Transmission planetary gear carrier with support shaft and its production process

Abstract

The invention discloses a transmission planetary gear carrier with a support shaft. The transmission planetary gear carrier comprises a support plate, a hollow cover plate parallel to the support plate and supporting legs connected with the support plate and the hollow cover plate, wherein the support plate and the hollow cover plate are correspondingly provided with multiple gear holes for small gears to be installed, the middle of the support plate penetrates the hollow cover plate and is provided with the support shaft, and the support plate and the support shaft form an integral structure. A production process of the transmission planetary gear carrier comprises the steps of (a) forming the support plate disc portion and a support shaft rod through warm-cold forging, forming the support plate and the support shaft through spline machining and rolling and performing carburizing treatment; (b) forming the hollow cover plate and the supporting legs through machining; (c) welding the hollow cover plate, the supporting legs and the support plate. The defect brought by assembly during classified manufacture of the planetary gear carrier and the support shaft in the prior art in a friction welding or press-fitting mode is overcome, the cutting-milling machining frequency and machining step number are decreased, the production efficiency is high, the production cost is low, the product quality is stable, the internal tissue density is high, the comprehensive mechanical performance is good, and the service life is long.

Description

technical field [0001] The invention belongs to the technical field of automatic transmissions and power shift transmissions, and relates to a production process of a planetary gear frame of a transmission, in particular to a production process of a planetary gear frame of a transmission with a support shaft. Background technique [0002] A typical planetary gear set consists of a planet carrier and a set of planet gears. The planet carrier determines the position of the gears and holds the gears properly in the desired position. There are many variations in the design of the planet carrier. The design of the bracket is determined by the design of the gear set and the method chosen for producing the bracket. Integral bracket assemblies are currently formed by machining parts formed from solid metal workpieces by casting or pouring from materials such as powdered metal or cast iron. Due to the cost of producing the stent assembly, most stent assemblies are made from multip...

AI Technical Summary

Problems solved by technology

[0003] The planetary gear carrier and the support shaft are manufactured separately, and two methods are currently used for their connection: one is to use the method of hot forging to forge the support plate first, after heat treatment and normalizing, then machining, the support shaft is connected as a whole by friction welding, The metal flow line is completely cut off, and the toughness of the welding part is very poor and easy to break; second, the bracket plate is forged by hot forging, after heat treatment and normalizing, and then machined, the inner hole in the middle of the bracket plate is cut and processed into an internal spline gear , the two ends of the bracket shaft are made into external spline gears, and finally one end of the bracket shaft is press-fitted with the inner spline gear of the bracket plate to form a whole, the metal flow line is also cut off, and there are still internal spline holes that are easy to break due to excessive press-fitting. The press-fit interference is not enough and easy to loosen, and the overall coaxiality is not good, especially when working, due to the high transmission speed, the dynamic balance is poor, which is easy to cause damage to related parts, which seriously affects the service life of the planetary gear carrier of the car transmission

In addition, the star gear carrier assembly has a large number of parts and a large number of processing steps, resulting in high production costs.

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