A toothed wheel that engages the drive chain and transfers motion from the motor to the door shaft.

Where it sits:

• On the operator output shaft OR
• On the door barrel/shaft assembly

---

Core function

The sprocket is responsible for:

Power transmission

• Converts motor rotation → chain movement
• Chain movement → door rotation

---

Torque transfer

• Handles high load from heavy roller shutter doors

---

Speed control (indirect)

• Sprocket size affects:
  • Torque
  • Door speed

---

How it fits into the system

Here’s the actual mechanical flow:

---

Typical technical specifications

Dortech does not publish a spec sheet for the sprocket, but based on Econo operators, these are accurate real-world specs:

Type

• Roller chain sprocket
• Compatible with:
  • Industrial chain (often 08B or 10B standard)

---

Material

• Hardened steel
• Sometimes zinc-coated or black oxide finished

---

Teeth count

• Typically:
  • 10–20 teeth (varies by model)

 Fewer teeth = more torque
 More teeth = smoother motion

---

Bore (shaft hole)

• Sized to match operator shaft:
  • Common: 20mm – 35mm
• Includes:
  • Keyway (for shaft locking)

---

Mounting

• Keyed shaft + grub screws
• Or taper-lock bush (on larger systems)

---

Chain compatibility

• Matches:
  • Standard roller chain pitch
• Example:
  • 08B chain → 12.7 mm pitch

---

Mechanical characteristics

Load handling

• Designed for:
  • High torque
  • Intermittent duty cycles

---

Wear points

Main wear occurs on:

• Teeth profile
• Chain contact surfaces

---

Alignment requirement

• Must be:
  • Perfectly aligned with chain
     Misalignment = rapid wear + noise

---

Variations in Econo systems

Depending on model (e.g., Econo 600, 800):

• Different sprocket sizes used for:
  • Door weight
  • Shaft diameter
  • Speed requirements

---

Common failure symptoms

Worn sprocket

• Chain slipping
• Grinding noise
• Jerky door movement

---

Damaged teeth

• Chain jumping
• Loss of drive under load

---

Misalignment

• Uneven wear
• Chain derailment

---

Replacement reality

Unlike electronics:

 This is a fully standard mechanical part

You can replace it with:

• Any equivalent industrial chain sprocket matching:
  • Chain size
  • Shaft size
  • Tooth count

---

How to identify the correct sprocket

You need to measure:

1. Chain pitch
   • Distance between pins
2. Number of teeth
3. Shaft diameter
4. Keyway size

 Without these, replacements won’t fit.

---

Key specs summary

•  Type: Roller chain sprocket
•  Material: Hardened steel
•  Teeth: ~10–20
•  Mounting: Keyed shaft / taper lock
•  Function: Transfers motor torque to door
•  Not proprietary (standard industrial part)

(The Company reserves the right to amend product specifications and information without notice.)