Where Harvest Performance Begins: Inside the Cleaning Star Gearbox
Sugar beet harvesting is one of the most mechanically punishing operations in British agriculture. Every October through January, machines working across the fens of Cambridgeshire, the silts of South Lincolnshire, and the chalk wolds of the East Riding face an unrelenting demand: separate hundreds of tonnes of fresh beet from wet soil, embedded stones, and leaf residue without damaging the crop or breaking the machine. At the mechanical centre of that cleaning process sits the cleaning star gearbox — a component that rarely earns headlines, but without which no modern beet harvester functions. This precision agricultural gearbox transfers rotational power from the main PTO input to the cleaning star shafts, driving the star-wheel assemblies that tumble beets across the cleaning section at carefully controlled speeds, knocking loose soil through the gaps while advancing the cleaned crop toward the elevator. A gearbox that delivers the wrong output speed, develops excessive backlash after the first season’s use, or fails catastrophically when a stone enters the cleaning section is not an inconvenience — it is the end of the harvest window for every farm in that contractor’s schedule. At Ever Power, we have been building agricultural gearboxes for close to three decades, and in that time we have learned precisely what the cleaning star application demands: robust materials science, meticulous sealing, and engineering tolerances that hold up when the conditions are at their worst.
The cleaning star gearbox is not interchangeable with a generic agricultural drive unit. Unlike gearboxes used in manure spreaders or mowers, this component operates under constant, variable-magnitude shock loading as beets strike the star elements, combined with a permanent contamination threat from fine silt, clay-laden water, and mildly corrosive sugar beet juice. Our engineers have addressed these specific challenges with a housing cast in GGG50 ductile iron, helical and spiral bevel gear sets precision-ground to AGMA 12 quality, and a multi-barrier sealing system that keeps the bearing environment clean even during prolonged operation on waterlogged ground. Whether your machine is a Holmer Terra Dos, a ROPA euro-Tiger, or a Grimme REXOR, an Ever Power cleaning star gearbox can be supplied as a direct-fit replacement or engineered to your exact dimensional and ratio requirements.
Ever Power Cleaning Star Gearbox — IP67-rated, AGMA 12 ground gears, built for UK sugar beet harvesting operations
How the Cleaning Star Gearbox Drives the Heart of Your Beet Harvester
After the topper and share assembly lift the roots from the ground, the raw beets — heavy with adhering soil, sometimes with leaf stumps still attached and occasionally with stones caught between them — are transferred onto the cleaning section. This section consists of four to eight parallel cleaning star shafts arranged in a slightly inclined ladder configuration. Each shaft carries a series of star-shaped rubber or polyurethane elements whose arms interlock with adjacent shafts, creating a rolling, agitating motion that separates soil downward through the gaps while moving the beets forward. The cleaning star gearbox sits at the input end of this shaft array, converting the machine’s PTO input into the transverse rotational output that drives each shaft. The reduction ratio — typically between 3.5:1 and 8:1 depending on machine design and soil conditions — determines the tip speed of the star arms and, critically, the balance between cleaning intensity and beet skin damage. Too fast, and the beet surface is abraded, causing sugar losses and downgrading at the factory weighbridge. Too slow, and soil adhesion on the cleaned beet exceeds the threshold tolerated by British Sugar’s intake specifications, costing the farm money per tonne delivered. The cleaning star gearbox is the single component that controls this balance, and getting the specification right is a commercial decision as much as an engineering one.
Spiral Bevel Power Transmission
Spiral bevel gears convert the horizontal PTO input into transverse shaft drive across the full cleaning width. The curved tooth profile distributes load across multiple contact points simultaneously, reducing noise, peak tooth stress, and vibration compared to straight-cut bevel alternatives — a meaningful advantage when the gearbox must survive thousands of hours of continuous field use.
Multi-Barrier Contamination Defence
Sugar beet juice is mildly acidic and an effective penetrant that exploits any gap in a conventional sealing system. Our Viton triple-lip shaft seals, combined with polyurethane face O-rings and optional nitrogen pre-charge on the housing, create a sealed environment that has resisted contamination ingress across independent field trials totalling over 3,000 harvest hours per unit.
Ratio-Matched Output for UK Soils
We supply cleaning star gearboxes across ratios from 3.5:1 to 8:1, with intermediate values available on custom order. Our application engineers will match the output shaft speed to your machine’s cleaning section geometry, throughput rating, and the soil type characteristic of your operating area — from the light sands of Breckland to the heavy boulder clays of north Lincolnshire.
Integrated Stone-Strike Protection
When a stone enters the cleaning section, impact torque spikes to three or four times the nominal value within milliseconds. Our shear-bolt overload protection, calibrated to activate before gear tooth or bearing damage occurs, pairs with oversized ISO C3 clearance output bearings to absorb transient loads that would crack a lighter-specified unit in the same event.
Technical Specifications & Performance Data
Standard production range — all parameters available in custom-engineered variants upon request
Six Reasons UK Dealers and OEMs Specify Ever Power
Engineering and commercial advantages that go beyond basic performance claims
High-Shock Load Resistance
Stone-strike events are not theoretical — they occur multiple times per harvest shift in UK fields, particularly in the chalky soils of the Yorkshire Wolds and the flint-rich ground of parts of East Anglia. Our gearbox is designed to absorb peak torque spikes reaching three to four times the continuous rating without transmitting damage to gear teeth or shaft seats. The shear-bolt protection mechanism activates within 0.05 seconds of an overload event, preventing the cascading failure that a rigid drivetrain would otherwise experience.
IP67 Sealing as Standard
The UK harvest season routinely runs into November and December, with machines working through standing water, frost-thaw cycles, and prolonged rain. Our standard heavy-duty cleaning star gearbox is rated to IP67 — complete dust exclusion and protection against submersion to one metre — using Viton triple-lip seals on all rotating shafts and polyurethane O-ring face seals on all housing joints. Service life in continuous UK field use consistently exceeds 3,000 harvest hours before the first scheduled bearing replacement.
OEM-Grade Manufacturing Precision
Every cleaning star gearbox leaves our factory only after a no-load run-in test, backlash measurement against DIN 3961 Class 7 tolerance, a full contact pattern check, and a dimensional inspection report issued against the production drawing. Gear tooth profiles are ground — not just hobbed — to AGMA 12 quality. Test certificates and material conformity documents are available in English, complying with UK regulatory requirements following the post-Brexit adoption of domestic machinery safety regulations.
240+ Cross-Reference Part Numbers
Our cross-reference library covers over 240 cleaning star gearbox part numbers used across the Holmer, ROPA, Grimme, Vervaet, and ASA-LIFT beet harvester ranges. In most cases we can confirm compatibility and dispatch a replacement to our UK distribution partner in Peterborough within 36 hours of receiving a part number — a significant improvement on the multi-week back-order timelines reported by customers using direct OEM sources for the same component.
Flexible Pricing & UK Trade Terms
We supply everything from single-unit emergency replacements to 500-unit OEM production batches, with pricing that scales accordingly. UK buyers can receive formal quotations within 24 hours and choose from ex-works, CIF Felixstowe/Southampton, or DDP delivery terms. We work with established UK customs agents and logistics partners to ensure the post-Brexit import process adds no unexpected delay or paperwork burden to your procurement process.
Technical Support That Stays Available
Every cleaning star gearbox order ships with a bilingual installation manual, a lubrication service schedule, and a factory test certificate. Our application engineering team — engineers who have worked directly in agricultural machinery assembly and field support roles — remains available by email and video call for installation support, ratio verification queries, and in-season troubleshooting. The invoice being paid is not the end of our engagement with your operation.
Materials Built for British Harvest Conditions
Material selection for a cleaning star gearbox is driven entirely by what happens in the field, not by what looks good on a specification sheet. Sugar beet harvesting in the UK runs from late September through January, covering temperatures that can swing from 18°C during an Indian summer afternoon in Norfolk to well below zero during a frost in Lincolnshire. The soil itself varies from the light sandy loam of Breckland to the dense boulder clay of the East Riding, each type imposing different cleaning loads and different contamination challenges on the gearbox. A housing made from standard grey iron — as used in many lower-cost agricultural gearbox alternatives — becomes progressively brittle below 5°C and may crack when a stone impact delivers a localised load to a cold housing wall. This is why we specify GGG50 ductile iron for all our cleaning star gearbox housings: a material that delivers approximately three times the impact toughness of grey iron while retaining the excellent machinability, vibration damping, and castability that makes iron superior to steel for this application. Inside the housing, gear blanks are cut from case-hardening steel 20CrMnTi — a grade well-established in heavy-duty agricultural and construction machinery — then carburised to a case depth of 0.8 to 1.2 mm and precision-ground to AGMA 12 quality. The resulting tooth surface, at HRC 58 to 62, has the hardness to resist pitting and scuffing through thousands of hours of operation while the tough core beneath absorbs impact without fracture.
GGG50
Ductile Iron Housing
HRC 62
Max Gear Tooth Hardness
3,000 h
Field-Tested Service Life
IP67
Standard Seal Rating
AGMA 12
Gear Quality Grade
≥97%
Eficiência mecânica
Application Scenarios Across the UK Sugar Beet Industry
The UK harvests between 7 and 8 million tonnes of sugar beet annually, with the crop concentrated in the east of England — principally Lincolnshire, Norfolk, Suffolk, Cambridgeshire, and the East Riding of Yorkshire. British Sugar’s processing factories at Bury St Edmunds, Cantley, Newark, and Wissington are the primary destination for UK-grown beet, and their tare weight and contamination tolerance specifications directly determine the commercial requirement placed on every cleaning star gearbox in every machine operating in this country. Our cleaning star gearboxes are specified across the following distinct application types, each placing different engineering demands on the drivetrain.
Self-Propelled Beet Harvesters
Machines such as the Holmer Terra Dos T4-40 and ROPA euro-Tiger v8 feature large cleaning sections with multiple star rows spanning cleaning widths of up to three metres. These configurations require multi-output cleaning star gearbox arrangements delivering precisely synchronised shaft speeds to prevent beet rotation bias across the width of the cleaning table. Our tandem-output units handle this requirement with a single input driving paired outputs at independently verifiable speeds, confirmed by our run-in test facility before dispatch.
Trailed Multi-Row Beet Harvesters
Contractor operations across Lincolnshire and Norfolk frequently employ trailed harvesters such as the Grimme ROOTSTER 604. These machines draw all cleaning section power from the tractor 540 RPM PTO. Our cleaning star gearboxes for this application feature a standard 6-spline input shaft, integrated shear-bolt overload protection, and a ratio of 5:1 as a common starting point, adjusted to suit the specific machine’s shaft layout and target cleaning intensity on request.
On-Farm Cleaning Stations & Clamp Lines
Farms and co-operative clamp-management operations in East Anglia increasingly use static cleaning stations that process stored beet before loading for factory delivery, particularly when intake queues require holding the crop in outdoor clamps for extended periods. These fixed installations drive the cleaning star shafts from electric motors rather than PTO. Our gearboxes for this application are supplied with B5 or B14 motor flange options and an IP67 rating that resists the prolonged water exposure typical of outdoor clamp environments.
Beet Loading & Transfer Equipment
Self-loading beet vehicles and grab loaders used in farm-to-lorry transfer sometimes incorporate a secondary cleaning pass — a star roller section at the discharge chute — that reduces soil carryover onto the highway and lowers the load’s tare weight at the factory intake. Gearboxes in this application experience intermittent duty cycles but must start reliably under full static load, which requires starting torque capacity of at least 130% of the continuous rating. Our models carry this margin as a standard design provision.
PTO Shafts and Agricultural Gearboxes: The System That Protects Both
A cleaning star gearbox, however precisely engineered, cannot deliver its full rated service life if it is paired with an incorrectly specified or poorly maintained PTO shaft. The PTO shaft — the articulated torque tube running from the tractor or machine power source to the gearbox input flange — is the first mechanical link in the drivetrain chain, and its condition directly determines the quality of the torque signal that reaches the gearbox input shaft. An undersized PTO shaft running at excessive articulation angle imposes bending moments on the gearbox input shaft bearing that the bearing race was not designed to carry in addition to its radial and axial gear loads. The result is accelerated bearing wear, oil seal displacement, and eventual gearbox failure — often attributed incorrectly to a gearbox manufacturing fault when the root cause was always the shaft selection. This is a system problem, and it demands a system answer.
Ever Power supplies a complete range of PTO shafts to complement our agricultural gearboxes, covering continuous torque ratings from 500 Nm for light trailed machines to 4,500 Nm for high-capacity self-propelled harvesters. Our PTO shafts feature wide-angle universal joints with up to 80 degrees of articulation, overrunning clutches for inertia management on machines with high cleaning section mass, and shear-bolt or friction torque limiters that are calibrated to coordinate with the cleaning star gearbox’s own integrated protection mechanism. When you order a cleaning star gearbox from Ever Power, our application engineering team will specify the correct PTO shaft series, tube profile, compressed and extended lengths, and CE-compliant guard to ensure the complete drivetrain is matched and balanced as a coherent system — not two separately sourced components that happen to connect at a flange.
Customer Success: Fenland Agricultural Contracting, Cambridgeshire
Fenland Agricultural Contracting Ltd
Sugar beet harvesting contractor · March, Cambridgeshire · 2,400+ hectares per season
The challenge: During the 2021 harvest season, Fenland Agricultural Contracting experienced repeated early failure of the cleaning star gearbox on their lead Holmer Terra Dos T4. An exceptionally wet September had left the fen peat soils saturated, with beets arriving at the cleaning section carrying 28–34% soil adhesion — significantly above the 15% the machine’s cleaning section was designed to handle at standard throughput. The elevated load, combined with continuous ingress of fine silty water into the gearbox sealing system, resulted in bearing seizure after 180 harvest hours. The original equipment manufacturer’s replacement part was quoted at eighteen weeks delivery from Germany — a timescale that would have written off every harvest contract the company held for the remainder of that season, representing over 900 hectares across four farm clients in the Cambridge fens.
The Ever Power solution: The company’s machinery dealer in Peterborough contacted us with the original OEM part number and a dimensional photograph of the failed gearbox. Our engineering team cross-referenced the unit to a compatible heavy-duty limpeza da caixa de engrenagens estrela in our production inventory, confirmed the reduction ratio and output shaft configuration, and arranged dispatch to the dealer’s Peterborough depot within 36 hours. We additionally supplied a matched PTO shaft fitted with a friction torque limiter calibrated to 1.1 times the gearbox’s continuous rated torque — a protective measure that the farm’s operations manager subsequently credited with preventing two further overload events during the remainder of the season, when stone contamination remained higher than normal due to post-lifting soil movement during the wet conditions.
The outcome: The Ever Power cleaning star gearbox completed 1,847 continuous harvest hours across the 2021 and 2022 seasons before its first scheduled bearing inspection — at which point both main bearings showed minimal wear and were returned to service. Fenland now carries one Ever Power cleaning star gearbox as a dedicated in-field spare for each of their two machines. The cost of that inventory is recovered within six hours of any avoided in-season failure. The 2022, 2023, and 2024 seasons recorded zero unplanned gearbox stoppages on either machine in the fleet.
“When the OEM couldn’t help us inside eighteen weeks, Ever Power had a gearbox at our dealer in thirty-six hours. That is not just selling a part — that is understanding what a beet harvest means for a contracting business. We have not gone back to OEM supply since.”
— Operations Manager, Fenland Agricultural Contracting Ltd, March, Cambridgeshire
Verified Feedback from UK Agricultural Buyers
“We rebuilt the entire cleaning section on our ROPA euro-Tiger and used Ever Power gearboxes based on a recommendation from a contractor we know in Norfolk. Two full seasons since then — nothing to report. The sealing quality is visibly superior to what we removed, and the output speed consistency across both shafts is exactly what the original was supposed to deliver and never quite did.”
James Alderton
Farm Manager, Alderton Farms Ltd · King’s Lynn, Norfolk
“As a machinery dealer covering most of south Lincolnshire, I need suppliers who understand harvest urgency — not suppliers who quote three-week lead times in October. Ever Power’s cross-reference library covers every cleaning star gearbox application I have seen in this county, their response to quote requests is same-day, and the technical documentation they provide is good enough to hand directly to a farm fitter without any editing from us.”
Mark Thornton
Parts Manager, Thornton Agricultural Machinery · Spalding, Lincolnshire
“We placed an OEM order for fourteen cleaning star gearboxes for a new machine programme last year. Ever Power sent a pre-production sample for dimensional and performance approval, made one shaft modification based on our integration engineer’s feedback, and delivered the full production batch five weeks ahead of our assembly start date. Rejection rate at incoming inspection: zero. That is the level of supply reliability we need to build on.”
Sarah Clements
Procurement Director, Northern Harvester Systems Ltd · York, Yorkshire
Manufacturing Capability & Custom Engineering Service
Ever Power operates a 35,000-square-metre manufacturing campus housing CNC gear hobbing machines, gear grinding centres, 5-axis machining centres, coordinate measuring machine (CMM) inspection cells, and a dedicated gearbox run-in and test facility. This level of vertical integration — from raw billet and ductile iron casting through to a finished, tested, documented cleaning star gearbox — means we control every variable that determines production quality. Batch-to-batch dimensional repeatability, material traceability from cast billet to shipping document, and the ability to incorporate design modifications at prototype or early production stage without the cost and schedule penalties that arise when design and manufacturing are split across multiple subcontractors: these are the operational advantages that UK buyers on OEM programmes cite most frequently when explaining why they stay with Ever Power across multiple machine generations.
Our product customisation service for cleaning star gearboxes covers every dimension of the specification. UK customers can supply a part number for cross-referencing, a reference gearbox for reverse measurement, a 2D dimensional drawing, or a 3D CAD file in STEP or IGES format. If you are developing a new machine concept and need a cleaning star gearbox designed from a torque budget, geometric envelope, and target unit cost, our application engineering team can deliver a written technical proposal within five working days. We have successfully developed bespoke cleaning star gearboxes for four independent UK harvester manufacturers and specialist integrators in the past decade. Three of those supply relationships are ongoing, and two have expanded from initial prototype orders into multi-year series production agreements. Our manufacturing capability also covers painting, labelling, and packaging to customer-specific requirements — meaning the unit can arrive at your assembly line ready to fit without any intermediate processing.
35,000 m²
Manufacturing Facility
240+
Beet Harvester References
5 Days
Custom Proposal Turnaround
ISO 9001
Quality Management System
30 Years
Agricultural Gearbox Experience
Perguntas frequentes
Practical answers for UK agricultural machinery dealers, OEMs, farm engineers, and beet harvesting contractors
What is the best cleaning star gearbox for a sugar beet harvester operating in the heavy clay soils of Lincolnshire, and how do I choose the right gear ratio?
For heavy clay conditions typical of north and south Lincolnshire — where soil adhesion on freshly lifted beets is often above 25% — we recommend our heavy-duty cleaning star gearbox model with an IP67 seal rating and a gear ratio in the 5:1 to 6:1 range. The higher reduction ratio generates greater shaft torque, allowing the cleaning stars to work through heavy clay loads without stalling, while keeping star tip speed within the range that avoids excessive beet surface damage. We always recommend confirming the ratio against your machine’s specific shaft geometry — contact our application team with your machine model and we will specify the correct unit for your operating conditions.
How much does it cost to replace a cleaning star gearbox on a Holmer Terra Dos in the UK, and what price difference can I expect compared to the OEM supplier?
The price of an Ever Power cleaning star gearbox compatible with a Holmer Terra Dos is typically 30 to 45% lower than the OEM replacement price quoted through the official Holmer dealer network in the UK. The exact figure depends on the specific ratio, seal specification, and delivery terms (ex-works, CIF Felixstowe, or DDP UK). We provide formal written quotations within 24 hours of receiving the part number or application details — just contact us with your machine model and the original part number from the failed gearbox, and we will confirm compatibility and pricing by return.
Where can I find a reliable cleaning star gearbox supplier for emergency beet harvester repairs in East Anglia or Lincolnshire with fast UK delivery?
Ever Power works with a UK distribution partner based in Peterborough, which is well-positioned to serve the sugar beet heartlands of East Anglia and Lincolnshire. In most cases we can confirm stock availability and arrange dispatch within 36 hours of receiving a part number and delivery address. For genuinely urgent situations during peak harvest, we also work with express freight carriers that provide overnight and same-day pallet services to agricultural addresses in Norfolk, Suffolk, Cambridgeshire, and Lincolnshire. Contact us as early as possible after a failure — even an initial enquiry email with a photograph and the OEM part number will let us begin the identification process immediately.
How do I know when my beet harvester’s cleaning star gearbox needs replacing rather than repairing, and what warning signs should I look for before the season starts?
The most reliable pre-season indicators of a cleaning star gearbox approaching end of life are: audible bearing rumble under load at operating temperature, backlash measurably outside the DIN Class 7 tolerance band, oil that is dark and metallic-particle-laden at the first scheduled oil change of the season, and any visible oil seepage around shaft exits. If the unit has accumulated more than 2,500 hours without a bearing renewal, we recommend proactive replacement before the season rather than reactive replacement during it. The cost of a planned gearbox swap during the pre-season service window is a fraction of the revenue loss from an in-harvest stoppage. We can supply a replacement unit in advance for installation at your convenience.
Can Ever Power supply custom-engineered cleaning star gearboxes for UK agricultural OEMs building new beet harvester models, and what is the minimum order quantity?
Yes — custom cleaning star gearbox development is a core part of our business, not an exception. We accept development projects from a single prototype unit upward, with no minimum order quantity for the design and prototype phase. Series production typically begins at 10 units per batch, though we work with smaller initial production runs for new machine programmes that are ramping up. The process from a first technical discussion to a fully approved, tested production gearbox typically takes 10 to 14 weeks. We have worked with four UK-based harvester manufacturers and integrators on custom gearbox programmes in the past decade and maintain active supply relationships with three of those customers on current production models.
What is the difference between a cleaning star gearbox and a standard agricultural gearbox, and why does the beet harvester application require a specialist unit?
A standard agricultural gearbox — the type used in fertiliser spreaders, mowers, or power harrows — is designed for relatively steady torque loads with infrequent shock events. A cleaning star gearbox faces a fundamentally different duty cycle: continuous operation under variable load, repeated shock pulses from stone and soil impacts, constant contamination pressure from fine silt and sugar beet juice, and output shaft loads that include significant radial components from the star shaft weight and cleaning force reactions. These requirements drive specific design choices — heavier housing sections, wider bearing inner races, sealed lubrication systems, and overload protection mechanisms — that are not present in general-purpose agricultural gearboxes and cannot be retrofitted cost-effectively after purchase.
Why is it important to pair a cleaning star gearbox with a correctly rated PTO shaft, and what can go wrong if I use an undersized or mismatched PTO shaft on my beet harvester?
An undersized PTO shaft running at excessive articulation angle imposes bending loads on the gearbox input shaft bearing that the bearing was not designed to carry in combination with its normal gear reaction forces. Over time — often within a single harvest season in severe cases — this causes the input bearing inner race to develop fretting damage, the oil seal to shift on the shaft and lose its sealing lip contact, and the gear mesh to develop misalignment-induced contact pattern errors. The gearbox then fails in a way that looks like a manufacturing defect but is actually a system installation error. Matching the PTO shaft specification to the gearbox is not optional — it is the foundation of the drivetrain’s service life. Ever Power supplies matched PTO shafts with every cleaning star gearbox order on request, with a written system compatibility statement included in the shipping documentation.
How long does a high-quality cleaning star gearbox typically last in UK sugar beet harvesting conditions, and what maintenance schedule should I follow to maximise service life?
In UK beet harvesting conditions — with the typical mix of light and heavy soils, wet autumn weather, and extended harvest windows — an Ever Power heavy-duty cleaning star gearbox will typically reach 2,500 to 3,500 harvest hours before the first bearing replacement is needed, assuming the correct GL-5 oil grade is maintained and the oil is changed at the 500-hour or annual interval (whichever comes first). The most important maintenance actions are: oil level check before each harvest season, oil and filter change after the first 50 hours and then every 500 hours, visual seal inspection at each machine service, and torque limiter shear-bolt inspection after any known stone-strike event. Full service documentation and a maintenance record sheet are included with every gearbox we ship.
Ever Power Agricultural Machinery — UK B2B Supply
Ready to Specify Your Cleaning Star Gearbox for Beet Harvester Applications?
Send us a part number, a machine model, or a dimensional drawing. Our application engineers will confirm compatibility and have a formal quotation with you within 24 hours — including matched PTO shaft recommendations where required.
Ever Power Agricultural Machinery | ISO 9001 Certified | Supplying UK agricultural OEMs, dealers, and contractors | edit by gzl
