This standard specifies the test methods for mining hydraulic axial piston pumps. This standard applies to the test of mining hydraulic axial piston pumps with hydraulic oil or other mineral oils of equivalent performance as the working medium and a rated pressure not exceeding 40MPa. MT/T 489-1995 Test methods for mining hydraulic axial piston pumps MT/T489-1995 Standard download decompression password: www.bzxz.net

Coal Industry Standard of the People's Republic of China
MT/T489-1995
Test Methods for Hydraulic Axial Piston Pumps for Mining
Published on December 18, 1995
Published by the Ministry of Coal Industry of the People's Republic of China and implemented on May 1, 1996
Coal Industry Standard of the People's Republic of China
Test Methods for Hydraulic Axial Piston Pumps for Mining
1 Subject Content and Scope of Application
This standard specifies the test methods for hydraulic axial piston pumps for mining. MT/T489-1995
This standard is applicable to the test of hydraulic axial piston pumps for mining with hydraulic oil or other mineral oils of equivalent performance as the working medium and a rated pressure not exceeding 40MPa.
2 Reference standards
GB2346 Nominal pressure series of hydraulic and pneumatic systems and components GB2347 Nominal displacement series of hydraulic pumps and motors GB7936 Determination method of no-load displacement of hydraulic pumps and motors MT/T490 Product quality classification of hydraulic inclined plate axial piston pumps for mining 3 Terms and symbols
3.1 Terms
3.1.1 Rated pressure
Continuous operation within the specified speed range and the highest output pressure that can ensure the design life. 3.1.2 No-load pressure
The output pressure of the self-priming pump does not exceed the test pressure of 3% of the rated pressure; the output pressure of the oil supply pump does not exceed the test pressure of 5% of the rated pressure.
3.1.3 Maximum pressure
The maximum pressure that can be used without damage or rapid wear of the pump. 3.1.4 Rated speed
The maximum speed that can ensure the design life under the rated pressure and specified oil inlet conditions. 3.1.5 Minimum speed
The minimum speed allowed to maintain a stable output at the rated pressure. 3.1.6 Displacement
The volume of liquid discharged per revolution of the pump shaft.
3.1.7 Nominal displacement
The nominal displacement of the product.
3.1.8 No-load displacement
The actual displacement measured at no-load pressure. 3.1.9 Effective displacement
The actual displacement measured at the set pressure. 3.1.10 Rated operating conditions
The operating conditions at rated pressure, rated speed and maximum displacement. Approved by the Ministry of Coal Industry of the People's Republic of China on December 18, 1995 and implemented on May 1, 1996
Symbols and units
Symbols and units are shown in Table 1.
Parameter name
Kinematic viscosity
Volumetric efficiency
Total efficiency
Vacuum degree
MT/T489-1995
Note: Before the instrument indication unit is unified, the following conversion is allowed: 1kgf/cm20.0980665MPa
1kgf·m=9.80665N·m
Test conditions
4.1 Test oil
Unit name
Liter per minute
Milliliter per revolution
Revolution per minute
Newton meter
Degrees Celsius
Square millimeter per second
4.1.1 Oil temperature: The pump inlet oil temperature of each test in the factory test should be 50±4℃. In the type test, except for those specified in Table 4, the oil temperature of other test items is 50±2℃.
2 Viscosity: The kinematic viscosity at 50℃ is 37~53mm2/s4.1.2
4.1.3 Cleanliness level:
The solid particle contamination level of the test oil shall not be higher than 19/16. 2 Test system diagram
It is recommended to use Figure B1 in Appendix B.
3 Measurement accuracy
The measurement accuracy level is divided into three levels: A, B, and C. The allowable system error of the measurement system is shown in Table 2. Table 2
Flow %
Accuracy level
Measurement parameters
Speed ​​%
Torque %
Temperature %
MT/T489-1995
Continued Table 2
Accuracy level
Note: The accuracy used in type test shall not be lower than Class B, and the accuracy used in factory test shall not be lower than Class C. 4.4 Position of measurement points
4.4.1 The pressure measurement point shall be set at 2 to 4d from the oil inlet of the tested pump (d is the inner diameter of the working pipe) and 2 to 4d from the oil outlet. 4.4.2 The temperature measurement point shall be set at 2 to 4d from the pressure measurement point and shall be farther away from the tested pump than the pressure measurement point. 4.4.3 The noise measurement point shall be on a hemispherical surface with a radius of 1m from the tested pump casing, and more than 10 measurement points shall be evenly selected. 4.5 Steady-state conditions for parameter measurement
All parameters (pressure, flow, torque, speed, etc.) of each set point should be measured simultaneously. When measuring the same stable point several times, the allowable variation range of the average displayed value of each parameter should comply with the provisions of Table 3 to be considered a steady-state condition. Table 3
Measurement parameters
Pressure%
Flow%
Accuracy grade
Note: The accuracy used in type tests shall not be lower than Class B, and the accuracy used in factory tests shall not be lower than Class C. 5 Test items
5.1 Type test: refers to a test that comprehensively inspects the performance and quality of the hydraulic pump. It is divided into developmental tests and quality stability tests. 5.1.1 Developmental test: Test all type test items. 5.1.1.1 Developmental tests must be conducted in any of the following situations: a.
Development of new products (including transfer of old products to other factories); when changes in component design, process or materials used may affect its performance and durability; b.
When the results of factory tests and quality stability tests have unacceptable deviations. 5.1.1.2 The number of tested products shall not be less than 3 units, and samples shall be taken from trial prototypes or batch products, one of which shall be subjected to developmental tests, and the remaining 2 or more units shall be subjected to factory tests.
5.1.2 Quality stability test: For some type test items, quality stability tests must be conducted in any of the following situations: 5.1.2.1
When the factory itself or the quality supervision unit or the competent department regularly assesses and inspects the stability of product quality:; When users report that the product quality has obviously declined or require this test. 5.1.2.2 The number of tested products shall not be less than 3 units. Samples shall be taken from the finished products of users or manufacturers, one of which shall be tested for quality stability, and the remaining 2 or more units shall be tested at the factory.
MT/T489-1995
5.2 Factory test: refers to the test conducted before the hydraulic pump leaves the factory to check the performance of the components. 5.2.1 Every unit of the manufactured products must be tested at the factory. 5.2.2 The factory test items are divided into two categories: mandatory test items and random test items. The number of random tests shall be 2% of each batch of products, but not less than 2 units; if the random test items fail to meet the standards, the random tests shall be doubled. If there are still unqualified items, the batch of products shall be tested one by one. 6 Test content and methods
6.1 Air tightness inspection and running-in
6.1.1 Air tightness inspection: The inner cavity of the tested pump is filled with 0.18MPa clean gas, and then immersed in the anti-rust liquid for a residence time of not less than 1min.
6.1.2 Running-in: At rated speed, start from no-load pressure and run-in step by step. The running-in time and pressure level are determined according to needs, and the running-in time at rated pressure shall not be less than 2 minutes.
Note: Air tightness inspection and running-in should be carried out before component testing. The shell of non-enclosed components is not subject to air tightness inspection. 6.2 Type test
6.2.1 Development test:
The test shall be carried out in accordance with the provisions of Table 4.
Test items
Displacement verification
Test content and method
Start at maximum displacement and no-load pressure, run for more than 10 minutes after reaching rated speed, then gradually load, run to rated pressure in stages, and then run for more than 5 minutes
Efficiency test
Self-priming test
Variable characteristics
(1) Under maximum displacement and rated speed conditions, gradually load the outlet pressure of the tested pump to about 25% of the rated pressure. After stable operation, measure a parameter related to efficiency. 1. According to the above method, at least 40%, 55%, 70%, 85% and 100% of the rated pressure are measured respectively. (2) Measure the efficiency of each test pressure level at rated speed when 75%, 50% and 25% of the maximum displacement
(3) Measure the data of each test pressure level at rated speed of 100%, 85%, 70%, 55%, 40% and the minimum design speed
(4) At rated speed and maximum displacement, measure the efficiency of each test pressure level at oil temperature of 20~30℃ from no-load pressure to rated pressure respectively. Volumetric efficiency at 0℃ and 70～80℃
Measure the displacement when the suction port vacuum is zero under the conditions of maximum displacement, rated speed and no-load pressure. Based on this, gradually increase the suction resistance until the displacement drops by 1%, and then measure its vacuum (1) Constant power variable pump:
&. Determination of the minimum pressure switching point: adjust the variable mechanism to make the test pump in the minimum pressure switching state, and measure the pump outlet pressure b. Determination of the maximum pressure switching point: adjust the variable mechanism to make the test pump in the maximum pressure switching state, and measure the pump outlet pressure.
(1) The whole process Normal operation
(2) At rated speed, the displacement under no-load condition should be 95% to 110% of the nominal displacement
(1) The volumetric efficiency and total efficiency under rated conditions shall not be lower than the values ​​specified in MT/T490
(2) Draw the efficiency characteristic curve (see Figure B3 in Appendix B)
(3) The characteristic curve or equivalent curve of flow rate, efficiency and power changing with pressure (see Figures B5 and B6 in Appendix B)
The vacuum degree complies with the values ​​specified in MT/T490
The pressure-flow characteristic curve complies with the design requirements of the drawing. The repeatability error should be less than ±10% (Figure B4 in Appendix B)
Test items
Variable characteristics
Noise test
Low temperature test
High temperature test
Overload test
Overspeed test
MT/T489-1995
Continued Table 4
Test contents and methods
c. Determination of constant power characteristics: Adjust the variable mechanism according to the design requirements, measure the corresponding data of pressure and flow, and draw the constant power characteristic curve (pressure-flow characteristic curve), see Figure B4 in Appendix B. d. Other characteristic tests are carried out according to the design requirements (2) Constant pressure variable pump:
Constant pressure static characteristic test: Load at maximum displacement and rated speed, and draw the flow-pressure characteristic curve under different set pressures. As shown in the figure below: g.
33%P,
Set pressure: 33%p, 66%p, 100%p
Output flow: 0
In the above figure, the upper and lower curves shall not be less than 10 points respectively; the safety valve in the test system shall not be opened
(3) Other types of variable pumps:
Test according to the drawings and their technical requirements or user requirements. At rated speed and maximum displacement, measure the noise value when the pressure is 100%, 73%, 67%, 50%, and 36% of the rated pressure respectively (it should be measured at more than six evenly distributed positions at different cross-sections on the 1/2 sphere with a radius of 1m from the test pump housing)| |tt||The temperature of the tested pump and the inlet oil temperature are both below -10℃, and the pump is started under the maximum displacement and no-load pressure conditions.
The oil viscosity is based on the design requirements.
Under the rated conditions, a continuous operation test is conducted with the oil at an inlet temperature of more than 90℃.
The oil viscosity is based on the design requirements.
Under the maximum displacement and rated speed conditions, a continuous operation test is conducted with the maximum allowable pressure or 125% of the rated pressure (the higher one is selected). During the test, the inlet oil temperature of the tested pump is 30-60℃.
Under the maximum displacement, maximum speed or 115% of the rated speed (the higher one is selected), a continuous operation test is conducted with the rated pressure and no-load pressure respectively. During the test, the inlet oil temperature of the tested pump is 30～60℃. The constant pressure error Apa is not greater than 1MPa. It meets the specified value of MT/T490. There is no abnormal phenomenon after starting for more than 5 times. This test can be exempted if the user has no requirements. There is no abnormal phenomenon after continuous operation for more than 1h. There is no abnormal phenomenon after continuous operation for more than 10h. There is no abnormal phenomenon after continuous operation for more than 15min. Test items ||Impact test
Continuous overload
Continuous full load
Frequent variable
Observation test
Efficiency inspection
External leakage inspection
Inspection test
MT/T489-1995
Continued Table 4
Test contents and methods
(1) Fixed displacement and manual variable pump:
At maximum displacement and nominal speed, the impact test shall be carried out with an impact frequency of 1/6 to 1/2 Hz. At rated pressure, the pressure should be maintained for more than 1/3 cycle, and the unloading pressure should be less than 10% of the rated pressure. (2) Constant power variable pump: At maximum displacement and rated speed (about 40% of rated pressure), the impact test is carried out at a frequency of 1/6 to 1/2 Hz. At rated pressure, the pressure should be maintained for more than 1/3 cycle, and the unloading pressure should be less than 10% of the rated pressure. (3) Constant pressure variable pump: At rated speed, rated pressure, and flow rate between 10%qvmax≤q≤80%qvmax, the constant pressure section impact (stage) cycle test is continuously carried out. (4) Other variable forms: According to the variable characteristics of maximum power or user requirements, the inlet oil temperature of the tested pump is 30 to 60℃ during the above impact tests. The continuous operation test is carried out at 1.25 times the rated pressure at rated speed and maximum displacement. During the continuous operation, the external leakage, inlet temperature, and the maximum temperature of the pump casing are measured regularly. During the test, the inlet oil temperature of the tested pump is 30-60℃
Under rated working conditions, continuous operation test is performed. During operation, external leakage, inlet temperature, maximum temperature of pump casing, etc. are measured regularly. Under rated speed and 50% rated pressure working conditions, the tested pump is made to perform frequent variable tests at the specified frequency from less than 5% of the maximum displacement to the maximum displacement
During the whole process of 1-13 tests, observe external leakage, noise vibration, temperature, etc.
After completing the above specified test items, measure the volumetric efficiency and total efficiency under rated working conditions
During the whole process of the above test items, check the leakage of fixed seals and rotating seals
a, static seal: press clean absorbent paper to the static seal part, then remove it. If there is oil stain on the paper, it is oil leakage;
b.Dynamic seal: Place white paper under the dynamic seal. If there are oil drops on the paper within the specified time, it means oil leakage
(1) No abnormal phenomenon after continuous test for more than 100,000 times. (Bidirectional pump allows 50,000 times of forward and reverse rotation) (2) Record the impact waveform. (For quantitative, manual variable and constant power variable pumps, see Figure B7 in Appendix B; for constant pressure variable pumps, see Figure B8 in Appendix B)
No abnormal phenomenon after continuous operation for more than 100 hours
No abnormal phenomenon after continuous operation for more than 1000 hours. (Bidirectional pumps are allowed to run forward and reverse for more than 500 hours each) (1) Frequent variable 20,000 times (Bidirectional pumps are allowed to run forward and reverse for 10,000 times each)
(2) Frequency should be greater than 1/4Hz
No abnormal phenomenon, all indicators meet the specified values ​​of MT/T490
Rated efficiency and total efficiency meet the specified values ​​of MT/T490
(1) No trace of oil leakage is allowed at the fixed sealing part.
(2) Leakage at the rotary sealing part should meet the specified values ​​of MT/T490
Note: ④ The volumetric efficiency calculated in No. 2, 7, 10, 11, and 12 is based on the no-load displacement at the rated speed of No. 1. ② The operating time (number of times) in the test items No. 6 to 13 refers to the cumulative time (number of times) after deducting the accident time (number of times) unrelated to the tested pump. ③ If the continuous overload test No. 11 is selected, the overload test No. 8 and the continuous full load test No. 12 can be omitted. If 12 and 8 are selected, the test No. 11 can be omitted.
④ The volumetric efficiency reduction value after the type test shall not be lower than the specified value of MT/T490. 6
6.2.2 Quality stability test
The test shall be carried out in accordance with the provisions of Table 5.
Test items
Displacement verification
Efficiency test
Impact test
Continuous overload
Continuous full load
Efficiency inspection
Observation test
MT/T489-1995
Test contents and methods
Perform in accordance with the corresponding provisions of 1 in Table 4
Perform in accordance with the corresponding provisions of 2(1) in Table 4
Perform in accordance with the corresponding provisions of Article 10 in Table 4 Regularly conduct
Perform in accordance with the corresponding provisions of Article 11 in Table 4
Perform in accordance with the provisions of Article 12 in Table 4
Perform in accordance with the provisions of Article 15 in Table 4
During the entire test process of the above-mentioned specified items, check the external leakage of the fixed seal and rotary seal parts and observe the noise, vibration, temperature, etc.
The sum under rated working conditions should meet the specified values ​​of MT/T
490
Continuous test for more than 200,000 times without abnormality. (Bidirectional pumps are allowed to be forward and reversed for 100,000 times each) Record the impact waveform
Continuous operation for more than 200 hours without abnormality. (Bidirectional pumps are allowed to be forward and reversed for 100 hours each)
Continuous operation for more than 1000 hours without abnormality. (Bidirectional pumps are allowed to be forward and reversed for 500 hours each) The volumetric efficiency under rated working conditions should meet the specified values ​​of MT/T490
No abnormality. All indicators meet the specified values ​​of MT/T490
Note: ① The continuous operation test time (number of times) in No. 3, 4, and 5 refers to the cumulative time (number of times) after deducting the accident time (number of times) unrelated to the tested pump. ② No. 4 and 5 can be selected at will.
③ The decrease in volumetric efficiency and total efficiency after the test is completed shall not be lower than the specified values ​​of MT/T490. 6.3 Factory test
The test shall be carried out in accordance with the provisions of Table 6.
Test items
Nominal displacement
Verification test
Efficiency test
Overload test
Variable characteristics
Impact test
Test content and method
Measure displacement at maximum displacement, rated speed and no-load pressure conditions
Measure leakage and volumetric efficiency at rated conditions (rated pressure, rated speed, maximum displacement)
Measure total efficiency under the above conditions
At rated speed and maximum displacement, gradually increase pressure to 125% of the rated pressure and operate for more than 1 minute
Operate at rated speed, maximum displacement and rated pressure for more than 1 minute, so that the variable mechanism of the tested pump reciprocates three times throughout the full stroke. Perform 100 impact tests according to the corresponding methods specified in the type test
At rated speed, the displacement at no-load pressure conditions should be 95% to 1 of the nominal displacement. 10%
Volumetric efficiency, total efficiency and external leakage shall comply with the specified values ​​of MT/T490
Normal operation
Normal response during variable process, stable pressure, no periodic pressure fluctuation
No abnormal phenomenon
Test items
Observation test
Cleanliness
Data processing
MT/T489-1995
Continued Table 6| |tt||Test content and method
During the test of item 15, check the external leakage, noise, vibration, temperature rise, etc. of the fixed seal and rotary seal parts according to the provisions of Appendix A.
The volumetric efficiency n% (%) is calculated according to formula (1): V.ge/ne
Where: 9
No-load pressure output flow, L/min;
Test pressure output flow, L/min;
V. Test pressure output effective displacement, mL/rV.—No-load pressure output effective displacement, mL/r;ne
—Test pressure speed, r/min;
No-load pressure speed, r/min.
7.2 The total efficiency n(%) is calculated according to formula (2):
Where: p
Output test pressure, MPa;
2 yuan nT, × 10
p'. Input pressure, positive if greater than atmospheric pressure, negative if less than atmospheric pressure, MPa, Ti—input torque, N·m.
7.3 Power calculation:
7.3.1 Output hydraulic power P., kW:
Ph=qe·pe/6×10
2 Input mechanical power Pm, kW:
Pm=2 yuan nT1/60000
7.4 Test data table:
Test data records shall be in accordance with the provisions of Appendix C.
No abnormal phenomenon. All indicators meet the specified values ​​of MT/T490
(1)
(2)
(3)
(4)
A1 Subject content and scope of application
MT/T489—1995
Appendix A
Weighing test method for internal cleanliness of hydraulic components (supplement)
This test method specifies the method of measuring the content of solid particle contaminants in the inner cavity of hydraulic components (the surface in contact with the working medium) by weighing, that is, the weighing test method for internal cleanliness of hydraulic components. This test method is applicable to the general test of internal cleanliness of hydraulic components. A2 Principle
Rinse the inner cavity of the hydraulic component with clean cleaning fluid. The rinsed cleaning fluid is filtered through two overlapping filter membranes of the same accuracy and size under vacuum conditions. After filtration, the weight difference between the two filter membranes is the weight of the solid particle contaminants contained in the inner cavity of the component. A3 Cleaning fluid and testing supplies
A3.1 Cleaning fluid
Petroleum ether (boiling range 90～120℃) filtered through a mixed cellulose ester microporous filter membrane with a pore size of 0.45um. Note: If there is no petroleum ether, No. 120 industrial gasoline can be used instead. A3.2 Testing supplies
A set of membrane filters (glass or stainless steel); a.
A funnel cover (can be replaced by cultured blood); c.
Filter membrane: mixed cellulose ester microporous filter membrane, diameter not less than 50mm, nominal pore size 0.8μm. d.
A suction flask;
A vacuum device with a vacuum degree of 87.72kPa (i.e. 658mm mercury column). e.
Several culture dishes with lids;
One pair of stainless steel flat-nosed tweezers;
An analytical balance with an accuracy of 0.5 mg;
An air-free drying oven maintained at 80°C; Cleaning utensils (aluminum box or plastic box, measuring cup, manual pressure oil gun, syringe, white silk cloth). A4 Testing procedures and requirements
A4.1 Cleanliness testing should be carried out in a clean room, and operators should wear work clothes and hats made of long-fiber textiles. A4.2 Take an appropriate amount of cleaning solution to clean the testing utensils. A4.3 Take two culture dishes (numbered A and B), weigh them separately and record their original weights (GA, GB). A4.4 Use a forge to clamp two sheets with an aperture of 0.8μm filter membranes (numbered A and B) are placed in two corresponding culture dishes. Put the culture blood with the half-open lid into a drying oven, keep it at 80℃ for 30 minutes, close the lid, take it out and cool it in the room for 30 minutes, and then weigh the first weight (GA1, GB1). A4.5 Clean the outer surface of the measured component. A4.6 Disassemble the measured component (do not disassemble the process screw plugs and interference fit parts), and plug the holes that do not lead to the product cavity with clean plastic covers.
A4.7 Remove the seals of each joint surface (except the hydraulic cylinder piston seal) and wipe the sealing surface with a white silk cloth. A4.8 Put all the inner cavity parts into the box. Use a manual pressure oil gun, a measuring cup, etc. to hold cleaning liquid to rinse the inner cavity of the product shell and the holes that communicate with the inner cavity 9
.
MT/T489-1995
A4.9 Parts that are not in contact with the working medium (such as the flange of the pump, the handle of the valve, the earrings of the cylinder, the connecting screws between parts, etc.) are not cleaned. A4.10 For parts that are partially in contact with the working medium, only the contact parts of the parts are cleaned. A4.11
Put the cleaned parts and used testing tools on the aluminum box and let the residual cleaning liquid drip into the aluminum box. A4.12 Wipe the inner cavity of the product with a white silk cloth. When there is no obvious dirt visually, it can be considered clean. A4.13 Take out the filter membranes A and B from the culture III, stack them with A on the top and B on the bottom and fix them in the filter device. A4.14 Stir the cleaning liquid after cleaning, pour it into the filter device, cover it with the funnel cover and filter it. Then rinse the liquid container with 50mL of filtered cleaning liquid. When about 2 mL of residual liquid is filtered, open the funnel cover and rinse the side wall of the funnel with the cleaning liquid from the cleaning container; cover the cover. Continue to filter until it is dry.
A4.15 While filtering, use a syringe to suck in the filtered cleaning liquid and inject it along the side wall of the funnel for cleaning until there is no oil on the filter membrane. A4.16 Stop filtering.
A4.17 Loosen the filter membrane clamp, take out the filter membranes A and B, put them back into the original culture blood, put them in the drying oven with the half-open cover, keep the temperature at 80℃ for 30 minutes, close the cover, take them out and cool them in the room for 30 minutes, and weigh them for the second time (GA2GB2). If all the cleaning liquid after rinsing cannot be filtered in one time, it can be done several times according to the contents of A4.3 to A4.17. A5 Arrangement of test data
Calculation of the weight of polluted particles:
G=(GA2-GA1)-(GB2-GB1)
Where: GA2-weight of the upper filter membrane after filtration, mg; GA1-weight of the upper filter membrane before filtration, mg; GB2-weight of the lower filter membrane after filtration, mg; GB1-weight of the lower filter membrane before filtration, mg. A5.1 If the difference between GB2 and GB1 is greater than 0.5 mg, it indicates that the filter membrane has not been fully rinsed and needs to be retested (repeat A4-A5) and increase the amount of rinsing and cleaning liquid.
A5.2 If there are more than two filter membranes after filtration and rinsing, the same method can be used to calculate the weight of dirt on each pair of filter membranes, and then add them up.
A6 Test report
The test report format of the hydraulic component internal cleanliness weighing test method is specified in the following table. Table A1 Test report of internal cleanliness of hydraulic components by weighing method Tested unit
Tested product
Testing time
Technical index
Testing locationwww.bzxz.net
Testing personnel
Measured particles
Total weight
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