Hub bearing long downhill test device and method

Abstract

The invention provides a long downhill test device for a hub bearing. The long downhill test device comprises a main shaft rotating mechanism, a transient heating module, a synchronous controller, a steering knuckle, a circulating cooling system, an induction heating unit and a hood. Through the combination of constant rotating speed and transient high-temperature loading, the extreme working condition of frequent braking of an automobile in the long downhill running process can be fully simulated, and a more reliable bearing product is provided for automobile manufacturers. The invention further provides a hub bearing long downhill test method, by applying the hub bearing long downhill test device, the long downhill frequent braking working condition of an automobile can be fully simulated, the reliability and durability of the hub bearing under the high-temperature and high-speed conditions can be evaluated, and a basis is provided for optimizing bearing design.

Description

Technical Field

[0001] This invention relates to the field of wheel hub bearing testing technology, specifically to a wheel hub bearing long downhill test device and method. Background Technology

[0002] In the automotive industry, wheel bearings are critical components, and their reliability and durability directly affect the safety and performance of the entire vehicle. Especially under long downhill driving conditions, frequent braking operations cause a sharp rise in brake disc temperature, while the wheel bearings endure significant thermomechanical stress under the combined load of high temperature and high-speed rotation. This extreme condition places higher demands on the design and manufacturing of wheel bearings, thus requiring a testing device and method that can accurately simulate long downhill driving conditions to verify the reliability and durability of bearings in actual use.

[0003] Existing wheel bearing testing technologies primarily focus on testing single mechanical loads or static thermal loads, making it difficult to comprehensively simulate the complex thermo-mechanical combined load environment under long downhill conditions. For example, some testing devices can only perform mechanical load testing at constant speeds, but cannot simultaneously apply transient high-temperature loads; while other devices can heat the brake discs, the heating rate and temperature control precision are insufficient, failing to accurately reflect the rapid temperature rise characteristics under actual operating conditions. Furthermore, existing technologies lack the ability to precisely control test conditions; for example, the matching of key parameters such as heating rate, target temperature range, and rotation speed is poor, leading to significant deviations between test results and actual operating conditions.

[0004] A more prominent problem is that current testing methods often neglect the impact of combined thermo-mechanical loads on wheel hub bearing performance. During long downhill runs, the brake disc temperature can rapidly rise from room temperature to over 500°C in a short period, while the wheel hub bearing continues to operate at high speeds. This complex thermo-mechanical coupling poses severe challenges to the bearing's material properties, sealing performance, and lubrication performance. However, existing technologies fail to fully consider this characteristic, resulting in test results that cannot comprehensively assess the bearing's failure modes and safety performance under extreme conditions. Summary of the Invention

[0005] This invention develops a test device and method for wheel hub bearings that can accurately simulate long downhill conditions. By simultaneously applying high-speed rotation and transient high-temperature loads, the reliability and durability of wheel hub bearings under complex thermo-mechanical combined loads are comprehensively evaluated.

[0006] The technical solution of this invention is implemented as follows: A wheel hub bearing long downhill test device includes a main shaft rotation mechanism, the output end of which is provided with a connecting plate, and a brake disc and a wheel hub bearing are sequentially fixed on the connecting plate by bolts; wherein, the main shaft rotation mechanism is configured to drive the brake disc and the wheel hub bearing to rotate at a constant speed. It also includes a transient heating module located outside the brake disc, configured to heat the brake disc to 500℃-600℃ at a temperature rise rate of ≥150℃ / min; It also includes a synchronization controller, which is configured to synchronously activate the transient heating module when the spindle rotation mechanism is running, so that the hub bearings bear thermal loads while rotating.

[0007] Furthermore, it also includes a steering knuckle located outside the wheel hub bearing, with one end of the steering knuckle fixed to the platform via a connector.

[0008] Furthermore, it also includes a circulating cooling system configured to provide forced cooling for the spindle rotation mechanism and the transient heating module.

[0009] Furthermore, the main shaft rotation mechanism has a cooling chamber, and the transient heating module is a pipe-type induction coil; the cooling system includes a water tank, a circulating water pump, and a cooler. The cooling fluid in the water tank is pumped by the circulating water pump to the cooling chamber and the pipe of the pipe-type induction coil to remove heat, and then cooled by the cooler before flowing back to the water tank.

[0010] Furthermore, it also includes an induction heating unit configured to heat the transient heating module.

[0011] Furthermore, the induction heating unit includes a power controller and an induction transformer electrically connected to the power controller. The induction transformer is electrically connected to the transient heating module, and the power controller controls the heating of the transient heating module.

[0012] A method for testing wheel hub bearings on a long downhill slope, using the aforementioned testing device for wheel hub bearings on a long downhill slope, includes the following steps: S1. The hub bearing is driven to rotate continuously at a constant speed by the main shaft rotation mechanism, the speed simulating the speed of a car driving downhill; S2. Apply a transient high-temperature load to the brake disc through the transient heating module, so that the brake disc heats up to the target temperature range of 500℃-600℃ at a temperature rise rate of ≥150℃ / min, and maintains this temperature for ≥20 minutes. S3, wherein the induction heating is performed synchronously with the bearing rotation to form a thermo-mechanical composite load on the hub bearing.

[0013] Furthermore, the constant rotation speed is 400-500 rpm, and the target temperature range is 530-570℃.

[0014] Furthermore, the temperature rise rate is 180-220℃ / min, and the temperature holding time is 20-25 minutes.

[0015] The beneficial effects of the technical solution provided in this application are as follows: This invention, by combining constant rotational speed with transient high-temperature loading, can fully simulate the extreme operating conditions of frequent braking during a car's long downhill driving, providing automakers with more reliable bearing products. In particular, the design of the circulating cooling system and radiator ensures equipment safety and data accuracy during testing. Furthermore, through thermo-mechanical composite load testing of wheel hub bearings, their performance under high-temperature, high-speed rotation conditions can be comprehensively evaluated, thereby optimizing product design. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the wheel hub bearing long downhill test device of the present invention; Figure 2 This is a partially enlarged schematic diagram of the wheel hub bearing long downhill test device of the present invention; Figure 3 This is a partial explosion diagram of the wheel hub bearing long downhill test device of the present invention; Figure 4 This is a partial cross-sectional schematic diagram of the wheel hub bearing long downhill test device of the present invention; Figure 5 This is a test cycle diagram for the present invention.

[0018] In the diagram: 10, main shaft of the testing machine; 20, connecting disc; 30, brake disc; 40, wheel hub bearing; 50, steering knuckle; 51, connecting piece; 60, transient heating module; 71, brake disc temperature sensor; 72, bearing temperature sensor; 80, machine cover; 81, radiator one; 82, radiator two. Detailed Implementation

[0019] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] This invention provides a wheel hub bearing long downhill test device and method for simulating frequent braking conditions during long downhill driving of a car. Its core lies in the coordinated operation of the main shaft rotation mechanism, transient heating module, synchronous controller, and other auxiliary components to achieve comprehensive testing of the wheel hub bearing under combined thermo-mechanical load conditions. The following is in conjunction with the appendix... Figure 1 To be continued Figure 4 The specific designations of each component are also detailed, along with the detailed embodiments of the present invention.

[0021] like Figure 1 As shown, the main structure of the test device includes a spindle rotation mechanism 10, a connecting plate 20, a brake disc 30, a wheel hub bearing 40, a steering knuckle 50, a transient heating module 60, a circulating cooling system, an induction heating unit, and a hood 80 and radiators 81 and 82. These components together constitute a complete test system to simulate the extreme working conditions experienced by the wheel hub bearings when a car is driving down a long slope. The spindle rotation mechanism 10, as the core driving component of the entire device, has a connecting plate 20 fixed to its output end. The brake disc 30 and wheel hub bearing 40 are sequentially fixed to the connecting plate 20 by bolts. The spindle rotation mechanism 10 is configured to drive the brake disc 30 and wheel hub bearing 40 to rotate at a constant speed, which is set between 400 rpm and 500 rpm to simulate the actual vehicle speed when driving down a long slope. The spindle rotation mechanism 10 has a cooling chamber inside, which is forcibly cooled by a circulating cooling system to ensure stable operation of the spindle rotation mechanism 10 in high-temperature environments.

[0022] A transient heating module 60 is located outside the brake disc 30, and its function is to apply a transient high-temperature load to the brake disc 30. The transient heating module 60 preferably employs a pipe-type induction coil design, with a 3mm gap between it and the brake disc 30. This gap value is precisely calibrated to ensure heating efficiency while preventing equipment damage due to an excessively small gap. The transient heating module 60 is configured to heat the brake disc 30 to the target temperature range of 500℃ to 600℃ at a temperature rise rate of ≥150℃ / min, and maintain this temperature for ≥20 minutes. To ensure heating uniformity, the pipe-type induction coil of the transient heating module 60 must be precisely aligned with the surface area of ​​the brake disc 30, ensuring that the brake disc 30 is completely within the effective heating range of the induction coil. Furthermore, before the test begins, the entire surface of the brake disc 30 must be uniformly coated with matte black paint and dried. This step helps improve the high-temperature resistance of the brake disc 30 and prevents damage caused by high temperatures during the test.

[0023] The synchronization controller is a key component for realizing the thermo-mechanical composite load. Its function is to activate the transient heating module 60 simultaneously with the operation of the spindle rotation mechanism 10, thereby forming a thermo-mechanical composite load on the hub bearing 40. The synchronization controller dynamically adjusts the operating parameters of both by real-time monitoring of the rotational speed signal of the spindle rotation mechanism 10 and the temperature signal of the transient heating module 60, ensuring the stability of the thermo-mechanical composite load during the test. For example, when the temperature of the transient heating module 60 deviates from the target temperature range, the synchronization controller automatically adjusts the output power of the induction heating unit to quickly restore the temperature to the target range. Similarly, if the rotational speed of the spindle rotation mechanism 10 fluctuates, the synchronization controller will also stabilize the speed by adjusting the input power of the drive motor.

[0024] The steering knuckle 50 is located outside the wheel hub bearing 40 and is fixed to the platform via a connector 51 to simulate the installation and stress conditions of the wheel hub bearing 40 in an actual vehicle. The connector 51 employs a combination of high-strength bolts and locating pins to enhance the connection rigidity between the steering knuckle 50 and the platform, preventing loosening due to vibration during the test. The design of the steering knuckle 50 fully considers the stress characteristics of the wheel hub bearing 40 in an actual vehicle, accurately simulating the stress state of the wheel hub bearing 40 during long downhill driving, thereby improving the reliability of the test results.

[0025] The circulating cooling system is a crucial component ensuring the stable operation of the testing apparatus in high-temperature environments. Its specific structure includes a water tank, a circulating water pump, a cooler, a flow sensor, and a temperature sensor. Cooling fluid is pumped from the water tank to the cooling chamber of the spindle rotation mechanism 10 and the pipe-type induction coil of the transient heating module 60, where it carries away heat. After being cooled by the cooler, it flows back to the water tank. The flow sensor and temperature sensor monitor the flow rate and temperature of the cooling fluid in real time. When abnormal values ​​are detected, the system automatically adjusts the cooler's operating parameters to restore cooling effectiveness. Through this closed-loop control design, the circulating cooling system effectively prevents the impact of high temperatures on equipment performance, ensuring the safety of the testing process and the accuracy of the data.

[0026] The induction heating unit includes a power controller, an induction transformer, and a temperature controller. The induction transformer is electrically connected to the transient heating module 60, and its heating is controlled by the power controller. The power controller adjusts its output power to precisely control the heating rate of the transient heating module 60, thereby meeting the heating requirements under different test conditions. The temperature controller monitors the temperature changes of the transient heating module 60 in real time and dynamically adjusts the output power of the power controller according to the set target temperature range. The design of the induction heating unit enables the transient heating module 60 to reach the target temperature range in a short time while maintaining temperature stability, providing reliable heating for the experiment.

[0027] A housing 80 covers the brake disc 30, wheel hub bearing 40, and steering knuckle 50, with the output shaft of the main shaft rotation mechanism 10 passing through and extending into the housing 80. A radiator 81 is located on the top of the housing 80, directing airflow inwards, while a radiator 82 is located on the other side, directing airflow towards the main shaft rotation mechanism 10, to enhance heat dissipation. Both radiators 81 and 82 employ axial flow fan designs, with their airflow and pressure parameters optimized through calculation to ensure uniform temperature distribution within the test apparatus. The design of the housing 80 not only protects the test apparatus from external interference but also further enhances the stability of the test environment through the coordinated operation of radiators 81 and 82.

[0028] A method for testing wheel hub bearings on a long downhill slope, using the aforementioned testing device for wheel hub bearings on a long downhill slope, includes the following steps: S1. The hub bearing 40 is driven to rotate continuously at a constant speed by the main shaft rotation mechanism 10, the speed simulating the speed of a car driving downhill. S2. A transient high-temperature load is applied to the brake disc 30 through the transient heating module 60, so that the brake disc 30 is heated to the target temperature range of 550°C at a temperature rise rate of 200°C / min, and the temperature is maintained for 23 minutes. Then it is cooled and continues to operate for 330 minutes to simulate the working conditions of frequent braking when the whole vehicle is going down a long slope. S3, wherein the induction heating is performed synchronously with the bearing rotation to form a thermo-mechanical composite load on the hub bearing 40; S4. Conduct experiments based on experimental cycle spectra.

[0029] Example 1

[0030] In some embodiments, the test load spectrum defined in step S2 is as follows, which simulates the frequent braking of a car during a long downhill test:

[0031] In some embodiments, step S4, "conducting an experiment based on the test load spectrum," means: a. The transient heating module 60 should have a 3mm gap with the brake disc 30. The brake pads of the brake disc 30 should be located in the middle of the pipe-type induction coil of the transient heating module 60 to achieve uniform heating. If the gap between the pipe-type induction coil and the brake disc 30 is too large, it will affect the heating rate. If the gap is too small, it will cause damage to the coil. b. Install non-contact bearing temperature sensor 72 and non-contact brake disc temperature sensor 71 corresponding to the wheel hub bearing 40 and brake disc 30, respectively. Their temperature measurement range is 0-1500℃, and they are used to monitor the temperature changes of the wheel hub bearing 40 and brake disc 30 during the test. c. The entire surface of the brake disc 30 is uniformly sprayed with matte black paint and allowed to dry before testing. This is to increase the high temperature resistance of the brake disc 30 and prevent damage to the brake disc 30 during the test. d. Input the test cycle spectrum into the equipment program; e. Start the test, and the equipment will automatically record the time-speed-temperature change curve.

[0032] f. After the test, disassemble the wheel hub bearing 40 and observe whether there are any high-temperature failures in the inner and outer rings, cage, seals, and other parts of the wheel hub bearing 40. This is to evaluate the reliability and durability of the bearing under frequent braking conditions. The implementation of this technical solution can fully simulate the frequent braking conditions of a vehicle during long downhill slopes, providing automakers with more reliable bearing products and thus improving the competitiveness of the entire automotive industry chain.

[0033] Comparative Example 1

[0034] The procedure is followed according to the steps in Example 1, wherein the test load spectrum defined in step S2 is as follows:

[0035] Comparative Example 2

[0036] The procedure is followed according to the steps in Example 1, wherein the test load spectrum defined in step S2 is as follows:

[0037] Comparative Example 3

[0038] The procedure is followed according to the steps in Example 1, wherein the test load spectrum defined in step S2 is as follows:

[0039] In summary, the shortcomings of Comparative Example 1 are that the brake disc is heated too much, causing the brake disc 30 and wheel hub bearing 40 to fail rapidly. Even under extreme conditions during normal testing, the temperature is far from reaching this level, thus failing to achieve the purpose of verification. The shortcomings of Comparative Example 2 are that the rotation speed is too low, which cannot simulate the extreme speed conditions during long downhill tests. The shortcomings of Comparative Example 3 are that the heating temperature of the brake disc 30 is too low, which cannot simulate the bearing safety performance under extreme temperature rise.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A test device for long downhill testing of wheel hub bearings, characterized in that, It includes a main shaft rotation mechanism (10), the output end of which is provided with a connecting plate (20), and a brake disc (30) and a wheel hub bearing (40) are fixed on the connecting plate (20) in sequence by bolts; wherein, the main shaft rotation mechanism (10) is configured to rotate the brake disc (30) and the drive wheel hub (40) bearing at a constant speed; It also includes a transient heating module (60) located outside the brake disc (30), which is configured to heat the brake disc (30) to 500°C-600°C at a temperature rise rate of ≥150°C / min; It also includes a synchronization controller, which is configured to synchronously activate the transient heating module when the spindle rotation mechanism (10) is running, so that the hub bearing (40) bears the thermal load in the rotating state.

2. The wheel hub bearing long downhill test device according to claim 1, characterized in that, It also includes a steering knuckle (50) located outside the hub bearing (40), one end of which is fixed to the platform by a connector (51).

3. The wheel hub bearing long downhill test device according to claim 1, characterized in that, It also includes a circulating cooling system configured to provide forced cooling for the spindle rotation mechanism (10) and the transient heating module (60).

4. The wheel hub bearing long downhill test device according to claim 3, characterized in that, The main shaft rotation mechanism (10) has a cooling chamber, and the transient heating module (60) is a pipe-type induction coil. The cooling system includes a water tank, a circulating water pump and a cooler. The cooling fluid in the water tank is pumped by the circulating water pump to the cooling chamber and the pipe of the pipe-type induction coil to remove heat. After being cooled by the cooler, it flows back to the water tank.

5. The wheel hub bearing long downhill test device according to claim 1, characterized in that, It also includes an induction heating unit configured to heat the transient heating module (60).

6. The wheel hub bearing long downhill test device according to claim 5, characterized in that, The induction heating unit includes a power controller and an induction transformer electrically connected to the power controller. The induction transformer is electrically connected to the transient heating module (60), and the power controller controls the heating of the transient heating module (60).

7. A method for testing wheel hub bearings on a long downhill slope, using the wheel hub bearing long downhill slope testing apparatus according to any one of claims 1-6, characterized in that, Includes the following steps: S1. The hub bearing (40) is driven to rotate continuously at a constant speed by the main shaft rotation mechanism (10), which simulates the speed of a car driving downhill. S2. Apply a transient high-temperature load to the brake disc (30) through the transient heating module (60) so that the brake disc (30) is heated to the target temperature range of 500℃-600℃ at a temperature rise rate of ≥150℃ / min, and maintain this temperature for ≥20 minutes. S3, wherein the induction heating is performed synchronously with the bearing rotation to form a thermo-mechanical composite load on the hub bearing (40).

8. The method for testing wheel hub bearings on a long downhill slope according to claim 7, characterized in that, The constant rotation speed is 400-500 rpm, and the target temperature range is 530-570℃.

9. The method for testing wheel hub bearings on a long downhill slope according to claim 7, characterized in that, The temperature rise rate is 180-220℃ / min, and the temperature holding time is 20-25 minutes.

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