Description:FIELD OF INVENTION
[0001] Embodiments of the present disclosure relate to the field of automotive component testing and calibration, and more particularly to a thermal static calibration apparatus for testing viscous fan clutches and a method thereof.
BACKGROUND
[0002] Conventional systems for testing and calibrating viscous fan clutches in motor vehicles typically involve dynamic testing procedures on specialized test rigs. These conventional test rigs perform dynamic testing by subjecting the fan clutches to operational conditions that simulate real-world use.
[0003] The conventional testing procedure uses a dial gauge positioned onto the closed valve lever and an electrical blower to provide the necessary heat to the bimetal strip. As the bimetal strip is heated, it expands, causing the valve lever to open gradually. Temperature versus deflection readings are recorded systematically until the deflection value falls within a specified range. The collected data is then used to create a graph plotting temperature against deflection, which allows for the generation of a line equation. The slope of this line is analysed to determine the precise temperature at which the assembly engages, and this temperature is used to calculate the final pin length according to specified requirements.
[0004] While effective, the conventional dynamic testing process is time-consuming and resource-intensive. Each sample cycle takes approximately seven minutes, resulting in a daily production output of only 120 units per shift. Additionally, the process consumes significant amounts of power and requires considerable floor space for the large test rigs.
[0005] Hence, there is a need for an improved thermal static calibration apparatus for testing viscous fan clutches and a method thereof which addresses the aforementioned issue(s).
OBJECTIVE OF THE INVENTION
[0006] An objective of the present invention is to enhance the testing and calibration process of viscous fan clutches by reducing the cycle time and increasing the daily production output.
[0007] Another objective of the present invention is to achieve significant energy savings by reducing the power consumption of the calibration process by up to 90%.
[0008] Another objective of the present invention is to boost productivity by 50%, allowing for a higher number of units to be calibrated per shift.
[0009] Another objective of the present invention is to provide a more compact calibration system that optimizes floor space utilization in testing facilities.
[00010] Another objective of the present invention is to develop a calibration machine that is easy to use, thereby simplifying the testing process and reducing the potential for operator error.
[00011] Another objective of the present invention is to maintain or improve the precision and accuracy of temperature versus deflection measurements in the calibration process.
[00012] Another objective of the present invention is to align with sustainable practices by reducing power consumption and resource usage in the calibration process.
[00013] Another objective of the present invention is to enable comprehensive data recording and analysis, generating temperature versus deflection graphs and accurately determining engagement temperatures for optimal pin length calculation.
BRIEF DESCRIPTION
[00014] In accordance with an embodiment of the present disclosure, a thermal static calibration apparatus for testing viscous fan clutches is provided. The apparatus includes a test rig comprising a mechanical fixture, wherein the mechanical fixture is configured to hold a viscous fan clutch which is half-assembled, wherein the viscous fan clutch comprises a cover, valve lever, dividing disc assembly, pin, and bimetal strip. The apparatus also includes an air heater positioned orthogonally to the viscous fan clutch, wherein the air heater is configured to provide heat directly to the bimetal strip to cause thermal expansion. The apparatus further includes a linear variable differential transformer (LVDT) positioned in contact with the valve lever of the viscous fan clutch, wherein the linear variable differential transformer is configured to measure displacement of the valve lever as the bimetal strip expands. The apparatus also includes a data recording module electrically connected to the linear variable differential transformer and configured to record temperature and corresponding deflection readings from the linear variable differential transformer. Furthermore, the apparatus includes a control unit connected to the air heater and the data recording module, wherein the control unit is configured to receive and process signals from the linear variable differential transformer to monitor the displacement of the valve lever; to generate a temperature versus deflection graph based on the recorded data to analyse a slope of the temperature versus deflection graph to determine the engagement temperature of the viscous fan clutch and to calculate a final pin length of the viscous fan clutch based on the determined engagement temperature.
[00015] In accordance with another embodiment of the present disclosure, a method for assembling a viscous fan clutch comprising a cover, valve lever, dividing disc assembly, pin, and bimetal strip, for securing the viscous fan clutch onto a mechanical fixture of a test rig. The method also includes heating the bimetal strip using an air heater positioned orthogonally to the viscous fan clutch to cause thermal expansion. The method further includes positioning a linear variable differential transformer (LVDT) in contact with the valve lever for measure displacement of the valve lever as the bimetal strip expands. The method also includes recording temperature and corresponding deflection readings from the linear variable differential transformer using a data recording module for processing the recorded data for generating a temperature versus deflection graph. Furthermore, the method includes analysing the slope of the temperature versus deflection graph for determining the engagement temperature of the viscous fan clutch. The method also includes calculating a final pin length of the viscous fan clutch based on the determined engagement temperature.
[00016] To further clarify the advantages and features of the present disclosure, a more particular description of the disclosure will follow by reference to specific embodiments thereof, which are illustrated in the appended figures. It is to be appreciated that these figures depict only typical embodiments of the disclosure and are therefore not to be considered limiting in scope. The disclosure will be described and explained with additional specificity and detail with the appended figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[00017] The disclosure will be described and explained with additional specificity and detail with the accompanying figures in which:
[00018] FIG. 1 illustrates a schematic representation of a thermal static calibration apparatus, in accordance with an embodiment of the present disclosure;
[00019] FIG. 2 illustrates a schematic representation of a clutch of the thermal static calibration apparatus of FIG. 1, in accordance with an embodiment of the present disclosure;
[00020] FIG. 3 illustrates a graphical representation of the thermal calibration of a fan clutch of FIG. 1, in accordance with an embodiment of the present; and
[00021] FIG. 4 illustrates a flow chart representing the steps involved in a method for calibrating a viscous fan clutch using a thermal static calibration unit in accordance with an embodiment of the present disclosure.
[00022] Further, those skilled in the art will appreciate that elements in the figures are illustrated for simplicity and may not have necessarily been drawn to scale. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the figures by conventional symbols, and the figures may show only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the figures with details that will be readily apparent to those skilled in the art having the benefit of the description herein.
DETAILED DESCRIPTION
[00023] For the purpose of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiment illustrated in the figures and specific language will be used to describe them. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended. Such alterations and further modifications in the illustrated system, and such further applications of the principles of the disclosure as would normally occur to those skilled in the art are to be construed as being within the scope of the present disclosure.
[00024] The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such a process or method. Similarly, one or more devices or subsystems or elements or structures or components preceded by "comprises... a" does not, without more constraints, preclude the existence of other devices, sub-systems, elements, structures, components, additional devices, additional sub-systems, additional elements, additional structures or additional components. Appearances of the phrase "in an embodiment", "in another embodiment" and similar language throughout this specification may, but not necessarily do, all refer to the same embodiment.
[00025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this disclosure belongs. The system, methods, and examples provided herein are only illustrative and not intended to be limiting.
[00026] In the following specification and the claims, reference will be made to a number of terms, which shall be defined to have the following meanings. The singular forms “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise.
[00027] Embodiments of the present disclosure relate to the field of automotive component testing and calibration, and more particularly to a thermal static calibration apparatus for testing viscous fan clutches and a method thereof. The apparatus includes a test rig comprising a mechanical fixture, wherein the mechanical fixture is configured to hold a viscous fan clutch which is half-assembled, wherein the viscous fan clutch comprises a cover, valve lever, dividing disc assembly, pin, and bimetal strip. The apparatus also includes an air heater positioned orthogonally to the viscous fan clutch, wherein the air heater is configured to provide heat directly to the bimetal strip to cause thermal expansion. The apparatus further includes a linear variable differential transformer (LVDT) positioned in contact with the valve lever of the viscous fan clutch, wherein the linear variable differential transformer is configured to measure displacement of the valve lever as the bimetal strip expands. The apparatus also includes a data recording module electrically connected to the linear variable differential transformer and configured to record temperature and corresponding deflection readings from the linear variable differential transformer. Furthermore, the apparatus includes a control unit connected to the air heater and the data recording module, wherein the control unit is configured to receive and process signals from the linear variable differential transformer to monitor the displacement of the valve lever; to generate a temperature versus deflection graph based on the recorded data to analyse a slope of the temperature versus deflection graph to determine the engagement temperature of the viscous fan clutch and to calculate a final pin length of the viscous fan clutch based on the determined engagement temperature.
[00028] FIG. 1 illustrates a schematic representation of a thermal static calibration apparatus, in accordance with an embodiment of the present disclosure. The apparatus (100) includes a test rig (110) comprising a mechanical fixture (120), wherein the mechanical fixture (120) is configured to hold a viscous fan clutch (130) which is half-assembled, wherein the viscous fan clutch (130) comprises a cover, valve lever (150), dividing disc assembly (160), pin (170), and bimetal strip (180). In one embodiment, the test rig (110) may include a mechanical fixture (120) specifically designed to securely hold a half-assembled viscous fan clutch (130) during the calibration process. In such embodiment, the mechanical fixture (120) may include adjustable clamps and supports to ensure precise positioning and stability of the fan clutch (130) components. In one specific embodiment, the viscous fan clutch (130) may include several key elements such as a cover (140) that houses and protects internal components, a valve lever (150) that regulates the clutch engagement, a dividing disc assembly (160) that separates the fluid chambers, a pin (170) that plays a crucial role in the engagement mechanism, and a bimetal strip (180) that responds to temperature changes by expanding or contracting. The mechanical fixture's (120) design may accommodate these components, ensuring that the bimetal strip (180) is exposed to controlled heating while the valve lever's (150) movement is accurately measured. This configuration may allow detailed analysis and calibration of the viscous fan clutch's (130) performance, ensuring optimal functionality and meeting specific customer requirements.
[00029] The apparatus (100) also includes an air heater (190) positioned orthogonally to the viscous fan clutch (130), wherein the air heater (190) is configured to provide heat directly to the bimetal strip (180) to cause thermal expansion. In one embodiment, the test rig (110) may incorporate an air heater (190) strategically positioned orthogonally to the viscous fan clutch (130) to ensure efficient and direct heat transfer. This orthogonal positioning may align the air heater (190) perpendicularly to the plane of the clutch, allowing the heat to be directed precisely at the bimetal strip (180). The air heater (190) is configured to generate a controlled stream of hot air, which uniformly heats the bimetal strip (180). As the bimetal strip (180) is exposed to the rising temperature, it undergoes thermal expansion. This expansion process is critical, as it causes the bimetal strip (180) to deflect, which in turn triggers the movement of the valve lever (150) within the clutch assembly. The precise and direct application of heat ensures that the bimetal strip (180) responds accurately to temperature changes, facilitating a reliable and repeatable calibration process. The design of the air heater (190) may ensure that it provides consistent and stable heating, minimizing fluctuations that could affect the calibration accuracy of the viscous fan clutch (130).
[00030] Furthermore, the apparatus (100) includes a linear variable differential transformer (LVDT) (200) positioned in contact with the valve lever (150) of the viscous fan clutch (130), wherein the linear variable differential transformer is configured to measure displacement of the valve lever (150) as the bimetal strip (180) expands. In one embodiment, LVDT (200) may be a high-precision sensor designed to measure linear displacement with exceptional accuracy. As the bimetal strip (180) within the clutch assembly is heated and expands, it induces a gradual opening or displacement of the valve lever (150). The LVDT (200) detects this minute displacement by converting the linear movement of the valve lever (150) into an electrical signal. This configuration ensures that even the smallest movements are captured with high fidelity. The LVDT (200) is mounted on an adjustable arm or fixture to ensure it maintains optimal contact with the valve lever (150) throughout the calibration process, regardless of the lever’s position. The data generated by the LVDT (200) is transmitted to a data recording module (210), where it is logged alongside the corresponding temperature readings. This precise measurement of the valve lever's (150) displacement is crucial for creating accurate temperature versus deflection profiles, which are essential for determining the exact engagement temperature and subsequent calibration of the viscous fan clutch (130). The use of an LVDT (200) ensures that the calibration process is both reliable and repeatable, providing consistent results that meet stringent quality standards.
[00031] The apparatus (100) also includes a data recording module (210) electrically connected to the linear variable differential transformer and configured to record temperature and corresponding deflection readings from the linear variable differential transformer. In one embodiment, the data recording module (210) may be designed to systematically record both temperature and corresponding deflection readings with high accuracy. As the LVDT (200) measures the displacement of the valve lever (150) induced by the thermal expansion of the bimetal strip (180), the data recording module (210) simultaneously captures these measurements. The module may be equipped with advanced electronics that ensure precise synchronization between the temperature readings and the deflection data, allowing for real-time data acquisition. The temperature readings are typically obtained from an integrated temperature sensor that monitors the environment around the bimetal strip (180). This dual data capture system allows for the creation of detailed temperature versus deflection profiles, which are essential for analysing the performance and engagement characteristics of the viscous fan clutch (130). The data recording module (210) is configured to store this information in a digital format, facilitating easy retrieval and analysis. Additionally, it may feature interfaces for connecting to external data processing systems, enabling further analysis and calibration adjustments based on the recorded data. The integration of the data recording module (210) into the test rig (110) ensures a seamless and efficient calibration process, enhancing the accuracy and reliability of the viscous fan clutch (130) performance assessment.
[00032] The Apparatus (100) further includes a control unit (220) connected to the air heater (190) and the data recording module (210). The control unit (220) is configured to receive and process signals from the linear variable differential transformer to monitor the displacement of the valve lever (150). The control unit (220) is also configured to generate a temperature versus deflection graph based on the recorded data to analyse a slope of the temperature versus deflection graph to determine the engagement temperature of the viscous fan clutch (130). The control unit (220) is further configured to calculate a final pin length of the viscous fan clutch (130) based on the determined engagement temperature.
[00033] In one embodiment, the control unit (220) may be is equipped with advanced microprocessors and software algorithms, enabling it to perform multiple critical functions in the calibration process. It receives real-time signals from the Linear Variable Differential Transformer (LVDT) (200) to monitor the displacement of the valve lever (150) with high precision. The control unit (220) continuously processes these displacement signals alongside temperature readings captured by the data recording module (210), ensuring synchronized data acquisition.
[00034] Upon receiving the data, the control unit (220) may generate a temperature versus deflection graph, plotting the relationship between the heat applied to the bimetal strip (180) and the corresponding movement of the valve lever (150). This graph may be essential for understanding the performance characteristics of the viscous fan clutch (130). The control unit's (220) software analyses the slope of the temperature versus deflection graph to pinpoint the exact engagement temperature the temperature at which the valve lever (150) reaches a critical deflection point indicating clutch engagement.
[00035] Furthermore, the control unit (220) may be configured to use this engagement temperature as a key parameter in calculating the final pin length of the viscous fan clutch (130). This calculation may be based on predefined algorithms and design specifications that correlate the engagement temperature with the optimal pin length necessary for proper clutch operation. The control unit (220) can adjust the calibration process dynamically, ensuring that the viscous fan clutches (130) meet precise operational standards. Overall, the control unit's (220) integration into the test rig (110) enhances the automation, accuracy, and efficiency of the calibration process, allowing for real-time adjustments and ensuring that the final product meets stringent quality and performance criteria.
[00036] In one embodiment, the control unit (220) may include a display interface configured to provide real-time visualization of temperature and deflection data. in such embodiment, this display interface may be typically an LCD or touch screen, which may be configured to present a clear and comprehensive view of both temperature and deflection readings as they are being recorded. The display interface may be strategically positioned for easy accessibility, allowing operators to monitor the calibration process closely. It may feature a user-friendly graphical user interface (GUI) that can dynamically update to reflect the ongoing changes in temperature and corresponding valve lever (150) displacement. In such embodiment, the display interface may operator in view real-time plots of temperature versus deflection graphs, observe the slope of these graphs, and analyse the performance characteristics of the viscous fan clutch (130) as the calibration progresses. The interface may also provide additional functionalities, such as zooming in on specific data points, overlaying multiple graphs for comparison, and displaying numerical values for precise measurement analysis.
[00037] This real-time visualization capability not only enhances the operator’s ability to ensure that the calibration process is proceeding correctly but also allows for immediate detection of any anomalies or deviations from expected behaviour. The control unit’s (220) display interface thus plays a critical role in enhancing the efficiency, accuracy, and user-friendliness of the calibration system, ensuring that each viscous fan clutch (130) is calibrated to meet exacting standards.
[00038] In one exemplary embodiment, the data recording module (210) may include an integrated digital storage unit designed to securely store temperature and deflection readings captured during the calibration process. This digital storage unit may ensure that all critical data is preserved in a reliable, easily accessible format. The storage capacity may be sufficient to handle extensive datasets, allowing for comprehensive recording of multiple calibration cycles. This feature facilitates detailed post-process analysis, enabling engineers to review and analyse the performance characteristics of each viscous fan clutch (130) accurately. The digital storage unit's robust configuration guarantees data integrity and supports efficient data retrieval, contributing to the overall precision and effectiveness of the calibration system.
[00039] FIG. 2 illustrates a schematic representation of a clutch of the thermal static calibration apparatus of FIG. 1, in accordance with an embodiment of the present disclosure. The figure shows a mechanical fixture (120) designed to securely hold a half-assembled viscous fan clutch (130) during the calibration process. The viscous fan clutch (130) assembly includes several crucial components:
a. Cover (140): The outer housing that protects the internal components and ensures structural integrity.
b. Valve (230): This component primarily regulates the engagement and disengagement of the clutch based on thermal input from the bimetal strip (180).
c. Dividing disc assembly (160): This assembly separates different fluid chambers within the clutch, essential for its proper functioning.
d. Valve lever (150): A pivotal component that regulates the engagement and disengagement of the clutch based on thermal input.
e. Bimetal strip (180): Positioned within the assembly, this strip expands or contracts in response to temperature changes, driving the movement of the valve lever (150).
f. Actuating Pin (170): A key element that interacts with the valve lever (150), playing a crucial role in the clutch's engagement mechanism.
g. Pin Seal (240): Ensures the fluid within the clutch does not leak, maintaining the correct pressure and fluid levels for optimal performance. The seal is critical for preventing contamination and ensuring the longevity of the clutch components.
h. Reservoir Chamber (250): A chamber within the clutch that stores the viscous fluid. The reservoir is designed to supply the necessary fluid to the working areas of the clutch, allowing for smooth and consistent operation.
i. Working Chamber (260): The working chamber in the viscous fan clutch (130) contains the viscous fluid that engages the fan by transmitting torque. It is designed to ensure proper fluid flow and efficient heat dissipation within the clutch assembly.
j. Housing (270): The housing serves as the outer shell of the viscous fan clutch (130), protecting internal components from dust, debris, and environmental factors. It is made of durable materials like aluminium or steel to ensure structural integrity and longevity.
k. Bearing (280): The bearing supports rotational motion within the clutch assembly, reducing friction and wear on moving parts. It ensures smooth operation by minimizing mechanical resistance, contributing to the overall efficiency and lifespan of the clutch.
l. Shaft (290): The shaft is the central component that transmits rotational force from the engine to the viscous fan clutch (130). It connects the clutch to the drive mechanism, enabling the transfer of power necessary for the fan's operation.
[00040] Collectively, these elements work in concert within the thermal static calibration apparatus (100) to maintain precise control over clutch engagement and disengagement processes. Through careful calibration and adjustment, they ensure optimal performance and reliability in automotive cooling systems, responding effectively to varying operating conditions and temperature fluctuations.
[00041] FIG. 3 illustrates a graphical representation of the thermal calibration of a fan clutch of FIG. 1, in accordance with an embodiment of the present. The graph (300) displays a line graph. X-axis (310) represents Temperature (in degrees Celsius) and Y-axis (320) represents Thermal calibration for fan clutch (130) engagement.
[00042] Two data points are plotted and connected by a line: (T_{1}) (Case 1): At this temperature, a certain deflection (D_{1}) is recorded. (T_{2}) (Case 2): At this temperature, a different deflection (D_{2}) is recorded.
[00043] The graph (300) likely represents how temperature influences valve openings in relation to fan clutch (130) engagements in vehicles. The deflection measurements ((D_{1}) and (D_{2})) at specific temperatures are crucial for understanding this behaviour. Further analysis would reveal the exact impact of temperature on the system’s performance.
[00044] The graph (300) suggests that as temperature increases, there’s a response related to fan clutch (130) engagement. A set point (330) is unregulated/evaporated test rig (110). This graph (300) likely pertains to thermal testing of vehicle components, specifically examining how temperature affects valve openings in relation to fan clutch (130) engagements.
[00045] FIG. 4 illustrates a flow chart representing the steps involved in a method for calibrating a viscous fan clutch using a thermal static calibration unit in accordance with an embodiment of the present disclosure. The method (400) includes assembling a viscous fan clutch comprising a cover, valve lever, dividing disc assembly, pin, and bimetal strip, for securing the viscous fan clutch onto a mechanical fixture of a test rig in step 410. More specifically, the method begins by gathering the necessary components: cover, valve lever, dividing disc assembly, pin, and bimetal strip. Further, securely assembling these components to form the viscous fan clutch. The cover encloses the internal mechanisms, while the valve lever and dividing disc assembly play crucial roles in the clutch’s operation. Further, attaching the assembled viscous fan clutch onto a mechanical fixture within the test rig.
[00046] In one embodiment, securing the viscous fan clutch onto a mechanical fixture may include securing the viscous fan clutch onto a mechanical fixture via adjustable clamps for securely holding the viscous fan clutch in place during the calibration process. In this step, the goal is to securely hold the viscous fan clutch in place during the calibration process. The method involves using adjustable clamps to fasten the viscous fan clutch onto a mechanical fixture within the test rig. These clamps allow precise positioning and ensure that the fan clutch remains stable throughout the calibration. By securing the clutch with adjustable clamps, any unwanted movement or vibration is minimized, leading to accurate measurements during the calibration.
[00047] The method (400) also includes heating the bimetal strip using an air heater positioned orthogonally to the viscous fan clutch to cause thermal expansion in step 420. More specifically, positioning an air heater orthogonally (perpendicular) to the viscous fan clutch. Applying heat to the bimetal strip using the air heater. As the bimetal strip heats up, it undergoes thermal expansion due to its unique properties. This expansion is essential for subsequent measurements.
[00048] In one embodiment, heating the bimetal strip comprises regulating the air heater for maintaining a constant heating rate for uniform expansion. During the calibration process, the bimetal strip undergoes thermal expansion due to heating. To achieve consistent and uniform expansion, the air heater is carefully regulated. The air heater maintains a constant heating rate, ensuring that the bimetal strip expands predictably. Uniform expansion is crucial because it directly affects the deflection of the valve lever and, consequently, the overall behaviour of the viscous fan clutch.
[00049] Further, the method (400) also includes positioning a linear variable differential transformer (LVDT) in contact with the valve lever for measure displacement of the valve lever as the bimetal strip expands in step 430. More specifically, method (400) includes placing a Linear Variable Differential Transformer (LVDT) in contact with the valve lever. The LVDT precisely measures the displacement of the valve lever as the bimetal strip expands. By monitoring this displacement, we can understand how the clutch responds to temperature changes.
[00050] The method (400) further includes recording temperature and corresponding deflection readings from the linear variable differential transformer using a data recording module for processing the recorded data for generating a temperature versus deflection graph in step 440. More specifically, the method (400) includes utilizing a data recording module to capture temperature and corresponding deflection readings. These readings are obtained during the thermal expansion process. The data will be processed later to create a temperature versus deflection graph.
[00051] Furthermore, the method (400) includes analysing the slope of the temperature versus deflection graph for determining the engagement temperature of the viscous fan clutch in step 450. More specifically, the method includes plotting the recorded data points on the graph. The slope of the temperature versus deflection graph provides insights. Specifically, it helps determine the engagement temperature of the viscous fan clutch.
[00052] The method (400) further includes calculating a final pin length of the viscous fan clutch based on the determined engagement temperature in step 460. More specifically, based on the determined engagement temperature, calculate the final pin length. The pin length directly affects the clutch’s performance. Precise calibration ensures optimal cooling system operation. In one embodiment, calculating the final pin length is performed using a computational technique, by processing the temperature versus deflection data for determining the optimal pin length for the viscous fan clutch. In such embodiment, after determining the engagement temperature of the viscous fan clutch, the next step is to calculate the final pin length. This calculation is performed using a computational technique. The technique involves processing the recorded data points from the graph, specifically the temperature and corresponding deflection readings. By analysing this data, the optimal pin length for the viscous fan clutch is determined. The final pin length directly influences the clutch’s performance, ensuring that it engages optimally under specific temperature conditions.
[00053] Various embodiments of the present invention offer several advantages. Firstly, through securing the clutch on a mechanical fixture with adjustable clamps, precise positioning and stability are achieved, minimizing undesired movement or vibration. This meticulous setup ensures accurate measurements and dependable performance. Also, maintaining a uniform heating rate via regulated air heaters facilitates consistent expansion of the bimetal strip, thereby ensuring reliable outcomes. This controlled process allows the clutch to respond predictably to temperature changes, bolstering its reliability. Further, employing a data recording module to capture temperature and deflection readings enables comprehensive data collection. Analysing the temperature versus deflection graph derived from this data yields crucial insights into clutch behaviour, aiding in determining the engagement temperature. This data-driven approach enables optimization of the clutch's performance, enhancing overall efficiency. Moreover, utilizing computational techniques for calculating the final pin length streamlines the process, ensuring accuracy and efficiency in comparison to manual methods. By tailoring the clutch's engagement temperature and pin length, specific operational requirements are met, optimizing cooling system effectiveness, particularly in challenging environments. In summary, this integrated approach combines precision, uniformity, data-driven analysis, computational efficiency, and tailored adjustments to significantly enhance the reliability and effectiveness of viscous fan clutches.
[00054] The techniques described in this disclosure may be implemented, at least in part, in hardware, software, firmware, or any combination thereof. For example, various aspects of the described techniques may be implemented within one or more processors, including one or more microprocessors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or any other equivalent integrated or discrete logic circuitry, as well as any combinations of such components. The term “processor” or “processing subsystem” may generally refer to any of the foregoing logic circuitry, alone or in combination with other logic circuitry, or any other equivalent circuitry. A control unit including hardware may also perform one or more of the techniques of this disclosure.
[00055] Such hardware, software, and firmware may be implemented within the same device or within separate devices to support the various techniques described in this disclosure. In addition, any of the described units, modules, or components may be implemented together or separately as discrete but interoperable logic devices.
[00056] Depiction of different features as modules or units is intended to highlight different functional aspects and does not necessarily imply that such modules or units must be realized by separate hardware, firmware, or software components. Rather, functionality associated with one or more modules or units may be performed by separate hardware, firmware, or software components, or integrated within common or separate hardware, firmware, or software components.
[00057] It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the disclosure and are not intended to be restrictive thereof.
[00058] While specific language has been used to describe the disclosure, any limitations arising on account of the same are not intended. As would be apparent to a person skilled in the art, various working modifications may be made to the method in order to implement the inventive concept as taught herein.
[00059] The figures and the foregoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment. For example, the order of processes described herein may be changed and are not limited to the manner described herein. Moreover, the actions of any flow diagram need not be implemented in the order shown; nor do all the acts need to be necessarily performed. Also, those acts that are not dependent on other acts may be performed in parallel with the other acts. The scope of embodiments is by no means limited by these specific examples.
, Claims:1. A thermal static calibration apparatus (100) for testing viscous fan clutches, comprising:
a test rig (110) comprising a mechanical fixture (120), wherein the mechanical fixture (120) is configured to hold a viscous fan clutch (130) which is half-assembled, wherein the viscous fan clutch (130) comprises a cover (140), valve lever (150), dividing disc assembly (160), pin (170), and bimetal strip (180);
an air heater (190) positioned orthogonally to the viscous fan clutch (130), wherein the air heater (190) is configured to provide heat directly to the bimetal strip (180) to cause thermal expansion;
a linear variable differential transformer (LVDT) (200) positioned in contact with the valve lever (150) of the viscous fan clutch, wherein the linear variable differential transformer (200) is configured to measure displacement of the valve lever (150) as the bimetal strip (180) expands;
a data recording module (210) electrically connected to the linear variable differential transformer (200), and configured to record temperature and corresponding deflection readings from the linear variable differential transformer (200); and
a control unit (220) connected to the air heater (190) and the data recording module (210), wherein the control unit (220) is configured to:
receive and process signals from the linear variable differential transformer (200) to monitor the displacement of the valve lever (150);
generate a temperature versus deflection graph based on the recorded data to analyse a slope of the temperature versus deflection graph to determine the engagement temperature of the viscous fan clutch (130); and
calculate a final pin length of the viscous fan clutch (130) based on the determined engagement temperature.
2. The thermal static calibration apparatus (100) as claimed in claim 1, wherein the mechanical fixture (120) comprises adjustable clamps to securely hold the half-assembled viscous fan clutch (130) in place during the calibration process.
3. The thermal static calibration apparatus (100) as claimed in claim 1, wherein the air heater (190) is an electrical blower configured to provide uniform heat distribution to the bimetal strip (180).
4. The thermal static calibration apparatus (100) as claimed in claim 1, wherein the linear variable differential transformer (200) is mounted on an adjustable arm to ensure precise contact with the valve lever (150) of the viscous fan clutch (130).
5. The thermal static calibration apparatus (100) as claimed in claim 1, wherein the data recording module (210) comprises a digital storage unit configured to store temperature and deflection readings.
6. The thermal static calibration apparatus (100) as claimed in claim 1, wherein the control unit (220) comprises a display interface configured to provide real-time visualization of temperature and deflection data.
7. A method (400) for calibrating a viscous fan clutch using a thermal static calibration unit, wherein the method comprising:
assembling a viscous fan clutch comprising a cover, valve lever, dividing disc assembly, pin, and bimetal strip, for securing the viscous fan clutch onto a mechanical fixture of a test rig; (410)
heating the bimetal strip using an air heater positioned orthogonally to the viscous fan clutch to cause thermal expansion; (420)
positioning a linear variable differential transformer (LVDT) in contact with the valve lever for measure displacement of the valve lever as the bimetal strip expands; (430)
recording temperature and corresponding deflection readings from the linear variable differential transformer using a data recording module for processing the recorded data for generating a temperature versus deflection graph; (440)
analysing the slope of the temperature versus deflection graph for determining the engagement temperature of the viscous fan clutch; and (450)
calculating a final pin length of the viscous fan clutch based on the determined engagement temperature. (460)
8. The method (400) as claimed in claim 7, wherein securing the viscous fan clutch onto a mechanical fixture comprises the securing the viscous fan clutch onto a mechanical fixture via adjustable clamps for securely holding the viscous fan clutch in place during the calibration process.
9. The method (400) as claimed in claim 7, wherein heating the bimetal strip comprises regulating the air heater for maintaining a constant heating rate for uniform expansion.
10. The method (400) as claimed in claim 7, wherein calculating the final pin length is performed using a computational technique, by processing the temperature versus deflection data for determining the optimal pin length for the viscous fan clutch.

Dated this 17th day of July 2024

Signature

Jinsu Abraham
Patent Agent (IN/PA-3267)
Agent for the Applicant