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The Ultimate Guide to Miniature Thrust Bearings
Miniature thrust ball bearing is a special separate type of rotating ball bearing. Similar to other ball bearings, they allow rotation between parts, but they are designed to support high axial loads (parallel to the shaft) while rotating. In high-speed applications, miniature ball bearings require oil lubrication. Typically, they consist of two washers (shaft washer and seat washer), which can be flat or grooved (with raceways), a rolling ball element and a cage. The shaft washer is used to secure the shaft, and the seat ring is used to secure parts outside the shaft. In contrast to miniature ball bearings, miniature thrust bearings cannot withstand radial loads and are only designed to withstand axial loads and medium speeds in their applications. Ball thrust bearings are generally suitable for higher speed applications but carry relatively lower loads than roller thrust bearings. This blog will introduce in detail the materials, loads, dimensions and installation of miniature reasoning ball bearings, and provide you with constructive suggestions for choosing suitable bearings.
Miniature thrust ball bearings refer to thrust bearings with an inner diameter within 10 mm. Miniature thrust ball bearings are divided into grooved and non-grooved. Miniature one-way thrust bearings can bear one-way axial load, and two-way bearings can bear two-way axial load. Thrust ball bearings with spherical seats have self-aligning properties that eliminate the effects of installation errors. Miniature thrust bearings have low friction torque and are typically used in low to medium speed applications. Thrust ball bearings cannot bear radial loads. Higher load ratings are achieved when miniature thrust ball bearings have grooves in their raceways. When raceway grooves are added, the friction between the ball and cage and the shaft and housing during rotation will be greatly reduced.
Materials for miniature thrust ball bearings
Usually, the material of the two washers and balls is chromium steel, and the material of the cage is brass or stainless steel. In medical equipment and miniature precision instrument applications, choosing the right miniature thrust bearing is crucial. If higher corrosion resistance is required, stainless steel thrust bearings are a good choice. The material of both washers, ball and cage is stainless steel (SS440C). Hybrid ceramic ball miniature thrust bearings are also becoming increasingly popular.
Miniature thrust ball bearing load
The load-bearing capacity of miniature thrust bearings is a very important indicator, which determines the maximum load that the bearing can bear in practical applications. The load-bearing capacity of bearings is affected by many factors, including size, material, lubrication method and rotation speed. The working principle of miniature thrust ball bearings is relatively simple. It mainly forms an oil film through lubricant, reducing the contact area between the bearing and the bearing seat, thereby reducing the friction and wear exerted on the bearing. When an axial load is applied, the bearing is acted upon by forces. The direction of the force is parallel or perpendicular to the axis, and the bearing will produce corresponding stress and deformation, thereby bearing axial load and torque.
Dimensions: Usually expressed by the outer diameter, inner diameter and width of the bearing. Under the same material and lubrication conditions, the larger the bearing size, the greater the load-bearing capacity.
Material: usually expressed by indicators such as elastic modulus, yield strength and hardness. Materials with high strength, high hardness and high toughness have higher load-bearing capabilities, but their manufacturing costs also increase accordingly. Chrome steel balls and washers carry higher loads than stainless steel bearings. Bearings with steel cages and copper cages can withstand higher loads and speeds than bearings with plastic cages.
Lubrication: directly affects the friction coefficient and wear degree of the bearing. Grease lubrication or oil lubrication is usually used. Oil lubrication has better lubrication effect and heat dissipation performance, but requires a complex lubrication system and higher cost.
Rotation speed: High rotation speed will produce greater inertia force and centrifugal force, which will produce greater load on the bearing. Therefore, when the rotational speed is high, it is necessary to use bearings with higher load-bearing capacity or use multiple bearings to work in parallel.
A basic criterion for selecting a miniature thrust bearing is its ability to withstand axial loads. This capability is quantified by the load ratings provided by the manufacturer, but it is also critical to understand how to calculate these values based on specific application requirements.
Miniature thrust ball bearing specifications
| Part Number | Washers Type | Seal Type | Bore Dia | Outer Dia | Height | Ball Material | Dynamic Thrust Load | Max Speed (X1000 rpm) | Weight |
| F10-18 | flat raceway | Open | 10 mm | 18 mm | 5.5 mm | 52100 Chrome Steel | 2230 N | 2.5 | 6 g |
| F10-18M | grooved raceway | Open | 10 mm | 18 mm | 5.5 mm | 52100 Chrome Steel | 2230 N | 2.5 | 5.4 g |
| F2-6 | flat raceway | Open | 2 mm | 6 mm | 3 mm | 52100 Chrome Steel | 117 N | 16 | 0.6 g |
| F2X-7 | flat raceway | Open | 2.5 mm | 7 mm | 3.5 mm | 52100 Chrome Steel | 156 N | 15 | 0.9 g |
| F3-8 | flat raceway | Open | 3 mm | 8 mm | 3.5 mm | 52100 Chrome Steel | 600 N | 11 | 0.6 g |
| F3-8M | grooved raceway | Open | 3 mm | 8 mm | 3.5 mm | 52100 Chrome Steel | 600 N | 11 | 0.9 g |
| F4-10 | flat raceway | Open | 4 mm | 10 mm | 4 mm | 52100 Chrome Steel | 658 N | 6 | 2 g |
| F4-10M | grooved raceway | Open | 4 mm | 10 mm | 4 mm | 52100 Chrome Steel | 658 N | 6 | 1.5 g |
| F4-9 | flat raceway | Open | 4 mm | 9 mm | 4 mm | 52100 Chrome Steel | 800 N | 8 | 1.5 g |
| F4-9M | grooved raceway | Open | 4 mm | 9 mm | 4 mm | 52100 Chrome Steel | 800 N | 8 | 1.2 g |
| F5-10M | grooved raceway | Open | 5 mm | 10 mm | 4 mm | 52100 Chrome Steel | 950 N | 5.1 | 2.10 g |
| F5-11 | flat raceway | Open | 5 mm | 11 mm | 4.5 mm | 52100 Chrome Steel | 988 N | 5 | 2.40 g |
| F5-11M | grooved raceway | Open | 5 mm | 11 mm | 4.5 mm | 52100 Chrome Steel | 988 N | 5 | 2.1 g |
| F5-12M | grooved raceway | Open | 5 mm | 12 mm | 4 mm | 52100 Chrome Steel | 988 N | 5 | 2.1 g |
| F6-12 | flat raceway | Open | 6 mm | 12 mm | 4.5 mm | 52100 Chrome Steel | 1600 N | 5 | 2.5 g |
| F6-12M | grooved raceway | Open | 6 mm | 12 mm | 4.5 mm | 52100 Chrome Steel | 1600 N | 5 | 2.2 g |
| F6-13M | grooved raceway | Open | 6 mm | 13 mm | 5 mm | 52100 Chrome Steel | 1600 N | 5 | 2.20 g |
| F6-14M | grooved raceway | Open | 6 mm | 14 mm | 5 mm | 52100 Chrome Steel | 1800 N | 4 | 3.5 g |
| F7-13M | grooved raceway | Open | 7 mm | 13 mm | 4.5 mm | 52100 Chrome Steel | 1422 N | 4 | 2.6 g |
| F7-15 | flat raceway | Open | 7 mm | 15 mm | 5 mm | 52100 Chrome Steel | 2200 N | 3.6 | 4.4 g |
| F7-15M | grooved raceway | Open | 7 mm | 15 mm | 5 mm | 52100 Chrome Steel | 2200 N | 3.6 | 6.5 g |
| F7-17M | grooved raceway | Open | 7 mm | 17 mm | 6 mm | 52100 Chrome Steel | 2600 N | 3.5 | 6.5 g |
| F8-16 | flat raceway | Open | 8 mm | 16 mm | 5 mm | 52100 Chrome Steel | 2500 N | 4 | 5 g |
| F8-16M | grooved raceway | Open | 8 mm | 16 mm | 5 mm | 52100 Chrome Steel | 2500 N | 4 | 4.5 g |
| F8-19M | grooved raceway | Open | 8 mm | 19 mm | 7 mm | 52100 Chrome Steel | 3452 N | 3 | 9.1 g |
| F9-17 | flat raceway | Open | 9 mm | 17 mm | 5 mm | 52100 Chrome Steel | 578 N | 8 | 5.1 g |
| F9-20M | grooved raceway | Open | 9 mm | 20 mm | 7 mm | 52100 Chrome Steel | 3356 N | 2.5 | 9.9 g |
Miniature thrust ball bearing applications
The application of micro thrust plane bearings can provide excellent performance such as smooth, noiseless, and high-speed rotation. They are mainly used in CNC machine tools, medical equipment, precision instruments, auto parts, optical instruments, sweeping robots, smart homes, etc. Micro thrust bearings are widely used in the medical device industry, such as implants, radio frequency knives, artificial ventilators, surgical robots, etc. These medical devices require high precision, high wear resistance, high-speed rotation and smooth operation. Miniature thrust ball bearings can meet these requirements. At the same time, the application of miniature thrust plane bearings also improves the safety and efficiency of medical devices, reduces medical risks, and improves patient treatment effects.
Installation steps of thrust ball bearings
The usual steps for installing a thrust ball bearing are as follows: first install the housing washer, then place the cage with the steel ball assembly on top, and finally add the shaft washer. Shaft washers secure the axis of the shaft and allow it to rotate. The fit between the thrust bearing and the shaft is generally a transition fit, and the fit between the ferrule and the bearing inner hole is a clearance fit. Therefore, this type of bearing is convenient to install.
Conclusion
Selecting the appropriate miniature thrust bearing requires an evaluation of speed, load, and bearing material. Bearing engineers must consider load carrying capacity, dimensional tolerances and lubrication requirements. Material options range from 440C stainless steel to AISI 52100 steel and can include the use of silicon nitride ceramic balls with flat or grooved washers. Axial load capacity calculated from engineering formulas is important in selecting the correct bearing for your application. If you are not sure which miniature thrust ball bearing to choose, please contact Aubearing’s engineers. Aubearing is a professional thrust ball bearing manufacturer that has been ISO9001:2015 certified and has the ability to customize thrust bearings.