Self-propelled boom lift steered by platform steering cylinder

Aerial Work Platform · 6th of 7

Aerial Work Platform
Steering Cylinder

The operator stands in the basket, 30 metres above the wheels, steering with a joystick — no mechanical linkage, no steering wheel, no direct line of sight. The steering cylinder must translate tiny joystick movements into precise wheel turns at walking speed on polished concrete.

63–200mmBore

≤1,000mmStroke

0–6 km/hWalking Speed

Joystick at 30 Metres, Wheels at Ground Level — Remote Steering Without Line of Sight

The crane steering cylinder (#23) responds to a steering wheel with direct mechanical feedback — the driver feels the road through the wheel. The mining steering cylinder (#28) overcomes massive tyre friction on gravel — brute force is the priority. The aerial platform steering cylinder operates in a completely different paradigm: the operator is in the basket, 20–40 metres above the ground, steering the chassis by pushing a joystick — no mechanical linkage, no haptic feedback, no direct view of the wheels.

The operator judges the steering angle by looking down from the basket at the chassis below — a perspective distorted by height, parallax, and the boom structure. The steering cylinder must respond proportionally and predictably to the joystick signal: small joystick deflection = small wheel turn, medium deflection = medium turn, full deflection = full lock. Any non-linearity, dead-band, or overshoot makes the machine feel unpredictable from the basket — and the operator overcorrects, weaving between racking columns instead of driving a straight line.

Korea Ever-Power manufactures the steering cylinder with the bore finish, seal friction, and response characteristics that joystick-from-basket control demands, as the sixth of seven aerial work platform hydraulic cylinders.

Technical Specifications

Parameter	Specification
Product	Aerial Work Platform Steering Cylinder
Function	Steering system for chassis tyres (joystick-controlled)
Bore	63 mm – 200 mm
Rod	36 mm – 140 mm
Stroke	≤ 1,000 mm
Max Pressure	30 MPa
Application	Self-propelled boom lift, scissor lift
Certification	ISO 9001 · EN 280 / ANSI A92 compatible

Indoor Navigation — Polished Floors, Non-Marking Tyres, 50 mm Clearance

Bore finish Ra 0.1 µm — the finest in the catalogue

At walking speed on polished concrete with non-marking tyres, the steering forces are minimal — the cylinder operates at 5–15% of its pressure capacity. At this low pressure, seal friction dominates the response. A Ra 0.2 µm bore (standard for all other products) produces noticeable stick-slip at low speed. Korea Ever-Power hones the steering cylinder bore to Ra 0.1 µm — the finest finish in the entire 31-product catalogue — to eliminate stick-slip at walking speed.

Dual control stations — basket and ground level

A joystick in the basket (for drive-while-elevated) and a second control at ground level (for transport and trailer loading). The steering cylinder must respond identically to both — same sensitivity, same proportionality, same turn rate. If the ground-level control feels different from the basket control, the operator will misjudge steering angles when switching between stations. Contact Korea Ever-Power for platform steering specifications.

Self-propelled scissor lift navigating warehouse

Manufacturing Process

Bore (63–200 mm) honed to Ra 0.1 µm — the finest specification in the Korea Ever-Power mobile machinery catalogue. PTFE-composite guide rings eliminate metal-to-metal contact. Low-friction polyurethane seals selected for near-zero breakaway friction at 5–15% of rated pressure. Chrome 50 µm. Seals rated -30 °C to +80 °C.

Every steering cylinder is hydrostatic tested at 45 MPa and proportional-response tested — the cylinder is connected to a proportional valve, and the extension rate is measured at 10 valve opening positions (5%, 10%, 15%… 50% of full opening). The response must be linear (±10%) across the entire range — ensuring the joystick-to-wheel relationship is predictable from the basket.

OEM & ODM

What You Provide

Platform model, chassis type, steering geometry (Ackermann/parallel), wheel size, tyre type (non-marking/standard), required steering angle, bore/rod/stroke, system pressure, proportional valve specification, joystick response curve, and steering linkage drawing.

What the Factory Delivers

Steering cylinder with Ra 0.1 µm bore finish, PTFE guides, low-friction seals, 50 µm chrome, and mounting dimensions. Hydrostatic + proportional-response test certificate. Seal kits. Browse the mobile machinery cylinder family and the Korea Ever-Power catalogue.

Workshop

FAQ

Can the platform steer while the boom is elevated with workers?

Yes — most self-propelled boom lifts allow drive-while-elevated at reduced speed (0.5–1.5 km/h). The steering cylinder operates normally during this mode. The platform's tilt sensor monitors chassis lean during turns — if the lean exceeds the safe limit (typically 3–5°), the safety system stops the drive and steering.

Why Ra 0.1 µm instead of the standard 0.2 µm?

At walking speed on smooth floors, the steering operates at very low pressure (5–15% of rated). At this low pressure, the oil film between the seal and the bore is extremely thin — any bore roughness is transmitted through the film as friction. A finer bore finish (0.1 vs 0.2 µm) halves the friction at low pressure, eliminating the stick-slip that makes joystick steering feel jerky and unpredictable.

Do scissor lifts use the same steering cylinder as boom lifts?

Similar specification but smaller — scissor lifts typically use 63–100 mm bore (lighter machine, shorter wheelbase). Boom lifts use 100–200 mm bore. Both share the same response requirements: low-speed precision on indoor floors with joystick control. Korea Ever-Power supplies both ranges. Browse telescopic cylinders and forklift cylinders.