Effective measures to reduce gear transmission noise
With the rapid development of the modernization of machinery industry, higher and higher requirements are put forward for the noise index of gear transmission in some fields (for example, the noise index of a certain type of three-stage planetary reducer is 52dB), especially when the decibel value is reached, the problem of no noise is also put forward.After many years of efforts and unremitting practice, we have obtained some effective measures to reduce the gear transmission noise.
to ensure the quality of raw materials
The commonly used materials for gear manufacturing are 40Cr, 20CrMnTi, 40CrNi and other alloy steels and 45 steel.In order to guarantee the quality of raw materials, we adopt the fixed-point purchase method, which is like the choose and buy, shougang, baosteel, handan steel steel production quality, the factory also have to pass strict inspection, chemical composition after determination of grain size and purity, its purpose is to facilitate timely adjust the heat treatment process, control heat treatment deformation, improve the quality of tooth profile processing.
prevent heat treatment deformation
After rough machining or fine forging, the tooth blank should be normalized to eliminate the internal residual stress.In normalizing or tempering treatment, the temperature uniformity in the furnace must be maintained, and the workstation fixture is used to uniformly heat and cool the workpiece;Try to use cyanide treatment, it is lower than carburizing quenching temperature, deformation is small, and than nitriding or carburizing cheap, used for cyanide treatment equipment, must use drip type UNIC gas carburizing nitriding furnace;Part of the high frequency quenching and cyaniding gear parts can also be used soft nitriding process to obtain high hardness value and thicker white layer.
improve the processing accuracy of tooth blank
1. Improve the machining accuracy of the gear hole: the size accuracy of the gear hole must be distributed around the middle difference of the deviation value of the hole, generally fixed at ±0.003 ~ ±0.005mm. If the deviation is out of tolerance and within the range of the design requirements of the hole, it must be respectively transferred to the gear cutting process, in order to take measures;At the same time, the straightness of the hole must be controlled within 0.003mm;
2. Control the end face runout and radial runout of the tooth blank: the end face runout of the tooth blank is a project that directly affects the tooth tolerance. When processing the two end faces of the tooth blank, we must ensure that the parallelness is within 0.01mm, and then fine boring on the fixture to ensure the hole to the end face runout tolerance;When cutting teeth, be sure to use the table 100% calibration circle, in order to ensure the radial runout tolerance of gear ring.
gear processing measures
1. Gear cutting tools: (1) all purchased gear cutting tools must be tested and meet the requirements of AA level. If the gear cutting tools fail to meet the requirements, all must be fine shovel grinding;(2) All gear tools are treated with titanium plating to improve tool durability, improve the wear of tool tooth tip, and prevent the gear root arc from being too large;③ the gear m=0.3 ~ 0.8 adopts the top cutting hob;The gear of m=1 ~ 2 adopts tooth top trimming hob, and the amount of trimming is R=0.1m ~ 0.15m.(4) to improve the gear tip interference, without affecting the strength of the gear, increase the coefficient of tooth tip height, increase (0.05 ~ 0.1) m;Improved tool tip durability to avoid tooth root interference during gear transmission.
2. Gear cutting processing process: (1) gear cutting equipment by the motor place every year to check the accuracy, can not meet the requirements must be repaired, especially the radial clearance of the machine tool spindle must be controlled below 0.01mm, the cutter shaft diameter jump 0.005mm below, the cutter shaft channeling 0.008mm below, the cutter diameter jump control below 0.003mm, the end jump below 0.004mm;(2) the clearance between the outer diameter of the mandibular shaft and the workpiece hole of the gear cutting tool must be guaranteed within 0.001 ~ 0.004mm;The thread on the spindle shall be grinded by the thread grinder under the positioning of the two cores, and the verticality shall be less than 0.003mm, and the diameter jump shall be less than or equal to 0.005mm;Tooling and tightening nut must ensure that the internal thread and the datum surface once clamped into the car, the parallelism of the washer should be less than or equal to 0.003mm;③ The processed gear parts must be evaluated by a full-time inspector, and the inspection items are FW, FR, FI ", FI ", Fβ, FF.
the processing after heat treatment
1. For the gear holes with soft nitriding and high frequency quenching of the teeth, the method of loading before heat treatment and grinding after heat treatment is adopted to ensure the machining accuracy and reduce the production cost;
2. For the gear holes treated by cyanide, the grinding process of indexing circle positioning and Archimedes helix locking is adopted.
Uphold civilized production
According to the data, more than 30% of gear transmission noise from the reason of burr and bump.In order to solve this problem, we have taken the following measures: gear parts after processing all the use of station fixture transport;Gear shaft parts after hobbing, immediately cover the plastic pipe into the next process, and with plastic sleeve delivery;In order to remove burr and improve the surface roughness and machining precision of tooth surface, the gear parts after cyanide treatment must undergo liquid sandblasting and honing process.
Due to the effective measures taken, the gear transmission noise index of the military and civil gear reducer produced by the unit is all up to the standard at each inspection time, and has been generally praised by the users.After many years of mass production practice has proved that these measures are desirable, the effect is obvious
Contact: Jack He
Add: BuildingA 125 WeiMin Road,DongSheng Town,ZhongShan city,GuangDong Province,China