While bearing radial loads, spherical bearings may have to bear certain axial loads.

When bearing radial loads, the support shaft and bearing seat hole must provide reliable and uniform support for the spherical plain bearing so that the spherical plain bearing can operate at full load. Therefore, it is particularly important to select and maintain a correct fit between the spherical bearing and the bearing seat hole to avoid rotation between the spherical bearing and the bearing seat hole. In addition, the surface of the bearing seat hole that matches the spherical bearing must be processed to a certain degree of accuracy.

When bearing an axial load, the compression fixation of the bearing seat hole or the outer ring of the spherical bearing must ensure that no large axial relative displacement occurs or is pressed out under the action of the axial load. Therefore, it is particularly critical to determine the thickness and chamfering of the bearing seat hole and select the appropriate pressure reduction method.

The purpose of installing and fixing the spherical bearing is to determine the dimensional and geometric tolerances of the inner diameter, thickness, chamfer, etc. of the spherical bearing seat hole, and select the appropriate compression method to ensure that after the spherical bearing is installed and fixed, the radial load is guaranteed At the same time, the bearing can withstand the largest possible axial force, ensuring that the bearing's performance such as starting torque, rotation flexibility, etc. are not affected, and ensuring the motion function of the spherical bearing.

It should be noted that by compressing the bearing seat hole or the outer ring of the spherical bearing, the axial push-out force that the spherical plain bearing can withstand is very limited. Therefore, if the push-out force requirement is relatively large, other axial fixation methods must be adopted. method.

1 Structural type of spherical bearing

According to the axial fixation method of the bearing seat hole or the outer ring of the spherical plain bearing, the spherical plain bearing has two basic structural types, one structural type has a chamfered outer ring. One structural type has an outer ring with a mounting groove.

2. Cooperation between the spherical bearing and the bearing seat hole

2. 1 Fitting dimensional tolerance of bearing seat hole

The outer ring of the spherical plain bearing and the bearing seat hole adopt the basic shaft system, and the matching size tolerance of the bearing seat hole is Js7.

2.2 Surface roughness of bearing seat hole

The surface roughness of the bearing seat hole Ra≤1.6μm.

2.3 Dimensions and tolerances of bearing seat holes

2.3.1 Dimensions and tolerances of outer ring chamfer type spherical bearing housing bore

The dimensions of the outer ring chamfer type spherical bearing bearing seat hole are as shown in Figure 3, the diameter of the bearing seat hole D, the thickness dimension of the bearing seat hole W, the width dimension of the bearing outer ring C, the chamfer size of the outer ring of the bearing r, the bearing seat hole The diameter dimension DH of the countersink is according to Table 1, and the depth dimension H=h+r+0.1. The dimensional tolerance of W is ±0.05.

2.3.2 Dimensions and tolerances of bearing seat holes for spherical plain bearings with mounting grooves in the outer ring

The size of the bearing seat hole of a spherical plain bearing with a mounting groove in the outer ring, the diameter of the bearing seat hole D, the width of the bearing outer ring is C, the thickness of the bearing seat hole W = C, and P is the depth of the mounting groove of the spherical plain bearing.

Dimensions, r is the chamfer of the bearing seat hole. Generally, r=P-0.1, and the dimensional tolerance of r is ±0.05.

The dimensional tolerance of the thickness dimension W of the outer ring chamfer type spherical bearing is the same as the dimension C of the bearing outer ring width, and the dimensional tolerance of W is ±0.05.

2.4 Shape and position tolerance of bearing seat hole

2.4. 1 The geometric tolerance of the bearing seat hole of the outer ring chamfer type spherical plain bearing The geometric tolerance of the bearing seat hole should be greater than the corresponding dimensional tolerance by

One less IT level,

2.4.2 Shape and position tolerances of the bearing seat hole of spherical plain bearings with mounting grooves on the outer ring

The geometric tolerance of the bearing housing bore should be at least one IT grade higher than the corresponding dimensional tolerance.

3 Inspection before installation of spherical bearings

3. 1 Inspection before installation of non-self-lubricating spherical bearings

The inspection requirements before installation of non-self-lubricating spherical bearings are as follows:

Check the oil filling period on the outer packaging to ensure that the oil filling period of the spherical bearing is within the validity period.

Check that the spherical bearings are free of damage, rust, metal chips and other dirt. The bearings rotate flexibly, make no noise, are not over-tightened or sluggish.

Before the bearing is installed, the outer diameter and outer ring width of the bearing must be measured, the bearing seat hole size and geometric tolerance must be measured, and the bearing and bearing seat must be selected.

3.2 Inspection before installation of self-lubricating spherical bearings

The inspection requirements before installation of self-lubricating spherical bearings are as follows: Measure the no-load starting torque of the spherical plain bearing.

Check that the spherical bearings are free of damage, rust, metal chips and other dirt. The bearings rotate flexibly, make no noise, are not over-tightened or sluggish.

Before the bearing is installed, the outer diameter and outer ring width of the bearing must be measured, the bearing seat hole size and geometric tolerance must be measured, and the bearing and bearing seat must be selected.

4. Installation of spherical bearings

The installation process of spherical bearings is as follows:

First, apply zinc yellow primer, epoxy resin primer, sealant or grease to the bearing seat hole;

Use a special press-fitting tool to press-fit the spherical plain bearing, ensuring that the press-fitting force is parallel to the axis of the bearing seat hole and is only applied to the end face of the outer ring of the spherical plain bearing. Slowly and evenly apply the press-fitting force to press the spherical plain bearing into the bearing seat hole. For spherical plain bearings with single-sided closing and fixed, the bearing should be pressed to the bottom of the bearing seat hole during installation, so that there is no axial gap between the spherical bearing and the bearing seat hole; for bearings with double-sided closing and fixed, the bearing should be pressed to the bottom of the bearing seat hole during installation. In the middle of the hole,

After the bearing is installed, use a clean white cloth to wipe off excess zinc yellow primer, epoxy resin primer, sealant or grease. The entire operation should be done carefully to avoid scratching the surface of the parts.

5 Fixing tools for spherical bearings

The fixation of the spherical bearing means to squeeze the mounting groove of the spherical bearing or the special groove of the bearing seat hole through a compression tool or a punch, so that the mounting groove of the spherical bearing or the special groove of the bearing seat hole undergoes plastic deformation, and the joint bearing is fixed. Part of the material of the mounting groove or the special groove of the bearing seat hole is filled into the chamfer of the bearing seat hole or the chamfer of the outer ring of the spherical bearing, so that the bearing does not displace when bearing axial load, which is also called the compression of the spherical bearing.

The compression of the spherical bearings uses traditional steel balls or rollers to compress or press. During the compression process, the size of the compression force, the axial feed amount, the speed of the compression tool, etc. should be determined according to the pressure of the spherical bearing and the bearing seat hole. There are no definite parameters and mathematical formulas, and it often depends on the operator's experience. In this way, it is easy to cause the starting torque to increase sharply or the clearance to decrease sharply after the spherical bearing is compressed, or even cause the spherical bearing to lock up, causing the spherical bearing to lose its function. Therefore, the traditional method of pressing or punching with steel balls or rollers must be improved.

6 Pressure reduction of spherical bearings

The spherical plain bearing is pressed into the bearing seat hole to compress, and the compressing pressure is applied to ensure that the compressing pressure is parallel to the axis of the bearing seat hole and is evenly and slowly applied to the bearing outer ring through the pressure head. When the setting surface of the compression tool fits the end surface of the bearing seat, When, keep the closing pressure for about 15 s.

7 Inspection of spherical bearings after compression

7. 1 Closing quality inspection

Closing quality inspection includes the following aspects:

Wrinkles, cracks and burrs are not allowed at the closing area, and rolling marks are allowed;

An edge gap is allowed at the closing area, that is, the shell material is allowed to have unfilled chamfers. When inspected with a plug gauge, a maximum edge gap of 0.10 mm is allowed.

After closing, use a clean white cloth dipped in gasoline to clean, and seal and rust-proof the closing area.

7.2 Rotational flexibility or no-load starting torque inspection

For non-self-lubricating spherical plain bearings, the rotational flexibility of the spherical plain bearing should be checked after the pressure is removed. The rotational flexibility of the spherical plain bearing is allowed to be reduced, but it should be able to rotate and swing.

For self-lubricating spherical plain bearings, the no-load starting torque of the spherical plain bearing should be checked after pressure is applied. The no-load starting torque after pressure is applied must not exceed twice the upper limit of the range specified by the bearing standard.

7.3 Axial push-out force or axial displacement inspection

The axial push-out force inspection is only performed on the process test piece, while the axial displacement check is suitable for part inspection, axial push-out force or axial displacement inspection

When checking the axial push-out force or axial displacement, slowly load no more than 20% of the specified load, adjust the measuring device to zero, and then slowly load to the specified load. There is no relative displacement or no relative displacement between the bearing and the bearing seat. More than 0.03 mm.

7.3.1 Axial push-out force of spherical plain bearings with outer ring chamfer type

If there is an axial push force requirement on the design drawing, the axial push force requirement given in the design drawing shall be followed; if there is no axial push force requirement on the design drawing, the axial push force shall be calculated.

7.3.2 Axial push-out force of spherical plain bearings with mounting grooves on the outer ring. If there is an axial push-out force requirement on the design drawing, follow the axial push-out force requirement given in the design drawing; if there is no axial push-out force requirement on the design drawing , then calculate the size of the axial pushing force.

RLB Spherical Plain Bearing

RLB Spherical Plain Bearings are high-quality bearings designed for use in numerous applications in the industrial and automotive sectors. These bearings are designed to handle both radial and axial loads, making them a versatile solution for a wide range of applications. 

RLB Spherical Plain Bearings are made from premium materials, including high-quality chrome steel and a variety of synthetic materials, to ensure long-lasting, reliable performance. The bearings are precision engineered and manufactured to the highest quality standards, ensuring they meet the specific requirements of each application.

The bearings are designed to offer exceptional durability and resistance to wear, even in harsh operating conditions. They are designed to operate smoothly and efficiently, minimizing friction and reducing energy consumption. This allows for improved equipment performance and an extended service life for both the bearings and the equipment they are used in.

RLB Spherical Plain Bearings feature a unique design that allows for easy installation and maintenance. The spherical shape of the bearing's inner and outer ring surfaces allows for self-alignment, ensuring a reliable fit and efficient operation. The bearings are also designed to be easy to disassemble, making it easy to perform routine maintenance and repairs.