QD Bushings
QD bushings, or quick-disconnect bushings, are indispensable in the industrial power transmission and agricultural sectors for a wide array of applications including sprockets, sheaves, pulleys, and synchronized drives. At AGKNX, our QD bushings are synonymous with superior holding power and unmatched strength across diverse applications. Crafted from high-grade steel and precision-machined for perfect fitment, our QD bushings offer reliability and durability that stand the test of time.
QD Bushing Dimensions
| QD Bushing Type | Dimensions(in) | Bolt Circle (in) | Cap Screws Included | Set Screw Size | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| A | B | D | E | F | G | L | No. | Thread | Length (in) | |||
| JA | 3/8 | 1.375 | 2 | 11/16 | 9/16 | 1/8 | 1-1/16 | 1-21/32 | 3 | 10-24 | 1 | 10-24 |
| SH | 7/16 | 1.871 | 2-11/16 | 7/8 | 13/16 | 3/16 | 1-5/16 | 2-1/4 | 3 | 1/4-20 | 1-3/8 | 1/4 |
| SDS | 1/2 | 2.187 | 3-3/16 | 7/8 | 3/4 | 3/16 | 1-3/8 | 2-11/16 | 3 | 1/4-20 | 1-3/8 | 1/4 |
| SD | 1/2 | 2.187 | 3-3/16 | 1-5/16 | 1-1/4 | 3/16 | 1-13/16 | 2-11/16 | 3 | 1/4-20 | 1-7/8 | 1/4 |
| SK | 9/16 | 2.812 | 3-7/8 | 1-3/8 | 1-1/4 | 3/16 | 1-15/16 | 3-5/16 | 3 | 5/16-18 | 2 | 5/16 |
| SF | 9/16 | 3.125 | 4-5/8 | 1-1/2 | 1-1/4 | 1/4 | 2-1/16 | 3-7/8 | 3 | 3/8-16 | 2 | 5/16 |
| E | 3/4 | 3.834 | 6 | 1-7/8 | 1-5/8 | 5/16 | 2-5/8 | 5 | 3 | 1/2-13 | 2-3/4 | 3/8 |
| F | 13/16 | 4.437 | 6-5/8 | 2-13/16 | 2-1/2 | 3/8 | 3-5/8 | 5-5/8 | 3 | 9/16-12 | 3-5/8 | 1/2 |
| J | 1 | 5.148 | 7-1/4 | 3-1/2 | 3-3/16 | 3/8 | 4-1/2 | 6-1/4 | 3 | 5/8-11 | 4-1/2 | 5/8 |
| M | 1-1/4 | 6.500 | 9 | 5-1/2 | 5-3/16 | 3/8 | 6-3/4 | 7-7/8 | 4 | 3/4-10 | 6-3/4 | 3/4 |
| N | 1-1/2 | 7.000 | 10 | 6-5/8 | 6-1/4 | 7/16 | 8-1/8 | 8-1/2 | 4 | 7/8-9 | 8-1/2 | 3/4 |
| P | 1-3/4 | 8.250 | 11-3/4 | 7-5/8 | 7-1/4 | 1/2 | 9-3/8 | 10 | 4 | 1-8 | 9-1/2 | 7/8 |
| W | 2 | 10.437 | 15 | 9-3/8 | 9 | 1/2 | 11-3/8 | 12-3/4 | 4 | 1-1/8-11.5 | 11-1/2 | 1 |
| S | 3-1/4 | 12.125 | 17-3/4 | 12-1/2 | 12 | 1/2 | 15-3/4 | 15 | 5 | 1-1/4-15.5 | 15-1/2 | 1-1/4 |
What are the QD Bushings?
QD bushings, or quick-disconnect bushings, are indispensable in the industrial power transmission and agricultural sectors for a wide array of applications including sprockets, sheaves, pulleys, and synchronized drives. At AGKNX, our QD bushings are synonymous with superior holding power and unmatched strength across diverse applications. Crafted from high-grade steel and precision-machined for perfect fitment, our QD bushings offer reliability and durability that stand the test of time. Designed for effortless installation and removal, our QD bushings feature a single split extending through the entire length, allowing for both conventional and reverse mounting styles to accommodate your precise needs. These innovative components excel even in the most demanding conditions and rugged applications worldwide. We maintain a comprehensive inventory of standard sizes and also offer custom QD bushings, including stainless steel options, upon request.
Key Benefits of QD Bushings
Quick disconnect (QD) bushings offer several advantages in industrial applications, particularly for mounting pulleys, sprockets, and sheaves onto shafts. Here are the key benefits:
1. Ease of Installation and Removal: QD bushings are designed for quick and straightforward mounting. They require only a few screws to secure or release, saving significant time compared to other bushing types like taper-lock, which are built for more permanent setups.
2. Strong Clamping Force: Their split design and gradual taper provide a tight, reliable grip on the shaft, ensuring components stay securely in place without slippage, even under high torque loads.
3. Versatility: QD bushings accommodate a wide range of bore sizes and shaft diameters, making them compatible with various sprockets, pulleys, and other components. This flexibility reduces the need for custom machining.
4. Time Efficiency: The quick-disconnect feature allows for rapid component changes, minimizing downtime during maintenance or reconfiguration of machinery.
5. Durability: Typically made from robust materials like steel or cast iron, QD bushings handle significant torque and wear, offering long-term reliability in demanding environments.
6. Reduced Shaft Damage: The design distributes load evenly, minimizing wear or scoring on the shaft, which can extend the lifespan of both the shaft and the bushing.
Applications of QD Bushings
1. Industrial Machinery
- Conveyor Systems: QD bushings are used to mount pulleys or sprockets in conveyor belts for material handling in industries like manufacturing, mining, and logistics.
- Pumps and Compressors: They secure components in pumps and compressors, enabling efficient power transfer in HVAC systems, water treatment plants, and industrial processes.
- Mixers and Agitators: QD bushings are employed in mixers for food processing, chemical production, and pharmaceuticals to ensure reliable torque transmission.
2. Agricultural Equipment
- Tractors and Harvesters: QD bushings are used in power take-off (PTO) systems and other driveline components to connect pulleys or gears for tasks like plowing, harvesting, or irrigation.
- Grain Handling Systems: They mount sprockets in augers and conveyors for moving grain in silos or processing facilities.
3. HVAC Systems
- Blowers and Fans: QD bushings are used to attach fan blades or pulleys in heating, ventilation, and air conditioning systems, ensuring smooth operation in commercial and industrial HVAC setups.
4. Power Transmission Systems
- Belt Drives: QD bushings are commonly used with V-belt or timing belt pulleys in applications requiring variable speed or torque, such as in textile machinery or printing presses.
- Chain Drives: They mount sprockets for chain-driven systems in packaging machines, bottling lines, and automotive assembly lines.
5. Mining and Quarrying
- Crushers and Screens: QD bushings are used in heavy-duty equipment like rock crushers and vibrating screens to mount drive components, handling high torque and shock loads.
- Conveyor Drives: They facilitate power transmission in belt or chain conveyors used to transport ore, coal, or aggregates.
6. Automotive and Transportation
- Belt and Pulley Systems: QD bushings are used in auxiliary systems like alternators, water pumps, or air conditioning compressors in heavy-duty vehicles.
- Rail and Marine Applications: They secure components in propulsion systems or auxiliary machinery in trains and ships.
7. Food and Beverage Processing
- Packaging Equipment: QD bushings are used in conveyors, fillers, and capping machines due to their ability to be quickly swapped out for maintenance in hygienic environments.
- Mixing and Grinding: They secure components in blenders, grinders, and slicers, supporting high-speed operations with minimal downtime.
8. Renewable Energy Systems
- Wind Turbines: QD bushings are used in gearboxes and generators to connect rotating components, allowing for easy maintenance in remote installations.
- Solar Tracking Systems: They mount gears or pulleys in mechanisms that adjust solar panels for optimal sun exposure.
Pumps and Compressors
Belt and Pulley Systems
Conveyor Systems
Tractors and Harvesters
Crushers and Screens
Wind Turbines
QD Bushing Installation Steps
Conventional mounting involves inserting the bolts through the sprocket/sheave first, then threading them into the bushing. The assembly is then positioned onto the shaft with the bushing flange facing inward and the bolt heads facing outward, as illustrated in Figure 2.
Reverse mounting, on the other hand, requires placing the bolts through the bushing first, and then threading them into the sprocket/sheave. The assembly is then placed onto the shaft with the sprocket/sheave facing inward and the bolt heads facing outward, as depicted in Figure 2. Conventional mounting is typically the preferred method.
(1) Thoroughly clean the shaft, bushing bore, outside of the bushing, and the sprocket/sheave hub bore to remove any oil, paint, or dirt. Additionally, ensure to file away any burrs.
Note: Avoid lubricating the bushing taper, hub taper, bushing bore, or shaft to prevent the risk of sprocket/sheave hub fracture. DO NOT USE LUBRICANTS.
(2) To assemble the sprocket/sheave and bushing, begin by sliding the sprocket/sheave onto the tapered bushing surface, ensuring proper alignment. Align the unthreaded holes in the sprocket/sheave hub with the threaded holes in the flange of the bushing. Proceed to hand-tighten the cap screws with lock washers installed. Then, mount the sprocket/sheave and bushing assembly onto the shaft, positioning the bushing flange either inward or outward based on your configuration requirements. Some assemblies allow for a reverse mount, with the bushing flange facing outward while still facilitating cap screw installation from the outside of the assembly.
(3) With the key resting in the shaft keyway, position the assembly onto the shaft, allowing for slight axial movement of the sprocket/sheave, which may occur during the tightening process. Alternatively, for installing large or heavy parts in a conventional mount, it might be easier to mount the key and bushing on the shaft first. Then, place the sprocket/sheave on the bushing and align the holes accordingly.
Note: When mounting sprockets/sheaves on a vertical shaft, take precautions to prevent the sprocket/sheave and/or bushing from falling during installation.
Figure 2
(4) Alternatively, tighten the cap screws in sequence until the sprocket/sheave and bushing tapers are fully seated together. Apply approximately half of the recommended bolt torque as specified in Table 2.
(5) Inspect the alignment and axial runout (wobble) of the sprocket/sheave, and make adjustments as needed to ensure proper alignment.
(6) Continue alternating the tightening of the cap screws until reaching the recommended torque values specified in Table 2 below. Do not exceed the recommended torque once reached.
Note: Excessive bolt torque can lead to sprocket/sheave and/or bushing breakage. When properly mounted, there should be a gap between the bushing flange and the sprocket/sheave.
(7) When available, tighten the set screw to securely hold the key in place during operation.
Caution: Excessive bolt torque can lead to sprocket/sheave and/or bushing breakage.
Note: To ensure proper drive performance, it is recommended to achieve full bushing contact on the shaft.
(8) When available, tighten the set screw to securely hold the key in place during operation.
| Bushing Style | Bolts (in) | Torque Wrench | ||
|---|---|---|---|---|
| Qty. | Size | lb-ft | lb-in | |
| H | 2 | 1/4×3/4 | 7.9 | 95 |
| JA | 3 | 10-24×1 | 4.5 | 54 |
| SH & SDS | 3 | 1/4-20×1 3/8 | 9.0 | 108 |
| SD | 3 | 1/4-20×1 7/8 | 9.0 | 108 |
| SK | 3 | 5/16-18×2 | 15.0 | 180 |
| SF | 3 | 3/8-16×2 | 30.0 | 360 |
| E | 3 | 1/2-13×2 3/4 | 60.0 | 720 |
| F | 3 | 9/16-12×3 5/8 | 75.0 | 900 |
| J | 4 | 5/8-11×4 1/2 | 135.0 | 1620 |
| M | 4 | 3/4-10×6 3/4 | 225.0 | 2700 |
| N | 4 | 7/8-9×8 | 300.0 | 3600 |
| P | 4 | 1-8×9 1/2 | 450.0 | 5400 |
| W | 4 | 1 1/8-7×11 1/2 | 600.0 | 7200 |
| S | 5 | 1 1/4-7×15 1/2 | 750.0 | 9000 |
Table 2 – QD Bushing Bolt Torque Values
QD Bushing Remove:
(1) Loosen and remove all mounting bolts.
(2) Insert cap screws into all threaded jack screw holes.
(3) Loosen the bushing by first tightening the screw furthest from the bushing saw slot, then, alternately tighten the remaining screws. Keep tightening the screws in small but equal increments until the tapered sprocket/sheave and bushing disengage.
Note: Excessive or unequal pressure on the bolts can break the bushing flange, making removal impossible without destroying the sprocket/sheave.
