Products
Planetary Gearboxes
Our cost-effective planetary gearheads give your design the strength and precision it needs, without stretching your budget. These gearheads offer impressive torque density, compact size, and reliability without the premium cost of high-end planetary systems.
Built with robust precision-cut metal geartrains and optimized gear geometry, they provide quiet operation, consistent output, and long life. Their modular, lightweight construction allows for a wide range of gear ratios, mounting options, and customizable features to meet specific performance needs.
Key Features
- Modular, customizable design - multiple stages, gear ratios, lengths, shafts, and mounting options
- Compact and lightweight footprint for space-constrained applications
- Exceptional efficiency - precision-machined components minimize energy loss
- Low backlash and high accuracy for positioning and motion-control tasks
- Durable and reliable - evenly distributed forces reduce wear under heavy or repetitive loads
- High torque density in a compact cylindrical form factor
- Any mounting position with lifetime synthetic grease lubrication
- IP65 protection for industrial environments
Product Series
Choose a series for detailed specifications, frame sizes, and downloads.
SB Series - High-Precision Planetary Gearboxes
The SB Series is a high-precision planetary gearbox line designed for servo motor applications. Available in frame sizes 042, 060, 090, 115, 142, 180, and 220 with reduction ratios from 3:1 to 100:1, SB reducers deliver rated output torques from 19 Nm (042SB) to 1,140 Nm (220SB) depending on ratio and frame size.
- Super precision backlash P0: ≤1 arcmin (3:1–10:1 ratios)
- Precision backlash P1: ≤3 arcmin
- Standard backlash P2: ≤5–7 arcmin
- Rated input speed: 3,000 rpm (standard) / 6,000 rpm (high speed)
- Efficiency ≥97% (single stage, 3:1–10:1)
- Protection IP65, synthetic grease lubrication
SBR Series - Right-Angle Planetary Gearboxes
The SBR Series combines a planetary reduction stage with a right-angle bevel output box, enabling compact 90° power transmission for space-constrained machine layouts. Frame sizes 060 through 220 with ratios from 3:1 to 200:1.
- Right-angle output with integrated bevel stage
- Super precision backlash P0: ≤4 arcmin
- Precision backlash P1: ≤6–7 arcmin
- Standard backlash P2: ≤9 arcmin
- Rated output torque up to 2,000 Nm (220SBR, low ratios)
- Efficiency ≥94–97% depending on ratio range
Economy Series Planetary Gearboxes
The Economy Series (SEP, SEPR, SEPB, SEPRB, PNX, and related SAE/SAF/SBF lines) delivers cost-effective planetary reduction for volume OEM programs - compact torque density, IP65 protection, and flexible motor integration without premium high-precision pricing.
- Cost-effective positioning for high-volume and budget-sensitive OEM designs
- Backlash ≤7–10 arcmin on inline spur-gear models
- IP65 protection class with lifetime lubrication
- Flexible integration with PMDC, BLDC, BLDC servo, and stepping motors
- Modular standardized sizes with single- and multi-stage ratios
- Custom manufacturing available for shafts, flanges, and ratios
Specifications
| Series available | SB, SBR, Economy (SEP/SEPR/SEPB/SEPRB/PNX) |
|---|---|
| SB frame sizes | 042, 060, 090, 115, 142, 180, 220 |
| SBR frame sizes | 060, 090, 115, 142, 180, 220 |
| SB reduction ratios | 3:1 to 100:1 (single and multi-stage) |
| SBR reduction ratios | 3:1 to 200:1 (single and multi-stage) |
| SB backlash (P0 / P1 / P2) | ≤1 / ≤3 / ≤5–7 arcmin |
| SBR backlash (P0 / P1 / P2) | ≤4 / ≤6–7 / ≤9 arcmin |
| Efficiency | ≥94–97% |
| Protection class | IP65 |
| Operating temperature | −10°C to +90°C |
| Lubrication | Synthetic lubricating grease |
| Mounting | Any direction |
| Noise (SB, 3000 rpm no load) | ≤56–70 dB(A) depending on size |
| Service life | 20,000 hrs continuous (catalog rated) |
Configuration Options
- Single-stage and multi-stage reduction ratios
- Precision levels P0 (high precision), P1, and P2 (standard backlash)
- Multiple frame sizes from 042 through 220
- Input shaft adapters for servo, stepper, BLDC, and PMDC motors
- Custom shaft lengths, flange patterns, and mounting orientations
- Right-angle output with SBR Series for compact machine layouts
Applications
- Robotics - articulated arms, cobots, mobile platforms, and joint actuation
- Semiconductor equipment - precision positioning and wafer handling
- Machine tools and CNC machines
- Industrial automation - conveyors, packaging, and material handling
- Renewable energy - solar tracking and wind turbine subsystems
Economy Series - 1-Stage vs 2-Stage Backlash
Typical backlash values for inline and right-angle Economy Series planetary gearheads (catalog rated; confirm for your ratio and load).
- Inline (SEP / SEPB / SAE / SAF) - 1-stage: ≤7 arcmin
- Inline (SEP / SEPB / SAE / SAF) - 2-stage: ≤10 arcmin
- Right-angle (SEPR / SEPRB) - 1-stage: ≤13 arcmin
- Right-angle (SEPR / SEPRB) - 2-stage: ≤16 arcmin
- Precision Economy helical lines (SAE/SAF/SBF): ≤7–10 arcmin depending on stage and series
WR / E / F Suffix Options
Many SEI gearmotor and gearbox lines use letter suffixes to denote mounting and output configuration. Confirm the exact suffix with SEI when ordering adapters or complete gearmotor assemblies.
- WR - right-angle gearbox or worm/right-angle output variant
- E - round (circular) mounting flange
- F - square mounting flange
- Suffix availability varies by series; Economy, AGV, and AC gearmotor lines share this naming where applicable
AGV & AMR Planetary Gearheads
Dedicated planetary lines for automated guided vehicles (AGVs) and autonomous mobile robots (AMRs) combine high duty-cycle torque density with ratios suited to drive wheels, lift axes, and travel mechanisms.
- SPG, SDPG, SRS, and SAGV series for mobile robot drive and lift applications
- Helical planetary stages with IP65 sealing for continuous operation
- See the AGV series hub for SPG, SAGV, and SRS model details and catalogs
- Gearbox–motor matching and assembly guidance available under Resources
Downloads
Catalogs and datasheets for this product line.
FAQ
- What is the difference between SB and SBR Series gearboxes?
- SB Series provides inline (coaxial) output for standard servo motor mounting. SBR Series adds a right-angle bevel output stage for applications requiring 90° power transmission in a compact envelope.
- Which motors can mount to SEI planetary gearboxes?
- SEI planetary gearboxes accept servo motors, stepping motors, BLDC motors, and PMDC motors through standardized input adapters. Economy Series units are specifically designed for flexible integration across these motor types.
- What backlash options are available?
- SB Series offers P0 (≤1 arcmin), P1 (≤3 arcmin), and P2 (≤5–7 arcmin) precision levels. SBR Series offers P0 (≤4 arcmin), P1 (≤6–7 arcmin), and P2 (≤9 arcmin). Contact us to select the appropriate level for your positioning requirements.
Related Products
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Planetary DC Gearmotors
Round helical planetary gearmotors paired with BLDC or PMDC motors for high torque and low noise.
Learn moreReady to spec your next motion system?
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