EP-Truck Mixers Planetary Gearbox
The EP-Truck Mixers Planetary Gearbox is a purpose-built planetary drive gearbox for concrete transit mixer trucks, operating through the standard hydrostatic transmission chain of hydraulic pump — hydraulic motor — planetary reducer. Sixteen standard configurations (E1–E16) cover power inputs from 307 kW to 727 kW with output torques reaching 18,020 N·m, accommodating drum volumes from 3 m³ to 20 m³. All gears are produced from 20CrMnTi alloy steel carburized and ground to ISO 1328-1 Grade 5–6.
1. Model Specifications — E1 to E16
The table below lists the complete performance data for all sixteen EP-Truck standard models. Select the model whose gear ratio, input speed, and output torque best match your hydraulic motor output shaft specification and drum torque requirement. For drum sizes not covered by the table below, or for applications requiring a non-standard output flange, contact our technical team for a customized planetary drive gearbox configuration. Our engineers respond to specification inquiries from Colombia-based fleet operators and OEM builders within one business day.
| Item No. | Gear Ratio | Power (kW) | Output Torque (N·m) | Input Speed (RPM) | Weight (kg) |
|---|---|---|---|---|---|
| E1 | 14.60 | 591.78 | 16,000 | 540 | 256 |
| E2 | 18.20 | 445.05 | 15,000 | 540 | 256 |
| E3 | 28.27 | 565.97 | 16,000 | 1,000 | 290 |
| E4 | 16.13 | 525.60 | 15,700 | 540 | 256 |
| E5 | 18.20 | 400.55 | 13,500 | 540 | 256 |
| E6 | 21.10 | 307.36 | 12,010 | 540 | 256 |
| E7 | 13.40 | 726.18 | 18,020 | 540 | 280 |
| E8 | 28.27 | 583.66 | 16,500 | 1,000 | 330 |
| E9 | 25.89 | 696.02 | 18,020 | 1,000 | 290 |
| E10 | 13.40 | 644.78 | 16,000 | 540 | 256 |
| E11 | 25.89 | 333.72 | 16,000 | 540 | 290 |
| E12 | 13.40 | 644.78 | 16,000 | 540 | 256 |
| E13 | 14.40 | 506.25 | 13,500 | 540 | 256 |
| E14 | 21.10 | 307.11 | 12,000 | 540 | 256 |
| E15 | 25.80 | 698.45 | 18,020 | 1,000 | 290 |
| E16 | 13.38 | 727.26 | 18,020 | 540 | 256 |
2. How the Truck Mixers Planetary Gearbox Works
Every concrete transit mixer truck relies on a three-stage hydrostatic power chain to turn its drum. The diesel engine drives a hydraulic pump; the pump supplies pressurized fluid to a hydraulic motor mounted at the rear of the truck body; and the motor's high-speed, low-torque shaft connects directly to the input flange of the truck mixers planetary gearbox. The gearbox then reduces that motor speed dramatically — by ratios from 13.38:1 to 28.27:1 depending on the selected model — while multiplying output torque up to 18,020 N·m to rotate the mixing drum at the slow, controlled speeds needed for charging, agitating in transit, and discharging concrete.
Inside the housing, the EP-Truck uses a compound differential planetary gear arrangement. The hydraulic motor shaft drives a sun gear at the center. Three or more planet gears mesh simultaneously with the sun gear and with a fixed ring gear secured to the housing wall. The planet carrier — connected to the output flange — rotates around the sun gear at a speed determined by the gear tooth counts of all three elements. Because the torque is divided equally among all planet gears in contact at any moment, peak Hertzian contact stress on each individual tooth flank is reduced substantially compared with a single gear pair carrying the entire load. This load-sharing architecture is why the EP-Truck can handle the severe cyclic and shock loads a concrete mixer drum imposes without requiring a physically large or excessively heavy housing.
A second important characteristic is the coaxial (in-line) input-output shaft arrangement. The hydraulic motor, planetary gearbox, and drum axis all share the same centerline, which simplifies the mounting geometry on the truck subframe and eliminates the off-axis bending moments that would arise from an offset drive arrangement. For ready-mix fleet operators in Colombia's infrastructure market — running trucks on the 4G highway construction corridors across Cundinamarca, Antioquia, and Valle del Cauca — this structural simplicity translates directly into lower maintenance labor and faster on-road gearbox replacement when needed.
3. Five Key Advantages of the EP-Truck Series
1. Sixteen Configurations to Match Any Drum Size
With models E1 through E16, fleet managers and OEM builders can select the exact gear ratio and power rating that matches their drum volume and hydraulic motor specification — without over-buying capacity or compromising torque reserve. Input power ranges from 307.11 kW (E14) to 727.26 kW (E16), and output torques span 12,000 N·m to 18,020 N·m. Whether the application is a compact 3 m³ urban delivery truck in Bogotá or a 12 m³ high-output mixer serving a dam construction project in the Colombian Andes, there is a correctly sized EP-Truck model to match it precisely. This model breadth eliminates the compromises that come with using an oversized or undersized planetary drive gearbox, protecting the hydraulic system from overload and avoiding unnecessary fuel consumption from an over-rated unit.
2. Carburized 20CrMnTi Gears for Long Service Under Cyclic Load
All gear elements — sun gear, planet gears, and ring gear — are machined from 20CrMnTi alloy steel, carburized in a controlled atmosphere at 920–940°C, oil-quenched, and tempered to achieve a surface hardness of 58–62 HRC with a case depth of 0.6–1.5 mm. Core hardness is retained at 33–48 HRC to provide the toughness to absorb the shock loads that occur during drum reversal with partially hardened concrete. Gear flanks are precision ground to ISO 1328-1 Class 5–6 (Ra ≤ 0.8 µm). This hardness-depth and surface-finish combination is what allows the EP-Truck to sustain a design life exceeding 15 years at typical fleet utilization rates — a meaningful advantage for Colombian ready-mix operators managing total cost of ownership across large truck fleets.
3. Direct OEM Compatibility — No Adapter Modifications
The EP-Truck input flange and hydraulic motor interface are dimensioned to match SAE and metric hydraulic motor face specifications commonly fitted to transit mixer trucks, including those branded Sany, Zoomlion, XCMG, and leading European mixer manufacturers. The output drum flange bolt pattern is produced to match the most widely used drum attachment standards. For fleet operators sourcing a truck mixer gearbox replacement in Bogotá, Cali, or Barranquilla, this direct-fit design eliminates fabrication of new mounting plates or shim packs — reducing replacement time from a potential multi-day chassis modification to a single workshop shift and returning the truck to revenue service as quickly as possible.
4. IP65 Protection for Outdoor Construction Site Conditions
Concrete mixer trucks work in environments that are hostile to mechanical drives: alkaline cement slurry splashes every load cycle, high-pressure wash-down is routine, and tropical rain is unavoidable on Colombian job sites. The EP-Truck housing is sealed to IEC 60529 IP65 — fully dustproof and resistant to water jets from any direction. FKM (Viton) radial shaft seals are specified at all rotating shaft exits because their fluoroelastomer chemistry resists cement alkalinity and synthetic gear oil degradation across the -25°C to +120°C operating range. The cast iron housing receives an epoxy primer and polyurethane topcoat, further protecting against corrosion in the coastal tropical climates of Cartagena and Barranquilla.
5. 100% Factory Run-Test Before Shipment
Every EP-Truck unit is loaded on our full-power test bench before being approved for shipment. The bench test verifies output torque transmission under load, operating noise level (dB measurement at 1 m), housing surface temperature rise after stabilized running, and seal integrity under pressurized oil. This 100% inspection policy eliminates infant-failure units that would otherwise create field failures within the first few hundred hours — a type of quality failure that is disproportionately costly on a revenue-earning concrete truck. The test certificate accompanies each unit, providing the technical documentation often required by fleet maintenance managers and insurance underwriters in the Colombian construction equipment sector.
4. Materials and Construction Detail
The service environment for a planetary gearbox on a concrete transit mixer is among the most demanding in the entire construction equipment sector. The unit must survive daily alkaline cement wash, high-pressure hosing during truck cleaning, road vibration from paved and unpaved job site haul roads, thermal cycling between cold pre-start conditions at high-altitude Colombian sites like Bogotá (2,600 m elevation) and hot operating temperatures during extended pours in lowland tropical regions. Every material and component in the EP-Truck is selected with this operating reality in mind — not merely against a datasheet torque rating.
Housing — HT250 Gray Cast Iron
Cast iron provides inherent vibration damping and dimensional stability. The HT250 grade (min. tensile strength 250 MPa) resists housing distortion under the gear separating forces generated at full rated torque. Exterior surfaces receive a two-coat corrosion protection system: epoxy primer plus polyurethane topcoat, resistant to both cement alkalinity and industrial cleaning agents used in Colombian ready-mix operations.
Gears — 20CrMnTi Alloy Steel
Sun, planet, and ring gears are machined from 20CrMnTi chromium-manganese-titanium alloy steel. After carburization in a controlled-atmosphere furnace and oil quenching, surface hardness reaches 58–62 HRC with a case depth of 0.6–1.5 mm. Core hardness (33–48 HRC) absorbs shock loads. CNC profile grinding to ISO Grade 5–6 ensures quiet, even load distribution at all operating speeds and torques.
Shafts & Planet Carrier — 42CrMo4
Input and output shafts plus the planet carrier are produced from 42CrMo4 (AISI 4140 equivalent) chromium-molybdenum steel, heat-treated to 28–32 HRC. For larger-frame models (E8, E9, E15 with 1,000 RPM input), the planet carrier is produced as an FCD45 ductile iron casting to handle the combined bending and torsional moment from the drum load at peak output torque without carrier deflection.
Bearings — Tapered & Cylindrical Roller
All shaft positions use grade-matched tapered or cylindrical roller bearings selected to ISO/TR 1281-1 methodology, targeting an L10h life exceeding 20,000 operating hours under rated torque. Planet pin positions use needle roller bearings with hardened inner rings to maximize radial load capacity within the constrained space inside the planet carrier pockets.
Seals — FKM (Viton)
FKM radial shaft seals at all shaft exits perform across -25°C to +120°C and resist degradation from synthetic ISO VG 220 gear oil and cement alkaline contamination — failure modes that cause premature seal replacement in gearboxes fitted with standard NBR (nitrile) seals. Static face joints use EPDM O-rings at all inspection covers and drain/fill plugs.
5. Application Scenarios
The EP-Truck Mixers Planetary Gearbox is designed primarily for concrete transit mixer trucks, but the same engineering platform serves a broader range of rotating drum and mixing applications wherever high-torque, compact, and durable planetary drive units are required. The following scenarios reflect the actual deployment contexts where this heavy-duty truck mixer gearbox has demonstrated consistent, low-maintenance performance.
Ready-Mix Concrete Transit Mixer Trucks
This is the primary design application. Transit mixer trucks operating in Colombia's urban ready-mix market — supplying residential towers, shopping centers, and road base works in Bogotá, Medellín, Cali, and Barranquilla — depend on a reliable truck mixers planetary gearbox to charge, agitate, and discharge concrete across 8–12 hour daily shifts. The EP-Truck series covers all drum sizes commonly operated on Colombian roads, from compact 4 m³ trucks for tight urban access to 10–12 m³ vehicles for high-output infrastructure pour sites.
Infrastructure Construction Project Fleets
Colombia's ongoing 4G and 5G road and highway concession program is one of the largest infrastructure investments in the country's history, spanning departments from La Guajira to Nariño. Batch plant operations supplying these job sites operate large truck fleets around the clock, making gearbox reliability and the availability of spare parts a direct commercial risk factor. The EP-Truck's broad model range, OEM-compatible mounting, and established spare-parts network through our Colombian distribution partners supports fleet continuity in even the most remote project locations along the Andes corridors.
Volumetric Mixer and On-Site Batching Units
Volumetric concrete mixers — which carry dry aggregate and cement separately and batch to order at the delivery point — use a similar hydrostatic drum drive architecture to standard transit mixers but may operate with lower drum speeds and higher torque requirements. Several EP-Truck models at higher gear ratios (E3 at 28.27:1, E8 at 28.27:1, E11 at 25.89:1) are well-suited to these applications, where the planetary reducer for truck mixer must maintain precise drum speed control at very low RPM output throughout the batching cycle.
Replacement and Retrofit in Existing Fleet Units
Many ready-mix operators in Medellín, Cali, and Cartagena are actively sourcing a truck mixer gearbox replacement for aging fleet units where the original factory gearbox has reached end-of-life. Rather than replacing the entire truck, installing a new EP-Truck unit restores the vehicle to full operational specification at a fraction of new truck cost. The EP-Truck's matched OEM flange dimensions ensure straightforward installation by a competent workshop technician using standard tools, avoiding the costly down time of custom engineering work on an aging but otherwise serviceable truck chassis.
Industrial Mixer and Agitator Drive Applications
Beyond concrete trucks, the EP-Truck planetary drive gearbox platform is adapted for stationary industrial agitators, chemical mixing tanks, and slurry drum systems where a compact high-torque coaxial drive is required. Colombian mining operations in the Chocó and Cesar departments, for example, use similar planetary drive units in ore-slurry agitation circuits where high-torque reliability and minimal maintenance access to remote locations share the same engineering priorities as a concrete transit mixer fleet operating on urban construction routes.
6. Regulatory and Compliance Framework
Procurement of truck mixer drive components is governed by a combination of national construction safety regulations, vehicle equipment standards, and mechanical drive technical norms. Buyers in Colombia and export markets should confirm applicable requirements with a qualified regulatory consultant before finalizing procurement specifications.
Colombia — MINTRANSPORTE and ICONTEC
In Colombia, concrete mixer trucks are regulated as heavy goods vehicles under the jurisdiction of the Ministerio de Transporte (MINTRANSPORTE). Mechanical components including the drum drive gearbox must satisfy the vehicle's type-approval and roadworthiness certification requirements under Decreto 1079 of 2015 (the Unified Regulatory Decree for the Transport Sector). ICONTEC (Instituto Colombiano de Normas Técnicas) publishes NTC standards aligned with ISO for mechanical drives; imported gearboxes classified under HS Code 8483.40 are cleared through DIAN (Dirección de Impuestos y Aduanas Nacionales) with applicable duty and VAT as per Colombia's current tariff schedule. Environmental management of spent gear oil must comply with Decreto 4741 of 2005, which classifies used lubricating oils as hazardous waste requiring collection by a licensed operator.
European Union — CE Machinery Directive 2006/42/EC
Gearboxes incorporated into machinery placed on the EU market must support CE conformity marking of the assembled machine in accordance with Directive 2006/42/EC. The EP-Truck documentation package includes a Declaration of Incorporation per Annex II B, enabling OEM machine builders to complete their own CE marking process. Applicable harmonized standards include EN ISO 12100 (risk assessment and reduction) and EN 61000-series EMC standards for electrically driven variants.
United States — AGMA and OSHA
In North American markets, gear drive design and rating follows AGMA 2001-D04 (fundamental rating factors for spur and helical gear teeth) and AGMA 6014-A06 (gear power rating for cylindrical shell and trunnion supported equipment). OSHA 29 CFR 1910.219 mandates mechanical guarding of all rotating power transmission components accessible to workers, including mixer truck drum drive shafts and couplings.
Brazil — ABNT / INMETRO
Brazil's ABNT (Associação Brasileira de Normas Técnicas) standards for mechanical power transmission align with ISO norms. INMETRO may require conformity assessment for certain machinery components; importers should verify current requirements with a certified Brazilian customs agent. Lubricant disposal in Brazil is governed by CONAMA Resolution 362/2005 for re-refining and disposal of waste lubricating oils.
7. About Us
We are a specialized manufacturer of planetary gearboxes and agricultural and construction drive systems, with over decades of focused application engineering in truck mixer and feed mixer planetary gearbox design. Our production facility operates CNC gear profile grinding machines, Zeiss coordinate measuring equipment . Our metallurgical laboratory performs Rockwell hardness testing, Brinell surface checks, and metallographic structure verification on every heat-treatment batch — not as a sampling exercise but as a production control step covering each gear-cutting batch.
Our quality management system follows ISO 9001 principles. We supply OEM truck mixer planetary gearbox components to mixer truck manufacturers and concrete equipment fleet importers in more than 40 countries, with an active and growing distribution network in Colombia covering Bogotá, Medellín, Cali, Barranquilla, and Cartagena.
WorkShop
8. Related Products — Complete Drive System Supply
A correctly selected planetary gearbox for truck mixers is the heart of the drive train — but it functions as part of a system. We also manufacture and supply the complementary drive components that complete your transmission from engine to drum, allowing you to source a fully engineered, pre-matched drive system from a single technical partner. This one-stop supply approach eliminates the interface specification errors that frequently occur when components are sourced from multiple suppliers independently, and simplifies after-sale technical support across your entire drive chain.
Drive Motor
Frequently Asked Questions
Q1. Which model of EP-Truck planetary gearbox for truck mixers is right for a 10 m³ drum transit mixer operating in Bogotá?
For a 10 m³ drum, models E7 (13.40:1, 18,020 N·m, 540 RPM input), E9 (25.89:1, 18,020 N·m, 1,000 RPM input), or E10 (13.40:1, 16,000 N·m, 540 RPM) are typically appropriate — the best selection depends on your hydraulic motor's actual output shaft speed and torque, not just drum volume alone. Please share your hydraulic motor model number and drum specification with our technical team for a confirmed model recommendation tailored to your specific truck configuration.
Q2. Which EP-Truck model is best for a concrete mixer truck with a 1,000 RPM hydraulic motor and a 12 m³ drum in Medellín?
For a 1,000 RPM hydraulic motor input with a 12 m³ drum, models E3 (28.27:1, 16,000 N·m), E8 (28.27:1, 16,500 N·m), E9 (25.89:1, 18,020 N·m), and E15 (25.80:1, 18,020 N·m) all accept 1,000 RPM input and deliver the torque range appropriate for this drum size. Model E9 or E15 at 18,020 N·m provides the highest torque reserve for applications where the drum is frequently started under load with stiff or high-slump concrete mixes — which can be common at Medellín's altitude of approximately 1,500 m where concrete temperature management during mixing requires extended agitation cycles.
Q3. What truck mixer gearbox spare parts should I stock at a Cartagena workshop for servicing a fleet of 20 transit mixers?
For a fleet of 20 transit mixers, a well-stocked Cartagena workshop should maintain: FKM radial shaft seal kits (one full set per active model), bearing replacement kits for both input and output positions, drain and fill plugs with O-rings, a stock of ISO VG 220 synthetic gear oil, and at minimum one complete spare gearbox unit per four trucks for immediate swap-out capability. Sun gear and planet carrier assemblies should be accessible through your authorized distributor on a 3–5 day call-off basis. We provide a model-specific spare-parts catalogue for every EP-Truck model to support local workshop inventory planning.
Q4. How can I verify whether a planetary gearbox for truck mixer for sale meets ISO and AGMA quality standards before purchasing?
A credible supplier should be able to provide: a gear accuracy certificate referencing ISO 1328-1 Grade classification and measured flank deviation values for a representative unit from the production batch; a heat treatment batch record showing Rockwell hardness results and metallographic structure confirmation; bearing selection calculations referencing ISO/TR 1281-1 L10h life; and a pre-shipment run-test certificate showing operating torque, noise level in dB, and housing temperature rise under load. For the EP-Truck Series, all four of these documents are included in the standard shipping package as a matter of course.
Q5. What gear oil should I use in an EP-Truck planetary reducer for truck mixer operating in Colombia's tropical coastal climate?
We specify ISO VG 220 mineral gear oil as the standard fill for moderate climates. For truck mixers operating in Colombia's hot coastal zones — Barranquilla, Cartagena, and Santa Marta, where ambient temperatures frequently exceed 35°C — we recommend a synthetic ISO VG 220 or 320 gear oil for its superior thermal stability and extended drain intervals. Oil level should be checked every 250 operating hours; a full oil change is due every 2,000 hours or annually (whichever is earlier). Always dispose of used gear oil through a licensed waste-oil collector as required under Colombian Decreto 4741 of 2005.
Q6. What is the correct maintenance schedule for a planetary drive gearbox on a concrete transit mixer running double shifts in Colombia?
For a double-shift operation (16+ hours per day), we recommend: daily visual inspection of seals and mounting fasteners at pre-shift walkaround; oil level check every 250 operating hours; full oil drain, flush, and refill with fresh ISO VG 220 gear oil every 1,500 hours (vs. 2,000 hours for single-shift); full inspection of bearings, planet pins, and seal condition at 4,000 hours or every 2 years. Keeping a simple paper logbook of oil changes and any abnormal noise events per unit is one of the most effective tools for catching early-stage problems before they become catastrophic failures that sideline a truck during a critical concrete pour.
Q7. What makes a planetary drive unit for drum mixer more reliable than a helical or worm gear alternative for concrete truck applications?
The key advantage of planetary architecture for drum mixer drives is load sharing: three or more planet gears carry the torque simultaneously, reducing peak tooth contact stress to roughly one-third compared with a single gear pair of equivalent rating. This translates into smaller housing size, lower weight, higher efficiency (97–98% per stage versus 75–85% for a comparable worm drive), and substantially better shock-load tolerance — critical for concrete drums that encounter sudden impulse loads when starting under partially loaded or partially hardened concrete conditions.
Editor: PXY
