Drive connections
Couplings and Magnetic Couplings
Couplings connect a driver, usually an electric motor, to a pump, gearbox or other driven machine, and they accommodate small shaft misalignment while transmitting torque. Magnetic couplings do the same without a mechanical connection through a containment shell, which allows sealless pump designs. Globseals can help you identify hubs, inserts and complete couplings and quote replacements.
- Jaw, gear, disc, tyre couplings
- Spiders and elastic inserts
- Magnetic coupling spares
- Torque and shaft details
Overview
The coupling you see on a pump set is the main wear item in the drive train after the bearings and seals. Elastomer inserts harden and crack, hubs wear on keyways, and bolts loosen. Replacing inserts early prevents damage to shafts and bearings. Misalignment is the usual cause of premature failure, so check alignment when refitting.
Magnetic couplings use paired magnet assemblies, an outer drive magnet on the motor side and an inner driven magnet on the pump shaft, separated by a non-magnetic containment shell. Because no shaft passes through the casing, the pump has no dynamic shaft seal.
Types
- Jaw (spider) couplings: two hubs with an elastomer spider; compact and widely used for small and medium drives.
- Pin-and-bush and tyre couplings: higher torque and better misalignment tolerance, often with rubber elements.
- Gear couplings: metal gears in a sleeve, for high torque and speed.
- Disc and diaphragm couplings: metallic, backlash-free, used where precision matters.
- Grid couplings: steel grids with covers and lubricant.
- Rigid couplings and taper-lock bushes: for aligned shafts and to mount hubs.
- Magnetic couplings: for magnetic-drive pumps and agitators; ask for a technical review.
Materials and element options
| Part | Common materials | Notes |
|---|---|---|
| Hubs | Cast iron, steel, aluminium, stainless | Match the shaft diameter and keyway. |
| Elastic inserts | NBR, polyurethane, hytrel-type polyester | Different hardnesses give different torque and damping. |
| Magnets | Neodymium or samarium cobalt | Neodymium grades lose strength at elevated temperature; samarium cobalt handles higher temperature. Confirm limits. |
| Containment shell | Stainless steel, alloys, plastic or ceramic | Material affects eddy-current heating and chemical compatibility. |
Values here are typical only; always confirm against the manufacturer's data for your application. Strong magnets present a hazard to people with pacemakers and attract tools, so handle assemblies carefully.
How to choose
- Identify the type from the hub shape and the insert; photograph both halves.
- Measure bore diameters, keyway widths, hub lengths and overall dimensions.
- Note motor power and speed to estimate torque, including starting duty.
- Check for taper-lock bushes, which need the bush size too.
- For magnetic couplings, give the pump model and the medium temperature; the pump manufacturer data governs.
Alignment tolerance and speed rating differ between designs. Review with pump repairs and refurbishment if a shaft or keyway is damaged.
Information to send with your enquiry
The more of the following you can supply, the faster the part can be identified and quoted.
- Coupling type, make and size code where marked
- Bore sizes, keyways and hub lengths
- Motor kW, speed and starting method
- Pump model and nameplate
- Spider or insert hardness colour code, if visible
- Taper-lock bush size
- Photos of both halves
- Magnetic couplings: medium, temperature and pump model
Genuine and compatible replacements
Customers can enquire about genuine or compatible replacement parts for equipment from manufacturers such as Burgmann, John Crane, Chesterton, Grundfos, KSB, Flygt, Lowara, Goulds, Sulzer, Flowserve, Klinger, Flexitallic, Trelleborg and others. A genuine part is supplied by or made to the original equipment manufacturer's specification and part number. A compatible part is made to fit the same dimensions and duty, usually by another manufacturer, and may differ in material or finish. Spiders and inserts from different makers often fit the same hubs but vary in hardness and torque. Hubs are less interchangeable because of bore and keyway tolerances. State clearly in your enquiry which you want, and say whether a part number or sample is available.
How to buy
Globseals supports three ways to buy, and the right one depends on how well the part is defined.
- Buy online where a product listing shows a confirmed price. Products are being added to the shop progressively, so not every item in this category is listed yet.
- Request a quote for custom, bulk or unpriced items. Spiders, hubs and complete couplings are quoted. Use the quote request page.
- Technical review when identification is unresolved. Examples include magnetic couplings, high-speed gear couplings, and damaged shafts. Start with Find My Seal or upload a drawing.
You can also phone 011 079 6033 or WhatsApp 079 508 0989, or email info@globseals.com. See delivery and collection for how orders are handled; courier costs are quoted per order.
Options & specifications
| Types available | Jaw, pin-and-bush, tyre, gear, disc, grid, rigid, magnetic |
|---|---|
| Insert materials | NBR, polyurethane, polyester elastomer |
| Key dimensions | Bore, keyway, hub length, overall diameter |
| Typical use | Motor-to-pump, gearbox and fan drives |
| Magnet options | Neodymium or samarium cobalt on enquiry |
| Order mode | Quote; technical review for magnetic couplings |
Options, materials and turnaround are confirmed on your written quote.
How ordering works
- 1
Identify
Gather part number, dimensions or a photo of the part.
- 2
Send
Submit it through the quote form, WhatsApp or email.
- 3
Review
Our team checks the details and asks about any gaps.
- 4
Order
Confirm the quote or buy online where a price is listed.
Frequently asked questions
How do I know when to replace a coupling spider?
Cracks, hardening, powdery wear and noise or vibration are signs. Replace it with the hubs checked for wear.
What causes coupling failure?
Misalignment, overload, heat and incorrect fitting are the usual causes. Alignment checks help.
Can I replace a mechanical seal with a magnetic coupling?
Not on an existing pump without redesign. Magnetic-drive pumps are designed for that arrangement.
What information do you need for a quote?
Type, bore sizes, keyways, and a photo are normally enough. Add motor power and speed for sizing.
Do magnetic couplings have temperature limits?
Yes, magnets lose strength at elevated temperature. Confirm limits with the pump or coupling manufacturer.
Request a quote for Couplings and Magnetic Couplings
Related services
Pumps and Pump SparesGlobseals supplies pump spares and, on enquiry, pumps for water, process and general industrial duty. Pump spares are…View 
Shaft Repair SleevesA grooved or worn shaft ruins any new seal or packing set. Instead of replacing or re-machining the…View 
Special Products and Engineered ComponentsNot every part appears in a catalogue. Older machines, imported equipment and modified plant often need seals, bushes,…View - Pump Repairs and RefurbishmentPumps are the heart of many plants, and a failed pump quickly becomes a production problem. Globseals supports…View
- Pump and Seal Maintenance GuideGood maintenance extends seal life and reduces unplanned stops. This guide offers a general routine for pumps and…View
Request a QuoteUse this page for custom, bulk or unpriced items, or whenever you want a written quotation. A good…View 
Expansion JointsExpansion joints absorb thermal movement, misalignment and vibration in pipework so that pumps, valves and vessels are not…View 
Valves and Valve SparesValves control, isolate or protect pipework, and their sealing parts, namely stem packing, seats, body gaskets and O-rings,…View
Send bore, keyway and type details for a coupling quote.
Send your brief, quantities and deadline. We reply with a clear written quote and confirm the turnaround before anything goes to production.
