What is a rack?
The tooth profile of the rack is a straight line rather than an involute (which is a plane for the tooth surface), equivalent to a cylindrical gear with an infinite radius of the indexing circle. It is divided into straight tooth rack and helical tooth rack, which are paired with straight tooth cylindrical gear and helical tooth cylindrical gear respectively.
Instructions for Rack Assembly
The rack can be docked and installed to any length. The gap between the two racks during assembly needs to be adjusted to fit the tooth pitch. The installation of the rack requires the use of locating pins.
Step 1
Position and tighten the rack.
Step 2
Use a reverse gear gauge to position the next rack.
Step 3
Check each interface one by one and use a round bar to check the parallelism of the gear rack.
Can be used in printing machinery, drilling machines, woodworking machinery, servo motor power transmission, manual rocker arms, automatic work platforms, packaging machinery, and automatic machine tools.
Two phenomena of rack tooth surface damage
After the damage of the rack, the teeth cannot mesh with each other, and such parts cannot continue to be used. What are the damages to the tooth surface?
Firstly, the concept of gluing refers to the "scratch" or "bite" caused by the cutting of the lubricating oil film between the meshing tooth surfaces on the rack tooth surface. The oil film is cut open. The main reason for such a situation is that the load increases during operation, the gear rotates rapidly, the meshing speed of the tooth surface is fast, and high-speed rotation occurs. The rack and gear mesh with each other, and the meshing point is in a sticky state due to high temperature and pressure. The metal powder generated by wear and tear causes this phenomenon, especially when this situation occurs once, the bonding of the tooth surface will continue to expand.
Another type of damage to the tooth surface is pitting corrosion, which is a phenomenon where pressure is applied to the meshing part of the gear and rack, causing work hardening. This hardening begins to peel off from the inside of the metal, so the tooth surface treated with overheating can also have this problem. Generally, this phenomenon is easy to occur in the early stage of tooth transmission. If this phenomenon occurs, the rack and gear must be stopped from use. If no treatment is given to pitting, it will gradually become a large dent, and many of the pitting parts are generated near the node. If there is pitting corrosion and the tooth surface continues to be used, it may cause problems such as tooth surface fracture due to excessive force. After the tooth surface wear occurs, we need to replace the gear and rack components in a timely manner. Otherwise, excessive tooth surface wear will seriously affect the work of mechanical equipment, delay production, and cause economic losses.
The selection of gear materials is very important
Toothed parts, as one of the important mechanical components for transmitting power, are very important in their material selection and processing, such as aircraft, ships, trains, automobiles, tractors, diesel engines, machine tools, construction machinery, mining machinery, and memory machinery. Precision machinery is used in gear wheels, racks, bevel gears, and helical gears. There are many types of gear materials and their specifications vary greatly. Engineering plastics, ceramics, non-ferrous metals, and black metals can all be used as gear and rack materials, such as gear racks, with specifications ranging from 0.05mm to 40mm. The sizes and working conditions are also different, and their failure forms are diverse, so the selection of materials must be reasonable.
