6.12.2025 / 4 minute read

30-Ton Hospital-Grade MRI Transport Elevator – Zero Pit Machine-Room-Less Lift for Tsinghua University

Overview

This custom-engineered lifting system features a quadruple hydraulic synchronous drive with Q460D high-strength steel structure (yield strength ≥460MPa).

Designed for pit-less installation (overhead ≤3.8m) and machine-room-free operation, compatible with existing 4500×3200mm hoistway at Tsinghua University research facility.

Basic Parameters

Parameter	Standard	Custom Range
Rated Load	30,000 kg	10,000-50,000 kg
Ultimate Load	50,000 kg (10min)	–
Leveling Accuracy	±2.5 mm	±1.0-±3.0 mm
Speed	0.15 m/s	0.05-0.25 m/s
Platform Size	3500×2800 mm	2500×2000-5000×3500 mm
Travel Height	15 m (5 stops)	≤30 m (10 stops)
Hydraulic Pressure	35 MPa	25-42 MPa
Vibration Control	VC-C (≤25 μm/s)	VC-B upgrade
Safety Factor	8.0 (EN 81-20)	≥6.0
Platform Levelness	≤0.5°/m	≤0.2°/m

The Challenge

Extreme Load Capacity
- Structural deflection ≤1/1500 at 50-ton load (ISO 4301)
Precision Positioning
- Repeat leveling accuracy ≤±3mm per ISO 22200
Vibration Control
- VC-C vibration criteria compliance (1-80Hz band)
Space Constraints
- Machine-room-less design (control cabinet depth ≤250mm)
- Pit-less installation (cylinder embedment ≤300mm)

Solutions

Composite Load Structure
- Four-column box girder frame (400×400mm section)
- Topology-optimized FEA (max stress ratio ≤0.7)
Quadruple Hydraulic Synchronization
- 4×Φ300mm plunger cylinders with closed-loop control
- Laser ranging real-time correction (0.1mm resolution)
Active Vibration Isolation
- Hydro-pneumatic dampers (>90% attenuation)
- Piezoelectric accelerometer feedback
Compact Power Unit
- Dual-pump redundancy (80mL/r displacement)
- Embedded valve manifold (depth ≤200mm)

Advantages

Metric	This System	Conventional
Leveling Accuracy	±2.5 mm	±10 mm
Vibration	18 μm/s	50-100 μm/s
Load/Weight Ratio	4.2:1	2.5:1
Start-up Shock	≤0.1g	≥0.3g
Energy Consumption	0.8 kWh/cycle	2.5 kWh/cycle