Frame spindle thermal problems

2019 - frame spindle thermal problem 12 - 05 heat bilges cold shrink is the basic nature of matter, matter ( Objects) Volume and linear dimensions with ups and downs and small changes in temperature, is a basic natural phenomena. Machinery industry in the application of this nature have a lot of clever, for example, rolling bearing and shaft, the interference fit between the heat take electromagnetic bearing inner ring on its pore size larger for installation, some engine bearing outer ring ( Or bearing) Interference fit is installed on the wall hole, liquid nitrogen frozen outer ring with short time measures to reduce the size and so on, most of the ingredients of fixed mechanical USES material, the linear expansion coefficient has been measured, and as a standard parameters to design calculation and theory respectively. Figure 1 spinning workshop temperature linear expansion coefficient of some of the material in a day, 24h） Can reach more than 10 ℃, fluctuations in the normal operation of the spinning equipment, and is a disadvantage. Spinning frame with the increase of the number of ingot, the length has been extended, when reach to a certain extent, the negative effects of heat bilges cold shrink, will no longer be a negligible problem. In the field of spinning frame car and long long, this phenomenon in recent years has caused some bad results. Colony system, for example, stainless steel belt tensioning degree as the temperature changes ( The total length is essentially) With cause GuanShuan position changes, the linear expansion accumulation to a certain value, catch a pig and GuanShuan coaxial degree of serious decline, unable to properly inserted yarn tube. Figure 2 linear expansion accumulation with a dislocation caused adverse effect is shown in figure 2, therefore, must from the mechanical design, the structure is improved in order to solve the problem, for example, the segment positioning, release expansion section, not on the whole length accumulation, this paper will be the main shaft as an example, analyses the application of this thought. Ring spinning spindle is segmented by coupling together, figure 3 is a more traditional connection method. Figure 3 spline shaft end connection diagram in the shaft end, through the key, the columnar hough coupling two shaft etc, in turn, series all the spindle, the spindle's role is to transfer circumferential torque, don't pass the axial load, which makes the piecewise linear expansion quantity is it possible to release. When the coupling is fastening screw locking, despite gaps between the shaft end design, but the pressure caused by the lock, and the maximum static friction force is huge, between the two axis equivalent to string together to become a shaft, temperature rise of elongation length, always will accumulate, can consider to block release of axial elongation. The join method, two shaft alignment is depends on the bearing seat through false shaft equipment guarantee, coupling should not be the guarantee of coaxial coupling effect is to protect the key and the circumferential torque transfer, based on this, you can consider the coupling of the inner hole machining steps into shape, small hole and shaft end, between a larger inner hole and shaft smaller radial clearance, release amount of linear expansion. Coupling (figure 5 steps Signal, without the key) D < d, T, two shaft end clearance section release long shaft to the thermal capacity, is a very useful idea, there are many kinds of its form, can change the type of coupling, such as flexible coupling, torque transfer is not need to worry about the problem, the key is how to control costs. （ Source: textile machinery),