Description

Spur gear ring and pinion, as the mechanical element that transforms the rotary motion into linear motion, is usually compared to ball screw. It has advantages and disadvantages to replace ball screw with rack. The advantages of rack are simple machinery, large bearing capacity and unlimited length, etc.. However, one of the disadvantages is backlash. The advantages of ball screw are high accuracy and small backlash, while the disadvantage is the length limitation caused by deflection.

The advantages of straight rack are simple machinery, large bearing capacity, unlimited length, etc.

The range of the spur gear ring and pinion gear consists of metric pitches of modules 1.0 to 16.0. Styles include spiral, straight (spur). Rack length of up to 2.00 meters is standard, and unlimited stroke length can be achieved through end-to-end installation sections. These are called "racks with machined ends". The straight racks is subjected to overall quenching and tempering, with superior mechanical performance, high strength and resistance to deformation. Therefore, it supports high-load work. Through high-frequency quenching, the teeth have high hardness and excellent wear resistance.

The purpose of heat treatment of spur gear ring and pinion processing products is to improve the hardness and wear resistance of gears, and then to increase the service life of gears. However, improper quenching will also cause the cracking and deformation of gear processing products. How to reduce the cracking and deformation?

First of all, it is necessary to select gear material correctly and design the tooth shape properly. For gears with complex shapes, it is best to use gear steel with high hardenability, so that it can be cooled in slowly cooling quenching medium to reduce internal stress. For gears with high accuracy requirements, bottom deformed steel can be selected and graded or isothermally quenched. When designing the gear, try to reduce the difference in cross section thickness and avoid thin edges and sharp corners; make the transition as smooth as possible at the interface at the junction of difference thickness of the gear. For large gears, the separate splicing structure should be used to create conditions that can still be deformed by machining after heat treatment. Secondly, preliminary heat treatment and casting should be performed correctly. Gear blanks should be obtained through appropriate preliminary heat treatment, such as normalizing, annealing, quenching and tempering treatment, to meet the requirements of mechanical processing and final heat treatment. When casting gear blanks, it is necessary to minimize casting defects, which are easz to cause cracking and deformation of the gear during quenching. Finally, a reasonable heat treatment process should be adopted. Try to achieve uniform heating during heating to reduce the thermal stress during heating; for large gears, preheating should be used. Select the suitable quenching temperature. In general, try to select the lower limit of the quenching temperature. The proper selection of the quenching medium and cooling method, under the premise of meeting the performance requirements, should choose a more tempered quenching medium, or adopt the methods of staged quenching, isothermal quenching and so on.

After spur gear ring and pinion processing, there are many small areas on the gear that are insufficient in hardness, which are called soft spot. Soft spots are often the center of gear wear or fatigue fracture, reducing the service life of the gear, so soft spots are not allowed on the finished gear. The main causes of soft spots are as follows:

1. The metallographic structure of the gear is not uniform, such as carbide segregation, band structure or large ferrite in the steel. In this case, forging or appropriate preliminary heat treatment should be performed before quenching to make the structure as uniform as possible.

2. The carbon concentration on the surface of the gear is uneven or the gear carbon is not uniform after local decarburization or carburizing, and it becomes a soft spot after quenching in the low carbon area.

3. Insufficient cooling capacity of the quenching medium. For example, impurities such as oil or soap mixed in water can easily cause soft spots on the gears.

4. Improper operation, such as the surface of the workpiece is not clean, the oxide film or dirt has not been removed; the workpiece is immersed in the quenching medium, the movement is insufficient, etc. will form soft spots.

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FAQ

Q: Can Yunxiang Machinery manufacture metric gears?

A: Of course! We have the tools to manufacture any metric size.

Q: What should to do if I cannot identify the gear?

A: Please send us your damaged gear! We specialize in reverse engineering.

Q: Do you have a minimum order quantity?

A: Our minimum requirements depend on the parts ordered. Send us your drawings, pictures, sample gears or specifications and we will let you know the minimum requirements for the part.

Q: Is there a rack and pinion on your website in stock?

A: Everything we do is made to order. All parts on our website are pre-designed and will be manufactured at the time of ordering, so you can request different sizes of end face widths, eyelets, wheels, etc.

Q: Can Yunxiang Machinery manufacture Gears that are not on this site?

A: Of course! We can provide custom gears with the same excellent delivery options as standard gears.

Q: How to get the lowest price?

A: Increase the quantity. The more parts you order, the lower the price you get.

Q: Can I use other materials besides steel to make gear rack?

A: The price of racks is not fixed. Generally, we need to quote according to customer's required parameters such as material, tooth type, module, length, accuracy, type, spiral angle and special customization!

http://ja.yxjx-rack.com/