In the field of industrial power transmission, the efficiency, reliability, and adaptability of the deceleration motor as the core driving component directly affect the operating cost and maintenance cycle of the entire production system. As a global leader in drive technology, SEW Eurodrive's R-series parallel axis reduction motors are widely used in various industries such as material handling, food processing, mining, chemical engineering, and mixing due to their excellent performance, extremely low maintenance requirements, and highly modular configuration. This article is based on official product information, systematically sorting out the technical parameters, gearbox design characteristics, motor characteristics, installation methods, and optional accessories of the R series, providing a detailed technical reference for engineers and selection personnel.
Product Series Overview
The R series parallel axis reduction motor is one of the main models in the SEW Eurodrive product line, known for its compact parallel axis structure, extremely high transmission efficiency, and sturdy cast casing. This series covers a wide range from low-power to large-scale industrial applications:
Power range: 0.05 HP to 433 HP (approximately 0.037 kW to 323 kW)
Reduction ratio: 1.3 to 23401 (multi-stage combination can achieve a wide range of output speeds)
Output torque: up to 159300 lb · in (approximately 18000 Nm)
The R series reduction motor can be configured with different levels of reduction mechanisms (1, 2, or 3) according to demand to balance efficiency and reduction ratio. All models adopt modular design, supporting multiple motor interfaces, installation methods, and optional components, which can flexibly adapt to various industrial environments.
Design features of gearbox
2.1 High efficiency transmission
The gear transmission efficiency of the R series reducer depends on the number of stages:
Level 1 deceleration: Efficiency ≥ 98.5%
Level 2 deceleration: Efficiency ≥ 97%
Level 3 deceleration: Efficiency ≥ 95.5%
High efficiency means lower energy loss, less heat generation, and longer lubricant life, thereby reducing the total lifecycle cost.
2.2 Gear manufacturing process
All gears are made of certified steel and undergo carburizing or carbonitriding heat treatment, with a surface hardness of 58-62 HRC (Rockwell C grade). This high hardness ensures that the gear has infinite fatigue strength (theoretically, tooth surface fatigue failure will not occur under rated load). The gear tooth surface undergoes grinding or shaving precision machining to ensure:
Extremely low operating noise
Minimum frictional heating
The highest mechanical efficiency
2.3 Bearing and Shaft Design
Bearings: Anti friction bearings (mostly roller bearings or ball bearings) are used, and the selection is optimized according to the load capacity to ensure long service life and the ability to withstand high radial/axial loads.
Key Connection: Both the input and output shafts are equipped with captured keys to prevent key detachment during installation or operation, thereby improving safety.
2.4 Box and Sealing
The material of the box varies according to the model and size:
R37 to R167: Made of high-strength cast iron, grade SAE 30 or equivalent GG20. Cast iron has excellent vibration damping performance and rigidity, making it suitable for high torque applications.
R27: Adopting high-pressure die cast aluminum box body, light weight, good heat dissipation, suitable for low-power models.
The box design adopts high cross section modulus and rugged monolithic structure to maximize rigidity and reduce deformation. All flange faces are equipped with O-ring seals, which can effectively prevent oil leakage even when installed on non completely flat surfaces.
The sealing system is one of the highlights of the R series: it adopts an exclusive two-piece sealing design, including:
Internal patented bi helix FKM fluororubber seals provide excellent high temperature and chemical resistance.
External double lip nitrile rubber (Nitrile/Buna N) seals effectively prevent external pollutants (dust, moisture) from entering.
This combination provides three sealing surfaces, greatly enhancing protection and extending the life of bearings and gears.
2.5 Output shaft and inspection convenience
Output shaft: available in metric or imperial sizes for easy matching of transmission components of different standards.
Central threaded hole at the shaft end: convenient for fixing shaft accessories such as sprockets and pulleys.
Detachable inspection cover: It can inspect the internal gear status or perform maintenance without disassembling the entire machine.
2.6 Impact resistance
The impact load capacity of the R series reducer meets or exceeds the AGMA 6009-A00 standard, and can withstand common instantaneous overloads and impacts in industrial environments. It is suitable for impact load conditions such as crushers and conveyors.
Motor characteristics
The R series comes standard with or can be equipped with SEW high-performance motors, which have the following characteristics:
Inverter duty: The motor design is suitable for variable frequency drive, and the insulation system can withstand PWM voltage spikes to ensure long-term operational reliability.
Wiring terminals: convenient for quick on-site connection, no need to disassemble the motor during maintenance.
Low rotor inertia: suitable for applications with high cycle frequency (frequent start stop) and precise control, such as positioning systems.
Efficiency level: Optional EISA (Energy Independence and Security Act) IE3 "Premium" efficiency motor, meeting the latest energy efficiency regulations.
Global applicability: Supports 50Hz, 60Hz, or 50/60Hz dual frequencies, and can be exported to Europe (CE certification) and other regions.
For special environments, CSA hazardous area certified motors, ATEX explosion-proof motors, etc. can also be selected.
Installation method and flexibility
The R series supports multiple installation configurations to adapt to different mechanical structures:
Installation type applicable model description
B5 flange with centering stop for all sizes, in compliance with IEC standards, used for precise centering installation
B14 flange R07~R87 small-sized flange with centering stop, suitable for space limited occasions
Foot/flange combination R07~R87 provides both foot and flange mounting surfaces, providing the highest flexibility
The extended bearing flange (RM) specific model is designed for agitator applications, and the extended bearing can withstand greater cantilever loads and axial thrust
All models can be ordered for horizontal, vertical, or inverted installation as needed, with no need to modify the internal lubrication system
This modular installation concept enables the R series to be easily integrated into existing equipment designs, reducing non-standard processing costs.

Optional attachments and special features
To meet specific operating conditions or regulatory requirements, the R series offers a wide range of optional components:
5.1 Motor Adapter
C-face adapter: allows installation of NEMA standard motors.
IEC motor adapter: matches standard IEC flange motors, making it easy to replace motors from other brands.
5.2 Protection and anti-corrosion
Corrosion protection: Special coating treatment is applied to the box, fasteners, and shaft, suitable for corrosive environments such as chemical plants and offshore platforms.
Long term storage protection: Special anti rust oil is added at the factory, sealed and packaged, and can be stored for more than 2 years without rusting.
5.3 Bearing Upgrade
For models R57 to R107, heavy-duty spherical roller bearings can be used instead of standard bearings to significantly improve radial load capacity and impact resistance.
5.4 Sealing upgrade
FKM fluororubber seals can be used instead of standard nitrile rubber seals, with a wider temperature range (-40 ° C~200 ° C) and stronger chemical corrosion resistance.
5.5 Braking System
Fail safe brake: spring-loaded, electrically released, suitable for applications with frequent start stop or high safety requirements (such as elevators and conveyor belts).
5.6 Cooling and Protection
Forced cooling fan: When the motor needs to operate for a long time at low frequencies (<20Hz), an independent power supply fan can be optionally installed to avoid low-speed overheating.
Thermostat or thermistor: Built into the motor winding, connected to the frequency converter or protective relay to achieve overheating shutdown protection.
5.7 Connection and Encoder
Plug connector: enables quick replacement of motors without the need for rewiring, reducing downtime.
Dual speed motor: Provides two independent pole pairs to achieve two fixed speeds.
Motor encoder: Optional built-in or external incremental/absolute encoder for closed-loop speed or position control.
5.8 Special motors
Servo motor: can be combined with R series reducers to form a high dynamic response servo reducer motor for positioning and synchronous control.
Summary of Technical Data
Range of parameter values
Power 0.05~433 HP
Reduction ratio 1.3~23401
Maximum output torque of 159300 lb · in
Efficiency (1/2/3 levels) 98.5%/97%/95.5%
Gear hardness 58-62 HRC
Box material: cast iron (R37-R167) or die cast aluminum (R27)
Sealed patent double helix FKM+double lip nitrile rubber
Installation methods B5, B14, foot/flange, mixer flange
Motor standard NEMA or IEC, 50/60Hz, IE3 optional
Protection level standard IP55, optional higher
Certification CE, CSA, ATEX optional
Typical application areas
The R series parallel axis reduction motor is widely used in:
Material handling: belt conveyor, chain conveyor, bucket elevator, drum conveyor line
Food and beverage: mixers, mixers, filling equipment
Mining and cement: crushers, vibrating screens, screw conveyors
Chemical and Pharmaceutical: Reactor Stirring, Centrifuge
Pulp and paper: calender, rewinder
Automobile manufacturing: assembly line conveyor, lifting platform
Wastewater treatment: scraper, aerator
Selection and ordering suggestions
When choosing the R series deceleration motor, the following factors should be considered comprehensively:
Required output torque and speed: Calculate the required torque based on the load and select the appropriate machine base size according to the reference sample.
Installation direction: Determine whether to install horizontally, vertically, or upside down in order to choose the correct lubrication method (oil pool lubrication or forced lubrication).
Environmental conditions: temperature, humidity, corrosiveness, dust level (IP protection level), whether ATEX or CSA explosion-proof is required.
Control mode: Whether variable frequency drive, encoder feedback, or brake are required.
Energy efficiency requirements: Is it necessary to use IE3 high-efficiency motors to meet regulatory subsidies.
Maintenance convenience: Do you need plug connectors, detachable inspection covers, etc.
SEW Eurodrive provides professional selection software (such as SEW driver calculation tools) and global technical support to help customers quickly determine the optimal configuration.