Belt-disc brake of wheel tractor of class 1.4
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C.41, il.6, Table 2, bibliography 9, Annex 1.
In this course design, a belt disc brake of the wheel factor class 1.4 was developed. Braking is carried out due to creation of brake moment on the drum and brake discs. This mechanism has good heat transfer and relatively small dimensions and mass, it also does not load the transmission shaft, which positively affects the reliability of the tractor as a whole.
RH hose with brake................................................................ A1
RH shaft..................................................................... A2
Brake disc..................................................................................... A2
Brake bushing................................................................................. A3
Tractor braking dynamics.......................................................... A2
Schematic diagram of the braking system......................................... A4
At present, a comprehensive mechanization of the production of grains and vegetables has not yet been completed, while large volumes of production are carried out manually. Nevertheless, as in other crops, the entire increase in the production of crops should be due to an increase in labor productivity. However, the energy content of labor in work with crops is still much lower, than in arable and other general-purpose works If tractors with a capacity of up to 300 hp are produced for the latter, then tractors with a capacity of up to 7580 hp are used in stealing. but these tractors, as practice has shown, do not provide the necessary increase in productivity in the cultivation of crops. The demand to increase productivity and reduce costs in agricultural production has caused a tendency in the world tractor industry to increase tractor capacity. It should be noted that these requirements are feasible only in conditions of large farms, with large volumes of production for the full use of tractor capacity. Rational use of capacity by increasing operating speeds is often limited by agricultural technology. The realization of power by increasing the capture of agricultural machines or combining operations with the usual arrangement of a tractor and an agricultural unit is not always achieved. The reason for this is the lack of adaptability of serial tractors to work with wide-gripping systems, which perform several technological operations in one pass of the unit.
The work of the All-Russian Institute of Agricultural Mechanization, the All-Russian Institute of Sugar Beet and many other research institutes, as well as foreign experience, confirm that the most progressive trends in the field of production mechanization are the combination of several technological operations based on the use of combined machine-tractor units (MTA). Reducing the number of tractor passes along the field is aimed at preserving the soil structure, saving labor costs, energy, material, and increasing labor productivity.
However, the structural and other parameters of tractors of the traditional layout, created at one time exclusively for traction operations, turned out to be unacceptable for compiling high-efficiency units in a hinged version. The reason for this is the absence of a front power take-off shaft, the necessary reserve of free load capacity of tires, as well as the loss of longitudinal stability and controllability during rear hanging of agricultural machines. With a repeated decrease in the labor intensity of cultivating steep and vegetable crops, research and design organizations of agriculture and industry have developed progressive technological processes with combinations of operations, for the introduction of which, when using wide-grip machines, a steep tractor of traction class 1.4 is required.
Modern trends in the creation of machine tractor units and the requirements in this regard for a universal propelled tractor:
Increase of specific power.
Maximum energy saturation with minimum dimensions.
Ensuring maximum persistence of soil structure.
Improved ergonomic properties of tractor.
Maximum automation of MTA.
The possibility of connecting an agricultural machine both at the back and at the front of the tractor.
Presence of rear and front power take-off shafts to drive active working elements.
Possibility of placing a silo for sowing material and fertilizers on a tractor.
Ensuring the required level of safety of the tractor driver's workplace.
Tractor LTZ60AB is designed for: cultivating grains, plowing, sowing grains and grasses, harvesting grains and spikes, carrying out transport and loading and unloading operations. The tractor is aggregated with more than 120 machines and tools, capturing the entire complex of agricultural work. The wide possibilities of aggregating the LTZ 60AB tractor allow it to be used not only in agricultural work, but also in construction, forestry, landscaping, earthworks.
Levers and control pedals are located in comfort zones. Steering wheel has tilt angle and height adjustments. A heater is used to heat the cabin. Hot liquid of diesel cooling system is used as heat carrier. Ventilation plant with air purification filter is used for cabin ventilation. Sprung seat of driver has adjustment of height, stiffness of suspension, inclination of back and longitudinal movement.
Rationale for the project theme
Brakes are designed for:
- reducing the translational speed of movement or emergency stopping of the machine;
- holding the machine on slope or lifting;
providing, if necessary, rotation of the tractor.
The brakes shall meet the following requirements:
- develop high braking torque at small dimensions; - provide smooth braking;
- prevent spontaneous braking;
-be balanced from the action of radial forces;
- have good heat dissipation;
- have the required durability;
-be convenient and easy to maintain.
According to the purpose, the brakes are divided into stopping and parking. The parking brake is designed to hold the machine on a lift or slope, and is characterized by the limit lifting angle at which the machine can stand. The stop brake is designed to reduce the translational speed of movement or emergency stopping of the machine, and is characterized by braking carried by the machine from the initial speed to the complete stop.
According to the shape of the friction surfaces, the brakes are divided into:
In this course project, we will consider combined brakes. This type of brake will allow for less wear and tear of the friction surfaces and therefore greater reliability compared to other types; good heat transfer.
In order to ensure a high technical level and patent purity of the design being developed, it is necessary to carry out patent studies, which include the search, selection and analysis of patent and research information related to scientific discoveries and technical solutions in the art.
As the main sources, we use the description of inventions and copyright certificates stored in the patent fund of the Lipetsk Regional Scientific Library.
The description of the invention describes the name of the invention, the field of technology to which the invention relates, a brief description of the technical solutions.
Patent materials are viewed in at least 10 years. In the process of performing the patent search, we compile tables in which we enter data on the search regulations and bibliographic data of selected copyright certificates and patents, the text of the claims.
When determining the technical level and trend of development of this type of technology, the depth of search is 30 years.
Conclusions and recommendations on the project theme
During the course project, the belt-disc brake of the wheeled tractor class 1.4 was designed.
A patent search was conducted, where various versions of the brake design were analyzed.
Brake torque, deceleration, braking time and stopping distance are determined.
Calculations were made for the strength of the most important and loaded parts of the main gear.
The environmental assessment of the project showed that the developed brake meets the requirements of modern engineering in terms of environmental efficiency.
This brake design is promising for further improvement.
The developed brake has better performance and reliability indicators than the base brake.
Barsky, I.B. Design, basis of theory and calculation of tractors: Textbook for technical schools [Text ]/I.B. Barsky, D.F. Bryukhovets, V.V. Ivanov. - M.: Higher School, 1971 - 430 s.
Sharipov, V. M. Design and calculation of tractors [Text]: a textbook for university students studying in the specialty "Automobile and Tractor Engineering "/V. M. Sharipov, M.: Mechanical Engineering, 2004.592s.
Guskov, V.V. Tractors 4III. Design and calculation [Text ]/V. Guskov, I.P. Ksenevich, Yu.E. Antonov, A.S. Solonsky - Mn.: Vysh. School, 1981.- 383s.
Orlov, P.I. Fundamentals of design. Reference manual. In two books. Book 2. [Text ]/P.I. Orlov. - M.: Engineering, 1988.786 p.
Anuryev, V.I. Handbook of the Designer of the Mechanical Engineer [Text ]/V.I. Anuryev - M.: Mechanical Engineering, 1974.416s.
Zyuzin, A.A. Methodological instructions for the implementation of the technological part of the graduate design "Design of technological processes of assembly" for students of the specialty 1501.00 - "Automotive and Tractor Engineering" [Text ]/A.A. Zyuzin - Lipetsk LGTU, 1996.30s.
Stepin, P.A. Resistance of materials [Text]: Textbook for universities/
P.A. Stepin - M.: Vysh. school, 1973.303p.
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