V-Belt Pulleys

Using a v-belt, a mechanical linkage with a trapezoidal cross-section, to transmit power between axles is accomplished using V-belt pulleys (also known as vee belt sheaves). These components provide a high-speed, slip- and misalignment-resistant power transmission solution.

Power transmission between two parallel axles is the only application for V-belt pulleys. The geometry of the groove or grooves that run around the pulley's circumference and serve as a v-guide belt and traction points distinguishes a v-belt pulley from other types of pulleys (round belt, flat, etc.).

Compared to round or flat belt gearboxes, v-belts offer superior traction, speed, and load capabilities. They also have a longer service life and require little maintenance. Since heavy loads force the belt deeper into the pulley's groove and create friction, they actually improve transmission efficiency.

V-belt drives typically run at 1,500 to 6,000 feet per minute, with 4,500 feet per minute being the best speed for normal belts. Although some narrow v-belts may move at up to 10,000 feet per minute, these pulleys need to be dynamically stabilized. To support a multiple-belt drive, V-Belt Pulleyscan be arranged side by side, or a single pulley can have numerous grooves around its circle. Several belts are used in this sort of drive to distribute torque and offer mechanical redundancy.

Types of V-Belt Pulleys
Transmissions with v-belts employ a variety of pulley types, each with a unique application. In some cases, flat-belt pulleys are appropriate when the driven pulley is rotated opposite from the pulley being driven, as is frequently done with ribbed v-belts.

Standard pulleys are pulleys with conventional dimensions, one or more grooves, and a hexagonal design that fit with conventional small-engine v-belts.

Integrated spokes that run radially on companion pulleys are mounted as part of the pulley. As a result, pulleys with fractional horsepower have an attractive high strength-to-weight ratio.

In many v-belt drives, idler pulleys are only used as belt tensioners, which are crucial for maintaining the tension needed to power the transmission. Since no torque must be transmitted to this axle, idlers can interact with either the wedged or flat side of the v-belt. Idler pulleys are necessary for transmissions when the driver must pass obstacles, or the driven pulley cannot maintain a good arc of contact with the v-beltto transmit torque. However, they limit the belt's service life and the drive's efficiency.

With a variable pitch, variable speed pulleys can change the driving RPM, frequently within a range denoted as a percentage. Additionally helpful for maintaining belt tension under dynamic loads are these pulleys.

Two or more non-adjustable grooves encircle the same shaft with varying pitches on step pulleys. These pulleys alter the transmission's speed ratio.
Components of V-Belt Pulley
Grooves
The grooves used in pulleys are intended for a certain type and breadth of v-belt. The selection guide for v-belts and v-ribbed belts provides a more in-depth look at v-belts. Pulleys do not require any design modifications to interact with cogged v-belts, which are widely used to increase the flexibility and heat dissipation of conventional and narrow v-belts. The symbol for cogged belts is often an "X" in the belt denomination. As long as the pitch widths and angles are the same, it is common to interchange the pulleys for standard and narrow v-belts.

Mounting
The pulley's bore diameter must, first and foremost, be a geometric match for the mating shaft. The pulley spins about an axle. The most popular way to accommodate this axle is by using a simple bore, which allows the pulley to rotate freely about the axis without transferring any torque. Although this bore is employed in idler pulley applications, it is ineffective for transmitting power. Additional mounting designs include:

Set screw: A through-hole enables a screw to be tightened against the axle perpendicularly.
Keyway: To transfer torque between components, an offset slot or shaft assures a snug fit along the axle.
Press-on: To transfer torque between components, an offset slot or shaft guarantees a snug fit along the axle.
Weld-on: The pulley's hub is joined to the axle via welding.
A tapered hub bolted onto the shaft is known as a tapered bushing.
Hub with a clamp: A clamp tightens a split hub around the axle.

Specifications for V-Belt Pulley
● When choosing v-belt pulleys, it's vital to consider the following factors.
● The style and dimensions of the belt being incorporated, or the belt profile.
● When measured between the edges of the grooves, the outside diameter is the distance across the pulley.
● The center diameter of a pulley in a transmission is the distance between its shafts. Center distances for V-belt transmissions must not exceed three times the diameter of the largest pulley to avoid excessive sliding.
● Grooves, including the quantity, angle, and width of the flanges in the grooves of the pulley.
● Pitch diameter, also known as the pulley's diameter where the belt is attached, is important to a drive's strength-to-weight ratio.
● The angle of contact, or how tightly the belt is wound around the pulley.

We have hundreds of sizes of Sheaves (Pulleys) and their partner styles of bushings in stock for the wide varieties of V-belt drives. Should you want assistance, our sales team would be more than pleased to provide it. Both bore sheaves and bushing-style sheaves have been completed. Your go-to distributor for V-belt pulleys is Rainbow Precision Products.