一. Installation Steps for Angular Contact Ball Bearings

Angular contact ball bearings are installed in pairs and require the application of a preload. Proper installation significantly enhances the operating precision of the host machine and extends bearing service life; conversely, improper installation not only fails to meet precision requirements but also compromises service life.

1. Installation Configurations

Angular contact ball bearings can be installed in three configurations: back-to-back, face-to-face, and tandem arrangements.

(1) Back-to-Back Installation

In a back-to-back configuration (where the wide end faces of the two bearings face each other), the lines of contact angle diverge along the axis of rotation. This arrangement increases angular rigidity and resistance to deformation in both radial and axial directions.

(2) Face-to-face mounting

In a face-to-face arrangement (where the narrow faces of the two bearings face each other), the lines of contact angles converge toward the axis of rotation, resulting in lower angular rigidity. Since the inner rings protrude beyond the outer rings, clamping the outer rings together eliminates the initial clearance and allows for the application of a preload.

(3)Tandem Arrangement

In a tandem arrangement (where the wide faces of both bearings face the same direction), the lines of contact angle are parallel and oriented in the same direction, allowing the two bearings to share the working load acting in that direction. However, to ensure axial stability, a pair of bearings arranged in tandem must be installed in opposition to another pair at the other end of the shaft.

2. Calculation and Adjustment of Preload

Preload can be achieved by grinding the end face of one bearing ring or by clamping the bearings together using spacers of specific thicknesses placed between the inner and outer rings, thereby ensuring tight contact between the rolling elements (balls) and the raceways.

Preload adjustment is verified through a no-load running test. After passing assembly inspection, angular contact ball bearings must undergo a no-load running test at operating speed for at least two hours; the temperature rise should not exceed 15°C.

二. Installation Precautions

1. Installation Environment

Bearing installation should be performed in a clean, dust-free room. Bearings must be carefully selected and matched, and spacers must be precision-ground; while maintaining equal heights for the inner and outer ring spacers, the parallelism of the spacers must be controlled to within 1 µm.

2. Maintaining Cleanliness

Bearings must be thoroughly cleaned before installation. During cleaning, the inner ring's tapered face should point upward, and the bearing should rotate smoothly without any sticking or resistance. After drying, the specified amount of grease should be applied; for oil-mist lubrication, a small amount of oil-mist lubricant should be used.

Bearings should be cleaned with gasoline or kerosene and dried before use, ensuring proper lubrication. Grease lubrication is commonly used, though oil lubrication is also an option. When using grease, select a high-quality product with excellent properties regarding purity, oxidation resistance, rust prevention, and extreme-pressure (EP) performance. The grease fill quantity should be 30%–60% of the free space within the bearing and housing; overfilling should be avoided.

3. Tools

Specialized tools should be used for bearing installation to ensure even force distribution; striking the bearing directly is strictly prohibited. Apply uniform pressure around the circumference of the bearing ring's end face to press it into place; do not strike the bearing end face directly with a hammer or similar tool, as this may damage the bearing. For fits with small interference, a sleeve may be used at room temperature to cover the bearing ring's end face; by striking the sleeve with a hammer, the ring is pressed in evenly.

For large-scale installations, a hydraulic press may be used. During the pressing process, ensure that the end faces of the outer ring and inner ring are pressed firmly against the housing shoulder and shaft shoulder, respectively, leaving no gaps.

4. Pre-installation Inspection

Before installation, carefully inspect the quality of the mating surfaces on the shaft and housing, as well as the shoulder faces, grooves, and connecting surfaces. All mating surfaces must be thoroughly cleaned and deburred; any molding sand must be completely removed from the unmachined surfaces of castings.

5. Storage Environment

Bearings should be stored in a clean, well-ventilated area free from corrosive gases, with a relative humidity not exceeding 65%. For long-term storage, periodic rust-prevention measures should be taken.

6. Internal Clearance Adjustment

Internal clearance must be adjusted when installing single-row tapered roller bearings. The specific clearance value should be determined based on operating conditions and the magnitude of the interference fit; testing may be required to determine the optimal value. Double-row tapered roller bearings and water pump shaft bearings have their clearance preset at the factory and do not require adjustment during installation.

7. Rotation Test

A rotation test should be performed after bearing installation. First, rotate the shaft or bearing housing manually; if there are no irregularities, proceed to operate the bearing under power at low speed without load. Then, gradually increase the rotational speed and load while monitoring for noise, vibration, and temperature rise. If any abnormalities are detected, stop operation and inspect the bearing. The bearing may be put into service only after passing the rotation test.