechanisms. This keeps the added complexity minimal while providing reliable detection capability.
Solution Approach 2:
The swellable ring is a simple, inexpensive component that can be easily replaced if it becomes saturated with oil or loses its swelling capability. This disposable nature reduces the risk and cost associated with adding detection functionality, as the component itself is simple and replaceable rather than complex and costly.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables timely detection of oil leakage before it affects the motor, allowing for proactive maintenance, reducing costs, and enhancing the safety and reliability of the robot joint.
Implementation Method 1
the swellable ring, when contacting oil, swells to apply a radial force to the output shaft
Implementation Method 2
a controller configured to detect the oil leakage by detecting at least one of the followings caused by the applied radial force: a torque change on the output shaft
Implementation Method 3
or a change in a current for driving the motor
Data Source
AI summary
Embodiments of the present disclosure provide an apparatus for determining oil leakage of a gearbox and an associated robot. The apparatus comprises a swellable ring arranged surrounding an output shaft of a motor coupled to the gearbox, the swellable ring, when contacting oil, swells to apply a radial force to the output shaft; and a controller configured to detect the oil leakage by detecting at least one of the following caused by the applied radial force: a torque change on the output shaft, or a change in a current for driving the motor. With the apparatus, before oil leaks into the motor, the user already knows or the motor has already been stopped. In this case, the robot using the apparatus can be operated more safely.