Belts, Sheaves & Pulleys
Complete belt drives from one catalog: industrial V-belts and gearbelts, the sheaves and pulleys they run on, and the tensioners and guards that finish the installation. Browning lines with standard catalog-number interchange.
Belts, Sheaves & Pulleys by Category
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About Belts, Sheaves & Pulleys
A V-belt drive is four decisions that have to agree with each other: the belt section, the sheave groove cut for that section, the bore or bushing that puts each sheave on its shaft, and the way the drive is tensioned. The group is stocked to be read in that order. Belts run from the fractional horsepower 2L through 5L sections up to the classical A, B, C and D sections, the notched AX and BX profiles, the narrow 3V, 5V and 8V sections and banded sets. Sheaves are listed by the section they are grooved for, how many grooves they carry, their outside diameter and whether the bore is finished or takes a Split Taper or Q-D bushing. Accessories carry the tighteners, idlers and adjustable motor bases that hold the tension once the drive is built.
Also known as: v-belt drives, belt drives, v belts and pulleys, sheaves and belts
Series in this category
- Belts — Browning V-belts in the FHP, classical, notched, narrow and banded families, listed by section and length.
- Sheaves and pulleys — V-belt sheaves, fractional horsepower sheaves and synchronous belt pulleys, by groove section and bore type.
- V-belt sheaves — One to eight grooves in the A, B, C, 3V, 5V and 8V sections, finished bore or bushed, plus the combination B5V groove.
- Belt drive accessories — Tighteners and idlers for fixed centers, and adjustable motor bases for drives tensioned by moving the motor.
- Split taper bushings — The Browning Split Taper bushing line that the bushed sheaves and sprockets are built around, in bores from 3/8 inch upward.
- Q-D bushings — The Q-D bushing line for Q-D bored sheaves, sprockets and pulleys, in bores from 1/2 inch upward.
Related guides: FHP V-belt sizes, V-belt sheave sizes, Split taper bushing sizes, Q-D bushing sizes, Cross-reference help
How to choose belts, sheaves & pulleys
- The belt section and the groove have to be the same
- A V-belt carries load on its sides, so it has to sit at the right depth in a groove cut for its own section. A 4L or A belt runs in an A groove, a B or 5L belt in a B groove, and the narrow 3V, 5V and 8V sections in grooves cut for them. Combination grooves exist and are stated as such: a B5V sheave takes A, B and 5V belts, while TB and B sheaves take A and B belts but not 5V.
- Apply a service factor before you size anything
- Horsepower ratings are published for a single belt at a 1.0 service factor with the smaller sheave at 1750 rpm. The drive is sized on the motor horsepower multiplied by an overload service factor for the driven machine and the hours it runs: 1.0 to 1.2 for agitators, blowers and centrifugal pumps, 1.2 to 1.4 for bucket elevators and piston compressors, 1.3 upward for crushers and mills, and a minimum of 2.0 where the machine can choke.
- Check the geometry before ordering the parts
- Center distance should not exceed three times the sum of the two sheave diameters, nor be less than the diameter of the large sheave, and the arc of contact on the smaller sheave should not fall below 120 degrees. Belt speed on cast iron sheaves cannot exceed 6,500 feet per minute, and below 1,000 feet per minute another type of drive is usually the better answer.
- Finished bore or bushed decides what you order
- A finished bore sheave is machined for one shaft size and mounts with a setscrew and key. A bushed sheave is ordered as two parts, the sheave and a bushing in the shaft size, which is what lets one sheave serve a range of shafts and what makes the bushing letter part of the order. The listing states which it is, and a bushed sheave without its bushing will not go on a shaft.
- Always replace a set, never one belt
- Belts in a multiple-groove drive share the load only while they are the same length under tension, so a new belt run beside used ones takes more than its share and fails early. Replace the whole set as a matched set, and replace sheaves whose grooves have worn rather than fitting new belts into them.
Specifications explained
| Specification | What it means |
|---|---|
| Belt section | The cross-section of the belt and of the groove it runs in: 2L through 5L, A, B, C and D, notched AX and BX, or narrow 3V, 5V and 8V. |
| Number of grooves | How many belts the sheave carries, from one to eight. It has to equal the number of belts in the drive. |
| Bore type | Finished bore, rough bore for machining, Split Taper bushed or Q-D bushed, which is how the sheave mounts on the shaft. |
| Bushing used | The bushing letter the hub is bored for, such as H, B or Q1 on Split Taper and JA, SH, SDS, SK or SF on Q-D. |
| Outside diameter | The measured diameter of the sheave, which with the pitch or datum diameter of the pair fixes the drive ratio. |
| Outside length or pitch length | The two ways a belt length is stated. A belt part number carries one of them, so the pair has to be read consistently. |
Common questions
How do I identify a belt already on a drive?
Read the section and the length off the belt itself. An FHP number states the section and the outside length in tenths of an inch, so 5L500 is a 5L section belt 50.0 inches outside. A classical number states the section and a reference number, as in B148. A narrow number states the section, an X where the belt is notched, and the outside length in tenths, as in 5VX1180 for a notched 5V belt 118.0 inches outside.
Are 4L and A belts the same thing?
They are the same nominal width and run in the same groove, but they are different belts with different lengths and ratings, and the numbering differs. The stocked equivalents line up as 4L230 to A21 to AX21 at 23.2 inches outside, and continue in one-inch steps from there, so a substitution is made on the cross-reference rather than by matching the number.
What is a notched belt for?
The notches let the belt flex around a small sheave with less heat and less loss, so a notched AX, BX, 3VX or 5VX belt transmits more horsepower than the plain section of the same width and allows a smaller sheave or fewer grooves. The trade is grip: the raw edge construction grips hard enough that notched belts are not used on clutching drives where the belt is meant to slip.
Do I need an idler?
Only where the center distance cannot be adjusted. The preferred way to tension a drive is to move the motor, which is what an adjustable motor base is for, and every drive should be installed with some means of center adjustment because the belts bed in and need retensioning after the first hours of running. A tightener or idler is the answer where the centers are fixed, the wrap on the small sheave is short, or a long span whips.
