QC/T 299.12014 PDF in English
QC/T 299.12014 (QC/T299.12014, QCT 299.12014, QCT299.12014)
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Automobile hydraulic steering powerpump. Part1: Technical requirements
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QC/T 299.12014: PDF in English (QCT 299.12014) QC/T 299.12014
QC
AUTOMOBILE INDUSTRY STANDARD
OF THE PEOPLE’S REPUBLIC OF CHINA
ICS 43.040.50
T 23
Replacing QC/T 2992000
Automobile hydraulic steering power pump  Part 1:
Technical requirements
ISSUED ON: MAY 06, 2014
IMPLEMENTED ON: OCTOBER 01, 2014
Issued by: Ministry of Industry and Information Technology of PRC
Table of Contents
Foreword ... 7
1 Scope ... 9
2 Normative references ... 9
3 Terms and definitions ... 9
4 Performance requirements ... 12
5 Reliability requirements ... 14
6 Supplementary requirements ... 14
Appendix A (Informative) Calculation method of volumetric efficiency and total
efficiency of automobile hydraulic steering power pump ... 17
Appendix B (Informative) Seal type and size of Oring rubber ring at oil inlet and outlet
of automobile hydraulic steering power pump ... 18
Appendix C (Informative) Calculation and design method of performance parameters
of automobile hydraulic steering power system ... 20
Automobile hydraulic steering power pump  Part 1:
Technical requirements
1 Scope
This Part of QC/T 299 specifies the performance requirements, reliability requirements,
supplementary requirements for automobile hydraulic steering power pumps.
This Part applies to the quantitative pump in the fixedflow hydraulic steering power
system for automobiles (hereinafter referred to as the steering pump), such as steering
vane pumps and steering gear pumps.
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/T 2878 Fluid power systems and components  Ports  Dimensions and design
GB/T 3730.1 Motor vehicles and trailers  Types  Terms and definitions
GB/T 5179 Automobile steering system  Terms and definitions
GB/T 140392002 Hydraulic fluid power  Fluids  Method for coding the level of
contamination by solid particles
JB/T 982 Combined sealing washer
JB/T 7858 Method to determine cleanliness and acceptance criterions for hydraulic
components
QC/T 299.22014 Automobile hydraulic steering power pump  Part 2: Test method
QC/T 484 Automobile paint coating
3 Terms and definitions
The terms and definitions as defined in GB/T 5179, as well as the following terms and
definitions, apply to this section.
3.1
Displacement, q
The oil volume discharged by the steering pump per revolution, the unit is mL/r.
3.2
Minimum rotational speed, nmin
The minimum speed when the steering pump works stably, the unit is r/min.
3.3
Maximum rotational speed, nmax
The maximum rotational speed of the steering pump when it works stably, the unit
is r/min.
3.4
Open rotational speed
Operating speed at which the steering pump's flow control valve is open.
3.4.1
Noload open rotational speed, n1k
Under noload pressure, the working speed when the flow control valve of the
steering pump is opened, the unit is r/min.
3.4.2
Load open rotational speed, n2k
Under the working pressure of 0.6Pmax, the working speed when the maximum
control valve of the steering pump is opened, the unit is r/min.
3.5
Open flow
The output flow rate under the open rotational speed condition.
3.5.1
Noload open flow, Q1k
The output flow under the noload open rotational speed condition, the unit is L/min.
3.5.2
Load open flow, Q2k
The output flow rate under the condition of 0.6Pmax working pressure and open
rotational speed, the unit is L/min.
3.6
Limited flow, Qk
The output flow of the steering pump, within the specified speed range, the unit is
L/min.
3.7
Maximum pressure, Pmax
The highest pressure that allows the steering pump to operate in a short time (i.e.,
the set pressure when the safety valve is opened), the unit is MPa.
3.8
Noload pressure, P0
The output pressure when the oil outlet pressure does not exceed 5% of the
maximum pressure Pmax or 0.5 MPa, the unit is MPa.
3.9
Speed range
Under noload pressure, the range from the lowest speed to the highest speed, when
the steering pump works stably.
3.10
Driving power, N
The mechanical power that drives the steering pump, in kW.
3.11
Damage
The steering pump has leakage, abnormal noise, damaged parts, which cannot meet
its performance requirements.
conditions and requirements for ηv' and ηt' shall be determined through negotiation.
4.6 Air tightness.
There shall be no leakage at all parts and assembly surfaces. When the medium (water
or kerosene) immersion method is used for detection, there shall be no air bubbles;
when the pressure drop method is used for detection, the pressure drop is allowed to be
less than 1.8 x 104 MPa.
4.7 Noise.
Within the allowable speed and pressure range, the product must not have abnormal
noise; its noise shall meet the requirements in Table 2.
Note: Commercial vehicles and passenger cars are defined according to GB/T 3730.1.
4.8 Cleanliness.
The internal cleanliness of the product assembly shall meet the requirements in Table
3.
Note:
1 Please refer to 3.5 in GB/T 140392002 (ISO 4406) for details on the determination of
microscope counting code; refer to 3.4 in GB/T 140392002 (ISO 4406) for details on the
determination of automatic particle counter code.
2 For the cleanliness index of weighing method, refer to the acceptance criteria of JB/T 7858.
4.9 Drive power.
The mechanical power, which drives the steering pump, shall meet the requirements of
the manufacturer.
4.10 Pressure switch characteristics.
The characteristics of the pressure switch shall meet the requirements of the
manufacturer.
5 Reliability requirements
5.1 Constant rotational speed impact.
After the constant rotational speed impact test, the maximum pressure is allowed to
drop no more than 10%, compared to before the test; the flow rate is allowed to change
no more than 10%; the volumetric efficiency and total efficiency meet the requirements
after the reliability test in Table 1; damage is not allowed.
5.2 Durability of variable rotational speed cycle.
After the variable speed cycle durability test, the maximum pressure is allowed to drop
no more than 10%, compared to before the test; the flow rate is allowed to change no
more than 10%; the volumetric efficiency and total efficiency meet the requirements
after the reliability test in Table 1; damage is not allowed.
5.3 Durable to wear.
After testing through the wear durability method, the maximum pressure is allowed to
drop no more than 10%, compared to before the test; the flow rate is allowed to change
no more than 10%; the volumetric efficiency and total efficiency meet the requirements
after the reliability test in Table 1; damage is not allowed.
5.4 Low temperature.
Low temperature start shall be normal.
5.5 Vibration.
After the vibration test is completed, the maximum pressure is allowed to drop no more
than 7%; the flow rate is allowed to change no more than 10%; no damage is allowed.
5.6 Flow cutoff.
After the flow cutoff test, the components must not be damaged; the volumetric
efficiency is allowed to drop by no more than 3%.
6 Supplementary requirements
6.1 The installation of the steering pump and the main engine shall adopt the axial
positioning of the end face, the centering of the seam, the fixed connection of more than
Appendix C
(Informative)
Calculation and design method of performance parameters of automobile
hydraulic steering power system
C.1 Calculation of steering resistance torque Mr
Steering resistance torque M is calculated according to formula C.1.
Where:
Mr  Insitu steering resistance moment on asphalt or concrete road, N • m;
f  Sliding friction coefficient between the tire and the ground, which takes 0.7;
G1  Steering front axle load, N;
P  Tire pressure, Pa.
C.2 Calculation of minimum working pressure Pmin required for steering
The minimum working pressure required for steering is calculated, according to the
moment Mr which is calculated in formula C.1 and the cylinder diameter of the selected
power steering gear, using formula C.2.
Where:
Pmin  Minimum working pressure required for steering, MPa;
Mr  Insitu steering resistance moment on asphalt or concrete road, N • m;
RF  Pitch circle radius of sector teeth, mm;
S0  Working area of power steering gear cylinder, mm2;
S1  The area occupied by the outer diameter of the screw, mm2.
C.3 Calculation of theoretical flow Q0
The theoretical flow Q0 is calculated, according to formula C.3, using the maximum
instantaneous speed of the steering wheel.
Where:
Q0  Theoretical flow rate, L/min;
n  The maximum instantaneous speed of the steering wheel of the car, 1.5 for cars
and 1.25 for other vehicles, r/s;
t  Power steering gear's screw pitch, mm;
S  Actual working area of power steering cylinder, mm2.
C.4 Design of maximum pressure Pmax of steering pump
The result which is obtained from formula C.2 is the minimum working pressure
required for steering. Since the steering pump has a safety protection function, it must
be ensured that the working pressure shall not exceed the maximum design pressure of
the steering pump; the designed working pressure shall not be greater than 0.85 pmax.
Example 1:
The working pressure of the steering pump is 8 MPa, so the maximum pressure of the steering
pump is designed to be 10 MPa.
C.5 Flow matching design of steering pump
According to the flow as calculated in formula C.3, system leakage must also be
considered; the actually required flow is calculated according to formula C.4.
Where:
Q1  Actually required flow rate, L/min;
Q0  Theoretical flow rate, L/min;
Q2  Leakage in the steering gear, L/min.
C.6 Calculation of torque T
Where:
T  Torque, N • m;
...... Source: Above contents are excerpted from the PDF  translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
