锤式破碎机的英文文献和中文翻译(4)
5.2 The layout of the floor
Generally speaking, increasing the wall thickness is frame and box body strength and stiffness may be increased, but not as adding more favourable floor. Because of adding floor, increase the strength and rigidity, and can increase the wall thickness at the same time reduce the quality; Because the chassis of the crusher is casting, so, for casting, because do not need to increase the wall thickness, can reduce the casting defects; For some of the welding parts, thin wall easier to guarantee the quality of the welding.
When considering the casting, welding process and structural requirements of restrictions, such as to facilitate the installation and removal of sand mould, as well as the need to install additional parts within the frame, etc., often need to stand design into two sides open, or at least in some areas out of larger hole (that is, the manhole in the machine). Because to do so, inevitably weakened the rigidity of the frame, so adding floor is required. The structure shape, must consider the various important factors mainly include the process, cost, weight, etc. Even at the same time with the requirement of specific applications and different process (such as casting, welding, etc.) the structure of the designed into different shapes.
5.3 Design and calculation of the flywheel
Flywheel is used, the movement of the rotor is to store the kinetic energy, avoid crushing large or the shadow of the materials, loss of speed is not too big and reduce the peak load of the machine. The structure adopted web type.
6. Parts on the tolerance and fit
6.1 With the type of choice
After identified with category, you need to further determine the coordination with the adopted in which a specific cooperation, this is often difficult. For this, we need to understand the various coordination characteristics, and the components of the functional requirements, structural characteristics, carry on the omni-directional analysis of many aspects, such as working conditions. We can choose some of the standard manual priority to cooperate. And to choose in the manual also have more specific instructions.
6.2 Selection of general tolerances
General linear size tolerances is refers to the normal process conditions in the workshop, machine tool equipment general processing capacity can guarantee the tolerance. Under the condition of normal maintenance and operation, it represents the economic processing precision, so usually can not inspection. It is mainly applied to precision is lower than with size and function allows or larger than that of general tolerances. There are provisions in national standard, the use of general tolerances of linear dimension no separate note out of the limit deviation, and the general description on the drawing, technical papers.
6.3 Position tolerances
6.3.1 Shape tolerance project selection
Pick shape tolerance project according to the geometrical characteristics of the elements, structure features and functions of parts, and I will try to consider detection is convenient and economic benefits.
In the form tolerance of many projects, has a single control, comprehensive control. It is easy to understand, the former has roundness, flatness, straightness and so on. The latter such as cylindricity, mark shape tolerance, there is a principle is: should give full play to the function of comprehensive control tolerance of the project, for obvious reasons, one is to reduce the pattern shape tolerance on the project, the second is the decrease of the corresponding shape error detection. Graphs, and then take the spindle parts, to cooperate with rolling bearing diameter of axle neck, in order to ensure the accuracy of the rolling bearing assembly accuracy and rotation, should stipulate the axis of the cylindricity tolerance and shaft shoulder end face run-out tolerance. For shaft parts, the provisions of the radial circular runout or full run-out tolerance, so that both can control the roundness and cylindricity error, and can control the alignment error, it is convenient to test. By the same token, the side facing the axis straightness tolerance can replace with end face run-out tolerance all, face round beating when ignore the flatness error, can also be used instead of the end face axis perpendicularity requirement.
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