The matching use of single row tapered roller bearings requires selecting appropriate methods according to specific working conditions, and ensuring performance through strict installation and adjustment. The following are common matching methods and installation adjustment points:
1. Matching Method
Same Load Capacity Matching Method: Pair two bearings of the same model and specification that can withstand the same load and motion conditions. This method is suitable for installing two identical single row tapered roller bearings on the same shaft in equipment to improve the bearing's load-bearing capacity and rigidity. Same contact angle pairing method: Pair two single row tapered roller bearings with the same contact angle. Contact angle refers to the angle between the straight line installed between the inner and outer rings of a bearing and the axis of the bearing. Usually, the contact angles of single row tapered roller bearings are 15 °, 20 °, and 25 °. By using bearings with the same contact angle, the appropriate rigidity and torque transmission ability of the bearings can be maintained.
Reverse contact angle pairing method: Pair a single row tapered roller bearing with a contact angle of α and a single row tapered roller bearing with a contact angle of β, where α and β satisfy α+β=180 °. By using the reverse contact angle pairing method, the bearing's load-bearing capacity and stiffness can be improved.
. For example, on a machine tool spindle, a bearing with a contact angle of 15 ° is usually paired with a bearing with a contact angle of 25 °.Inverted cone bushing pairing method: Pair a pair of inverted cone bushings (one with a smaller diameter at the large end and the other with a larger diameter at the large end) with a single row tapered roller bearing.
. The advantage of the inverted cone bushing pairing method is that it makes the load distribution of the bearing more uniform, improving the life and reliability of the bearing.Combination assembly pairing method: Two bearings of the same model are combined with each other during installation to form a pair of bearings.
. This pairing method is suitable for special requirements, such as use in equipment with high impact loads and high speeds.II. Installation and Adjustment
Preparation before installation:
Ensure that the installation environment is dry and clean to prevent dust from entering the bearings.
.Check the machining quality of the mating surfaces of the shaft and housing, the end faces of the shoulders, grooves, and connecting surfaces to ensure that there is no damage, burrs, or dirt.
. Clean the bearings and mating surfaces, and apply an appropriate amount of lubricating grease.Installation process:
When installing a single row tapered roller bearing, it is usually necessary to adjust the clearance.
. The clearance value should be determined specifically based on different operating conditions and the size of the interference fit, and if necessary, experiments should be conducted to determine it. In the case of small interference fit, the bearing ring end face can be pressed with a sleeve at room temperature, and the sleeve can be hammered with a hammer to evenly press the ring through the sleeve. If installing in large quantities, hydraulic presses can be used. When the interference fit is large, the bearing can be installed using oil bath heating or sensor heating methods, with a heating temperature range of 80 ℃ -100 ℃ and a maximum of 120 ℃. At the same time, nuts or other appropriate methods should be used to tighten the bearings to prevent them from contracting in the width direction after cooling, resulting in a gap between the ring and the shaft shoulder. During installation, it is necessary to ensure that the outer ring end face is tightly pressed against the outer shell shoulder end face, and the inner ring end face is tightly pressed against the shaft shoulder end face, with no gaps allowed.Clearance adjustment:
The axial clearance adjustment of tapered roller bearings can be carried out on the shaft neck by adjusting the nut, washer, bearing seat hole internal thread, or using pre tightening springs.
. During the adjustment process, it is necessary to comprehensively consider factors such as installation layout, bearing spacing, shaft and bearing seat materials. In high load and high-speed application scenarios, special consideration should be given to the impact of temperature rise on clearance, and bearing clearance should be appropriately increased.In applications that operate at low speeds and are subject to vibration, it is recommended to use a clearance free or preloaded installation method to ensure good contact between the rollers and raceways of tapered roller bearings, distribute the load evenly, and avoid bearing damage caused by vibration impact.
. The size of axial clearance should be accurately measured using a dial gauge.Operation test:
After the bearing is installed, a rotation test should be conducted. First, rotate the shaft or bearing box by hand. If there are no abnormalities, use power to operate at low speed without load.
. Then gradually increase the rotational speed and load according to the operating conditions, and detect noise, vibration, and temperature rise. When abnormalities are found, the operation should be stopped and checked to ensure that the bearing performance is normal before delivery for use.