High-Speed Roller Ring Precautions on Use

Handling

1. Please use at least two people to move any product with a mass of 20 kg or more, or use a cart or another method of conveyance. Otherwise, it may cause injury or damage the unit.
2. Follow the installation procedure on p. 9 during installation. Additionally, do not disassemble the roller ring.
3. Take care not to drop or strike the roller ring. Otherwise, it may cause injury or damage the unit. Even if there is no outward indication of damage, a sudden impact could prevent the unit from functioning properly.
4. Wear appropriate safety gear, such as protective gloves and safety shoes, when handling the product.
5. When removing the Model RT from equipment, fasten the securing bolts so that the inner ring does not separate.

   Model No.	Securing bolt (hexagonal-socket-head type bolt)
   RT228 (G)	M3×12L 4 bolts
   RT297 (G)	M4×12L 4 bolts
   RT445 (G)	M5×16L 4 bolts
   RT665 (G)	M6×20L 4 bolts

Precautions on Use

1. Prevent foreign material, such as cutting chips or coolant, from entering the product. Failure to do so could damage the product.
2. If the product is used in an environment where cutting chips, coolant, corrosive solvents, water, etc., may enter the product, use bellows, covers, etc., to prevent them from entering the product.
3. Slight oscillations can inhibit the formation of an oil film between the raceways and the area of contact for the rolling elements, resulting in fretting. We recommend periodically rotating the roller ring several times to help ensure that an oil film forms on the surfaces and rolling elements.
4. Do not forcibly drive a pin, key, or other positioning device into the product. Press-fit it on gently. An impact could create indentations on the raceway and impair the product's function.
5. When installing the roller ring onto a housing, if the inner ring is fixed, hammer the inner ring to insert it. If the outer ring is fixed, hammer the outer ring. Hammering the movable (rotating) side may cause damage to the unit.
6. If the rigidity or accuracy of an attached component is insufficient, the bearing load will be concentrated at one location and performance will decline significantly Therefore, consider carefully the rigidity and accuracy of the housing and shaft, and the strength of the securing bolts.
7. The performance of the roller ring, including accuracy, rotational torque, and service life, may be reduced by heat generated by motor gears. Keep the roller ring sufficiently far away from areas where heat is generated and add a cooling system as required.
8. If the housing is asymmetrical, any thermal deformation of the roller ring will be also. This can increase the uneven load on the roller ring and reduce its performance, including accuracy, rotational torque, and service life.
9. Keep the inner and outer rings at a temperature of 60°C or less during use.
10. Please keep in mind that the rotational torque will change depending on rotational speed, temperature, type of grease, and load conditions.
11. The roller ring performance values listed in this catalog are obtained with the specified preload applied. The performance of the roller ring may change if the preload changes due to factors such as fit, the rigidity and machining accuracy of peripheral components, and the difference in temperature of the inner and outer rings.

Lubrication

1. Do not mix different lubricants. Even greases containing the same type of thickening agent may, if mixed, interact negatively due to disparate additives or other ingredients.
2. When using the product in locations exposed to constant vibrations or in special environments such as clean rooms, vacuums, and extreme heat or cold, use a lubricant suitable for its use/environment.
3. The consistency of grease and kinematic viscosity of base oil changes according to the temperature. Please keep in mind that the rotational torque of the roller ring may be affected by these changes.
4. Roller rings come with the standard grease listed on p. 8 applied, so they can be used immediately, but regular greasing is required to maintain good lubrication. Use the lubrication hole on the outer ring to replenish lubricant to the entire interior of the product every three to six months. The final lubrication interval/amount should be set at the actual machine. When the roller ring is filled up with grease, the initial rotational torque will increase due to grease resistance. Performing a warming-up operation will expel surplus grease, returning the torque to an appropriate value.
5. Perform the warming-up operation described below when first operating the product and after replenishing grease. Keep the inner and outer rings at a temperature of 60°C or less when performing a warming-up operation.

   Warming-up operation method
   1. Start operating the equipment at low speed and gradually increase the rotational speed in three or four stages up to the maximum.
   2. At each rotational speed, wait for the periphery of the bearing to reach a stable temperature before continuing.

6. The structure of peripheral components will require careful consideration if contamination due to grease around the edges of the device is a concern.
7. Contact THK if considering using a special grease or a lubricant other than grease.

Storage

When storing the roller ring, pack it as designated by THK and store it indoors in a horizontal position away from high or low temperatures and high humidity. Please note that if the product has been kept in storage for an extended period, the lubricant inside may have deteriorated. Please ensure that you replenish the lubricant before use.

Disposal

The product should be treated as industrial waste and disposed of appropriately.