The part that rotates around the axis in the machine is called the rotor of the machine. If a rotor has a uniform mass distribution and is manufactured and installed properly, the operation is balanced. Ideally, the pressure on the bearing, other than gravity, is the same as when the rotor is not rotating, with only static pressure.This rotor with only static pressure on the bearing when it rotates and does not rotate is called a balanced rotor. If the rotor has additional dynamic pressure to the bearing in addition to static pressure when it rotates, it is called an unbalanced rotor.
In fact, there is no absolute balanced rotor, while great vibration caused by big unbalance mass could do damage to the machines. そこで, dynamic balancing machine is widely applied to all industries, to reduce the unbalance weight to a reasonable balance accuracy grades. Rotors of different industries require different dynamic balance grades due to their features.
Here we list some dynamic balancing grade requirements for workpieces industries.
G630 | 630 | Crankshaft drives for rigidly mounted marine diesel engines, rigidly mounted crankshaft drives for large four-stroke engines |
G250 | 250 | Crankshaft drive for rigidly mounted high-speed four-cylinder diesel engines |
G100 | 100 | Crankshaft drives for six- and multi-cylinder diesel engines; complete (gasoline, diesel) engines for automobiles, trucks and locomotives |
G40 | 40 | Automobile wheels, rim wheels, wheel integrals; crankshaft drives of engines for automobiles, truck and locomotives |
G16 | 16 | Parts of pulverizers, agricultural machinery; individual parts of (gasoline, diesel) engines for automobiles, truck and locomotives |
G6.3 | 6.3 | Gas and steam turbines, including Helen (merchant marine) main turbine rigid turbine generator rotors; ターボチャージャー; machine tool drives; medium and large motor rotors for special requirements; small motor rotors; small motor rotors; turbo pumps |
G2.5 | 2.5 | Gears of Helen (merchant ship) main turbines; centrifugal separators; impellers of pumps; ファン; rotor parts of aviation gas turbines; フライ ホイール; general parts of machine tools; rotors of general motors; individual parts of generators with special requirements |
G1 | 1 | Tape recorder and record player drives; grinder drives; small armatures on special request |
G0.4 | 0.4 | Spindle, grinding wheel and armature of precision grinding machine, gyroscope |
G-Balance accuracy grade
M-rotor weight (キログラム)
r-correction diameter (ミリメートル)
N-working speed of rotor (回転数)
M-qualified unbalance amount (g)
M=9549MG/r x n