![]() ![]() Therefore, V-belts have a slightly lower efficiency than flat belts (approx. Animation: V-belt cross sectionĭue to the greater belt thickness of V-belts compared to flat belts, the energy required to bend the belt around the pulleys is higher. Otherwise, for example, belts designed for larger pulleys would bend too much and the flanks would buckle and then no longer rest flat. Since the V-belts only rest on the flanks, they are specially designed for a certain range of pulley diameters as well as for certain wrap angles. Expressed in figures, a factor of 3.1 or 3.6 for groove angles of 38° or 32°. \sin\left(\tfrac\) (due to the increased frictional force). In this way, a relationship between the radial force and the normal forces can be established using the groove angle \(\alpha\): The figure above shows that the radial force \(F_b\) must be balanced with the two resulting normal forces \(F_n\) on the flanks. ![]() Otherwise there would be no wedge effect! For the same radial force (bearing load), the total friction force is significantly higher for V-belts. The V-belt must therefore not touch the groove bottom, as the contact force must only come about by the flanks. The so-called groove angle \(\alpha\) is 38° or 32°, depending on the pulley diameter, whereby the belt only has contact with the pulley on the inclined flanks. V-belts can transmit significantly higher torques with the same bearing load than flat belts however, the efficiency is lower! To further increase the power transmission, two or more V-belts can also be arranged parallel to each other. Figure: Standard V-belt (wrapped)Ĭonversely, with the same pretensioning forces, much higher torques can be transmitted when using V-belts instead of flat belts. Accordingly, the bearing load is also significantly reduced. Therefore, only relatively low preload forces are necessary to generate the required frictional forces for power transmission. The wedge-shaped cross-section leads to high frictional forces on the flanks due to the “wedge effect”. ![]() The high bearing load when using flat belts can be significantly reduced by using V-belts. A disadvantage of flat belts, however, is the relatively high bearing load caused by the high pretensioning forces.įlat belts have high efficiency and flexibility as well as low wear and low noise levels however, they require relatively high pretensioning forces! V-belts Due to the relatively small belt thickness, the belt can be very strongly bent and thus allows the use with relatively small pulleys. 98 %) and thus on the maintenance of the belt. This also has positive effects on the service life and the efficiency (approx. Figure: Pulley for flat beltsįlat belts generally generate very little noise. This achieves self-centering of the belt and prevents it from running off and the belt keeps track. Depending on the width of the pulley, this hump usually ranges between 0.3 mm and 1.2 mm. To prevent the flat belt from jumping off the pulley, the cross-section of the pulley has a slight convex crown. The belt can then be used for multiple belt drives and for crossed belt drives.įlat belts allow high speeds and high torques to be transmitted (and thus high power). In this case, both sides of the belt are specially coated. Figure: Flat beltĭue to their design, flat belts can in principle run on both sides around the pulleys. The bottom layer where the belt has contact with the pulley, can be coated with special rubber to increase friction and wear resistance. The top layer on the opposite side only has a protective function. These force-transmitting cords are embedded in a rubber core between a top cover and a bottom cover. Today, however, steel or high-strength synthetic materials such as polyamide or aramide are used for tension cords. It has a rectangular cross-section and was often made of leather in the early days. ![]() The simplest type of belt is the flat belt. In this article, learn more about the different types of belts and their application, as well as the respective advantages and disadvantages. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |