How to Select a Right-Angle Gearbox for Conveyor Drives

To select a right-angle gearbox for a conveyor, start with the required belt speed and drive-pulley diameter, then determine the gearbox output speed, torque, ratio, and duty requirements. Check that the gearbox can handle the conveyor’s starting and running loads, operating hours, ambient conditions, mounting arrangement, and available space. Finally, verify motor compatibility, service factor, thermal capacity, and output-shaft details with the supplier before ordering.

Read more

A right-angle gearbox changes the direction of power transmission, commonly by 90 degrees, which can help fit a drive into a restricted conveyor layout. The correct unit is not simply the one with the desired ratio: its rated capacity and physical configuration must also suit the application. I use the following steps to help buyers define requirements and compare options.

Key Takeaways

• Calculate the required output speed from belt speed and drive-pulley diameter before choosing a reduction ratio.
• Size for actual starting, running, and possible shock loads—not only the motor’s rated power.
• Confirm service factor, thermal capacity, mounting position, lubrication, and output-shaft configuration.
• Provide the supplier with application details and drawings so the proposed gearbox can be checked against the installation.

Step 1: Define the Conveyor’s Required Output Speed

Begin with the conveyor’s target belt speed and the effective diameter of its drive pulley. For a directly driven pulley, output speed in revolutions per minute is approximately the belt speed in metres per second multiplied by 60, divided by the pulley circumference in metres. The result is a starting point; actual belt speed can also be affected by pulley diameter, belt slip, and the selected drive arrangement.

Use an illustrative speed calculation

For example, assume a belt speed of 0.5 m/s and a drive-pulley diameter of 0.20 m. The pulley circumference is approximately 0.628 m, so the required pulley speed is about 48 rpm. These figures illustrate the calculation only; they are not a recommendation for a particular conveyor or gearbox.

Next, compare the required gearbox output speed with the motor speed to estimate the reduction ratio. If a motor runs at approximately 1,440 rpm and the target output is 48 rpm, the nominal ratio is about 30:1. Confirm the actual motor speed, gearbox ratio options, and any speed-control requirements with the drive supplier.

Step 2: Determine Torque and Operating Load

Output torque depends on transmitted power and rotational speed. A commonly used estimate is torque in newton-metres = 9,550 × power in kilowatts ÷ speed in rpm. For an illustrative 1.5 kW input and 48 rpm output, this gives approximately 298 Nm before accounting for gearbox efficiency, service factor, and application-specific load conditions.

This calculation is a preliminary check, not a final gearbox rating. Conveyor starting torque can differ substantially from steady-running torque, particularly when the belt is loaded, inclined, or subject to frequent starts. Share the load profile with the supplier and check the gearbox’s permissible output torque and thermal rating against the complete drive duty.

Describe the load profile clearly

Record whether the conveyor starts empty or loaded, how often it starts and stops, and whether the load is steady, variable, or prone to impact. Include operating hours per day, expected starts per hour, incline, and any braking or reversing requirements. If these details are unknown, identify them as assumptions rather than treating them as confirmed design conditions.

Step 3: Choose a Suitable Right-Angle Gearbox Type

Right-angle gearboxes use different gear arrangements, including worm and bevel-based designs. Their efficiency, size, output arrangement, and operating characteristics vary by design and product series. Compare the manufacturer’s published data for the specific model rather than relying on general claims about an entire gearbox category.

With competitive price and timely delivery, WGT sincerely hope to be your supplier and partner.

Also establish whether the gearbox will connect directly to the motor or use a separate coupling, and whether the output is required as a shaft or hollow bore. Confirm the shaft diameter, key or other connection details, rotation direction, and whether a torque arm or additional support is needed. The choice must match both the conveyor design and the gearbox’s available configurations.

Step 4: Check Service Factor and Thermal Capacity

Service factor is used to account for the application’s operating conditions when comparing required load with gearbox capacity. The appropriate value depends on factors such as daily operating time, load variation, starts, and shock; it should come from the gearbox manufacturer’s selection guidance or engineering review. Do not apply one assumed factor to every conveyor.

Thermal capacity matters because a gearbox must dissipate the heat produced during operation. Ambient temperature, ventilation, mounting position, duty cycle, and input power can affect heat dissipation. Ask the supplier to confirm that the proposed model is suitable for the intended duty and installation conditions, especially where operation is continuous or the environment is warm.

Step 5: Verify Mounting, Environment, and Maintenance Needs

Check the installation drawing for mounting orientation, input and output positions, shaft centre distances, and available clearance. A gearbox that meets the ratio and torque requirement may still be unsuitable if its housing, motor position, or output shaft conflicts with the conveyor frame. Confirm the specified mounting position before finalizing the order because lubrication requirements can depend on model and orientation.

Describe the operating environment, including dust, moisture, washdown, corrosive exposure, and ambient temperature. Request the enclosure or protection details appropriate to that environment, along with information about seals, lubricant, and inspection requirements. Avoid assuming that a general-purpose unit is suitable for food-processing washdown or other demanding conditions without confirming the exact configuration.

Common Selection Mistakes

• Choosing by ratio alone: A matching speed ratio does not confirm adequate torque, thermal capacity, or service life for the stated duty.
• Using motor power as the only sizing input: The supplier also needs output speed, load behaviour, starts, operating hours, and conveyor conditions.
• Ignoring starting and shock loads: A steady-running estimate may not represent the peak demand during a loaded start or jam event.
• Overlooking installation details: Mounting orientation, shaft dimensions, rotation, and clearance can determine whether the selected unit fits.
• Leaving assumptions unstated: Unconfirmed belt speed, pulley diameter, or operating schedule can lead to an unsuitable proposal.

Prepare a Supplier Enquiry

A clear enquiry helps the gearbox manufacturer assess the application and identify missing information. I recommend sending a concise specification with the conveyor layout or drive-end drawing where available. Separate confirmed values from estimates so that the supplier can review the design on a sound basis.

Information to include

• Required belt speed, drive-pulley diameter, and target output speed.
• Motor power, motor speed, supply details, and any variable-speed control.
• Conveyor type, payload or load description, incline, and expected starting condition.
• Operating hours, starts per hour, reversing, braking, and potential shock loads.
• Mounting position, output shaft or hollow-bore requirements, and available space.
• Ambient conditions, exposure to dust or moisture, and maintenance expectations.

Work with WGT on Application Details

At WGT, we support machinery buyers by reviewing the information provided for right-angle gearbox selection and discussing the required ratio, output arrangement, mounting, and operating conditions. The final suitability of a gearbox depends on the actual application and the specifications of the selected model, so we do not treat a preliminary estimate as a confirmed design. Drawings, photographs, and operating data can help clarify fit and duty requirements.

Before requesting a quotation, identify the required quantity, target delivery schedule, and any customization or documentation needs. These details allow the supplier to address sourcing and configuration questions alongside the technical selection. For a conveyor project, send WGT the drive requirements and installation constraints to begin a focused review.

Conclusion: Select for the Complete Drive, Not Just the Gear Ratio

The right way to select a right-angle gearbox for a conveyor is to calculate the required output speed, estimate torque, and then verify the unit against real operating loads, service factor, thermal capacity, and installation conditions. Use calculations as screening tools and have the supplier confirm the proposed model against the complete duty. As a next step, gather the conveyor speed, pulley diameter, motor data, load profile, and mounting details, then submit them to WGT for an application-based discussion.