Stair lifts require high-torque, reliable, and smooth-operating motors to safely transport users up and down stairs. This guide covers motor types, power requirements, control systems, and safety considerations for optimal stair lift performance.
Pros:
• Simple, cost-effective, and easy to control.
• Provides high starting torque for smooth starts.
• Suitable for straight staircases with moderate loads.
Cons:
• Requires periodic brush maintenance (~2,000–5,000 hours).
• Lower efficiency (70–80%) compared to brushless motors.
Best for: Budget-friendly straight stair lifts.
Pros:
• Maintenance-free (no brushes), longer lifespan.
• Higher efficiency (85–95%), reducing battery drain.
• Smoother operation with Field-Oriented Control (FOC).
Cons:
• More expensive due to electronic controllers.
Best for: Curved stair lifts and premium models.
Pros:
• Robust, high torque for heavy loads (up to 160 kg+).
• No battery dependency (if hardwired to mains).
• Long lifespan with minimal maintenance.
Cons:
• Requires a gearbox, increasing complexity.
• Less efficient than BLDC for battery-powered lifts.
Best for: Heavy-duty commercial stair lifts.
|
Stair Lift Type |
Max Load |
Motor Power |
Torque (Nm) |
Speed (m/s) |
|
Straight (Residential) |
120 kg |
250W–400W |
15–30 |
0.07–0.15 |
|
Curved (Residential) |
136 kg |
400W–600W |
30–50 |
0.05–0.12 |
|
Heavy-Duty (Commercial) |
160 kg+ |
600W–1000W |
50–80 |
0.04–0.10 |
Torque Calculation:
T=(M⋅g⋅sinθ+μ⋅M⋅g⋅cosθ)⋅r/G
T: Required torque (Nm)
M: Total load (user + chair, in kg)
θ: Stair angle (typically 30°–45°)
μ: Friction coefficient (~0.02 for rails)
r: Drive wheel radius (m)
G: Gear ratio (if applicable)
Standard speed: 0.07–0.15 m/s (slow for safety).
Adjustable speed control (for user comfort).
• Motor drives a pinion gear along a toothed rail.
• Pros: Precise, high torque, good for curved stairs.
• Cons: Slightly noisier than chain drives.
• Motor drives a chain connected to the chair.
• Pros: Smooth, quiet, low maintenance.
• Cons: Slightly less precise than rack & pinion.
• Motor drives a rubber wheel gripping the rail.
• Pros: Simple, no gears/chains.
• Cons: Less reliable in wet/dusty conditions.
Recommendation:
► Curved stairs → Rack & pinion (precision needed).
► Straight stairs → Chain drive (quiet operation).
♦ PWM (Brushed DC): Simple speed adjustment.
♦ FOC (BLDC): Smoother acceleration/deceleration.
♦ Variable Frequency Drive (AC Motors): For hardwired systems.
✔ Electromagnetic Brakes: Auto-lock if power fails.
✔ Overspeed Detection: Stops motor if speed exceeds limit.
✔ Obstruction Sensors: Halts operation if an obstacle is detected.
✔ Battery Backup (for DC motors): Ensures operation during power outages.
|
Motor Power |
Battery Voltage |
Capacity (Ah) |
Backup Time |
|
250W–400W |
24V |
12–20Ah |
8–15 trips |
|
400W–600W |
36V |
20–30Ah |
6–12 trips |
|
600W–1000W |
48V |
30–40Ah |
5–10 trips |
Recommendation:
► Sealed Lead-Acid (SLA): Affordable but heavy.
► LiFePO4: Lightweight, long lifespan (preferred).
• No battery needed, but requires uninterrupted power.
• Best for commercial installations with backup generators.
(1) IP Rating (Ingress Protection)
• IP54: Basic dust/moisture resistance (indoor use).
• IP65: Protected against water jets (outdoor-capable).
(2) Temperature Tolerance
• Standard: 0°C to 40°C (indoor).
• Extended: -20°C to 50°C (outdoor models).
|
Application |
Motor Type |
Power |
Drive Mechanism |
Battery |
|
Straight Stairs (Home) |
BLDC |
300W |
Chain Drive |
24V 20Ah (LiFePO4) |
|
Curved Stairs |
BLDC |
500W |
Rack & Pinion |
36V 30Ah (LiFePO4) |
|
Heavy-Duty Commercial |
AC Gearmotor |
750W |
Rack & Pinion |
Hardwired (110/220V) |
For smooth, quiet operation → BLDC motor with FOC control.
Heavy loads/curved stairs → Rack & pinion drive.
Safety is critical → Backup battery, obstruction sensors, and auto-brakes.
Battery choice → LiFePO4 for longer lifespan and lighter weight.
By selecting the right motor and drive system, stair lifts can provide safe, reliable, and comfortable mobility for users. Would you like a specific motor design for your stair lifts chair? Please let us know your request now.
