The problem that stands out when a high-speed spindle is stuck is vibration. Carding machines are used to process cotton fibers and chemical fibers and belong to textile machinery. According to the spinning process, carding is an important process.
The front process of the carding machine is the opening and cleaning machine, and the latter process is the drawing frame (carding process) or the sliver coiler (combing process). Grinder A spinning machine that turns fiber strands into rovings. The main function is to draft and twist, and to wind the roving into a certain package to meet the processing requirements of the spinning frame.
The structure of the double twisting unit of the double twisting machine mainly includes the spindle braking device, the spindle part of the double twisting machine, the yarn winding device, and the special device of the double twisting unit. If the vibration is too large, it will increase the jumping phenomenon of the simple tube, and the yarn tension wave power increases, resulting in weak weak twist broken yarn twist zone; on the other hand, they will easily slide the bead yarn notch wear Beads, slivers of yarn that have been cut or rolled off. If the spindle vibration table is too large, it will also make the context spindle bearing subject to additional dynamic load, increase power consumption and wear, and reduce the service life.
Intense vibration increases fuel consumption, if not caused by fuel starvation, it will intensify heat, increased wear, surges in power consumption, and lower speed spindles, resulting in torsion resulting in an impact on product quality. Conversely, the wear of the side step promotes the increase of the vibration amplitude and the formation of a second vicious cycle. In order to reduce the vibration amplitude of the main shaft must be rotated in the corresponding increase in the manufacturing precision of the component part, and the vibration absorption effect is effectively used in the structural design.
Let's talk about the spindle vibration problem. The main shaft vibrates at a high speed and is a horizontal projection of the ingot end track in a circular, elliptical or other irregular compound quiet line. This phenomenon is called spindle wobble.
If the movement of the spindle end (or the rod) is projected in the vertical management plane, it will vibrate continuously as a kind of reciprocating position. When the main shaft is subjected to the instantaneous external force after vibration, such as the operation of the card with the impact of the coupling shaft, it is called the power or natural vibration generated by natural vibration, and the vibration frequency is called natural frequency or natural frequency. There are more than one natural frequency on the main axis, and there are many, the one with the lowest natural frequency is called first, followed by the second and third order, etc.
These frequencies relate to the magnitude of the given inertia and the elastic force of the vibrating system, both of which in turn determine the size of the structure and wool material. High frequency, low frequency big inertia force big elastic force. Due to the loss of resistance, the natural vibration of the instantaneous external force caused by the external force will gradually decrease, and even the luck tends to disappear.
If the damping is larger, it decays more rapidly. In short, after the natural vibration is excited, it disappears due to decay sooner or later. The vibration generated by the spindle of the carding machine under the continuous action of the periodic external force, the frequency of the vibration signal and the development and change of the external force and the frequency can be completely equal, which is called the forced vibration in China.
For the spindle, the periodic external force in this industry is mainly caused by the curved eccentricity of the rotating parts such as the spindle bar, keyboard, tube, and bobbin. When the innocence of these rotating parts does not fall on one axis of rotation, the centrifugal force generated during the rotation will itself cause the forced vibration of the chain link and the parts attached to it. The characteristic frequency of the change of centrifugal force is equal to the angular velocity of the flakes.
Therefore, the forced vibration working frequency of the spindle cannot be equal to its rotational angular velocity. Since the forced vibration is caused by different centrifugal forces, the enterprise can improve the economical precision of capital-revolving mechanical parts, and try to reduce the eccentricity of the mass plate, so that the amplitude can be gradually reduced. However, due to the eccentricity of the quality of the bobbin and the bobbin, it is difficult to effectively avoid it, so the forced vibration of the spindle cannot be completely eliminated.
As a simplified model, assume that the eccentric mass of the spindle bar and its accessories is m, offset e, as shown. 4-34, if the angular velocity of the main web is 0, the centrifugal force m(ey)d will force the rod to bend in-plane through the bearing centerline and rotate at the same angular velocity as the shaft.