GB/T 11362-1989 Calculation of rated power and transmission center distance of synchronous belt drives
Some standard content:
National Standard of the People's Republic of China
Synchronous belt drives
Calculation of power rating and drive centre distance
Synchronous belt drives
Calculation of power rating and drive centre distanceGB 11362-89
This standard adopts 1SO5295-1981 "Calculation of rated power and drive centre distance of synchronous belts". Subject content and scope of application
The small standard is a standard synchronous belt for two-wheel drive, and establishes a calculation formula for rated power and centre distance. 2 Definition
Rated power: The power that a synchronous belt can transmit when it works normally within a certain period of time under the premise that the transmission device is correctly installed and maintained, and under the specified geometric conditions and environmental conditions. The rated power depends on:
the pitch of the teeth of the belt and the pulley
the width,
the mass of the belt per meter;
the allowable working tension of the belt:
the angular velocity of the small pulley,
the number of teeth of the small pulley:
the number of teeth of the small pulley.
the reference rated power P.
the reference rated power is calculated according to formula (1) and (2): P=
(Ta - mV2) V
Formula: T. —The allowable working tension with a belt width of bsn, N is the maximum width of a standard belt with a pitch of Pb, that is, the reference width (see the table below), mm: hso
where: α -
the mass per unit length with a belt width of bs, kg/m; the speed of the belt, m/s.
V=OPbZ-×10 3
a small pulley angular velocity, rad/s:
pitch of the belt and pulley teeth, mm;
a small pulley tooth number.
Formula (1) is applicable to the case where the number of teeth is m6, see Chapter 4. Approved by the State Administration of Technical Supervision on June 12, 1989 (1)
Implementation on January 1, 1990
4 Rated power calculation
4.1 Exact formula
GB 11362-89
Base width
Base width bs
The rated power of a belt with a width of bs and a small pulley with a number of teeth of Zm is calculated according to formula (3): P = (K2K-T
Formula: p
Rated power of the belt when the belt width is hs, kW; - see Chapters 7 and 8 respectively.
4.2 Approximate formula
After simplifying formula (3) as follows, formula (4) can be used to make an approximate calculation of the rated power: P-Kz Kw P.
5 Center distance calculation
5.1 Accurate formula
First, use formula (5) to calculate the auxiliary angle 8:
Where: invo=tane-, (the value of the figure) can be determined by the step-by-step approximation method or by looking up the asymptote function table, the number of teeth in the range Zh-
.
Then use formula (6) to calculate the center distance α:
Ph (Z2 -Z.)www.bzxz.net
2-element cosg
According to formula (), (6) the calculation is generally correct, but when the value of Z,/Z, is close to 1, the above method should not be used, because the expression of a becomes the ratio of two trace quantities. In this case, it is recommended to use the method given in 5.2. 5.2 Approximate formula
First, calculate M by formula (7):
(2 Zh - Z, -22)
Then calculate the center distance according to formula ():
GB 11362—89
P (22 -Z1)
When the value of 22/Z is large, this method should be avoided and the method given in 4.1 should be used. 2b
6Number of meshing teeth Zm
The number of meshing teeth is given by formula (9):
Number of meshing teeth coefficient KL
When 2m≥6, K2= 1
8Width coefficient K
Coefficient K is given by formula (11);
When Z㎡<6,
Kz = 1 - 0.2 (6 - Zm)
The bs depends on the belt model, and its value is shown in the table. The calculation result of K is rounded to two decimal places. bs
A1 Design power
GB11362—89
Appendix A
Design calculation of synchronous belt transmission
(reference)
According to the prime mover and working machine used in the transmission, considering different operating times, the nominal power transmitted is multiplied by the correction factor (load correction factor and additional correction factor are shown in Table A2, Table A3, Table A1) to obtain the design power. A2 Select the pitch of the belt
Select the belt model according to Figure A1 based on the design power and the speed of the small pulley. When the selected code is close to the adjacent code, the two belt types are set in parallel and the best one is selected. A3 Reference rated power
For XL to XXH synchronous belts, when the number of teeth is Zm6, the rated power of the reference width, i.e. the reference rated power, is shown in Table A6 to Table A10
For MXI synchronous belts, the rated torque is calculated according to formula (A1), (A2), (A3). Bandwidth, mn
In the table: T
T = d (5. 00 9.50 ×10-6d*)
T=d(8.34-1.58×105d*)
T =t (11,7 - 2,22× 10-id2)
When the number of teeth is greater than ten or equal to 6, and the pulley peripheral speed is less than 33m/s, the maximum rated torque of the corresponding bandwidth is N·mm-small pulley pitch diameter, mm.
When the number of meshing teeth is less than 6, the rated torque is multiplied by the K value of GB11362-89 formula (10) to correct it. For XXL type synchronous belt, its base rated power is calculated according to GB11362-89 formula (1), the formula is less than T, and the value of m is shown in Table A5.
A Meshing teeth coefficient
Meshing teeth coefficient K. See GB11362-89 formula (10). A5 Width coefficient
Width coefficient K See GB11362-89 formula (11). A6 Correction of base rated power
Correct the base rated power to the rated power according to GB11362--89 approximate formula (4). A7 Select standard bandwidth
To meet the transmission requirements, the design power should be less than ten or equal to the rated power. H is calculated to obtain the required bandwidth and then the standard bandwidth is selected. AB Calculate the pitch diameter of the pulley
GB 11362-89
The number of teeth of the small pulley Z is determined according to the minimum number of teeth used by the pulley (see Table A1) and Table 5 of GB11361-89. The number of teeth of the pulley Z2 is calculated by the mountain formula (A4):
Z2-iZ1
After calculation, determine Z by rounding according to Table 5 of GB11361-89. The pitch diameters of the large and small pulleys are calculated according to formulas (A5) and (A6): d2
A9 Selection of pulleys and use of tensioning wheels
For the use of tensioning wheels, see Appendix A of GB11361-89. Center distance and belt length
A10.1 Belt length
The belt length is calculated by formula (A7):
Lp=2a cosh +-
Formula 4: L-
Belt length, mm;
Center distance, mm;
π(d,+d)
d,,di→large and small pulley pitch circle diameters, mm;@ =sin-l
n(d2-d,)
The belt length obtained by calculation is based on Table 3 of GB11616 "Synchronous Belt Dimensions", and the closest standard belt length is selected. (A4)
（A7)
A10.2 Center distance
After the belt length L, large and small pulley pitch diameters d2 and d are determined, the actual center distance is calculated according to formula (5), (6) or (7), (8) of GB11362-89
A11 Design calculation example
An asynchronous motor with a rated power of 2.2kW and a speed of 1430r/min drives a liquid mixer with a speed of 340r/min. The mixer works in one shift and runs at a full load of 2.2kW. The center distance requirement is about 500mm, and the pulley diameter is not limited. Try to design the synchronous belt drive of this liquid mixer.
The design steps are briefly presented as follows:
Give the special drive requirements
(1) Nominal power of the transmission: Pm=2.2kW; (2) Speed of the upper driven shaft: n,-1430r/min; Speed of the driven vehicle: nz-430r/mins (3)
Center distance requirement: 500mm right;
GB 11362--89
(4) Prime mover: 2.2kW asynchronous motor: Working machine: Liquid mixer (5) Operating hours: 24 hours a day
(6) Others: The pulley diameter is not limited. 2 Select the belt pitch
(1) Calculate the design power
a: The load correction factor K is obtained from Table A2. =1.8. Since no tensioning wheel is used, it means deceleration motion, so the additional correction factors in Table A3 and Table A4 are both zero.
b. Calculate the design power Pd
Pa=K,Pm=3.96kW.
（2）Select the belt pitch
From P=3.96kW and n,=1430rpm, we can find out from Figure A1 that the belt pitch code is H, and the corresponding pitch is Ph=12.700mm (see Table 1 of GB11616)
3 Determine the true diameter of the pulley and the length of the belt pitch line
（1）Determine the pulley diameter
From Table A1, we can get: for H-type belt, when the speed of the small pulley is n=1430r/min, the minimum allowable number of teeth of the pulley is Z,=18. Take the number of teeth of the small pulley Z,=18. Transmission ratio i=
The diameter of the small pulley is
The diameter of the human pulley is
（2）Select the belt length
n=4.086, Z2=Z,=73.55, and take Z2=72 according to the standard number of pulley teeth. n2
Calculate the belt length by formula (A9)
=291.06mm
Lp.= 2acos$ + yuan (d,+d) /2 +ad (d, -d,)/180 .......(A9
After calculation, in the formula = sin-
）=126° (first substitute a=500mm), Lp-1595.42mm.
According to Table 3 of GB11616, select the standard belt length Lp=1600.20mm which is closest to the calculated value. The number of teeth of this belt is Zb=126. (3) Determination of transmission center distance
a: Calculate according to the approximate formula
Calculate according to formulas (7) and (8) of GB11362-89, and the result is: Mf =
b. Calculate according to the correct formula
(2 Z- Z, - Zz) = 257.175mm
Pb (Z2-Zt)
Calculate according to formula (5) (6) of GB1132-89, the result is: 502.496mm
4 Select standard bandwidth
GB11362--89
=3.1416, inv=tg0-6 Calculate using the stepwise approximation method, 0=1.3518 (radians). Pb (Z,-Z1)
2cus 6
502.409mm
（1）Determine the reference rated power P
The number of teeth of the small pulley Z,=18 (diameter d1=72.766mm), the speed n=1430r/min, and the interpolation method of Table A8 obtains the reference rated power P of the H-type belt=11.37kW.
（2）Determine the rated power P
First calculate the required bandwidth b$ according to GB11362-89 formula (4), select the standard bandwidth, and then verify its working capacity according to GB11362-89 formula (3).
Meshing tooth number coefficient K2
Meshing tooth number Zm=ent
bBand width coefficient K
Table GB11362-89 Table 2.
Rated power P
(Z\Z)1 =7>6, so Kz=1
1.14., H-type belt bsg=76.2mm
PaKzKwPa=KzPrbs1-14 /b sp1.14kW () Select bandwidth bs
According to design requirements, "P
So bandwidth bs (
Select bandwidth according to GB11616 Table 4, 6s=38.1mm. Working capacity verification
P=(KzKwTa
mV2) V ×10-3kW
Permissible T: tensile force is obtained from Table A5. =2100.85N, unit length mass is obtained from Table A5 m=0.448kg/msb.
Circumferential speed of belt V=Ph·z,·n1/60000=5.45m/s1d.
1Capacity verification
× 2 100.85
× 5.45×10-3=5.16kW>3.96kW
×0. 448 ×5, 45 2
GB 11362—89
The rated power is greater than the design power, so the belt transmission capacity is sufficient. Results summary
(1) Belt: Select H-type synchronous belt, Pb=12.7mm, Z: -126, Lp=1600.2mm, bs=38.1mm. (2) Pulley: Z,--18, d/=72.77mm, Zz=72, fz=291.06mm. (3) Transmission center distance: Approximate formula calculation, a=502.4961m; accurate formula calculation, a=502.408mm. (4) For the rest, refer to
Table A! Minimum number of teeth used for pulley
Small pulley speed n
900 ~ ≤ 1 20
1200 ～ 1800
1800 3600
3600 ~ 4800
ny,r/min
50 000
40 000
0.02 0.03 0. 05
0.20.30.5
Pulley minimum half
Synchronous belt selection chart
200300500
Copier, computer, medical equipment
Sweeping machine, sewing machine office machinery,
Light load conveyor belt, packaging machine, rotary mixer, circular band saw,
Grinding plate, washing machine, paper machine, printing and adding
Mixer (cement, viscous body)
Leather conveyor (ore coal,)
Shaper, medium excavator, centrifugal
Compressor, vibrating screen, textile machine
(warping machine, winding machine), world transfer Compressor, compound engine, conveyor (disc, code, lifting type), water pump, washing machine, blast train (centrifugal, induced draft, exhaust) engine, exciter, winch, crane, rubber processing machine (calender, rolling extruder), textile machinery (spinning, spinning, twisting column, winding yarn), centrifugal separator, conveyor (cargo, spiral), hammer mill, paper machine (pulping), ceramic machine (silicon, viscosity mixing), mineral mixer, blower. GB 11362-89 Table A2 Load correction factor K.
AC motor (normal torque squirrel cage, synchronous motor), DC motor (parallel excitation), multi-cylinder internal combustion engine
Operation time
Intermittent use
Normal use
g ~10h
Continuous use
16 ~ 24h
AC motor (high torque, high slip single-phase, slip ring), DC motor (compound
invitation, series excitation), single-cylinder internal combustion engine
Operating time
GB11362—89
Table A3 Correction coefficient for using tensioning wheel
Position of clamping wheel
Inside of loose side
Outside of loose side
Inside of tight side
Outside of tight side
Note: When using clamping wheel, in addition to considering the coefficient in Table A2, the coefficient in this table shall be added to the load coefficient. Table A4 Correction coefficient for speed-increasing transmission
1.00 ~1.24
1. 25 ~ 1. 74
1. 75 ~ 2. 49
2.50 ~3. 49
Note: When speed-increasing transmission is used, add the coefficient in this table to the load factor. Table A5 Permissible working tension and mass per unit length Belt model Ta, N 244, 46 GB11362-89 Table A6 XL belt (pitch 5.080 mm, reference width 9.5 mm) Reference rated power P, kw Number of small pulleys and pitch diameter, mm 0, 046 0, 068 152 tt.0.075
Small pulley
r/min
GB11362—89
Table A7L type belt (pitch i9.525mm,
basic rated power P\,
basic width 25.4mm)
Small belt number of teeth, sharp section diameter,
60.6466.70
78.8384.89: 90.90 7.02:109.15|121.28133. 40145. 53
is the power value when the pulley circumferential speed is 33m/s at 1 hour, assuming that the pulley is made of carbon steel or titanium steel at 1 hour. 1.o1
14:271
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