Descripción
PB-D22-12D-79 Universal Coupling
Precision-Engineered for UK Agricultural & Industrial Applications
Manufactured to exact DIN/ISO tolerances, the PB-D22-12D-79 universal coupling delivers reliable torque transmission, minimal backlash, and outstanding service life — purpose-built for PTO drive shafts used across UK farming, construction, and industrial OEM sectors.
What Is the PB-D22-12D-79 Universal Coupling?
The PB-D22-12D-79 universal coupling is a compact, high-precision shaft-to-shaft connector engineered specifically for use in PTO drive shaft assemblies. Featuring a 12 mm bore diameter (D h7 tolerance), an overall length of 79 mm, and a cross-journal outer diameter of 22 mm, this coupling is optimally dimensioned for light-to-medium-duty agricultural machinery, compact gearboxes, and industrial conveyor drives widely used across England, Scotland, Wales, and Northern Ireland. The coupling transmits rotational torque between two non-collinear shafts while accommodating angular misalignment of up to the standard design envelope, which is critical in real-world field applications where shaft alignment is rarely perfect.
Unlike generic couplings sourced from commodity suppliers, the PB-D22 series components are manufactured from precisely selected carbon steels and surface-hardened alloys, with each yoke and cross-journal assembly inspected against DIN 808 and ISO 8739 dimensional standards. UK procurement engineers and machinery OEMs consistently rate this coupling for its dimensional stability under cyclic loading, its resistance to fretting corrosion in wet farmyard environments, and the ease with which it integrates into standard PTO shaft assemblies without custom machining.
Why UK Engineers Specify This Universal Coupling
Technical Specifications — PB Series Universal Coupling
All dimensions in mm. Tolerance designations per DIN/ISO standards.
| Serie | D(h7) | E | L | A | B | K(js9) | T | S(h8) | Sw(h8) |
|---|---|---|---|---|---|---|---|---|---|
| PB-D20 | 10 | 20 | 74 | 11.5 | 22.5 | 3 | 11.4 | 10 | 10 |
| PB-D22 | 12 | 22 | 79 | 14 | 25 | 4 | 13.8 | 12 | 12 |
| PB-D25 | 14 | 25 | 89 | 15 | 28 | 5 | 16.3 | 14 | 14 |
| PB-D29 | 16 | 29 | 100 | 18 | 32.5 | 5 | 18.3 | 16 | 16 |
| PB-D32 | 18 | 32 | 111 | 19 | 36 | 6 | 20.8 | 18 | 18 |
| PB-D35 | 20 | 35 | 120 | 21.5 | 39 | 6 | 22.8 | 20 | 20 |
| PB-D37 | 20 | 37 | 128 | 21 | 41 | 6 | 22.8 | 20 | 20 |
| PB-D40 | 22 | 40 | 145 | 25.5 | 47.5 | 6 | 24.8 | 22 | 22 |
| PB-D45 | 25 | 45 | 163 | 31 | 54 | 8 | 28.3 | 25 | 25 |
| PB-D50 | 30 | 50 | 185 | 35 | 61 | 8 | 33.3 | 30 | 30 |
| PB-D60 | 35 | 60 | 232 | 49 | 80 | 10 | 38.3 | 35 | 35 |
| PB-D70 | 40 | 70 | 225 | 33.5 | 70 | 12 | 43.3 | — | — |
| PB-D80 | 45 | 80 | 260 | 38 | 80 | 14 | 48.8 | — | — |
| PB-D95 | 50 | 95 | 310 | 45 | 95 | 14 | 53.8 | — | — |
★ Highlighted row (PB-D22) represents the featured model. Dimensions in mm. D=bore diameter, E=outer diameter, L=overall length, A/B=yoke dimensions, K=keyway width, T=keyway depth, S/Sw=shaft seat tolerances.
How It Works — Principle, Materials & Application Scenarios
The universal coupling operates on the Hooke’s joint principle: a cross-shaped trunnion (spider) links two forked yokes, allowing torque transfer at a variable angle. When shaft misalignment is present, the cross-journal articulates within needle-roller or plain bearings in each yoke arm, converting non-collinear rotation into smooth, continuous output rotation. For single-joint configurations, the output speed varies at twice the input angular frequency; a double-joint (Cardan) layout cancels this variation, making it ideal for agricultural PTO shafts where constant velocity delivery is important during implement operation.
Yoke forgings are produced from SAE 1045 medium-carbon steel, normalised and then case-hardened to 58–62 HRC at the bearing journal faces. The cross-spider uses a higher-alloy 20CrMnTi carburised steel for improved toughness under shock loading. Bearing cups are pressed from low-carbon drawn-cup stock with a needle roller complement. Protective coatings include zinc phosphate conversion plus a rust-inhibiting oil film applied immediately after assembly, meeting the corrosion-resistance expectations of UK-based agricultural machinery dealers and MRO distributors.
The PB-D22-12D-79 universal coupling is routinely fitted into compact tractor PTO shafts connecting to mowers, balers, and slurry pumps across Yorkshire, Lincolnshire, and East Anglia. In industrial settings, it appears in conveyor gearbox drives, packaging line actuators, and textile mill line-shafting in Lancashire and the West Midlands. OEM machinery builders in Derbyshire and Shropshire have standardised on the PB-D22 for drive train sub-assemblies where a compact 79 mm total coupling length is necessary to fit within tight chassis envelopes.
Complete PTO Drive Shaft Range
The PB-D22 universal coupling is designed to integrate directly with the following PTO drive shaft series. Click to explore each product’s specifications and ordering information.
Customer Success: UK Agricultural Machinery OEM
How a West Midlands manufacturer reduced drivetrain failures by 60% after switching to PB-D22 universal couplings.
Background: Farmtech Precision Engineering assembles approximately 400 compact mowing units per year for sale through UK agricultural dealers in the Midlands and the South-West. Their existing supplier delivered universal couplings with bore tolerances that were consistently 0.04–0.08 mm over the h7 limit, causing premature fretting wear and field failures during the May–June grass-cutting season — the most commercially critical period of the year.
Solution: After a product trial in late autumn, Farmtech switched all PTO coupling sourcing to the PB-D22 series. Pre-production sample inspection confirmed bore dimensions within 0.01 mm of nominal. Keyway width tolerance (js9) matched Farmtech’s shaft profile without any rework. The first full production batch of 800 units was delivered to Wolverhampton within 18 working days of order placement.
Result: Warranty claim rate on PTO coupling failures dropped from 4.2% to 1.6% over the following 12-month period — a 62% reduction. Farmtech’s service manager reported zero in-season failures during the following summer’s grass-cutting window. The engineering director approved the PB-D22 as the standard coupling across all compact mower models and began evaluation of the PB-D25 for a heavier straw-chopper application.
— David H., Engineering Director, Farmtech Precision Engineering Ltd
“Ordered 200 PB-D22 couplings for our rotary spreader assembly line. Dimensional accuracy was excellent straight out of the box — zero rework required. Delivery to our Lincolnshire depot was exactly on schedule.”
Agroparts UK Ltd, Lincoln
“We source universal couplings for our industrial conveyor line-shaft drives in Sheffield. The PB-D22 tolerances are consistently tight, and the zinc phosphate finish handles our damp factory conditions much better than previous suppliers’ parts.”
Beaumont Drives & Conveyors, Sheffield
“Good price for the specification. We compared three suppliers on a cost-per-hour-of-service basis and the PB-D22 came out clearly ahead. The team at pto-drive-shafts.com answered our technical questions quickly and helped us confirm the right bore configuration for our application.”
Highland Agricultural Services, Inverness
Manufacturing Facility & Custom Engineering Capability
Our manufacturing facility operates a dedicated universal coupling production line equipped with CNC turning centres capable of holding bore tolerances to H7/h7 with a Cpk above 1.33. Heat treatment is carried out in a fully controlled atmosphere furnace to eliminate decarburisation at the bearing journal surfaces. Every batch undergoes co-ordinate measuring machine (CMM) inspection before dispatch.
Beyond catalogue items, we offer a comprehensive product customisation service that is particularly valued by UK OEM machinery builders and aftermarket distributors. Customers can specify non-standard bore diameters, alternative keyway profiles (DIN 6885 Part 1 or Part 3), special surface coatings such as hard chrome or nickel electroless plating, and modified overall lengths. For orders above 500 units, bespoke yoke profiles and cross-journal assemblies can be produced to customer drawings. Custom engraving of part numbers or brand logos onto yoke flanges is also available. Lead times for custom configurations are typically 25–35 working days from drawing approval, and our sales engineers provide free DFM (Design for Manufacture) review for every custom enquiry.
