GB/T 21958-2017 PDF in English
GB/T 21958-2017 (GB/T21958-2017, GBT 21958-2017, GBT21958-2017)
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| GB/T 21958-2017 | English | 560 |
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Wheeled tractor -- Front drive axle
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| GB/T 21958-2008 | English | 759 |
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Front drive axle for wheeled tractor
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Standards related to (historical): GB/T 21958-2017
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GB/T 21958-2017: PDF in English (GBT 21958-2017) GB/T 21958-2017
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 65.060.10
T 63
Replacing GB/T 21958-2008
Wheeled tractor - Front drive axle
ISSUED ON. SEPTEMBER 29, 2017
IMPLEMENTED ON. APRIL 01, 2018
Issued by. General Administration of Quality Supervision, Inspection and
Quarantine of PRC;
National Standardization Administration.
Table of Contents
Foreword... 3
1 Scope... 6
2 Normative references... 6
3 Model compilation... 7
4 Technical requirements... 7
5 Test method... 10
6 Inspection rules... 11
7 Marking, packaging, transportation, storage... 13
Appendix A (Normative) Performance requirements and test methods for steering tie
rod components of front drive axle... 15
Appendix B (Normative) Front drive axle -- Technical requirements and test methods
for steering hydraulic cylinder... 17
Appendix C (Normative) Front drive axle -- Air tightness test method... 27
Appendix D (Normative) Front drive axle -- Steering durability test method... 29
Appendix E (Normative) Front drive axle -- Cleanliness limit determination method
... 32
Appendix F (Normative) Front drive axle -- Transmission efficiency measurement test
method... 35
Appendix G (Normative) Front drive axle -- Noise test method... 38
Appendix H (Normative) Front drive axle -- Oil temperature test method... 40
Appendix I (Normative) Front drive axle -- Limited slip differential locking
performance test method... 41
Appendix J (Normative) Front drive axle -- Reliability test method... 44
Wheeled tractor - Front drive axle
1 Scope
This standard specifies the model compilation, technical requirements, test methods,
inspection rules, marking, packaging, transportation, storage of front drive axles of
wheeled tractors.
This standard applies to the front drive axle of four-wheel drive tractors (hereinafter
referred to as the front drive axle).
2 Normative references
The following documents are essential to the application of this document. For the dated
documents, only the versions with the dates indicated are applicable to this document;
for the undated documents, only the latest version (including all the amendments) is
applicable to this standard.
GB 1922 Petroleum solvents for paints and cleaning
GB/T 10125 Corrosion tests in artificial atmospheres - Salt spray tests
GB/T 13306 Plates
GB/T 14039-2002 Hydraulic fluid power - Fluids - Method for coding the level of
contamination by solid particles
GB/Z 19848 Hydraulic fluid power - Component cleanliness - Guidelines for
achieving and controlling cleanliness of components from manufacture to
installation
GB/T 21957-2008 The fatigue-life testing method of the axle shaft and drive shaft
on the test stand, wheeled agricultural tractor
GB/T 24645 Slush seal performance of tractors - Test procedures
GB/T 24648.1-2009 Assessment of tractor reliability
JB/T 5615 Tractor transmission gear - Specifications
JB/T 5673-2015 Agriculture and forestry tractors and machinery - General
requirements of painting
4.1.1 The front drive axle shall comply with the requirements of this standard and be
manufactured according to the product drawings and technical documents approved by
the prescribed procedures.
4.1.2 The appearance quality shall meet the following requirements.
a) The exposed surface shall be free of defects such as bumps, rust, deformation of
parts.
b) The metal coating and oxidation treatment layer on the surface of the parts shall
not peel off and rust.
c) The surface of the exposed fasteners shall be galvanized, passivated or otherwise
subject to anti-rust treatment.
d) The painting of the front drive axle shall comply with the provisions of JB/T 5673-
2015.
4.1.3 All fasteners shall be tightened reliably and locked correctly; the tightening torque
requirements shall meet the specified values.
4.2 Assembly requirements
4.2.1 All parts made by the manufacturer shall comply with the requirements of the
drawings; purchased parts shall have a certificate of conformity.
4.2.2 The gears and splines of the front drive axle shall comply with the relevant
provisions of JB/T 5615.
4.2.3 After the front drive axle is assembled, turn the small bevel gear shaft. The entire
transmission system shall rotate freely without sticking; the speed difference between
the two sides of the wheel shall be less than 10%.
4.2.4 After the front drive axle is assembled, the toe and steering angle shall be adjusted
and locked according to the requirements of the whole machine.
4.2.5 After the front drive axle is assembled, put it into the leak test liquid at a test
pressure of 0.025 MPa ~ 0.050 MPa for air tightness test; hold the pressure for 3 minutes;
no bubbles shall appear in the parts of the front drive axle.
4.2.6 After the front drive axle passes the air tightness test, it shall be run-in tested. The
no-load run-in test time shall not be less than 20 minutes. During the run-in test, the
front drive axle shall have no abnormal sound and be flexible in steering.
4.2.7 Lubricating parts shall be filled with lubricating oil or grease as required.
4.3 Performance requirements
4.3.1 The front drive axle shall comply with the provisions of GB/T 24645 for anti-mud
and water tightness of the whole machine.
4.3.2 The front drive axle shall meet the requirements of the maximum steering angle
in the drawings or technical documents; its deviation shall not exceed 1°; it shall rotate
freely within the required range of the steering angle without interference.
4.3.3 The front drive axle shall pass 1 × 105 steering durability tests; it shall not produce
excessive clearance and severe wear; the wear value shall not exceed the designed wear
value.
4.3.4 The cleanliness index of the front drive axle shall not exceed 50 mg/L; the
maximum particle size shall not exceed 80 μm.
4.3.5 The transmission efficiency of the front drive axle shall not be less than 88%.
4.3.6 The noise of the front drive axle shall not exceed 85 dB(A).
4.3.7 The total continuous operation time of the front drive axle at the highest input
speed shall not be less than 3 h. After the oil temperature remains stable, the maximum
oil temperature shall not be higher than 90 °C; the temperature rise shall not exceed
70 °C.
4.3.8 When the front drive axle is loaded with 3 times the rated drive axle load, the
elastic deformation per meter of wheelbase shall not exceed 1.5 mm; the vertical
bending failure safety factor of the front drive axle shall not be less than 6.
4.3.9 The front drive axle shall be able to pass the durability test specified in 4.4 of JB/T
11673-2013.
4.3.10 The limited slip differential function of the front drive axle shall meet the
requirements of the whole machine for the anti-skid ability of the front wheels; the
locking coefficient of the limited slip differential of the front drive axle shall generally
not be less than 0.4.
4.3.11 When the differential lock of the front drive axle is engaged, the differential shall
be able to lock 100% reliably; there shall be no impact, slipping, abnormal noise,
disengagement, etc.
4.3.12 The performance requirements of the steering tie rod components of the front
drive axle shall comply with the provisions of Appendix A.
4.3.13 The steering hydraulic cylinder of the front drive axle shall comply with the
provisions of Appendix B.
4.3.14 The static torsional strength safety factor of the front drive axle's transmission
shaft components shall not be less than 2.0; the torsional fatigue life of the transmission
5.12 The oil temperature test of the front drive axle shall be carried out in accordance
with the provisions of Appendix H.
5.13 The transmission durability test of the front drive axle shall be carried out in
accordance with the provisions of JB/T 11673-2013.
5.14 The locking performance test of the limited slip differential of the front drive axle
shall be carried out in accordance with the provisions of Appendix I.
5.15 The test of the steering tie rod components of the front drive axle shall be carried
out in accordance with the provisions of Appendix A.
5.16 The durability test of the steering hydraulic cylinder components of the front drive
axle shall be carried out in accordance with the provisions of Appendix B.
5.17 The static torsional strength test of the transmission shaft components of the front
drive axle shall be carried out in accordance with the provisions of 3.2.1 of JB/T 5928-
2014.The torsional fatigue test of the transmission shaft components and the drive
wheel shaft components shall be carried out in accordance with the provisions of GB/T
21957-2008.
5.18 The vertical bending stiffness and vertical bending static strength test of the axle
housing of the front drive axle shall be carried out in accordance with the provisions of
3.2.2 of JB/T 5928-2014.
5.19 The vertical bending fatigue test of the axle housing of the front drive axle shall
be carried out in accordance with the provisions of 4.3 of JB/T 9828-1999.
5.20 The reliability test of the front drive axle shall be carried out in accordance with
the provisions of Appendix J.
6 Inspection rules
6.1 Inspection classification
The inspection of the front drive axle is divided into exit-factory inspection and type
inspection.
6.2 Exit-factory inspection
6.2.1 The front drive axle shall be inspected before leaving the factory. It can only leave
the factory after passing the inspection by the quality inspection department and issuing
a product certificate.
6.2.2 The exit-factory inspection items of the front drive axle are as shown in Table 1.
d) When the production is resumed after suspension for 6 months;
e) When the exit-factory inspection results are significantly different from the last
type inspection;
f) When the national quality supervision agency proposes to conduct type inspection.
6.3.2 When conducting type inspection, two sets shall be randomly selected from
qualified products which has passed the exit-factory inspection.
6.3.3 Type inspection items are shown in Table 1.
6.3.4 If the results of type inspection shall not be lower than the requirements of this
standard, the product is deemed to have passed the type inspection.
7 Marking, packaging, transportation, storage
7.1 The front drive axle shall be fixed with a product label in accordance with GB/T
13306 in a prominent position; its content includes.
a) Manufacturer name, address, trademark.
b) Product model and name.
c) Product main technical parameters.
- Total transmission ratio;
- Rated axle load, kN;
- Total mass, kg.
d) Product implementation standard number.
e) Product exit-factory number.
f) Product exit-factory date.
7.2 The packaging of the front drive axle shall ensure that it will not be damaged or lost
under normal transportation conditions.
7.3 The front drive axle is generally fixed with a special bracket and then installed naked.
It can also be packaged according to user requirements and shall be protected as follows.
a) A protective cover shall be added to the input spline;
b) Protective plugs shall be added to the exposed oil port;
Appendix A
(Normative)
Front drive axle -- Performance requirements and test methods for steering tie
rod components
A.1 Performance requirements
A.1.1 The extreme swing angle and swing torque of the ball pin component of the
steering tie rod joint along the axis of the tie rod shall meet the design requirements.
When the sliding surface is well lubricated, there shall be no blocking, jamming,
loosening.
A.1.2 The ball pin component of the steering tie rod joint shall have a dustproof device,
which shall be able to effectively prevent mud and dust from penetrating within the
extreme swing angle range of the ball pin.
A.1.3 The ball pin component of the steering tie rod joint shall pass the pull-out test;
the pull-out force shall meet the design requirements, with a safety factor of not less
than 1.5.
A.1.4 The threads of the steering tie rod and the steering tie rod joint shall be reliably
connected; no loosening or disengagement shall occur under normal use.
A.1.5 The strength and rigidity of each part and component of the steering tie rod
component shall meet the design requirements. The steering tie rod component shall
pass the compression test and the tensile test; no deformation, cracks, loose ball pins or
other damage shall occur.
A.2 Test method
A.2.1 Pull-out test of the ball pin component of the steering tie rod joint
A.2.1.1 The test bench shall have a device for applying axial tensile load; the error of
the applied load shall not exceed 2%.
A.2.1.2 Install the sample on the test bench; apply axial tensile force until the ball pin
is pulled out of the ball seat; measure the tensile force Fk.
A.2.1.3 Calculate the pull-out safety factor according to formula (A.1).
Where.
Sk - Static tensile strength safety factor;
Appendix C
(Normative)
Front drive axle -- Air tightness test method
C.1 Test description
This Appendix only introduces the method of immersion test, but other more advanced
air tightness test methods are encouraged.
C.2 Proportion of leakage test liquid
Mix the anti-rust liquid and water in an appropriate proportion; the value measured by
the sugar meter is 1 ~ 1.2.
C.3 Inflator
C.3.1 The inflator shall be able to provide more than 1.1 times the maximum test
pressure.
C.3.2 The inflator shall be equipped with a pressure adjustment device and meet the
requirements.
C.3.3 A pressure gauge is installed at the outlet of the inflation pipe. The pressure gauge
shall be installed in a position that is easy for the tester to observe. The accuracy of the
pressure gauge is 0.005 MPa; the range is 1.5 ~ 2.5 times the test pressure.
C.4 Test water tank
C.4.1 The depth of the test water tank shall be able to make any part of the front drive
axle 5 cm below the test liquid surface.
C.4.2 The inner wall of the test water tank shall be white.
C.4.3 The test liquid in the test water tank shall remain clear and transparent.
C.5 Test method
C.5.1 When the front drive axle is composed of three independent cavities, namely the
main reduction axle housing cavity, the left wheel side assembly cavity, the right wheel
side assembly cavity, the immersion test needs to be carried out on the three cavities at
the same time.
C.5.2 Fill the cavity of the front drive axle with gas at a test pressure of 0.025 MPa ~
0.03 MPa; place it in the test water tank so that any part of the front drive axle is 5 cm
below the test liquid surface.
Appendix D
(Normative)
Front drive axle -- Steering durability test method
D.1 Test equipment
D.1.1 The front drive axle's steering system durability test is conducted on a test bench
that simulates the installation of the host machine.
D.1.2 The test equipment shall be able to apply the required deflection resistance torque
to the front wheel in the left and right directions; be able to draw the performance curve
of the steering angle and steering resistance torque. The error of applying the deflection
resistance torque shall not exceed 5%.
D.1.3 The steering load is provided by the test bench hydraulic motor; the system
automatically records the number of turns, steering oil pressure, loading motor oil
pressure.
D.2 Test load
D.2.1 The front tire is inflated to the pressure value specified in the instruction manual
of the complete machine, which is equipped with the front drive axle.
D.2.2 The front wheel track is adjusted to the front wheel track, which is commonly
used by the complete machine equipped with the front drive axle.
D.2.3 The vertical load of the front drive axle is the maximum front wheel load of the
complete machine.
D.2.4 The deflection resistance torque is applied to the left and right front wheels on
average; the sum of the deflection resistance torques of the left and right front wheels,
M0, is calculated according to formula (D.1).
Where.
M0 - The sum of the deflection resistance moments of the left and right front wheels,
in Newton meters (N·m);
G - The load borne by the front drive axle, in Newtons (N);
a - Steering resistance arm, in meters (m);
b - Nominal width of the front tire, in meters (m);
Appendix E
(Normative)
Front drive axle -- Cleanliness limit determination method
E.1 Measuring instruments
E.1.1 Filter. Metal mesh, mesh size is 38 μm, no visible compilation and scratches.
E.1.2 Filter membrane. Porosity is 5 μm; the diameter size is selected according to
actual needs.
E.1.3 Microporous filtration device. Including vacuum pump, nylon hose, metal clamp,
funnel, filter membrane, filter membrane support frame, funnel seat, oil-resistant rubber
plug, suction filter bottle.
E.1.4 Cleaning liquid. NY-120 solvent oil as specified in GB 1922.
E.1.5 Porcelain plate, nylon brush, washing bottle, tweezers, thermometer, 202
medium-speed quantitative analysis filter paper, weighing bottle, magnet, etc.
E.1.6 One-ten-thousandth balance.
E.1.7 Oven, dryer.
E.1.8 Microscope with scale greater than 40×.
E.2 Test preparation
E.2.1 Cleanliness determination shall be carried out in a clean, well-ventilated room
with safety measures.
E.2.2 Operators shall wear clean work clothes, hats and shoes; wash their hands.
E.2.3 The apparatus and cleaning fluid used to determine cleanliness shall be clean.
E.2.4 Soak the filter in the cleaning fluid for 10 minutes; then take it out. After the
cleaning fluid evaporates, put it in a 105 °C ± 5 °C oven for 60 minutes. Put it in a dryer
to cool for 30 minutes. Weigh it for later use.
E.2.5 Put the filter membrane in a clean weighing bottle. Open the bottle cap and bake
it in a 90 °C ± 5 °C oven for 60 minutes. Close the bottle cap and take it out. Put it in a
dryer to cool for 30 minutes. Weigh it to constant weight (the difference between two
consecutive weighing is not more than 0.4 mg). Put it in a dryer for later use.
E.3 Impurity sampling
E.3.1 Randomly select the front drive axle that has passed the exit-factory inspection
as the sample to be tested. Clean the non-testing parts of the sample, to prevent
impurities from falling into the tested parts. Then drain all the lubricating oil.
E.3.2 Add cleaning liquid (half kerosene and half diesel) of not less than half the
capacity of lubricating oil; idle run at two-thirds of the maximum speed for 2 minutes;
immediately drain all the cleaning liquid.
E.3.3 Collect all the above lubricating oil and cleaning liquid separately (including oil
samples for brushing impurities on magnetic screw plugs).
E.4 Filtration and weighing of impurities
E.4.1 Use the filtration method of filter screen plus filter membrane. First, filter all the
turbid liquid obtained with a clean filter screen; use a microporous filtration device for
vacuum filtration; use a filter membrane for fine filtration.
E.4.2 After the whole liquid is filtered, rinse the filter screen and the wall with 0.05 L
of clean cleaning liquid, to collect the impurities on the filter membrane.
E.4.3 Place the filter paper in a clean weighing bottle. Open the bottle cap and dry it in
an oven at 105 °C ~ 110 °C for 30 minutes. Close the bottle cap and take it out. Put it
in a dryer to cool for 60 minutes. Weigh it to constant weight (weigh it on a balance;
the difference between two consecutive drying weighing is required to be no more than
0.4 mg). Put it in a dryer for use.
E.4.4 Place the filter paper with impurities in a weighing bottle. Place it in an oven at
105 °C ~ 110 °C. Open the bottle cap and dry it for 2 hours. Weigh it to constant weight.
E.4.5 The mass of impurities is the mass of the filter paper with impurities and the
weighing bottle minus the mass of the filter paper and the weighing bottle, in milligrams
(mg).
E.5 Impurity analysis and cleanliness calculation
E.5.1 Use a magnet wrapped in cellophane to sort out the iron filings in the impurities;
weigh the mass of the iron filings, in milligrams (mg).
E.5.2 Use a microscope to measure the size of the largest impurity (length × width), in
micrometers (μm).
E.5.3 Cleanliness is calculated according to formula (E.1).
Where.
......
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
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