Ball bearing outer ring heat exchange experiment and runner heat exchange characteristic evaluation method

Abstract

The invention relates to the technical field of bearing cooling and measurement, in particular to a ball bearing outer ring heat exchange experiment method. The method comprises the following steps: establishing a heat exchange tester aiming at a ball bearing outer ring, carrying out a test on runner heat exchange of a bearing outer ferrule, obtaining runner heat exchange characteristics through runner heat exchange characteristic evaluation and experimental data processing, obtaining a variation trend chart of the temperature of the outer surface of the tested bearing outer ferrule along with the flowing direction under different heating amounts, analyzing the heating amount to the heat exchange characteristics, and calculating the temperature of the bearing outer ferrule. According to the invention, the power-adjustable heating of the bearing outer ferrule is realized independently, the steady-state temperature distribution of the outer wall surface measuring points of the bearing outer ferrule of an experimental piece and the pressure loss in the flow channel under different heating and oil supply conditions can be quantitatively obtained, the cooling effect and multi-working-condition heat exchange characteristics of the flow channel in the bearing outer ferrule are evaluated, and the working efficiency of the bearing outer ferrule is improved. And a technical support is provided for a ferrule internal flow cooling technology.

Description

Technical Field

[0001] The invention belongs to the technical field of bearing cooling and measurement, and in particular relates to a ball bearing outer ring heat exchange experimental method. Background Art

[0002] Bearings are one of the important parts in mechanical transmission systems. They support and position rotating parts, reduce the friction coefficient during the operation of the mechanical system, and ensure the rotation accuracy. When high-speed ball bearings are running, a large amount of heat will be generated due to the friction between the components. In order to ensure that the structure does not overheat, lubricating oil needs to be supplied to cool it. As the speed of the bearings increases further, especially for the special needs of the aerospace field, traditional cooling methods are gradually unable to meet the requirements. Therefore, internal flow cooling technology for the outer ring of the bearing is developed. By designing flow channels inside the ring, the traditional "external flow cooling" is transformed into "internal flow forced cooling", thereby achieving the goal of improving cooling efficiency, reducing the bearing temperature field and reducing the demand for lubricating oil.

[0003] The outer ring internal flow cooling technology is still in the stage of extensive basic research, and the technical maturity is relatively low. There is currently no mature test method to measure the heat transfer effect of the cooling structure inside the outer ring, and there is an even greater lack of evaluation of the heat transfer effect. Summary of the invention

[0004] The purpose of the present invention is to avoid the shortcomings of the prior art and provide a ball bearing outer ring heat exchange test method to solve the technical problem that the cooling effect of the unconventional cooling device of the bearing ring cannot be measured.

[0005] To achieve the above object, the technical solution adopted by the present invention is: a ball bearing outer ring heat exchange test method, which is characterized by comprising the following steps:

[0006] Step 1: Connect the experimenter:

[0007] The experimental device comprises three parts: an oil supply system, a heating and temperature measuring system and an oil return system. The oil supply system comprises an oil tank, an oil supply pump, a flow sensor, a temperature sensor and a pressure sensor. The heating and temperature measuring system comprises an outer ring of a bearing with an internal flow channel to be measured, an inner channel heater, a temperature sensor for measuring the temperature of the outer surface of the ring and a stand for fixing the above components. The oil return system comprises an oil return tank and an oil return pump. The three systems of the oil supply system, the heating and temperature measuring system and the oil return system are connected by an oil delivery hose.

[0008] Step 2: Turn on the power and open the software: Turn on the power of the experimenter, open the experimental software through the software control terminal, and go to the next step when the readings of each sensor are normal;

[0009] Step 3: Preheat the lubricating oil in the oil supply system: Turn on the heater in the oil tank, set the oil supply temperature T, and stop heating after the temperature in the oil tank stabilizes at T;

[0010] Step 4: Turn on the oil supply pump and the oil return pump: adjust the output oil supply flow rate Q of the oil supply pump; when the liquid level in the oil return tank of the oil return system reaches one-fourth of the total volume of the oil tank, turn on the oil return pump and adjust the power of the oil return pump until the liquid level in the oil return tank is stabilized at one-fourth of the total volume of the oil tank;

[0011] Step 5: Turn on the heating wire heating: After the oil flow rate and temperature stabilize to the set value, set the heating power to 25%W watts and turn on the heating;

[0012] Step 6. Record data: Click the record data button in the software control software to start recording test data;

[0013] Step 7: Observe the temperature of the outer ring of the bearing under test until the average change of each measuring point is less than 0.1 degrees Celsius. It is determined that the heat exchange is stable under this condition. Increase the heating power W to 50%W watts and continue the test.

[0014] Step 8. According to the heat exchange stability certification standard of step 7, complete the heat exchange test at the oil supply flow rate, temperature, and heating power W of 25%W, 50%W, 75%W, and 100%W respectively;

[0015] Step 9. End data recording and stop heating: Click the record data button in the software control end to end data recording; set the heating power to 0, stop heating, continue to supply oil until the temperature of the outer wall of the outer ring of the bearing under test drops below 100 degrees Celsius, stop supplying oil, wait until there is no oil accumulation in the return oil tank, stop returning oil, turn off the power, and the test is over.

[0016] Furthermore, the lubricating oil in the oil supply system is aviation lubricating oil.

[0017] Furthermore, the oil supply temperature T is the temperature of the lubricating oil supplied by the lubrication system of the bearing under actual working conditions; and the oil supply flow rate Q is one quarter of the total lubricating oil supplied by the lubrication system of the bearing under actual working conditions.

[0018] Furthermore, the oil supply flow rate Q of the oil supply system is in the range of 0-3 L / min, and the oil supply temperature T is in the range of 40-70°C.

[0019] Furthermore, the heating power W is 25% of the total heat generated by the bearing under actual working conditions; The calculation is based on the Palmgren model, and the formula is as follows:

[0020] ,

[0021] ,

[0022] ,

[0023] ,

[0024] In the formula, is the total friction torque of the rolling bearing (N×m); is the friction torque related to the load on the bearing (N×m); is the torque related to the bearing type, speed and lubricant properties (N×m); is the bearing pitch diameter (m); is the bearing speed (r / min); is the kinematic viscosity of the lubricating oil (m 2 / s); is a coefficient related to bearing type and lubrication method, is a factor related to the bearing type and the load it is subjected to. To determine the calculated load for bearing friction torque;

[0025] Furthermore, the temperature sensor measuring point in the heating and temperature measuring system is located on the outer wall of the outer ring of the bearing to be measured, M temperature measuring zones are evenly distributed circumferentially, and N temperature measuring sensors are evenly distributed axially in each temperature measuring zone, where M and N are positive integers; there are a total of M×N measuring points; the temperature measuring sensor uses a PT100 temperature sensor.

[0026] Furthermore, the oil return tank is an open tank connected to the atmosphere, so that the lubricating oil outlet of the internal flow channel of the outer ring of the tested bearing is at normal atmospheric pressure, and the operating power of the oil supply pump and the oil return pump is different.

[0027] The method for evaluating the heat transfer characteristics of the flow channel during a heat transfer experiment of the outer ring of a ball bearing specifically includes: the temperature field of the outer ring is affected by three factors, namely, the oil supply flow rate, the oil supply temperature and the heating amount. The control variable method is used to study the influence of the three factors on the temperature field respectively, and a temperature change curve is drawn to obtain the heat transfer characteristics of the flow channel.

[0028] The experimental data processing method in the process of heat exchange experiment of the outer ring of a ball bearing specifically includes: the internal flow channel of the outer ring of the tested bearing is symmetrically distributed relative to the oil inlet and the oil outlet, two symmetrical temperature measurement zones are taken, and the heat exchange stable measurement point temperatures corresponding to a total of 8 working conditions are obtained, bad points that are 20% higher or lower than the average value are eliminated, and the average value is taken again as a point temperature on the outer surface of the outer ring; according to the above processing method, at least 4 points of temperature are taken out, and a plot is drawn along the half-circle lubricating oil flow direction angle (22.5°, 67.5°, 112.5°, 157.5°), and a trend diagram of the change of the outer surface temperature of the outer ring of the tested bearing with the flow direction under different heating amounts is obtained, and the effect of heating amount on heat exchange characteristics is analyzed.

[0029] Compared with the prior art, the present invention has the following technical effects: the described ball bearing ring heat exchange experimental method realizes power-adjustable heating of the outer bearing ring alone, and can quantitatively obtain the steady-state temperature distribution of n measuring points on the outer wall of the outer bearing ring of the test piece under different heating and oil supply conditions (oil supply temperature and oil supply amount), as well as the internal pressure loss of the flow channel, to evaluate the cooling effect of the internal flow channel of the outer bearing ring and the multi-operating condition heat exchange characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a flow chart of the present invention;

[0031] Figure 2 It is a schematic diagram of the heat exchange experiment principle of the present invention;

[0032] Figure 3 It is a schematic diagram of the structure of the heating and temperature measuring system of the present invention;

[0033] Figure 4 This is a graph showing the change trend of the outer surface temperature of the ferrule with different heating amounts as the flow direction changes when the oil supply flow rate is 3L / min and the oil supply temperature is 40°C;

[0034] In the figure: 1. Oil outlet; 2. Outer ring of the bearing with inner flow channel under test; 3. Inner flow channel heater; 4. Temperature sensor. DETAILED DESCRIPTION

[0035] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0036] In order to achieve the above object, the present invention provides the following specific implementation methods: the heat transfer experimental method of the outer ring of a ball bearing, such as Figure 1 As shown, it is characterized in that it includes the following steps:

[0037] Step 1: Connect the experimenter: Figure 2 As shown, the experimental device includes three parts: oil supply system, heating and temperature measurement system and oil return system. The oil supply system includes oil tank, oil supply pump, flow sensor, temperature sensor and pressure sensor. The heating and temperature measurement system includes, Figure 3 As shown, the oil outlet 1, oil inlet 5, outer ring of the bearing with internal flow channel 2, inner channel heater 3, temperature sensor 4 for measuring temperature on the outer surface of the ring and the stand for fixing the above components are located on the back of the ring. The oil return system includes an oil return tank and an oil return pump. The three parts of the system are connected by an oil delivery hose;

[0038] Step 2: Turn on the power and open the software: Turn on the power of the experimenter, open the experimental software, and if the readings of each sensor are normal, proceed to step 3;

[0039] Step 3: Preheat the lubricating oil in the oil supply system: Turn on the heater in the oil tank, set the oil supply temperature T, and stop heating after the temperature in the oil tank stabilizes at T;

[0040] Step 4: Turn on the oil supply pump and the oil return pump: adjust the output oil supply flow rate Q of the oil supply pump; when the liquid level in the oil return tank of the oil return system reaches one-fourth of the total volume of the oil tank, turn on the oil return pump and adjust the power of the oil return pump until the liquid level in the oil return tank is stabilized at one-fourth of the total volume of the oil tank;

[0041] Step 5: Turn on the heating wire heating: After the oil flow rate and temperature are stable to the required values, set the heating power to 25%W and turn on the heating;

[0042] Step 6. Record data: Click the record data button in the software to start recording test data;

[0043] Step 7: Observe the temperature of the outer ring of the bearing under test until the average change of each measuring point is less than 0.1 degrees Celsius. It is determined that the heat exchange is stable under this condition. Increase the heating power to 50%W and continue the test.

[0044] Step 8. According to the heat exchange stability certification standard of step 7, complete the heat exchange test at the oil supply flow rate, temperature, and heating power of 25%W, 50%W, 75%W, and 100%W respectively.

[0045] Step 9. End data recording and stop heating: Click the data recording button in the software to end data recording; set the heating power to 0 and stop heating. Continue to supply oil until the temperature of the outer wall of the outer ring of the tested bearing is lower than 100 degrees Celsius, stop supplying oil, and stop returning oil when there is no oil accumulation in the oil return tank, turn off the power, and the test is over.

[0046] In this embodiment, the lubricating oil used is aviation lubricating oil.

[0047] In this embodiment, the oil supply temperature T is the temperature of the lubricating oil supplied by the lubrication system of the bearing under actual working conditions.

[0048] In this embodiment, the oil supply flow rate Q is one quarter of the total lubricating oil amount supplied by the lubrication system of the bearing under actual working conditions.

[0049] In this embodiment, the heating power W is 25% of the total heat generated by the bearing under actual working conditions. The calculation is based on the Palmgren model, and the formula is as follows:

[0050] ,

[0051] ,

[0052] ,

[0053] ,

[0054] In the formula, is the total friction torque of the rolling bearing (N×m); is the friction torque related to the load on the bearing (N×m); is the torque related to the bearing type, speed and lubricant properties (N×m); is the bearing pitch diameter (m); is the bearing speed (r / min); is the kinematic viscosity of the lubricating oil (m 2 / s); is a coefficient related to bearing type and lubrication method, is a factor related to the bearing type and the load it is subjected to. Calculated load for determining bearing friction torque.

[0055] In this embodiment, the temperature sensor temperature measurement point in the heating temperature measurement system is located on the outer wall of the outer ring of the measured bearing, M temperature measurement zones are evenly distributed circumferentially, and N temperature measurement sensors are evenly distributed axially in each temperature measurement zone, where M and N are positive integers; there are M×N measurement points in total. The temperature measurement sensor uses a PT100 temperature sensor.

[0056] In this embodiment, the oil return tank is an open oil tank connected to the atmosphere, so that the lubricating oil outlet of the internal flow channel of the outer ring of the tested bearing is at normal atmospheric pressure, so the operating power of the oil supply pump and the oil return pump are different.

[0057] As a specific solution of this embodiment, the lubricating oil used is Pegasus II aviation lubricating oil.

[0058] As a specific solution of this embodiment, eight temperature measurement zones are evenly distributed circumferentially on the outer wall surface of the outer ring of the measured bearing, and four temperature measurement sensors are evenly distributed axially in each temperature measurement zone, for a total of 32 measurement points.

[0059] As a specific solution of this embodiment, the oil supply system has an oil supply flow rate range of 0-3L / min and an oil supply temperature range of 40-70°C.

[0060] As a specific scheme of this embodiment, the method for evaluating the heat transfer characteristics of the flow channel is as follows: the temperature field of the outer ring is affected by three factors, namely, the oil supply flow rate, the oil supply temperature and the heating amount. The control variable method is used to study the influence of the three factors on the temperature field respectively, and the temperature change curve is drawn to obtain the heat transfer characteristics of the flow channel.

[0061] As a specific scheme of this embodiment, the experimental data processing process is as follows: in this embodiment, the internal flow channel of the ring is symmetrically distributed relative to the oil inlet and the oil outlet, and two symmetrical temperature measurement zones are taken, with a total of 8 working conditions corresponding to the heat exchange stable measurement point temperatures, and bad points that are 20% higher or lower than the average value are eliminated, and the average value is taken again as a point temperature on the outer surface of the outer ring; in the 8 symmetrical temperature measurement zones in this embodiment, according to the above processing method, 4 point temperatures are taken out and plotted along the half-circle lubricating oil flow direction angle (22.5°, 67.5°, 112.5°, 157.5°).

[0062] As a specific solution of this embodiment, Figure 4 As shown in the figure, the temperature of the outer surface of the ferrule changes with the flow direction under different heating amounts when the oil flow rate is 3L / min and the oil temperature is 40℃, and the influence of heating amount on the heat transfer characteristics is analyzed:

[0063] (1) The temperature of the outer surface of the ferrule increases with the flow direction, and changes basically linearly;

[0064] (2) As the heating amount increases, the circumferential temperature difference of the ring increases and the circumferential temperature uniformity decreases; at 500W, the circumferential temperature difference is 10°C, and at 2000W, the circumferential temperature difference increases to 30°C.

[0065] (3) Uneven circumferential temperature can easily lead to reduced ring roundness, resulting in uneven radial clearance of the bearing, which may cause ball slippage and affect the safe operation of the bearing. Therefore, the increase in heating is not conducive to bearing safety. The flow supply of the inner flow of the ring needs to be designed to match the flow of the under-ring or jet lubrication.

[0066] In this embodiment, the pressure loss of the inner flow channel of the outer ring under the atmospheric outlet condition can be analyzed by means of the pressure sensor in the oil supply system.

[0067] 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 principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A ball bearing outer ring heat exchange test method, characterized in that: The following steps are involved: Step 1: Connect the experimenter: The experimental device comprises three parts: an oil supply system, a heating and temperature measuring system and an oil return system. The oil supply system comprises an oil tank, an oil supply pump, a flow sensor, a temperature sensor and a pressure sensor. The heating and temperature measuring system comprises an outer ring of a bearing with an internal flow channel to be measured, an inner channel heater, a temperature sensor for measuring the temperature of the outer surface of the ring and a stand for fixing the above components. The oil return system comprises an oil return tank and an oil return pump. The three systems of the oil supply system, the heating and temperature measuring system and the oil return system are connected by an oil delivery hose. Step 2: Turn on the power and open the software: Turn on the power of the experimenter, open the experimental software through the software control terminal, and go to the next step when the readings of each sensor are normal; Step 3: Preheat the lubricating oil in the oil supply system: Turn on the heater in the oil tank, set the oil supply temperature T, and stop heating after the temperature in the oil tank stabilizes at T; Step 4: Turn on the oil supply pump and the oil return pump: adjust the output oil supply flow rate Q of the oil supply pump; when the liquid level in the oil return tank of the oil return system reaches one-fourth of the total volume of the oil tank, turn on the oil return pump and adjust the power of the oil return pump until the liquid level in the oil return tank is stabilized at one-fourth of the total volume of the oil tank; Step 5: Turn on the heating wire heating: After the oil flow rate and temperature are stable to the set value, set the heating power W to 25%W watts and turn on the heating; Step 6. Record data: Click the record data button in the software control software to start recording test data; Step 7: Observe the temperature of the outer ring of the bearing under test until the average change of each measuring point is less than 0.1 degrees Celsius. It is determined that the heat exchange is stable under this condition. Increase the heating power W to 50%W watts and continue the test. Step 8. According to the heat exchange stability certification standard of step 7, complete the heat exchange test at the oil supply flow rate, temperature, and heating power of 25%W, 50%W, 75%W, and 100%W respectively; Step 9. End data recording and stop heating: Click the record data button in the software control end to end data recording; set the heating power to 0, stop heating, continue to supply oil until the temperature of the outer wall of the outer ring of the bearing under test drops below 100 degrees Celsius, stop supplying oil, wait until there is no oil accumulation in the return oil tank, stop returning oil, turn off the power, and the test is over.

2. A ball bearing outer ring heat exchange test method as claimed in claim 1, characterized in that: The lubricating oil in the oil supply system is aviation lubricating oil.

3. A ball bearing outer ring heat exchange test method as claimed in claim 1, characterized in that: The oil supply temperature T is the temperature of the lubricating oil supplied by the lubrication system of the bearing under actual working conditions; the oil supply flow rate Q is one quarter of the total lubricating oil supplied by the lubrication system of the bearing under actual working conditions.

4. A ball bearing outer ring heat exchange test method as claimed in claim 3, characterized in that: The oil supply flow rate Q of the oil supply system is in the range of 0-3L / min, and the oil supply temperature T is in the range of 40-70°C.

5. A ball bearing outer ring heat exchange test method as claimed in claim 1, characterized in that: The heating power W is 25% of the total heat generated by the bearing under actual working conditions; The calculation is based on the Palmgren model, and the formula is as follows: ， ， ， ， In the formula, is the total friction torque of the rolling bearing (N×m); is the friction torque related to the load on the bearing (N×m); is the torque related to the bearing type, speed and lubricant properties (N×m); is the bearing pitch diameter (m); is the bearing speed (r / min); is the kinematic viscosity of the lubricating oil (m 2 / s); is a coefficient related to bearing type and lubrication method, is a factor related to the bearing type and the load it is subjected to. Calculated load for determining bearing friction torque.

6. A ball bearing outer ring heat exchange test method as claimed in claim 1, characterized in that: The temperature sensor measuring point in the heating temperature measurement system is located on the outer wall of the outer ring of the bearing to be measured, with M temperature measurement zones evenly distributed circumferentially, and N temperature measurement sensors evenly distributed axially in each temperature measurement zone, where M and N are positive integers; there are M×N measuring points in total; the temperature measurement sensor uses a PT100 temperature sensor.

7. A ball bearing outer ring heat exchange test method as claimed in claim 1, characterized in that: The oil return tank is an open tank connected to the atmosphere, so that the lubricating oil outlet of the internal flow channel of the outer ring of the tested bearing is at normal atmospheric pressure, and the operating power of the oil supply pump and the oil return pump are different.

8. A method for evaluating the heat transfer characteristics of a flow channel during a heat transfer experiment of a ball bearing outer ring as described in claims 1 to 7, characterized in that: Specifically include: The temperature field of the outer ring is affected by three factors, namely, oil supply flow, oil supply temperature and heating amount. The control variable method is used to study the influence of the three factors on the temperature field respectively, and the temperature change curve is drawn to obtain the heat transfer characteristics of the flow channel.

9. A method for processing experimental data in a heat exchange experiment of a ball bearing outer ring as claimed in claims 1 to 7, characterized in that: Specifically include: The internal flow channels of the outer ring of the tested bearing are symmetrically distributed relative to the oil inlet and outlet. Two symmetrical temperature measurement areas are taken, and the heat exchange stable measurement point temperatures corresponding to 8 working conditions are obtained. The bad points that are 20% higher or lower than the average value are eliminated, and the average value is taken again as the point temperature on the outer surface of the outer ring; according to the above processing method, the temperatures of at least 4 points are taken out, and the plot is drawn along the half-circle lubricating oil flow direction angle (22.5°, 67.5°, 112.5°, 157.5°), and the change trend diagram of the outer surface temperature of the outer ring of the tested bearing with the flow direction under different heating amounts is obtained, and the effect of heating amount on heat transfer characteristics is analyzed.

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