Professional terminology for dynamic balance detection and dynamic balance calculation formula
How to solve the problem of the center of mass of a rotating object not being on its axis of rotation, which generates eccentric force and force distance, resulting in vibration and unnecessary impact force on the support during the rotation process. Need to use a balancing machine for dynamic balance detection, to find the eccentric weight, eccentric distance, and eccentric orientation; On this basis, eccentricity can be removed through weighting and weight reduction methods to ensure that the center of gravity of the rotating object is on its axis of rotation, while reducing vibration to ensure the balance of rotation.
Dynamic balancing, also known as double-sided balancing, can be used to balance the imbalance of any unbalanced rotor with two calibration surfaces. Static balancing cannot solve this problem, and can only be corrected on a dynamic balancing machine. Before conducting dynamic balance testing, it is necessary to understand the professional terminology and calculation formulas of dynamic balance testing.
If the balance accuracy requirement of a motor rotor is G6.3 level, the weight of the rotor is 0.2kg, the speed of the rotor is 1000rpm, and the correction radius is 20mm, then the allowable unbalance of the rotor is: because the motor rotor is generally balanced on both sides, the allowable unbalance allocated to each side is 0.3g. Before choosing a balancing machine, the required balance accuracy of the rotor should be considered first.
1、 Explanation of Dynamic Balance Terminology:
1. Rotor balance quality: an indicator for measuring the quality of rotor balance
In the equation G=eper ·Ω/1000:
G is the rotor balance quality, with a unit of mm/s ranging from G0.4-G4000 to 11 levels;
Eper is the allowable unbalance rate of the rotor, measured in gmm/kg or rotor mass eccentricity um;
Ω is the angle at which the rotor operates at its maximum speed, -2 π · m/60;
2. Allowable unbalance per unit mass of rotor (rate):
eper=G·1000/Ω=G·1000·60/（2π·n）
≈ 9549 · G/n, unit g · mm/kg or um;
2、 Simplified calculation formula for unbalanced quantity:
In the equation M=9549MG/r × n:
M - Mass unit of rotor (kg)
G - Selection of Accuracy Level
R - Calibration radius unit (mm)
N - Unit of working speed of the workpiece (rpm)
M - Unit of unbalanced qualified quantity (g)
3、 The calculation formula for allowable unbalance is:
In equation M * G * (60/2PI * r * n) X10 ^ 3 (g):
Mper - allows for imbalance;
M - represents the weight of the rotor itself;
The unit is - kg;
G - represents the balance accuracy level of the rotor;
The unit is - mm/s;
R - represents the correction radius of the rotor;
The unit is - mm;
N - represents the rotational speed of the rotor;
The unit is - rpm.
Before selecting a balancing machine, you need to roughly determine the balance level of the rotor. The International Organization for Standardization (ISO) established the globally recognized ISO 1940 balance level in 1940, which divides rotor balance levels into 11 levels, with increments of 2.5 times between each level, ranging from the highest demand G0.4 to the lowest demand G4000, in mm/s, representing the distance of unbalance to the rotor axis. As shown in the table below:
G4000
Crankshaft drive components for low-speed marine diesel engines with rigid devices with an odd number of cylinders
G1600
The crankshaft drive components of large two-stroke engines with rigid devices
G630
The crankshaft drive components of large four stroke engines with rigid devices; Crankshaft drive components for marine diesel engines with elastic devices
G250
The crankshaft drive component of high-speed four cylinder diesel engine with rigid device
G100
The crankshaft transmission components of six cylinder and multi cylinder high-speed diesel engines; Complete engines for cars, trucks, and locomotives
G40
Car wheels, hubs, wheel assemblies, transmission shafts, crankshaft drive components for six cylinder and multi cylinder high-speed four stroke engines with elastic devices
G16
Drive shafts with special requirements (propellers, universal joint drive shafts); Parts of the crusher; Parts of agricultural machinery; A single component of a sedan engine; Crankshaft drive components for six cylinder and multi cylinder engines with special requirements
G6.3
The gears of the main turbines of merchant ships and sea vessels; Drum of high-speed separator; Electric fan; Rotor components of aviation gas turbines; Pump impeller; Machine tools and common machine parts; General motor rotor; Individual components of engines with special needs
G2.5
Gas and steam turbines; Machine tool drive components; Medium and large motor rotors with special requirements; Small motor rotor; turbopump
G1
Drivers for magnetic tape recorders, record players, CDs, and DVDs; Grinding machine drive components; Small armature with special needs
G0.4
The spindle of a precision grinder; Motor rotor; gyroscope
How to solve the problem of the center of mass of a rotating object not being on its axis of rotation, which generates eccentric force and force distance, resulting in vibration and unnecessary impact force on the support during the rotation process. Need to use a balancing machine for dynamic balance detection, to find the eccentric weight, eccentric distance, and eccentric orientation; On this basis, eccentricity can be removed through weighting and weight reduction methods to ensure that the center of gravity of the rotating object is on its axis of rotation, while reducing vibration to ensure the balance of rotation.
Dynamic balancing, also known as double-sided balancing, can be used to balance the imbalance of any unbalanced rotor with two calibration surfaces. Static balancing cannot solve this problem, and can only be corrected on a dynamic balancing machine. Before conducting dynamic balance testing, it is necessary to understand the professional terminology and calculation formulas of dynamic balance testing.
If the balance accuracy requirement of a motor rotor is G6.3 level, the weight of the rotor is 0.2kg, the speed of the rotor is 1000rpm, and the correction radius is 20mm, then the allowable unbalance of the rotor is: because the motor rotor is generally balanced on both sides, the allowable unbalance allocated to each side is 0.3g. Before choosing a balancing machine, the required balance accuracy of the rotor should be considered first.
1、 Explanation of Dynamic Balance Terminology:
1. Rotor balance quality: an indicator for measuring the quality of rotor balance
In the equation G=eper ·Ω/1000:
G is the rotor balance quality, with a unit of mm/s ranging from G0.4-G4000 to 11 levels;
Eper is the allowable unbalance rate of the rotor, measured in gmm/kg or rotor mass eccentricity um;
Ω is the angle at which the rotor operates at its maximum speed, -2 π · m/60;
2. Allowable unbalance per unit mass of rotor (rate):
eper=G·1000/Ω=G·1000·60/（2π·n）
≈ 9549 · G/n, unit g · mm/kg or um;
2、 Simplified calculation formula for unbalanced quantity:
In the equation M=9549MG/r × n:
M - Mass unit of rotor (kg)
G - Selection of Accuracy Level
R - Calibration radius unit (mm)
N - Unit of working speed of the workpiece (rpm)
M - Unit of unbalanced qualified quantity (g)
3、 The calculation formula for allowable unbalance is:
In equation M * G * (60/2PI * r * n) X10 ^ 3 (g):
Mper - allows for imbalance;
M - represents the weight of the rotor itself;
The unit is - kg;
G - represents the balance accuracy level of the rotor;
The unit is - mm/s;
R - represents the correction radius of the rotor;
The unit is - mm;
N - represents the rotational speed of the rotor;
The unit is - rpm.
Before selecting a balancing machine, you need to roughly determine the balance level of the rotor. The International Organization for Standardization (ISO) established the globally recognized ISO 1940 balance level in 1940, which divides rotor balance levels into 11 levels, with increments of 2.5 times between each level, ranging from the highest demand G0.4 to the lowest demand G4000, in mm/s, representing the distance of unbalance to the rotor axis. As shown in the table below:
G4000
Crankshaft drive components for low-speed marine diesel engines with rigid devices with an odd number of cylinders
G1600
The crankshaft drive components of large two-stroke engines with rigid devices
G630
The crankshaft drive components of large four stroke engines with rigid devices; Crankshaft drive components for marine diesel engines with elastic devices
G250
The crankshaft drive component of high-speed four cylinder diesel engine with rigid device
G100
The crankshaft transmission components of six cylinder and multi cylinder high-speed diesel engines; Complete engines for cars, trucks, and locomotives
G40
Car wheels, hubs, wheel assemblies, transmission shafts, crankshaft drive components for six cylinder and multi cylinder high-speed four stroke engines with elastic devices
G16
Drive shafts with special requirements (propellers, universal joint drive shafts); Parts of the crusher; Parts of agricultural machinery; A single component of a sedan engine; Crankshaft drive components for six cylinder and multi cylinder engines with special requirements
G6.3
The gears of the main turbines of merchant ships and sea vessels; Drum of high-speed separator; Electric fan; Rotor components of aviation gas turbines; Pump impeller; Machine tools and common machine parts; General motor rotor; Individual components of engines with special needs
G2.5
Gas and steam turbines; Machine tool drive components; Medium and large motor rotors with special requirements; Small motor rotor; turbopump
G1
Drivers for magnetic tape recorders, record players, CDs, and DVDs; Grinding machine drive components; Small armature with special needs
G0.4
The spindle of a precision grinder; Motor rotor; gyroscope
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