A reduction gearbox housing for an electric drive axle carries the input and intermediate shafts, bearings, differential assembly and lubrication circuit of a single-speed or two-speed reduction unit mounted directly onto the e-motor and axle beam. It is used in battery-electric and fuel-cell buses, delivery vans, light trucks and off-highway equipment, where the housing must keep gears aligned under high input torque and a very wide speed range while damping noise that an e-powertrain no longer masks. Aluminium A356-T6 investment or low-pressure casting is preferred for weight saving and heat dissipation; ductile iron is selected when torque density, bearing seat stiffness or mounting loads dominate. Either way the part is cast near net shape and then finish machined on bearing bores, sealing faces and split lines to hold shaft centre distance and gear contact pattern.
Specifications
| Parameter | Specification |
|---|---|
| Material options | Aluminium A356-T6; ductile iron QT500-7 and QT600-3 for high-torque units |
| Casting process | Silica-sol investment casting or low-pressure die casting for aluminium; resin sand casting for iron |
| Machining | 5-axis CNC and horizontal machining centres, one-setup bore and face machining |
| Casting tolerance | ISO 8062-3 DCTG CT6 general, CT5 on bearing seat zones |
| Machining tolerance | Bearing bores IT6-IT7, centre distance within 0.03 mm, flatness 0.05 mm |
| Surface finish | Ra 1.6 um on sealing faces and bearing seats, Ra 3.2 um machined general, Ra 6.3 um as-cast |
| NDT | X-ray radiography to ASTM E155 on load zones, dye penetrant on machined aluminium, helium and air decay leak testing |
| Heat treatment | A356 to T6 solution treatment, quench and artificial ageing; iron grades normalised and tempered |
| Pressure testing | Housing cavity leak tested at 0.5-1.5 bar with air decay below 5 cc per minute |
| Documentation | PPAP Level 3, FAI report, EN 10204 3.1, CMM report, cleanliness report to VDA 19 and ISO 16232 |
Key features
- Bearing seats cast with controlled stock and finish machined in one clamping for true position
- Integrated oil galleries, baffles and pickup passages cast in, eliminating external pipework
- Rib patterns tuned by modal analysis to push structural modes above the gear mesh frequency
- Aluminium variants save 35 to 45 percent mass against a comparable iron housing
- Split-line and cover faces machined for liquid gasket or O-ring sealing, leak verified
- Threaded inserts and stud installation available as a sub-assembly operation
Applications
- Battery-electric bus and coach drive axles
- Light and medium commercial vehicle e-axles
- Fuel-cell commercial vehicle reduction units
- Off-highway and construction equipment electric drives
- Two-speed and disconnect e-axle modules
Quality and compliance
The housing programme runs under IATF 16949 with full APQP documentation and PPAP Level 3 submission before the first serial delivery. Each part is traceable to casting batch, heat treatment lot and machining work order. First article inspection covers every ballooned characteristic, and CMM reports are issued per batch with capability data for bearing bore diameter, centre distance and face flatness. EN 10204 3.1 material certificates accompany all deliveries, and for aluminium we add spectrographic analysis plus porosity grading. Cleanliness testing to VDA 19 and ISO 16232 verifies particle limits inside oil passages, and 100 percent leak testing is standard because an e-axle housing cannot be reworked after final assembly.
FAQ
Aluminium or ductile iron for an e-axle housing?
A356-T6 aluminium is the default for mass and thermal reasons and suits most passenger and light commercial axles. Ductile iron QT500-7 is specified when input torque exceeds roughly 2,500 Nm or where bearing seat stiffness and mounting loads govern the design.
How do you control porosity in aluminium housings?
We combine melt degassing, ceramic foam filtration and controlled solidification with X-ray verification. Critical zones are graded to ASTM E155 acceptance levels agreed with the customer in the PPAP control plan.
Can you supply the housing machined and assembled with bearings?
Yes. We deliver machined bare housings, or housings fitted with bearing outer races, seals, covers and fasteners as a sub-assembly on request.
What about NVH requirements?
We support customers with modal analysis during design, control wall thickness and rib geometry through the casting process, and verify with production part resonance checks where specified.
Do you provide leak test data with each shipment?
Yes. Every housing is leak tested, and the test result is recorded against the part serial number. Statistical records are available in the production part approval and ongoing control plan reporting.
CTA
Need a quote for Electric Axle Reduction Gearbox Housing? Send your drawing to sales@cnsandcasting.com or WhatsApp +86 137 7712 4360 for a fast RFQ response from Ningbo Ruican.
