Harmonic driveModel THD-17
THD-17 Harmonic Drive Unit, Size 17
Size 17 cup-type strain wave gear unit with cross-roller output bearing. Ratios 30:1 to 120:1, backlash ≤ 20 arcsec, 0.68 kg. For cobot and humanoid joints.
- Rated torque
- 21N·m
- Peak torque
- 44N·m
- Backlash
- 20 arcsec
- Efficiency
- 80%
Overview
The THD-17 is a sealed strain wave gear unit for compact robot joints. An elliptical wave generator flexes a hardened steel flexspline into a rigid circular spline, giving high single-stage ratios with practically no backlash. The integrated cross-roller bearing carries radial, axial and tilting loads, so the unit bolts straight into a joint without extra bearings.
Typical uses are cobot wrist and elbow joints, humanoid and legged robot actuators, SCARA arms and precision rotary stages.
Technical specifications
| Size | 17 |
|---|---|
| Type | Cup type, unit with cross-roller bearing |
| Ratio range | 30:1 to 120:1 |
| Rated torque at 2000 rpm | 21 N·m |
|---|---|
| Limit for repeated peak torque | 44 N·m |
| Limit for average torque | 34 N·m |
| Limit for momentary torque | 91 N·m |
| Positioning accuracy | 60 arcsec |
| Repeatability | ±10 arcsec |
| Hysteresis loss | 1 arcmin |
| Max input speed | 7,300 rpm |
|---|---|
| Limit for average input speed | 3,500 rpm |
| Weight | 0.68 kg |
|---|---|
| Lubrication | Grease, factory filled |
Values at rated input speed and room temperature. See the datasheet for test conditions and service-life basis.
Ratios, torque and price
| Ratio | Stages | Rated torque | Peak torque | Backlash | Efficiency | Price excl. GST | Availability |
|---|---|---|---|---|---|---|---|
| 30:1 | 1 | 16 N·m | 34 N·m | ≤ 20 arcsec | 80% | ₹38,500 | Made to order |
| 50:1 | 1 | 21 N·m | 44 N·m | ≤ 20 arcsec | 80% | ₹39,100 | 4 in stock |
| 80:1 | 1 | 29 N·m | 61 N·m | ≤ 20 arcsec | 80% | ₹39,700 | 2 in stock |
| 100:1 | 1 | 31 N·m | 65 N·m | ≤ 20 arcsec | 80% | ₹40,200 | 4 in stock |
| 120:1 | 1 | 31 N·m | 65 N·m | ≤ 20 arcsec | 80% | ₹40,800 | Made to order |
Drawings and CAD
Mounting and motor fit
- Input
- Wave generator with Ø6–10 mm bore, motor adapter flange on order
- Output
- Cross-roller bearing output flange
- Fits motors
- Frameless torque motors and 100–200 W servos
NEMA 17 steppers with adapter - Lubrication
- Grease, factory filled
- Protection
- IP54
Need a different flange, housing or coupling?
We machine input flanges for any servo or stepper, custom output flanges, housings and couplings for this model.
Send your motor detailsQuestions about the THD-17
Is the THD-17 a component set or a unit?
It is a unit: the wave generator, flexspline and circular spline come assembled with a cross-roller output bearing and seals. Component sets are available on request if you design your own housing.
Which ratio should I choose for a cobot joint?
100:1 is the common choice for elbow and wrist joints driven by frameless motors at 2,000–3,000 rpm. Use 50:1 where you need more output speed.
