234415B sewing machine bearings & china suppliers 234415B

Specifications

234415B sewing machine bearings & china suppliers 234415B
Brif introductions of thrust ball bearings

A thrust bearing is a particular type of rotary bearing. Like other bearings they permit rotation between parts, but they are designed to support a predominately axial load.

Thrust bearings come in several varieties.

• Thrust ball bearings, composed of ball bearings supported in a ring, can be used in low thrust applications where there is little axial load.
• Cylindrical thrust roller bearings consist of small cylindrical rollers arranged flat with their axes pointing to the axis of the bearing. They give very good carrying capacity and are cheap, but tend to wear due to the differences in radial speed and friction which is higher than with ball bearings.
• Tapered roller thrust bearings consist of small tapered rollers arranged so that their axes all converge at a point on the axis of the bearing. The length of the roller and the diameter of the wide and the narrow ends and the angle of rollers need to be carefully calculated to provide the correct taper so that each end of the roller rolls smoothly on the bearing face without skidding. These are the type most commonly used in automotive applications (to support the wheels of a motor car for example), where they are used in pairs to accommodate axial thrust in either direction, as well as radial loads. They can support rather larger thrust loads than the ball type due to the larger contact area, but are more expensive to manufacture.
• Spherical roller thrust bearings use symmetrical rollers of barrel shape, rolling inside an outer race with a spherical inner surface. They can accommodate combined radial and axial loads and also accommodate misalignment of the shafts. They are often used together with radial spherical roller bearings.
• Fluid bearings, where the axial thrust is supported on a thin layer of pressurized liquid—these give low drag.
• Magnetic bearings, where the axial thrust is supported on a magnetic field. This is used where very high speeds or very low drag is needed, for example the Zippe-type centrifuge.

They are commonly used in automotive, marine, and aerospace applications. They are also used in the main and tail rotor blade grips of RC (radio controlled) helicopters.

Thrust bearings are used in cars because the forward gears in modern car gearboxes use helical gears which, while aiding in smoothness and noise reduction, cause axial forces that need to be dealt with. The double helical or herringbone gear balances the thrust caused by normal helical gears.

One specific thrust bearing in an automobile is the clutch "throw out" bearing, sometimes called the clutch release bearing.

Thrust ball bearings consist of two precision chrome steel washers (ring) and a ball complement spaced by bronze retainer. They can be supplied with or without radius ball grooves in the rings. Thrust bearings are used under purely axial loads.

Fluid-film thrust bearings were invented by Australian engineer George Michell (pronounced Mitchell) who patented his invention in 1905. Michell bearings contain a number of sector-shaped pads, arranged in a circle around the shaft, and which are free to pivot. These create wedge-shaped regions of oil inside the bearing between the pads and a rotating disk, which support the applied thrust and eliminate metal-on-metal contact.

Michell's invention was notably applied to the thrust block in ships. The small size (one-tenth the size of old bearing designs), low friction and long life of Michell's invention made possible the development of more powerful engines and propellers. They were used extensively in ships built during World War I, and have become the standard bearing used on turbine shafts in ships and power plants worldwide. (See also Fluid_bearing#Michell/Kingsbury_tilting-pad_fluid_bearings)

Specifications of bearings 234415B

Feature of  bearings 234415B

  This type of bearings is separable and the contact angle is 90 degree.So the bearings can only carry axial load. While the bearings runing, the balls are extruded to the outside of raceway by centrifugal effect and easy to be scraped. So this typy of bearing can not be used under the high speeds condition.

The single direction bearings of them can only carry axial load in one direction, while the double can carry alternating axial load in either direction.

And the trust Ball Bearings with spherical outer ring have self-aligning functions.

In double-direction angular contact thrust Ball Bearings, the contact angle is 60 degree. they can take axial load forn double-directions and the unit load form axial and radial drection. Furthermore, the bearings have a capacity of axial space limiting,and also do a little to the radial space limiting.

CAGES of  bearings 234415B

Pressed steel and machined brass cages are commonly used.

APPLICATIONS of  bearings 234415B

The thrust Ball Bearings are used in lathe centers, automobile clutches, reducers and so on.

  Thrust ball bearings can handle loads in the axial direction only. Bearing rings mounted on the shaft are called shaft washers, and those mounted in the housing are called housing washers. Both washers contain raceways for the balls. Thrust ball bearings are available as both single and bi-directional types. The bi-directional thrust bearing incorporates a third washer and an additional set of balls. This center washer is located in the axial direction by a shaft shoulder and sleeve. Care must be taken in handling to prevent damage to the separable rings and ball assemblies. Typical applications: live centers in lathes, lead screws, automotive Clutches, kingpin supports, speed reducersPacking: Single box or in a plastic tube (bag) then in a carton, then packing in a wooden (steel) pallet.Producing types: 51100, 51200, 51300 series 2900, 900 series And all kinds of inch sizes plastic paper,carton box.

 Main types as below

 Characteristics of bearings 234415B
Thrust ball bearings are made up of series balls (with cage), a shaft washer (fit tightly with axis), and a house washer, balls are rotating between them. They only bear axial load in one direction, not radial load. As the axial load is evenly distributed on each ball, load capacity is very large. But the temperature is higher during working, allowing speed limit is lower. Thrust ball bearings are separable, single direction thrust ball and double direction thrust ball bearings according to their structures. The former can withstand axial load in one direction, the later can withstand axial load in both directions, but not bear radial load. They have the structure with a seat, and the installation surface is spherical, it has a self-aligning performance and reduces installation errors.

Type available:
a) Single-direction thrust ball bearings
b) Double-direction thrust ball bearings
c) Single-direction thrust angular contact ball bearings
d) Double-direction thrust angular contact ball bearings
e) Non-standard thrust ball bearings

We can supply all kinds of thrust ball bearings, such as below items: