The RA Series is a zero-backlash reducer designed for small to medium-size FA applications. It delivers high accuracy, rigidity, and speed.
The RA is suitable for equipment that demand motions with a high level of accuracy and speed.
The RA is suitable for equipment that demand motions with a high level of accuracy and speed.
Zero Backlash
The RollerDrive uses a unique preload mechanism to completely eliminate backlash and deliver output motions that are faithfully true to input commands.
Positioning accuracy is particularly good with direction reversing motions.
Positioning accuracy is particularly good with direction reversing motions.
Highest Level of Accuracy in the RollerDrive Series
Delivers good positioning accuracy and runout accuracy, which are otherwise difficult qualities to attain with a small reducer.
High Rigidity
The output shaft is a solid-piece cross roller bearing designed for durability against axial and radial loads.
High Speed
Max output speed 150 rpm (200 rpm for the RA40)
Choice of Motors
Dedicated fittings are available for mounting motors from various manufacturers.
High Efficiency, Direct Drive
Motor couples directly to the input shaft for a direct transfer of power with less transfer loss.
Lightweight, Compact
Features a compact aluminum-alloy housing for minimal footprint.
- Rotating arm and crystal pick up in semiconductor manufacturing equipment
- Precision stage drives for steppers (photolithography)
- Robot joints
- Rotary tables for polishing equipment
The performance of the RA Series depends on the lubrication system. The unit may have the standard grease lubrication system or the high-speed oil lubrication system. Which system is used depends on the user requirements. To determine whether the lubrication system chosen by Sankyo meets your application, make sure the unit is capable of operating under the conditions that satisfy our life expectancy values. This can be confirmed with the dynamic rated torque graph. The speed and torque must fall within the range highlighted in this graph.
Grease Lubrication
* Made to order.
| Model | RA40 | RA63 | RA80 | RA100 | RA125 | ||||
| Gear Ratio | 15 | 20 | 20 | 30* | 20 | 30* | 20 | 30* | |
| Max Torque for Starts/Stops | N・m | 57.7 | 129.3 | 202.3 | 147.9 | 564.8 | 250.3 | 938.6 | 637.5 |
| Maximum Allowable Input Speed | min-1 | 3,000 | 2,500 | 2,000 | 1,600 | ||||
| Allowable Mean Input Speed | min-1 | 900 | 800 | 700 | 600 | ||||
| Positioning Accuracy | Max arcsec | 90 | 60 | 40 | |||||
| Repeatability | Max arcsec | ±10 | ±7 | ±5 | |||||
| Surface Runout | Max μm | 10 | |||||||
| Allowable Axial Load | N | 999 | 1,657 | 3,302 | 3,724 | 8,178 | |||
| Allowable Radial Load | N | 669 | 1,359 | 2,819 | 3,109 | 7,452 | |||
| Allowable Moment Load | N・m | 33 | 79 | 210 | 284 | 764 | |||
| Product Weight | kg | 2.5 | 5.6 | 11.6 | 21.5 | 36.3 | |||
Oil Lubrication
* Made to order.
| Model | RA40 | RA63 | RA80 | RA100 | RA125 | ||||
| Gear Ratio | 15 | 20 | 20 | 30* | 20 | 30* | 20 | 30* | |
| Max Torque for Starts/Stops | N・m | 71.0 | 159.2 | 249.0 | 182.1 | 695.4 | 308.2 | 1,155.6 | 784.8 |
| Maximum Allowable Input Speed | min-1 | 3,000 | |||||||
| Allowable Mean Input Speed | min-1 | 1,300 | 1,100 | 1,000 | 900 | ||||
| Positioning Accuracy | Max arcsec | 90 | 60 | 40 | |||||
| Repeatability | Max arcsec | ±10 | ±7 | ±5 | |||||
| Surface Runout | Max μm | 10 | |||||||
| Allowable Axial Load | N | 999 | 1,657 | 3,302 | 3,724 | 8,178 | |||
| Allowable Radial Load | N | 669 | 1,359 | 2,819 | 3,109 | 7,452 | |||
| Allowable Moment Load | N・m | 33 | 79 | 210 | 284 | 764 | |||
| Product Weight | kg | 2.5 | 5.6 | 11.6 | 21.5 | 36.3 | |||
Operating Precautions
Do not operate the RollerDrive under conditions where the surface temperature may rise above 60℃. Operation under high temperatures can degrade lubrication oil.
