Tuthill 50286500 Timing Gear for HD Series Rotary Lobe Pumps
The Tuthill 50286500 is a genuine timing gear for Tuthill HD Series rotary lobe process pumps. In a rotary lobe pump the two impellers never touch each other, and the only thing holding them in phase is the pair of timing gears running in the oil filled gear case at the drive end. Everything about how the pump behaves inside the housing follows from how accurately those gears hold their relationship.
Timing gears are what make a rotary lobe pump work. The impellers never touch each other, so the gears alone hold them in phase, and any backlash that develops in the gear set shows up directly as impeller contact inside the housing. The parts list calls for two per pump and they are replaced as a matched pair. Timing gears run outside the product stream in their own oil bath, so they are not attacked by the fluid being pumped, but they do wear with hours and with shock loading. Backlash that has developed in the gear set is the thing to measure when a pump has started to tick, rattle or run hot, and it must be dealt with before the impellers make contact. Retime the pump and check impeller clearance whenever the gears are disturbed.
Key Features
- Genuine Tuthill timing gear
- Direct replacement for HD Series rotary lobe pumps
- Parts list calls for two per pump, replaced as a matched pair
- Runs in the oil filled gear case outside the product stream
- Holds the impellers in phase so they never contact each other
- Backlash in the gear set is the first sign that replacement is due
Applications
- Viscous and abrasive slurry transfer
- Corrosive acid and chemical process duty
- Fluids carrying suspended solids that must not be sheared
- Heavy process oils, resins and adhesives
- Scheduled overhaul of Tuthill rotary lobe process pumps
- Critical spares holding for continuous process plant
Specifications
- Brand: Tuthill
- Manufacturer Part Number: 50286500
- Part Type: Timing Gear
- Fits: Tuthill HD Series rotary lobe process pumps
- Quantity Required: 2 per pump
- Condition: New
Frequently Asked Questions
Q: Can the gears be turned on the shaft to adjust timing?
Only within the design of the build. The gear keys locate them, so retiming is done the way the service instructions describe rather than by guesswork.
Q: Does the pumped fluid reach the gears?
No. That is the point of the design. The gears and the bearings sit outside the product stream.
Q: Do both gears have to be replaced together?
Yes. They are a matched pair and fitting one new gear against a worn one leaves the backlash largely unchanged.
Q: How do I know the gears are worn?
Measure the backlash at the gear mesh. A ticking or rattling noise from the drive end under load is the usual first symptom.
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 timing gear.
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