The Design And Research Of Tractor Clutch

Tractors are the power machinery not to be replaced in modern agricultural production, which have extensive use with other corresponding farm tool.Although tractor clutch has gone through a hundred years. Today, the technologies of electron and information also promote the development of the clutch, which is faced with to technical renew. The vehicle industry of our country has some pretty backwards compared with other advanced countries. A lot of new products and technologies have introduced to China; however a distance for the digestion grasp of these technologies from abroad still has to go. Author has looked up the design document about clutches, and find a lot for the automobile, but a few for the tractor.This paper stands in domestic industry, taking a example of clutch designs for 65 horsepower tractor, hoping that this paper can play the part of the role to domestic industry and making reader and the engineers of relevant aspect vocation to get inspiration to enhance the performance of the product.The design of this paper has two outstanding properties: the high performance with relatively low cost.The key introduction of this paper is the design theory of the clutch. Dry type clutch has the major advantages as follow: its structure is simple, price is low, more reliable to use; But the wear and tear of the dry type clutch are serious and its friction coefficient is instable, which influences its life. The wet clutch is more reliable, life is longer, need not be often adjusted in use, temperature is lower because of friction surface with oil, has the ability of starting than winner, coefficient of friction stabilizes , service life is long. However, the performance of wet clutch advantage is in certain temperature scope, exceeding this temperature scope will take negative effect. Having so tight requirement, the structure of wet clutch is more complex than dry type, which is the major reason that the dry type clutch is used more.This paper has particularly researched the design and structure of dry type clutch major element in detail. The differences of the dry type clutches with different structure are as follow: the spring with opened groove dish shape can generate more transmogrification under identical load compared with ordinary dish shape spring; Diaphragm spring has special structural dish shape, but its design is more complex. The single flat dry type friction clutch has small moment of inertia, simple structure, adjustment convenience, compact size and thorough separation. As engine power increases constantly with its limited space of size, adopt two flat dry type clutches so as to increase the clutch biography ability to turn. Service life is longer than that of single flat, start is more steady, and prolong the life of transmission at the same time. In our country, most of the friction materials of clutches are the friction lining surface of asbestos base, which is suitable for light and middling load, and its cost is low; Powder metallurgical lining surface is suitable for heavy load, but its manufacturing cost is high. This paper has 3 innovation points:1) Compared with trapezoid groove dish-shape spring, discovering trapezoid groove in processing manufacture process is easy to produce concentrated stress and reduce its life. The paper improves on this foundation, which is changing trapezoid groove to arc groove; as a result, clutch life rises greatly.2) Although asbestos and cermets material have each adventure and shortcoming, the friction moment in the high temperature is very unstable. The paper joins some porcelain powder in asbestos organic friction material. Tests prove that its high temperature-resist capability is higher than former.3) Adding a set of clutch installation machine to control the separation of the clutch. If no this installation, making associate clutch to break away from joint only needs to continue stepping on foot pedal until loosening. But using the associate clutch installation separating machine, if the machine is controlled only once, it can maintain the clutch to separate for a long period. It makes the operation performance to be raised to fit for driver.This design has passed through every experiment by Shandong Weifang tractor factory carries out, proving that this clutch design accords with the requirement: high performance and low cost.