What is the difference between V-belts and flat belts?
1、平帶 flat-belt
In comparison to V-belts, flat belts require significantly higher pretensioning in order to transmit a certain torque without slippage. This especially applies to large transmission ratios and thereby low angles of contact. Tension pulleys with defined contact pressure are recommended in cases of this kind to reduce the transverse force
Flat belts are not advisable for high outputs at high speeds.
與 V 形皮帶相比，平帶需要更高的預緊力才能在不打滑的情況下傳輸一定扭矩。
這尤其適用於較大的傳輸比，從而降低接觸角度。在此類情況下，建議使用具有定義接觸壓力的張力滑輪，以減少橫向力
對於高速下的高輸出，不建議使用扁平皮帶。
Angle of contact increased by tension pulley for reducing transverse force.
2、齒形帶 V-belt
V-belts are characterized by their trapezium shaped (v-shaped) cross-section. They consist of a tensioning section of multiple layers of endlessly wound polyester fiber cord threads, the core which is made of a high-quality rubber mixture and the enclosure which is made of rubberized cotton or synthetic fabric. Depending on the intended use, different designs are used.
V 形帶的特點是其梯形（V 形）橫截面。它們包括多層無邊纏繞聚酯纖維線線的張力部分，核心由高品質的橡膠混合物制成，外殼由橡膠棉或合成織物制成。根據預期用途，使用不同的設計。
V-belt designs:
a) Standard V-belt, b) Narrow V-belt, c) Narrow V-belt – open-edged, toothed,
d) Wide V-belt (toothed), e) Double V-belt, f) Joined V-belt, g) Poly V-belt
To increase the flexibility of the belt, multiple toothed V-belts are used, enabling smaller diameters. When loaded, the V-belt pulls itself into the trapezium shaped groove of the pulley and generates the friction contact required for torque transmission through the V-effect on both edges. The V-belt itself may not touch the bottom of the groove.
為了增加皮帶的靈活性，使用了多個齒形 V 形皮帶，從而實現更小的直徑。加載時，V 形皮帶將自身拉入滑輪的梯形槽中，並通過兩側 V 效應產生扭矩傳輸所需的摩擦接觸。V 形皮帶本身可能無法觸及凹槽的底部。
The fact that high standard forces between pulleys and belts occur at low pretension (thereby offering a good friction connection) offers advantages for the V-belt. These advantages include low bearing load and reliable operation even in the case of small angles of contact. The V-belt is less efficient in comparison with the flat belt, as it is restricted by the high amount of flexing required and the associated significant temperature increase of the belt.
滑輪和皮帶之間的高標准力以低預緊（從而提供了良好的摩擦連接）發生，這一事實為 V 形皮帶提供了優勢。這些優點包括低軸承負載和可靠的操作，即使在小接觸角度的情況下。與扁平皮帶相比，V 型皮帶的效率較低，因為它受到所需的大量彎曲量和相關帶溫度顯著升高的限制。
With few exceptions, V-belts are manufactured as endless and supplied in standard lengths. Shaft spacing can therefore not be freely selected for the design of the V-belt gearbox. For installation reasons, certain constructive precautions are also to be taken.
除了少數例外，V 形皮帶是無止境的，以標准長度提供。因此，在 V 帶變速箱的設計中不能自由選擇軸間距。出於安裝原因，我們還要采取某些建設性的預防措施。