Some standard content:
JB/T 9101--1999
This standard adopts IS01940-1:1986 "Mechanical vibration-balance quality requirements for rigid rotors Part 1
Determination of allowable residual
unbalance".
This standard is a revision of ZBJ72042--90 "Balance of fan rotors". Only editorial changes were made to the original standard during the revision. This standard replaces ZBJ72042--90 from the date of implementation. Appendix A of this standard is a prompt appendix.
This standard is proposed and managed by the National Technical Committee for Standardization of Fans. The responsible drafting unit of this standard: Shenyang Blower Factory. The main drafters of this standard: Lin Xuemin, Chen Mingliang, Jiang Jilin. 398
1 Scope
Machinery Industry Standard of the People's Republic of China
Fan rotor balance
Fan rotor balance
JB/T9101-—·1999
Replaces ZBJ72042—90
This standard specifies the balancing method, balancing quality grade, balancing equipment accuracy requirements, calibration method and re-inspection regulations for fan rotors. This standard is applicable to the balancing of centrifugal fans and axial flow fan rotors or impellers. 2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T1184—1996 Tolerance of shape and position without tolerance value GB/T4201-1984 Verification method for general horizontal balancing machine GB/T6444—1995 Terminology of mechanical vibration balance 3 Terminology and symbols
The terms and symbols related to balance involved in this standard shall comply with the provisions of GB/T6444. 4 Rotor type
The fan rotor is divided into 8 types according to its structure, as shown in Figure 1. 5 Rotor balancing method
The fan rotor is generally a rigid rotor, and its balancing method is divided into single-plane (static) balancing and double-plane (dynamic) balancing. 5.1 Single-plane (static) balancing
5.1.1 Single-plane (static) balancing is a method of balancing based on the unbalanced amount of the rotating body being approximately on the plane where the center of mass of the rotating body is located, using a correction plane through swinging in the gravity field. 5.1.2 Conditions for single-sided (static) balancing a) When the maximum operating speed n<1500r/min, the ratio of the impeller (or pulley) width B to the impeller (or pulley) diameter D is less than or equal to 0.2;
b) When the maximum operating speed n≥1500r/min, the ratio of the impeller (or pulley) width B to the impeller (or pulley) diameter D is less than or equal to 0.1;
c) The static balancing equipment can meet the required rotor balancing quality level and can only perform single-sided (static) balancing. Note
1 Impeller width B refers to the maximum distance of the impeller projection on the axis. 2 Impeller diameter D refers to the maximum outer diameter of the impeller. Approved by the State Bureau of Machinery Industry on July 12, 1999. Implemented from January to January 2000.
5.2 Double-sided (dynamic) balancing
JB/T9101-1999
5.2.1 Double-sided (dynamic) balancing is a method of balancing the rotor using two correction planes when the rotor is rotating. 5.2.2 Conditions for using double-sided (dynamic) balancing a) Those that do not meet the conditions described in 5.1;
b) When the drawing clearly stipulates that double-sided (dynamic) balancing is required; c) When the vibration value of the bearing during the operation of the unit exceeds the allowable value. 5.3 Balance quality level of the rotor
5.3.1 For fans whose impellers are directly assembled on the motor shaft head (Figure 1a), the motor rotor has been balanced before leaving the factory. For this, it is allowed to balance the impeller separately according to the provisions of 5.1 and 5.2, and its balance quality level is 5.6mm/s. 5.3.2 For a cantilever-supported rotor with the impeller mounted at one end of the transmission group [Figure 1d)] and the center of mass of the rotor outside the left or right support, the impeller can be balanced separately, and the overall balancing is no longer required after the rotor is assembled. When the balancing shaft is manufactured according to the standard with high dimensional accuracy and coaxiality and the balancing shaft and the impeller hole are balanced together under the condition of seamless fit, the balancing quality level is 5.6mm/s, and the rotor mass is calculated as the sum of the impeller and balancing shaft masses. 5.3.3 For a cantilever-supported rotor with the impeller mounted at one end of the transmission group and the pulley mounted at the other end [Figure 1c)] and the center of mass of the rotor outside the left or right support, the impeller and pulley can be balanced separately [pulleys with all surfaces processed do not need to be double-sided (dynamic) balanced, and they are no longer balanced after assembly. When the balancing shaft is manufactured according to the standard with high dimensional accuracy and coaxiality, and the balancing shaft and the impeller or pulley hole are kept in a gap-free fit and balanced together, its balancing quality level is 5.6mm/s, and the rotor mass is calculated as the sum of the impeller and the balancing shaft mass.
5.3.4 The impeller is installed at one end of the transmission group, and the pulley is installed in the rotor between the two supports [Figure 1b)]. The provisions are the same as 5.3.3. 400
JB/T9101—1999
5.3.5 The supports are distributed on both sides of the rotor mass center [Figure 1e), and the entire rotor can be balanced at a balancing quality level of 6.3mm/s. When the mass center is located within the 1/3 length range of the middle of the two support spacing (see Figure 2), and the two correction planes are basically equidistant from the mass center, the mass on both sides is calculated as 1/2 of the rotor mass. If it exceeds the above range, the mass on both sides should be distributed according to the actual distance between the mass center and the two correction planes. The actual mass on each side. L/3
5.3.6 The supports are distributed on both sides of the rotor mass center [Figure 1f)], and the provisions are the same as 5.3.5. A
5.3.7 For the balancing of the transmission shaft (hollow shaft) [Figure 1g)], the reference surfaces of the balancing supports shall be provided at both ends. The reference surfaces shall be concentric with the surface of the journal and the shaft diameter at the coupling installation. The coaxiality tolerance shall not be greater than 0.02mm. The transmission shaft shall be double-sided (dynamic) balanced, and the balancing quality level shall be 6.3 mm/s.
5.3.8 For the balancing of the impeller of a single-stage large axial flow or cooling tower (Figure 1h) fan, single-sided (static) balancing shall be performed according to 5.1, and no balancing shall be performed after assembly on the transmission shaft. When a vertical static balancing machine is used for static balancing, the allowable unbalance amount of the impeller after balancing shall not be greater than the value specified in Table 1.
Impeller diameter
Allowable unbalance
g●mm
1) This machine number does not belong to the R40 series. According to the use requirements, it is temporarily retained. 6 Accuracy of balancing equipment and process equipment
Impeller diameter
6.1 Select the corresponding balancing equipment according to the mass of the balancing workpiece and the balancing quality grade. Allowable unbalance
96 000
121500
150000
234375
6.2 The balancing equipment needs to be measured regularly according to the provisions of GB/T4201, and its accuracy should be equal to or higher than the balancing quality requirements of the workpiece. 6.3 The balancing shaft itself should have sufficient rigidity, its mass should be minimized, and it should be double-sided (dynamic) balanced, and its balancing quality grade is 2. 5 mm/s.
6.4 There should be no gap between the balancing shaft and the impeller. The coaxiality tolerance between the balancing bearing surface of the balancing shaft and the shaft diameter at the driving end of the balancing shaft and the matching part of the workpiece should not exceed 0.02mm. The balancing bearing surface should be hardened, with a hardness of not less than 40HRC and a bearing surface roughness Ra value of not more than 1.60μm; the cylindricity tolerance should not be less than the 6th grade tolerance specified in GB/T1184. 6.5 If the rotor is a single-key structure, a half key (half the key mass, that is, the length and width of the key remain unchanged, and the height is halved) should be installed at the corresponding keyway for balancing compensation.
7 Correction methods and requirements
JB/T 9101 -- 1999
7.1 The material of the correction mass (counterweight) of the welded impeller shall be the same as that of the welded parent material, and its thickness shall not exceed that of the welded parent material. The same method as the welding blades shall be used to fully weld it on the outer surface of the impeller disc (cover). The correction mass (counterweight) shall be chamfered all around, with a neat appearance and no cracks in the weld. The number and position of the correction mass (counterweight) shall be the same as the requirements of 7.5. 7.2 The correction mass (counterweight) of the riveted impeller is generally fixed to the outer surface of the impeller disc (cover) by riveting. The material of the rivet is straight. The diameter and number (the number shall not be less than 2 and a certain spacing shall be left) shall be determined through strength calculation. The number, shape and position of the correction mass (counterweight) are the same as those in 7.1 and 7.5. 7.3 Impeller and pulley of cast structure When the correction mass (counterweight) is fixed to the steel plate with screws, the material, diameter and number of the screws (the number shall not be less than 2 and a certain spacing shall be left) shall be determined through strength calculation. Anti-loosening measures must be taken after the screws are tightened. The number, shape and position of the correction mass (counterweight) are the same as those in 7.1 and 7.5. 7.4. When the impeller requires very little correction mass (counterweight), it is allowed to use a grinding wheel to grind away the weight in the unbalanced weight direction, and the weld and rivet head position should be avoided. The grinding depth shall not make the wheel disc (cover) thickness less than the allowable value of the drawing, and the ground surface shall not have local annealing. The ground surface and the original surface shall have a smooth transition and no ridges. 7.5 The number of correction masses (counterweights) shall not exceed two on the same correction plane, and the phase difference between the two blocks shall not be greater than 90°. The minimum distance between the outer edge of the correction mass block (counterweight) and the outer edge of the impeller wheel disc (cover) shall not be less than 10mm. 7.6 The correction mass (counterweight) shall not be compensated by other attachments (such as thick paint). 8.1 The balance quality grade G is expressed by the product of the rotor mass eccentricity e and the rotor's maximum operating angular velocity w divided by 1000, as shown in formula (1):
Wherein: G--balance quality grade, mm/s; e--rotor mass eccentricity, um;
u--angular speed, a=
, rad/s;
n---maximum operating speed of the rotor, r/min. If n is replaced, the balancing quality grade G is expressed by formula (2): ee
8.2 When the balancing quality grade of the fan rotor is specified as 6.3mm/s (i.e. 6.3-et
, if the maximum operating speed of the rotor is known, the allowable mass eccentricity e (μm) of the rotor can be calculated according to formula (1) or formula (2), and can also be obtained from Table 2 or Figure 3. Table 2
Maximum operating speed of rotor n, r/min
Balancing quality grade
Allowable mass
Eccentricity e
9 Determination of allowable unbalance
JB/T 9101-
100020005000
50 000100 000
50010002000
Maximum operating speed r/s
9.1 For actual rotors or impellers, after the balance quality level is determined, the allowable unbalance U of the rotor can be calculated by multiplying the known allowable mass eccentricity of the rotor by the rotor mass m according to formula (3). U-em
Where: U-allowable unbalance of the rotor, g·mm; e-allowable mass eccentricity of the rotor·m; m-rotor mass, kg.
Professional and dedicated
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9.2 When one correction plane is used for single-sided (static) balancing (disc-shaped rotor), the allowable unbalance on the correction plane is equal to U. 9.3 When two correction planes are used for double-sided (dynamic) balancing, when the rotor mass center is located within the 1/3 length range between the two support spacings, and the two correction planes are basically equidistant from the mass center, the allowable unbalance on each correction plane is equal to half of U, that is; U= U=em
9.4 When the rotor mass center is located within the two support spacings, but the two correction planes are asymmetrically arranged with the mass center, the allowable unbalance U1 and U2 of the correction plane 1 and correction plane II need to be allocated according to the distribution ratio of the rotor mass (see Figure 4). From equations (5) and (6), it is obtained that: Ut= em (a+b)
· (5)
JB/T9101—1999
U, = em (a +b)
Where: U,--allowable unbalance of correction plane I, g·mm; Uz--allowable unbalance of correction plane 1, g·mm; b--distance between correction plane and center of mass, mm; a--distance between correction plane I and center of mass, mm. Correction plane 1
Correction plane II
9.5 In a certain correction plane, the correction mass (counterweight) m can be calculated according to the residual unbalance U and correction radius r in the correction plane; the relationship is shown in formula (7):
mir; = U.
Where: U
-residual unbalance of a certain correction plane displayed by the balancing machine, g·mm; r:——correction radius on the correction plane, mm; m——correction mass on the correction plane, kg. 10 Inspection and re-inspection of balancing quality
10.1 Inspection of balancing quality is divided into inspection carried out during normal production of the manufacturer and re-inspection of completed balanced rotors during delivery acceptance to users or product sampling. For balancing carried out during normal production of the manufacturer, the residual unbalance should be lower than the specified value of the allowable unbalance; during re-inspection during delivery acceptance to users or product sampling, the residual unbalance is allowed to exceed the specified value of the allowable unbalance. The limit values for the two inspections should comply with the provisions of Table 3.
Balance quality grade G
Normal production inspection limit value
≤90% specified value
Delivery acceptance or product sampling re-inspection limit value≤115% specified value
10.2 The re-inspection of double-sided (dynamic) balancing components on a soft-bearing dynamic balancing machine can be carried out by the following two methods. 10.2.1 Weight-added inspection
After the calibration mass (counterweight) has been fixed on the rotor, according to the scale reading and phase of the remaining unbalance on the two calibration planes displayed on the balancing machine instrument, add a test mass (test weight) to the phase of the biased weight in each calibration plane, so that it is equal to the allowable unbalance of the calibration plane, and then start the balancing machine to observe the instrument reading. If the new reading is more than 1 times the reading before the test mass (test weight) is added, the balance is considered qualified under the general accuracy requirements.
10.2.2 Test by graphing
After the calibration mass (counterweight) has been fixed on the rotor, and the scale readings and phases of the residual unbalance on the two calibration planes displayed by the balancing machine instrument are known, add a test mass (about 2 to 5 times the allowable unbalance of the calibration plane) on each calibration plane (the inspection of the two calibration planes should be carried out separately), and move it several times in equal parts on the calibration plane (a consistent calibration radius must be determined, see Figure 5). For each position moved, a scale reading and phase are obtained by the balancing machine instrument, and a sinusoidal curve diagram of the position, scale reading and phase is made according to the records (Figure 6). When no test mass (test weight) is added, the scale reading is A. When the test mass (test weight) is not present, the remaining unbalanced mass on the radius r (correction radius) of the circle with the test mass (test weight) is calculated according to formula (8): A
Where: g—
remaining unbalanced mass, kg;
k——test mass, kg;
A—the scale reading generated by the test mass (test weight) in the opposite phase of the remaining unbalanced amount; A. Scale reading without test mass.
·(8)
Then multiply the calculated g by the correction radius r to obtain the actual remaining unbalanced amount of the correction surface (the phase can be determined by Figure 6), and then compare it with the allowable unbalanced amount. If it is less than or equal to the limit value, it is qualified. This method is used as a balance grade requirement. The unbalance amount generated by the test mass (test weight) is the residual unbalance amount U
《, which is
the position sequence of the test mass (test weight)
the residual unbalance amount phase angle α
the angular position of the test mass (test weight) (°) 10.3 The residual unbalance amount of the double-sided (dynamic) balancing component can be directly read by the instrument on the hard-bearing balancing machine. 10.4 When inspecting the balance quality, the influence of the imbalance of the universal joint on the balance of the rotor must be eliminated. The method is that after the rotor is double-sided (dynamic) balanced, on the correction plane close to the universal joint side, the instrument shows that the scale reading of its residual unbalance amount is IAI (grids), the phase angle α (°), the rotor is rotated 180° relative to the universal joint, connected and then paralleled again, and the new scale reading is || (grids), and the new first two D is the residual unbalance amount of the rotor. By using the graphical method (Fig. 7) or equations (9) to (16), the result of eliminating the universal phase angle β(°) can be obtained; then
JB/T 9101—-1999
the residual unbalance of the rotor after the influence of the coupling unbalance is [(grid), phase angle 8(°). A= Alcosα
A, 「A|sinαwwW.bzxz.Net
B, = IBlcosp
B, IBIsinβ
101 = V(A, -B)*+ (A, - B,)
Wherein: A——projection of vector A on the horizontal axis; A,—projection of vector A on the y-axis; B.—projection of vector B on the α-axis; B,—projection of vector B on the y-axis. When A =B,>0,090°
When AB<0,8-90°
When 9090°:
= arctan
When 90<270°:
A,—B,
g=r + aictan
￥90°
A—6 grids 350°; B—10 grids 225°
.4-..+.+.+.+-.
10.5 Fill in the rotor or impeller balance inspection record card according to the format of Appendix A (suggested appendix). 11 Marking of balance requirements in design drawings
11.1 The position of the correction plane should be indicated in the design drawings. : 11.2 The maximum operating speed of the rotor or impeller, the rotor mass and the required balance quality level should be indicated in the design drawings. 406
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·（11)
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Product model and specification
JB/T9101-1999
Appendix A
(Suggestive appendix)
Fan rotor (impeller) balance inspection record card
Residual unbalance angle (seen from the drive end, the angle is recorded in the figure) Maximum operating speed
Balance quality grade G
Workpiece quality
Balance shaft quality
Balance Speed
Allowable unbalance
Residual unbalance
Maximum workpiece diameter
Correction radius
Correction mass (counterweight)
Dynamic balancing machine specifications and models
Operator:
Date:
Wheel cover side (Correction plane 1)
Inspector:
Date:
No.:
Wheel disc side (Correction plane 1)
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