In order to avoid reducer not through the factory test, is one of the reasons for the existence of intermittent high speed reducer noise; testing with ND6 type precision sound level meter, low noise reducer for 72.3Db (A), reached the factory requirements; and the high noise reducer for 82.5dB (A), are not up to the requirements of the factory. After repeated testing, analysis and improvement of the test, the conclusion is must in each link of production for the comprehensive management, can effectively reduce the noise of gear transmission.
1, the control precision of the gear: basic requirements: the precision of gear is verified by practice, the accuracy of the gear must be controlled in GB10995 887~8 grade, line speed than 20m/s gear, gear, gear ring from the limit deviation of radial run out tolerance, helix tolerance must be level 7 stable accuracy reach. To gear precision grade 7 cases, teeth to inverted shuttle, to prevent root boss.
2, the quality control of raw materials: high quality raw materials is a prerequisite for the production of high quality products, our company the largest amount of material of 40Cr and 45 steel gear. No matter which way, raw material to the plant will go through strict inspection, chemical composition, grain size determination of purity assessment. Its purpose is to adjust the heat treatment deformation, improve the quality of tooth shape processing in.
3, to prevent heat treatment deformation: the gear blank in rough machining into precision forging, normalizing or quenching and tempering treatment, in order to achieve:
(1) to soften the steel for machining;
(2) to eliminate the residual stress;
(3) refine the grain, improve the organization in order to improve the mechanical properties of steel;
(4) as the ultimate can make organizational preparations. It should be noted that, in normalizing or quenching and tempering treatment, must keep the furnace temperature uniformity, and using instrument, the uniform heating and cooling, is strictly prohibited stacking together. The need for drilling weight reduction gear, should be bored sequence arrangement after heat treatment. Gear final heat treatment using high-frequency hardening tooth surfaces make parts deformation small; tooth surface has high frequency quenched with high strength, hardness, wear resistance and fatigue limit, but the heart is still keep the plasticity and toughness enough. In order to reduce the deformation. Tooth surface high-frequency quenching should use the lower quenching temperature and heating time is short, uniform heating, slow cooling.
4, to ensure the precision of gear blanks: intermediate gear hole size accuracy requirements in the hole deviation difference about distribution, in ± 0.003~ ± 0.005mm; if the difference and classification must be in the hole of the design range, respectively, into the cutting process. Face of gear blank beating and radial runout is 6, set in the range of 0.01~0.02mm.
5, the cutting measures: gear cutter on purchased must be inspected, must reach AA level requirements. Gear cutting tool grinding must be on the tool face, radial groove adjacent pitch difference, groove pitch error, maximum cumulative cutter front and inner hole axis parallelism test. In the premise of not affecting the gear strength, improve the addendum coefficient, increase 0.05~0.1m, improve the tool, addendum coefficient, avoid the gear tooth interference. M=1~2 gear with addendum modification of circular hobbing cutter, rounding quantity R=0.1~0.15m. Eliminate the tooth top burr, improve gear tooth interference. Cutting equipment every year to an accuracy check, not up to the requirements of the repair must be carried out. The operator must also often self, especially in the machine tool spindle radial clearance is controlled below 0.01mm, the cutter shaft diameter jump below 0.005mm, the cutter shaft moving below 0.008mm. The installation precision tool: cutter runout is controlled below 0.003mm, the end face runout below 0.004mm. Cutting tooling precision, mandrel diameter and gap workpiece hole, guarantee within 0.001~0.004mm. Screw mandrel must be top class location in propylene, thread grinding by bed: verticality ≤ 0.003mm ≤ 0.005mm, jump. The nut must ensure that the internal thread and the datum once clamping washers car, parallel degree ≤ 0.003mm.
6, civilized production: gear transmission noise causes more than 30% from the burr, knocking. Some factories in gear box assembly, remove burr and knock against injury, is a kind of passive approach. (1) the gear shaft, gear hobbing gear immediately after a plastic protective sleeve dedicated into the next process, and with special protection to the plastic sleeve storage and shipping. (2) for honing process, reduce the tooth face roughness, burr, and to prevent damage, can effectively reduce gear noise.
7, take other materials and heat treatment, surface treatment: (1) the molding technology of powder metallurgy, gear teeth forming after high frequency quenching. (2) using graphite cast iron, gear cutting, then the soft nitriding. (3) using 40Cr material, gear cutting work, using soft nitriding or tooth copper processing. Comprehensive said, should effect a radical cure of gear transmission noise, gear materials and heat treatment to the precision of gear blank, is to ensure the accuracy of the gear is the key, civilization, production is the foundation of.
---------------------Shenzhen YuJiaxin Hardware Products Co., Ltd.