Tracked Roller Shaft Temperature Sensing Without Lubricant Leakage
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Solution Overview
Problem
Existing tracked undercarriage roller assemblies in machines like excavators face critical temperature increases due to unsuitable lubrication, leading to friction, wear, and potential damage, with existing temperature measurement methods risking lubricant leakage and sensor damage.
Innovation Solution
A temperature transducer is positioned in the shaft of the roller assembly, radially spaced from the bushing to measure shaft temperature proportional to the bushing temperature, with a housing seat preventing lubricant leakage and sensor exposure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a temperature sensor is positioned inside the roller assembly to measure bushing temperature directly, then measurement precision is improved, but the sensor is exposed to lubricant leakage and potential damage
Solution Approach 1:
The patent introduces the shaft as an intermediary element between the temperature sensor and the bushing. The sensor measures the shaft temperature at a location radially adjacent to the bushing, and the shaft's thermal properties are used to infer the bushing temperature. This intermediary approach allows temperature monitoring without direct sensor-bushing contact, avoiding lubricant exposure while maintaining measurement capability through thermal conduction principles.
2Productivity
If the roller assembly operates under high load conditions, then productivity is improved, but temperature increases leading to friction and wear
Solution Approach 1:
The patent implements a feedback mechanism by continuously monitoring the shaft temperature and comparing it against threshold values. When the temperature exceeds predetermined thresholds, the system generates warnings or alarms, enabling operators to adjust operations or maintenance schedules. This feedback loop allows the system to operate at high productivity levels while maintaining temperature control through timely interventions.
3Reliability
If lubrication is increased to reduce friction, then reliability is improved, but temperature measurement accuracy decreases due to lubricant interference
Solution Approach 1:
The shaft serves as a thermal intermediary that conducts heat from the bushing-lubricant interface to the temperature sensor. By positioning the sensor on the shaft rather than directly in the lubricant film, the system maintains reliable lubrication in the bushing-shaft interface while avoiding lubricant interference with the temperature measurement. The shaft's thermal conduction properties enable accurate temperature sensing without direct sensor exposure to the lubricated contact zone.
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
This setup allows early detection of abnormal temperature increases, preventing irreversible damage by maintaining lubrication and ensuring sensor integrity, thus extending the roller assembly's lifespan.
Implementation Method 1
the shaft (22) made of a material having a thermal conductivity such as to allow portions of the shaft (22) placed near the bushing (32) to change temperature as the temperature of the bushing (32) changes
Data Source
Figure 1
Figure 2
Figure 2A
AI summary
A tracked undercarriage roller assembly (17) comprises a roller body (18) having a through cavity (19) delimited by a radially inner surface (20), a shaft (22) inserted into the through cavity (19) of the roller body (18), a bushing (32) extending from a first axial end (32a) to a second axial end (32b) and radially interposed between the roller body (18) and the shaft (22), an annular chamber (34) at least partially filled with a lubricant and radially interposed between the shaft (22) and the bushing (32), a housing seat (37) obtained in the shaft (22) and comprising an inlet portion (39) facing an axial end surface (22d) of the shaft (22) and a measuring portion (40) placed inside the shaft (22) in an axial position comprised between the first axial end (32a) and the second axial end (32b) of the bushing (32), wherein the inlet portion (39) and the measuring portion (40) are each other aligned along an axial direction. A temperature transducer (41) is placed inside the housing seat (37) at the measuring portion (40), wherein the measuring portion (40) is placed at a radial distance from the bushing (32) between 8 millimetres and 50 millimetres.