Roper Pump N41-394-1 Gear Reducer 3.94 to 1 for 11 17 22 GHB
The Roper N41-394-1 is the 3.94 to 1 built-on gear reducer for 11, 17 and 22 GHB pumps. It sits in the middle of the ratio range offered for these frames, bringing a nominal 1750 revolutions per minute motor down to roughly 445 revolutions per minute at the pump. That is the speed band where a gear pump on genuinely thick product still has time to fill its tooth spaces completely on every revolution.
Filling is the whole reason viscous service calls for reduction. As liquid gets thicker it moves into the gear teeth more slowly, and a pump run too fast simply cannot draw enough product in to keep up, which shows up as flow well below the theoretical figure, a noisy pump and cavitation damage over time. Slowing the pump down cures all three at once. The reducer is built onto the pump head rather than mounted separately, so alignment between the reducer output and the pump shaft is fixed by machining instead of by shimming, and the only routine attention it needs is keeping the correct oil at the correct level.
Key Features
- Genuine Roper Pump Company built-on gear reducer, part number N41-394-1
- 3.94 to 1 reduction ratio, giving roughly 445 revolutions per minute from a nominal 1750 revolutions per minute motor
- Middle ratio of the range offered for these pump frames
- Mounts directly on the pump head so output alignment is fixed by machining
- Sized for the 11, 17 and 22 GHB pump frames
Applications
- 11, 17 and 22 GHB gear pumps on viscous service
- Asphalt, molasses and resin handling
- Heavy fuel oil and residual product transfer
- Feed supplement and heavy syrup duty
- Correcting a pump that is being run too fast for its product
Specifications
- Brand: Roper Pump Company
- Part Number: N41-394-1
- Part Type: Built-on gear reducer
- Ratio: 3.94 to 1
- Fits: 11, 17 and 22 GHB pump frames
- Configuration Note: GHB denotes a tapped port case with an outboard ball bearing and a built-on gear reducer
- Lubrication: Separate charge of gear oil, independent of the pumped liquid
- Condition: New
Frequently Asked Questions
Q: How can I tell my pump is turning too fast for the product?
Delivered flow well under what the displacement predicts, a harsher note from the pump than usual, and a suction gauge pulling further down than it should. All three point the same way.
Q: Will a slower pump wear out later than a fast one?
Generally yes. Lower rubbing speeds at the bearings and gear faces mean less heat and less wear, which is part of why reduction is specified on heavy duty even when flow allows a faster pump.
Q: Does the reducer need to be vented?
Most gear cases have a breather so pressure does not build as the oil warms. Keep it clear, because a blocked breather pushes oil straight out past the shaft seals.
Q: Can the reducer be run in either direction?
The pump itself is happy either way, but check the reducer arrangement for your unit before reversing rotation, and remember a single direction relief valve has to be positioned for the flow direction in use.
Not sure this is the right part? Send us a Picture of the pump plate on your pump and the CLR Marine team will confirm the correct gear reducer before you order.
CLRMarine
