With the rapid development of industrialization, gears have gradually come out in the industry, and in some fields, higher requirements have been put forward for the noise of gear rotation, especially when the decibel value is reached, And also raised the problem of no noise, let me tell you how to reduce the noise of gear rotation?
one. Guarantee the quality of raw materials
The commonly used materials for manufacturing gears are 40Cr, 20CrMnTi, 40CrNi and other alloy steels and 45 steel. In order to ensure the quality of raw materials, we adopt the method of fixed-point purchase, that is, to purchase high-quality steel produced by steel mills such as Shougang, Baosteel, and Handan Steel. The purpose of purity evaluation is to adjust the heat treatment process in time, control heat treatment deformation, and improve the quality of tooth profile processing.
two. Prevent heat treatment deformation
After rough machining or fine forging, the tooth blank must be normalized to eliminate internal residual stress; during normalizing or quenching and tempering, the uniformity of the furnace temperature must be maintained, and a station fixture should be used to make the workpiece evenly heated and heated. Cooling; try to use cyanidation treatment, which has lower temperature and less deformation than carburizing and quenching, and is cheaper than nitriding or carburizing. The equipment used for cyanidation treatment must use a drip-type UNIC gas carburizing and nitriding furnace; Some high-frequency quenched and cyanided gear parts can also be replaced by soft nitriding process to obtain high hardness value and thicker white layer.
three. Improve the machining accuracy of gear blanks
1. Improve the machining accuracy of the gear hole: the dimensional accuracy of the gear hole must be distributed around the middle difference of the hole deviation value, generally set at ±0.003 ~ ±0.005mm, if it is out of tolerance and within the design requirements of the hole , must be transferred to the tooth cutting process, so as 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 gear blank: The end face runout of the gear blank is an item that directly affects the tooth direction tolerance. When machining the two ends of the gear blank, it is necessary to ensure that the parallelism is within 0.01mm, and then fine boring on the tooling To ensure the runout tolerance of the hole to the end face; when cutting the teeth, be sure to use the 100% rounding of the table to ensure the radial runout tolerance of the ring gear.
Four. Measures in gear cutting
1. Gear cutting tools: ① All purchased gear cutting tools shall be inspected and must meet the requirements of AA level. All gear cutting tools that cannot meet the requirements shall be subjected to fine relief grinding; ② All gear cutting tools shall be titanium-plated to improve tool durability. , to improve the wear of the tooth top part of the tool and prevent the arc at the root of the gear from being too large; ③The gear with m=0.3～0.8 adopts the top cutting hob; the gear with m=1～2 adopts the tooth top rounding hob, and the rounding amount R= 0.1m～0.15m; ④Improve the tooth tip interference during gear transmission, increase the tooth tip height coefficient and increase (0.05～0.1) m without affecting the gear strength; improve the tool tooth tip durability and avoid gear transmission tooth root interference.
2. Gear-cutting process: ①The gear-cutting equipment shall be checked for accuracy once a year by the motor department. If it fails to meet the requirements, it must be overhauled. In particular, the radial clearance of the main shaft of the machine tool must be controlled below 0.01mm, the diameter of the cutter shaft is below 0.005mm, and the The shaft movement is less than 0.008mm, the tool diameter jump is controlled below 0.003mm, and the end jump is below 0.004mm; ②The gap between the outer diameter of the mandrel of the gear cutting tool and the workpiece hole must be within 0.001 ~ 0.004mm; the thread on the mandrel must be Under the positioning of the two centers, it is ground by a thread grinder to ensure that the verticality is less than or equal to 0.003mm, and the diameter jump is less than or equal to 0.005mm; the tooling and tightening nut must ensure that the internal thread and the reference surface are clamped and turned at one time, and the parallelism of the washer should also be ≤0.003mm; ③The processed gear parts must be evaluated by a full-time inspector, and the inspection items are Fw, Fr, Fi″, fi″, Fβ, Ff.
five. Processing after heat treatment
1. For the gear holes of soft nitriding and high-frequency quenching of teeth, adopt the method of heavy volume before heat treatment and the method of grinding holes after heat treatment to ensure machining accuracy and reduce production costs;
2. For the gear holes treated by cyanidation, the grinding process of index circle positioning and Archimedes spiral locking is adopted.
