QD Type Weld-On Hubs, or Quick Disconnect Weld-On Hubs, are specialized power transmission components designed for connecting a shaft to a hub via a locking assembly. The defining feature is the quick-disconnect mechanism, which allows for rapid installation, removal, and repositioning of the hub on the shaft without the need for extensive machining, keyways, or traditional fasteners like set screws that can damage the shaft. These hubs are "weld-on," meaning they are permanently welded onto a plate, flange, or another structural component of the machinery. This combination offers a robust, secure, and highly adaptable connection point for sprockets, pulleys, couplings, and other driven elements in heavy-duty industrial applications. Engineered for performance and durability, QD hubs from manufacturers like Raydafon Group are critical in systems requiring reliable torque transmission and easy maintenance.
Raydafon Group's QD Type Weld-On Hubs are manufactured to the highest industry standards, offering distinct advantages over conventional mounting solutions.
Selecting the correct QD Type Weld-On Hub requires careful consideration of several key parameters. Below are the standard specifications for Raydafon Group's product line. Always consult engineering drawings and our technical team for application-specific validation.
| Raydafon Model Series | Shaft Diameter Range (Inches) | Shaft Diameter Range (mm) | Hub Bore Diameter (Inches) | Hub O.D. (Approx. Inches) | Max. Torque Capacity (lb-ft)* | Standard Pilot Diameter |
|---|---|---|---|---|---|---|
| QD-WH-1000 | 1/2" - 3/4" | 12.7 - 19.05 | As per bushing | 4.5 | 850 | 2.125" |
| QD-WH-2000 | 7/8" - 1-3/8" | 22.2 - 34.93 | As per bushing | 6.0 | 2,500 | 3.000" |
| QD-WH-3000 | 1-7/16" - 2-1/4" | 36.5 - 57.15 | As per bushing | 8.5 | 6,800 | 4.250" |
| QD-WH-4000 | 2-3/8" - 3-1/4" | 60.3 - 82.55 | As per bushing | 11.0 | 12,500 | 5.500" |
| QD-WH-5000 | 3-3/8" - 4-1/2" | 85.7 - 114.3 | As per bushing | 14.0 | 22,000 | 7.000" |
*Torque values are approximate and depend on proper installation, bushing selection, and application conditions. Safety factors must be applied.
| Bushing Part Number | Fits Shaft Diameter (Inches) | Clamping Screw Size | Qty of Screws |
|---|---|---|---|
| RB-2020 | 7/8" | 1/2"-13 | 3 |
| RB-2021 | 1" | 1/2"-13 | 3 |
| RB-2022 | 1-1/8" | 1/2"-13 | 3 |
| RB-2023 | 1-1/4" | 1/2"-13 | 3 |
| RB-2024 | 1-3/8" | 1/2"-13 | 3 |
Raydafon Group's QD hubs are versatile components found in numerous industries where reliable power transmission is paramount.
Proper installation is critical to achieving the rated performance and service life.
Q: What does "QD" stand for in these hubs?
A: QD stands for "Quick Disconnect." It refers to the locking bushing system inside the hub that allows it to be firmly attached to or removed from a shaft quickly without needing to hammer, press, or use excessive force, and without damaging the shaft surface.
Q: Can a Raydafon Group QD Weld-On Hub be used on a keyed shaft?
A: While it is possible, it is generally not recommended or necessary. The primary advantage of a QD hub is its ability to grip a smooth shaft with tremendous force. Using it on a keyed shaft typically requires a special bushing and negates the shaft-protection benefit. For keyed applications, a standard weld-on hub with a keyway is often a more suitable choice.
Q: How do I select the correct bushing for my shaft size?
A: First, determine the exact diameter of your shaft. Then, match that measurement to the corresponding bushing part number within the hub series you've selected (based on torque requirements). The bushing must match the shaft diameter precisely. Refer to the Bushing Selection Guide in the product catalog or use the online configurator on the Raydafon Group website.
Q: What is the recommended torque for the clamping screws?
A: The required torque is specific to the hub series and bushing size. Raydafon Group provides detailed torque tables in the installation manual for each product. Using incorrect torque—either too low (causing slippage) or too high (risking bolt failure)—can lead to equipment damage. Always use a torque wrench.
Q: Can the hub be re-used after being welded onto a plate?
A: The hub body itself is a permanent component once welded. However, the true reusability lies in the system. If the entire welded assembly (hub + plate) needs to be moved to a different shaft or machine, it can be. The tapered bushing is fully reusable. If the hub needs to be separated from its welded plate, it would require cutting and re-welding, which is not a standard practice.
Q: How does a QD hub compare to a traditional split-taper bushing?
A: The principle is similar, but QD hubs are a standardized, engineered system with specific dimensions and pilot registers for mounting standard components like sprockets. Traditional split-taper bushings are more generic. Raydafon Group's QD system offers guaranteed interchangeability, higher torque ratings, and a more robust overall design for industrial use.
Q: What maintenance do QD Weld-On Hubs require?
A: Maintenance is minimal but important. Periodically check the tightness of the clamping screws, especially in high-vibration or high-cyclic load applications, and re-torque if necessary. Inspect the hub and weld area for cracks or signs of wear. Keep the area free of excessive debris and corrosion.
Q: Can Raydafon Group provide custom QD Weld-On Hubs for non-standard applications?
A: Yes. Raydafon Group's engineering department specializes in designing and manufacturing custom power transmission components. This includes non-standard bore sizes, special pilot diameters, unique flange configurations, and material specifications (e.g., stainless steel for corrosive environments). Contact our technical sales team with your application details.
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