Method for calculating clearance between shaft and bushes and rotary mechanism of base type cantilever iron notch drill

Abstract

The invention discloses a method for calculating clearance between a shaft and bushes. The shaft is a vertical shaft on which moment acts; the bushes are rare-earth nylon bushes; and a calculation formula of fit clearance between the vertical shaft and the rare-earth nylon bushes at the two ends of the vertical shaft is that L1 / L2 is more than 1 and less than 5. In the method, the misunderstanding that the rare-earth nylon bushes are not suitable to be adopted in the vertical shaft on which the moment acts is avoided; and a brand-new calculation formula is put forward according to tests, so the rare-earth nylon bushes can be possibly used on the vertical shaft on which the moment acts, and the problem that the vertical shaft on which the moment acts has extreme poor abrasive resistance, short service life and extreme high price due to the adoption of a graphite-inserted self-lubricating copper sleeve is solved. The invention also discloses a rotary mechanism of a base type cantilever iron notch drill. The rotary mechanism comprises vertical shafts arranged on rotational joints of each component and the rare-earth nylon bushes which are rotatably matched with the two ends of the vertical shaft, wherein the fit clearance between the rare-earth nylon bushes and the vertical shaft is determined by the calculation formula.

Description

(1) Technical field: [0001] The invention relates to a calculation method for the fit gap between a shaft and a bushing, in particular to a calculation method for a fit gap between a vertical shaft subjected to moment and a rare-earth nylon bush at both ends and a seat-type cantilever taphole machine using the calculation method of the rotating mechanism. (two) background technology: [0002] As a new type of solid anti-friction material, rare earth nylon is made by high temperature centrifugal casting with nylon as the base material and rare earth as the additive. During the operation of the bush made of rare earth nylon, a thin and hard solid lubricating film will be formed on the working surface, which is sticky, slippery and not easy to flow. The friction coefficient between the working surfaces is greatly reduced at the same time as the wear resistance. In heavy-duty, low-speed working occasions, the use of rare earth nylon bushings has better wear resistance, frictio...

AI Technical Summary

Problems solved by technology

[0004] However, the application of vertical shafts under the action of torque is also very common. However, rare earth nylon bushes are used for vertical shafts, and the fit clearance between the two is determined according to traditional empirical formulas, but rotation failures often occur. For example, rare earth nylon bushes were once used for seat type The rotating mechanism of the cantilever tapping hole machine is placed on each vertical shaft, and the matching clearance between the two is determined according to the traditional empirical formula, but serious shaft holding phenomenon occurs, resulting in ineffective rotation

After analysis, under the action of torque, the vertical shaft and the bushes at both ends are irregularly worn, and the working conditions are completely different from those of the horizontal shaft not subject to torque. The traditional empirical formula cannot be applied to the vertical shaft subject to torque. Therefore, people in the industry generally believe that rare earth nylon bushings are not suitable for use on vertical shafts subjected to torque.

Therefore, at present, the vertical shafts of the rotating mechanism of the seat-type cantilever taphole opener are still inlaid with graphite self-lubricating copper sleeves. Although the graphite-inlaid self-lubricating copper sleeves are more suitable for the environment with high temperature and dust pollution in front of the furnace, their wear resistance Relatively poor, not long lifespan and expensive

Images