In order to avoid intermittent high noise of radial drilling machine.Tested by ND6 precision sound level meter, the low noise radial drilling machine is 72.3Db(A), which meets the factory requirements. However, the high noise radial drilling machine is 82.5dB(A), which can not meet the factory requirements. After repeated testing, analysis and improvement experiments, it is concluded that the noise of gear transmission can be effectively reduced only by comprehensive treatment of each link of production.
1, control gear accuracy: the basic requirements of gear accuracy: through practice verification, gear accuracy must be controlled in GB10995-887-8 level, linear speed is higher than 20m/s gear, gear pitch limit deviation, gear ring radial runout tolerance, tolerance must be stable to reach 7 level accuracy. In the case of grade 7 precision gear, the teeth should be inverted shuttle, and the root boss should be strictly prevented.
2, control the quality of raw materials: high-quality raw materials are the prerequisite for the production of high-quality products, our company uses the largest material 40Cr and 45 steel manufacturing gear. No matter through which way, raw materials to the factory after strict chemical composition test, grain size determination, purity evaluation. The purpose is to adjust the heat treatment deformation in time and improve the quality of tooth profile machining.
3, to prevent heat treatment deformation: teeth blank in rough machining into fine forging, normalizing or tempering treatment, in order to achieve:
(1) soften the steel for cutting;
(2) Elimination of residual stress;
(3) Refine grain and improve microstructure to improve mechanical properties of steel;
(4) Organizational preparation for eventual handling. It should be noted that, in normalizing or tempering treatment, we must keep the temperature of the furnace uniform, and the use of workstation utensils, so that the workpiece evenly heating and cooling, strictly prohibit stacking together. For gears that need to be drilled to reduce weight, the drilling sequence shall be arranged after heat treatment. The final heat treatment of gear adopts high-frequency quenching on the tooth surface which makes the parts less deformed. The tooth surface obtained by high-frequency quenching has high strength, hardness, wear resistance and fatigue limit, while the core still retains sufficient plasticity and toughness. To reduce deformation. Low quenching temperature, short heating time, uniform heating and slow cooling should be adopted for high-frequency quenching of tooth surface.
4, ensure the accuracy of the blank: the precision of the size of the gear hole is required to be distributed around the middle of the deviation value of the hole, set at ±0.003~±0.005mm; If it is out of tolerance and within the scope of the hole design requirements, it must be classified and transferred to the gear cutting process respectively. The end face runout and radial runout of the gear blank are 6 grades, set in the range of 0.01~0.02mm.
5, cutting gear processing measures: purchased gear cutting tools must be inspected, must meet the AA requirements. After grinding a gear cutter, the radial property of the front edge of the cutter, the difference of adjacent chip slots, the maximum cumulative error of chip slots, and the parallelism between the front of the cutter tooth and the axis of the inner hole must be checked. On the premise of not affecting the strength of gear, the tooth top height coefficient is increased by 0.05~0.1m, to improve the tool tooth top height coefficient and avoid tooth root interference of gear transmission. Gear with M=1~2 adopts crown trimming hob, trimming R=0.1~0.15m. Eliminate crown burr and improve crown interference in gear transmission. Gear cutting equipment should be checked once a year for accuracy, and those not up to the requirements must be repaired. The operator should also often self-check, especially in the machine tool spindle radial clearance control in 0.01mm below, tool shaft diameter jump 0.005mm below, tool shaft movement 0.008mm below. Tool installation accuracy: tool radial runout control in 0.003mm below, end runout 0.004mm below. The precision of gear cutting tools, the clearance between the outer diameter of the mandrel and the workpiece hole, to ensure that within 0.001mm ~0.004mm. The thread on the mandrel must be grinded by the thread bed under the orientation of the third top: perpendicularity ≦0.003mm, diameter jump ≦0.005mm. Nut must ensure that the internal thread and datum level clamping at one time, the parallelism of the washer ≦0.003mm.
6, civilized production: gear transmission noise has more than 30% of the reasons from burr, bump. Some factories in the gear box before assembly, the removal of burrs and bumps, is a passive approach. (1) Gear shaft parts, after hobbing, the tooth part is immediately covered with special plastic protective sleeve and then transferred to the next process, and with the special plastic protective sleeve into storage and delivery. (2) Honing process, reduce tooth surface roughness, remove burrs, and prevent knock, can effectively reduce gear transmission noise.
7, adopt other materials and heat treatment, surface treatment :(1) can use powder metallurgy forming technology, gear teeth after forming high-frequency quenching. (2) Using graphite cast iron, gear cutting after soft nitriding treatment. (3) using 40Cr material, gear cutting work, soft nitriding treatment or copper plating teeth treatment. All in all, gear transmission noise must be eradicated, gear material and heat treatment is essential, precision of gear blank is guaranteed, precision of gear is the key, civilized production is the foundation.
Want to know the process of the products? ANTISHI has a mature team of engineers, who are very familiar with heat treatment processing and can deal with product processing problems including technical problems. In addition, in the installation and after-sales process, our engineer team can be assigned to solve difficulties. To help producers for convenient and efficient production has always been committed to the goal of our company, and ask for details of the customer can go to the website https://www.antsmachine.com/ . You can also directly send your questions to our email email@example.com for consultation.