Elevator & Lift Drive Systems · Industrial Gearbox Engineering · Australia
Technical Specifications
Engineering parameters for gearboxes used in elevator and platform lift applications, from compact goods lifts in commercial buildings to heavy industrial platform hoists at mine sites and port facilities.
| Parameter | Typical Range | Notes |
|---|---|---|
| Rated Load (SWL) | 100 kg – 20,000 kg | Platform hoists at upper end |
| Car / Platform Speed | 0.15 – 2.5 m/s | Goods lifts lower; high-rise passenger higher |
| Gear Ratio | 20:1 – 100:1 | Higher ratios for heavy loads or slow travel |
| Self-Locking | Mandatory (+ independent brake) | AS 1735 requires both for person-carrying lifts |
| Duty Class | M3 – M6 (FEM / AS 1418) | Based on trips per day and load spectrum |
| Brake Rating | ≥125% of maximum static load torque | AS 1735 minimum holding margin |
Elevator and Lift Types: Drive Requirements by Application
Australian elevator and lift installations cover a wide range from high-rise passenger lifts in CBD towers to small goods lifts in retail stockrooms and heavy platform hoists at industrial facilities. Each application type creates distinct gearbox requirements that cannot be addressed by a single standard.
Geared Traction Passenger Lifts
Traditional geared traction lifts use a worm gearbox to reduce the motor speed to the sheave (drive pulley) speed required for the rated car velocity. The worm gearbox is typically a custom-designed unit with the sheave mounted directly on the gearbox output shaft, integrating the drive, speed reduction, and mechanical braking functions into a single assembly mounted in the motor room above the lift shaft. AS 1735 Part 2 (Electric Passenger and Goods Lifts) requires the gearbox to provide a self-locking function under all operating conditions, verified by a standing test under maximum load with motor power removed. Additionally, a separately rated spring-applied electromagnetic brake must hold the loaded car against gravity — the worm gearbox self-locking and the mechanical brake together provide redundant load-holding that complies with the two-independent-mechanism philosophy underpinning Australian lift safety regulation.
The sheave diameter and reeving configuration determine the gearbox output speed from the car velocity. For a 2:1 reeved lift (the standard for most low- to mid-rise applications) with a 640 mm sheave running a car at 1.0 m/s: sheave surface speed = 2.0 m/s; sheave RPM = 2.0 × 60 / (π × 0.64) = 59.7 RPM. With a 2-pole motor at 2,900 RPM, the required gear ratio is 2,900 / 59.7 = 48.6:1. This is specified to the lift gearbox manufacturer as a specific ratio rather than a catalogue standard, as elevator gearboxes are engineered-to-order products rather than off-the-shelf selections.
Goods Lifts and Service Lifts
Goods lifts in retail stores, restaurants, and light industrial premises typically operate at lower speeds (0.15–0.5 m/s) with loads of 100–2,000 kg. These lifts use helical-bevel or worm gearboxes from standard industrial ranges, adapted with the AS 1735 documentation and testing requirements. The self-locking worm gearbox provides the baseline load-holding; a motor brake provides the AS 1735-required independent mechanical safety mechanism. Where the goods lift is not person-carrying, the regulatory requirements are less stringent, but the gearbox must still be sized for the rated SWL with a service factor of 2.0 and must include a backstop or brake to prevent uncontrolled descent on power loss regardless of whether passengers are carried.
Industrial Platform Hoists and Material Lifts
Industrial platform hoists at mine sites, construction facilities, and manufacturing plants lift heavy goods — often 5,000–20,000 kg — between levels. These do not fall under AS 1735 (which covers building lifts) but are regulated under AS 1418 (Cranes, Hoists, and Winches) and state WHS regulations. The gearbox duty class selection under AS 1418 uses the same FEM M-class system as overhead cranes: M3–M4 for occasional lifts (typically industrial platform hoists), rising to M5–M6 for more frequent cycle rates. The gearbox rated torque must be verified against the AS 1418 duty class dynamic load factor rather than a static torque calculation — the same distinction between hoist gearboxes and conveyor gearboxes discussed in the lifting equipment guide.
Self-Locking: The Defining Requirement for Elevator Gearboxes
The self-locking characteristic of a worm gearbox — where output shaft torque (from the suspended load) cannot back-drive the input through the worm mesh because the helix angle is below the friction angle — makes the worm gearbox the dominant technology for elevator drives. No other common gearbox type provides self-locking as an inherent property without additional mechanical devices.
However, AS 1735 does not permit reliance on worm self-locking as the sole load-holding mechanism for person-carrying lifts. The self-locking is acknowledged as a safety feature but is classified as friction-dependent rather than positive-mechanical, meaning it cannot be confirmed to function at 100% reliability under all temperature and lubrication conditions. The standard therefore requires a second independent load-holding mechanism — a spring-applied, electrically-released brake on the motor or gearbox shaft — that provides positive mechanical load holding regardless of gearbox condition. The brake must be rated to hold 125% of the maximum static load torque with motor de-energised.
This two-mechanism approach — worm self-locking plus independent brake — means that even if the worm mesh loses its self-locking margin due to high oil temperature after an extended run, the brake holds the car. Conversely, if the brake fails to apply cleanly on a power interruption, the worm self-locking prevents the car from moving. Both mechanisms must be tested independently at the annual inspection as part of the AS 1735 maintenance programme.
Gearbox Types and Drive Configurations
Engineered-to-order worm gearboxes with integrated sheave mounting, customised gear ratio, and AS 1735-documented self-locking verification. The sheave is mounted directly on the output shaft, forming a compact combined drive and speed reduction assembly. These are purpose-designed products supplied by specialist elevator equipment manufacturers rather than standard industrial gearbox suppliers. Key parameters: gear ratio to exactly match car speed to motor speed; self-locking torque margin at maximum operating temperature; brake integration dimensions; and certified documentation package for lift registration.
Standard industrial helical-bevel gear motor with integrated motor brake (spring-applied, electrically released). Not self-locking — the motor brake is the sole load-holding mechanism and must be sized accordingly. Suited to goods lifts, mezzanine platforms, and service lifts where the speed and load requirements fall within standard catalogue range and the separate brake is acceptable. Lower cost than custom worm units but requires formal brake sizing and AS 1418 documentation for the complete lift assembly.
Modern high-rise passenger lifts above 1.0 m/s increasingly use gearless permanent magnet motors with the sheave mounted directly on the motor shaft — eliminating the gearbox entirely. These require no gearbox lubrication, maintenance, or oil-level monitoring, and offer superior energy efficiency and speed control. The gearbox is relevant for gearless systems only in the ancillary drives: door operator gear motors, car-top safety circuit actuators, and machine room auxiliary equipment.
AS 1735 Regulatory Framework and Documentation
All lifts in Australia carrying persons must comply with AS 1735 (Lifts, Escalators, and Moving Walks) and must be registered with the relevant state authority before being put into service. This creates a documentation requirement for the drive gearbox that goes significantly beyond standard industrial supply.
The gearbox documentation required for AS 1735 registration typically includes: the gear ratio and rated output speed; the self-locking torque margin at maximum oil temperature (confirmed by calculation or test); the brake torque rating and engagement sequence; material test certificates for gear, shaft, and housing materials; dimensional drawings for the complete sheave-gearbox assembly; and a declaration of conformity confirming the design satisfies the relevant AS 1735 clause. This documentation is assembled by the lift manufacturer or installer and forms part of the Plant Design Registration submitted to SafeWork NSW, WorkSafe Victoria, or the equivalent state authority before the lift is commissioned.
Post-installation, all person-carrying lifts in Australia require a periodic inspection programme under AS 1735 and state WHS plant inspection regulations — typically 6-monthly or annual depending on state and lift classification. The inspection includes a physical test of the brake holding capacity, verification of gearbox oil level and seal condition, and a car speed test against the rated speed. These inspections must be conducted by an accredited lift inspector and the records retained as part of the plant registration file.
Applications Across Australian Buildings and Infrastructure
Sourcing Elevator and Lift Gearboxes in Australia
Person-carrying lift gearboxes are supplied as engineered-to-order units by specialist elevator equipment manufacturers, not as standard industrial catalogue items. The specification is developed collaboratively between the lift designer, the drive supplier, and the installation contractor to produce a unit that exactly matches the car speed, reeving configuration, and AS 1735 regulatory requirements of the specific installation.
For goods lifts and industrial platform hoists that fall under AS 1418, standard industrial gearboxes with AS 1418 documentation are available from industrial drive suppliers. The specification must include: rated output torque at the AS 1418 duty class dynamic load factor; gear ratio; self-locking confirmation for worm drives; brake torque rating and integration; AS 1418 duty class (M-class) confirmation; and the full documentation package required for plant registration. For bevel gear-based direction change elements in platform lift drive systems, providing bevel gear dimensional and load specifications to the supplier ensures correct mesh rating for the dynamic hoist loading conditions. Browse our elevator and lift drive solutions page, or contact our engineering team for a specification within one business day.
Frequently Asked Questions
Common questions from lift engineers, building managers, and facility maintenance teams about elevator and lift gearbox selection, compliance, and maintenance.