Planetary gearbox
APEX Dynamics AD / ADR / ADS planetary gearbox
Apex Dynamics high-precision helical planetary with a one-piece stainless planet cage and very short length; ADS adds a keyed input shaft for belt pulley or coupling drive.
Key specifications
| Backlash (max) | 1 arcmin |
|---|---|
| Length min | 70 |
Series ranges as published; individual models vary. The full datasheet, drawings and CAD models are available on request.
Options
- AD inline
- ADR right-angle
- ADS keyed input shaft
Typical applications
What a planetary gearbox is
A planetary gearbox reduces speed and multiplies torque using a central sun gear driven by the motor, several planet gears on a carrier, and an outer ring gear. Load is shared between the planets, so the gearbox is compact, coaxial and torque-dense. A single stage typically gives ratios of about 3:1 to 10:1, and stages are combined for higher ratios. Precision servo planetaries use ground helical or spur gears, preloaded output bearings and a motor adapter flange, with backlash typically a few arcminutes or less.
When engineers choose a planetary gearbox
Choose a planetary gearbox for most servo and stepper axes that need more torque, lower reflected inertia or a better inertia match. It is efficient, typically above 95% per stage, stiff and widely available in standard frames. The trade-offs are backlash, which is low but not zero, and limited single-stage ratio. For zero backlash in a compact joint, a strain-wave gear suits better. For very high shock loads, a cycloidal reducer may be more robust.
How to specify the APEX Dynamics AD / ADR / ADS
Send these with your enquiry and an engineer can confirm the right AD / ADR / ADS variant:
- Ratio and output speed (:1, rpm)
- Nominal and peak output torque (Nm)
- Emergency stop torque (Nm)
- Backlash (arcmin) and torsional stiffness (Nm/arcmin)
- Radial and axial output loads (N)
- Motor flange, shaft diameter and length (mm)
- Duty cycle, mounting orientation and lubrication
Common mistakes to avoid
- Sizing on motor torque times ratio without checking acceleration torque and service factors
- Ignoring the input speed limit at high motor speeds
- Mounting a pulley or pinion that overloads the output bearing
- Forgetting the gearbox efficiency and heat in continuous duty
APEX Dynamics AD / ADR / ADS: frequently asked questions
What is the APEX Dynamics AD / ADR / ADS?
Apex Dynamics high-precision helical planetary with a one-piece stainless planet cage and very short length; ADS adds a keyed input shaft for belt pulley or coupling drive. Published series figures include backlash 1 arcmin. It is available through our supply network, and our engineers can confirm the right variant for your application.
Who makes the APEX Dynamics AD / ADR / ADS?
The APEX Dynamics AD / ADR / ADS is made by APEX Dynamics (APEX Dynamics, Inc.) available through our supply network. Send us your requirement for pricing, lead time, datasheets and CAD.
What is the backlash of the APEX Dynamics AD / ADR / ADS?
The published series maximum backlash is 1 arcmin. Individual models and sizes in the AD / ADR / ADS 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.
How do I choose a planetary gearbox ratio?
Start from the load speed and motor speed range, then check inertia matching and torque. A ratio that brings the reflected load inertia close to the motor inertia improves dynamics. Then confirm peak output torque during acceleration is within the gearbox rating and that input speed stays under the limit.
What backlash does a precision planetary gearbox have?
Precision servo planetary gearboxes typically have backlash from below one arcminute to several arcminutes, depending on grade and stages. Lower backlash costs more. For most positioning axes, a few arcminutes is fine; for robot joints or optics, strain-wave or zero-backlash designs are used.
Further reading: How to select a planetary gearbox · Harmonic vs planetary vs cycloidal · Gearboxes and harmonic drives
Often compared with
Engineers specifying this series often compare it with:
Other planetary gearbox series
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