Single Reduction
One gear stage for higher output speeds, such as faster belt conveyors, mixers and fans.
- Ratio
- 5:1
- Stages
- 1
- Use
- Higher output speed
Single & Double Reduction Units, 5:1 to 25:1
A shaft mounted speed reducer (SMSR) slides over the driven shaft, typically a conveyor head pulley, and is held against rotation by an adjustable torque arm. The motor sits on top and drives the gearbox through a V-belt drive.
Because the unit hangs on the shaft it drives, there is no base plate to fabricate and no coupling to align. Combining the gearbox ratio with the belt drive also gives a wide choice of output speeds from standard motors.
- Nominal ratios of 5:1, 13:1, 20:1 and 25:1
- Output torque up to 45,000 Nm across the range
- Hollow output hub for 20 mm to 190 mm shafts
- Optional internal backstop against reverse rotation
Typical across the range; confirmed per grade or size with the quotation.
Key Benefits
No Foundation Required
The reducer is carried by the driven shaft and anchored by a torque arm, saving the steelwork, base plate and alignment work of a foot-mounted gearbox.
Flexible Output Speed
The gearbox ratio combined with a V-belt input drive allows overall reductions up to 200:1, so output speed can be set by changing pulleys rather than the gearbox.
Easy Belt Tensioning
The torque arm turnbuckle doubles as the belt tensioner. Adjusting its length moves the motor mount and sets belt tension without extra hardware.
Runback Protection
An optional backstop fits inside the housing by removing a cover plate, holding loaded inclined conveyors and elevators if power is lost.
Configurations
One shaft-mounted principle, configured for the speed, torque and safety needs of the drive.
Double Reduction
Two gear stages for slower, higher-torque duties such as conveyor head pulleys and bucket elevators.
- Ratios
- 13:1, 20:1, 25:1
- Stages
- 2
- Use
- Lower speed, higher torque
With Backstop
Internal backstop that allows rotation in one direction only, for inclined conveyors and elevators.
- Fitting
- Internal, behind cover plate
- Use
- Inclines and elevators
Complete Drive Kit
Gearbox, motor mount, V-belt drive and torque arm supplied as a matched set for the required output speed.
- Input
- V-belt drive from motor
- Overall ratio
- Up to 200:1
Technical Specification
Typical values across the range. Exact figures depend on the grade or size selected and are confirmed for your application with the quotation.
- Nominal ratios
- 5:1, 13:1, 20:1, 25:1
- Output torque
- Up to 45,000 Nm
- Output bore
- 20 to 190 mm, parallel bore or taper bush
- Input drive
- V-belt from motor, overall ratios to 200:1
- Reaction
- Adjustable torque arm with turnbuckle
- Backstop
- Optional, fitted internally
- Lubrication
- Oil bath, quantity set by mounting position
- Mounting
- Shaft mounted; flange mounting on request
Applications
Belt Conveyor Head Pulleys
The most common SMSR duty: driving the head pulley of a belt conveyor directly.
Inclined Conveyors
Backstop-equipped units hold loaded inclines when the drive stops.
Crushers & Screens
Compact drives for feeders, screens and crusher conveyors in quarries.
Cement & Aggregates
Elevator and conveyor drives in batching plants and cement handling.
Bucket Elevators
Vertical bulk handling where runback protection is required.
Mixers & Agitators
Shaft-mounted drives for mixing tanks and process equipment.
Frequently Asked Questions
Need an SMSR drive sized for your conveyor?
Send us the motor rating, speed, shaft sizes and application. Our UAE engineering team will recommend the right component and send a quotation.
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