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Brief introduction to thrust ball bearings

Brief introduction to thrust ball bearings

2021-07-12

Thrust ball bearing belongs to the separation type bearing, including a shaft ring (with the journal), a seat ring (with the bearing seat), and a group of steel ball and cage composition. When installing, it can be easily matched with the journal and bearing seat respectively.

Thrust ball bearings have one-way thrust ball bearings and two-way thrust ball bearings according to different structures, as well as angular contact thrust ball bearings.

One-way thrust ball bearings

One-way thrust ball bearings can bear axial load in one direction, but can not bear radial load. Able to do unidirectional axial positioning.

One-way thrust ball bearings are divided into plane seat rings and aligning seat rings. General plane seat ring is not allowed to have Angle error, but in bearing design, 0.5 ~ 1 mm clearance can be set aside between the outer diameter of the seal ring and the bearing seat mating surface for compensation. Thrust ball bearings with self-aligning seats can also be used to compensate for angular errors during installation. But the aligning seat needs to be ordered separately.

Two-way thrust ball bearings

Bidirectional thrust ball bearings can bear axial loads in both directions. But can not bear the radial load. Able to do axial positioning in both directions.

Bidirectional thrust ball bearings are also divided into plane seat rings and aligning seat rings. General plane seat ring is not allowed to have Angle error, but in bearing design, 0.5 ~ 1 mm clearance can be set aside between the outer diameter of the seal ring and the bearing seat mating surface for compensation. Thrust ball bearings with self-aligning seats can also be used to compensate for the angular errors in the installation. But the aligning seat needs to be ordered separately.

Angular contact thrust ball bearings

Angular contact thrust ball bearings mainly bear axial loads, and can also bear a small number of radial loads.

Compared with the thrust ball bearing of the same size, the allowable limit speed is higher. Able to do unidirectional axial positioning.

Angular contact thrust ball bearings have two contact angles of 45° and 60°, which are especially suitable for use in composite load applications where the axial load is mainly borne and radial load is given priority. It can also compensate the plane thrust ball bearing can only bear axial load but can not bear radial load. The radial load that the structure can bear depends on the size of the contact Angle. Generally speaking, the smaller the contact angle is, the greater the radial load capacity will be.

Thrust ball bearings with housing

The structure of thrust ball bearing with outer cover is basically the same as that of the unidirectional thrust ball bearing. But there is a cover on the seat ring (or a cover on both the inner and outer diameters of the seal ring). Because of the outer cover, the thrust ball bearing after the outer cover becomes an inseparable bearing, and the role of the outer cover is dustproof. The structure shown in Fig. 2 can also be filled with grease.

Thrust ball bearings with housing can bear axial loads in one direction, but cannot bear radial loads. Able to do unidirectional axial positioning.

We can also provide customers with other structural thrust ball bearings, such as resistance-free thrust ball bearings, tapered hole unidirectional thrust ball bearings, steel wire raceway unidirectional thrust ball bearings, and other products. If customers need it, you can consult with TG technical department.

We can also design and manufacture new thrust ball bearing products to meet customer's personalized requirements.

cage

Thrust ball-bearing cages generally use steel plate stamping cages, there are also automotive steel cages, brass solid cages, and glass fiber reinforced nylon 66, and other engineering plastic cages.

The smaller the load

In order to ensure the bearing obtain a good running state, thrust ball bearings, like other ball bearings and roller bearings, must be applied a certain amount of small load, especially for high speed, high acceleration, or work under the condition of frequent changes in the direction of load. Because of these working conditions, the inertial force of the ball and the cage and the friction in the lubricant will have a bad effect on the rolling and rotating accuracy of the bearing, and there may be harmful sliding movement on the bearing between the ball and the raceway.

The smaller axial load Fmin required by thrust ball bearings can be estimated by the following formula:

kN

Type in the

A - Small load constant, see bearing size table

N - Bearing speed, r/min

Larger smaller loads may be required when starting at low temperatures or when the lubricant viscosity is high. Normally, the weight of the bearing support itself plus the load borne by the bearing has exceeded the required small load. If the small load has not been reached, the structure bearing must be imposed with an additional axial load to meet the requirements of the small load. In the application of thrust ball bearings, axial tightening can generally be applied with springs.

Dimensions, tolerances

The dimensions of the standard thrust ball bearing conform to the provisions of GB/T273.2 "Rolling Bearing Thrust Bearing Dimensions General Scheme", GB/T301 "Rolling Bearing Thrust Ball Bearing Dimensions" and so on.

The tolerance of standard thrust ball bearings conforms to the provisions of GB/T307.4 "Rolling Bearing Thrust Bearing Tolerances" and so on.

The dimension tolerance class of standard thrust ball bearings is generally P0 (ordinary class). If customers have other special requirements for dimension and tolerance (including non-standard ones), TG can provide corresponding products.

Equivalent dynamic load

For the thrust ball bearing under dynamic load, its equivalent dynamic load can be calculated as follows:

α= 90° P = FA

α≠ 90° P = XFR + YFA

One-way bearing

When alpha = 45 °

Fa/Fr > E X = 0.66 Y =1 E = 1.25

When alpha = 60 °

Fa/Fr > e X = 0.92 Y =1 e = 2.17

Two-way bearing

When alpha = 45 °

Fa/Fr > E X = 0.66 Y = 1 E = 1.25

Fa/Fr≤ E X = 1.18 Y = 0.59 e = 1.25

When alpha = 60 °

Fa/Fr > E X = 0.92 Y = 1 E = 1.25

Fa/Fr≤ E X = 1.9 Y = 0.55 e = 2.17

Equivalent static load

For thrust ball bearings bearing static load, the equivalent static load can be calculated as follows:

α= 90° P0 = FA

α≠ 90° P0 = Fa + 2.3fr ·tanα

Type in the

Fa - Radial load, N

Fr - Axial load, N

Alpha - contact Angle

X -- Radial load coefficient

Y -- Axial load coefficient

thrust ball bearings

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