Strain-wave (harmonic) gear
LeaderDrive LCD strain-wave (harmonic) gear
Ultra-flat cup-type strain-wave gear with a very short axial length, light weight and high stiffness for its size.
Key specifications
| Ratio | 30–500:1 |
|---|
Series ranges as published; individual models vary. The full datasheet, drawings and CAD models are available on request.
Typical applications
What a strain-wave (harmonic) gear is
A strain-wave gear, often called a harmonic gear, reduces speed using three parts: an elliptical wave generator, a thin flexible toothed cup or hat called the flexspline, and a rigid circular spline with internal teeth. The wave generator deforms the flexspline so its teeth engage the circular spline at two points. Because the flexspline has typically two fewer teeth, each input turn advances it slightly, giving ratios of about 30:1 to 160:1 in one stage, with near-zero backlash.
When engineers choose a strain-wave (harmonic) gear
Choose a strain-wave gear for compact, lightweight, high-ratio reduction with near-zero backlash, such as robot joints, cobots, medical robots, aerospace and optics. Hollow versions allow cables through the centre. The trade-offs are torsional stiffness at low load, which is lower than some alternatives, limited input speed and the risk of tooth ratcheting under overload. For shock loads and heavy base joints, cycloidal reducers are often preferred.
How to specify the LeaderDrive LCD
Send these with your enquiry and an engineer can confirm the right LCD variant:
- Ratio (:1)
- Rated, peak and momentary torque (Nm)
- Input speed limits (rpm)
- Torsional stiffness (Nm/arcmin)
- Hysteresis and accuracy (arcmin)
- Component set or housed unit
- Hollow shaft diameter and output bearing loads
Common mistakes to avoid
- Exceeding momentary torque and ratcheting the teeth
- Ignoring low-load stiffness in precision control
- Poor housing tolerances for component sets
- Using the wrong lubricant or quantity
LeaderDrive LCD: frequently asked questions
What is the LeaderDrive LCD?
Ultra-flat cup-type strain-wave gear with a very short axial length, light weight and high stiffness for its size. Published series figures include ratio 30:1, ratio 500:1. It is available through our supply network, and our engineers can confirm the right variant for your application.
Who makes the LeaderDrive LCD?
The LeaderDrive LCD is made by LeaderDrive (Leader Harmonious Drive Systems Co., Ltd.) available through our supply network. Send us your requirement for pricing, lead time, datasheets and CAD.
What is the ratio of the LeaderDrive LCD?
The published series minimum ratio is 30:1. Individual models and sizes in the LCD range vary, so check the exact variant against your duty cycle, mounting and environment, or ask our engineers to confirm the right size for you.
Why do strain-wave gears have near-zero backlash?
The flexspline teeth are preloaded into the circular spline teeth by the elliptical wave generator, and many teeth engage at once. There is no clearance between teeth at the engagement zones, so backlash is close to zero. Lost motion comes mainly from elastic deflection.
What is the difference between a strain-wave component set and a housed unit?
A component set is the wave generator, flexspline and circular spline, which the machine builder mounts in its own housing with bearings. A housed unit adds a housing, output bearing and seals. Component sets save weight and space; housed units are easier to integrate.
Further reading: Harmonic vs planetary vs cycloidal · How to select a gearbox · Gearboxes and harmonic drives
Often compared with
Engineers specifying this series often compare it with:
Other strain-wave (harmonic) gear series
Spec builder
Configure LeaderDrive LCD
Select every part you need, answer the questions an applications engineer would ask, and see your summary before we ask for any details.
- 1Products
- 2Performance
- 3Environment
- 4Volumes
- 5Your spec
Engineer support
Need LeaderDrive LCD or a complete system around it?
Tell us what you need, whether it is this part, an equivalent or a complete axis built around it. An engineer will review your requirements and reply, normally within one working day.
- Reviewed by an engineer, not an autoresponder
- Like-for-like and better-fit alternatives
- Standard, modified and custom options
Prefer to configure it? Use the spec builder.