DE3041355A1 - KAEFIG FOR A BALL BEARING - Google Patents

Description

Ball bearings usually have an inner and an outer race and a plurality of balls arranged between them; the balls are held in their correct operating position by a cage. In practice, it is common for the cage to consist of two identical cages to manufacture assembled parts stamped from metal. The metal can be steel or brass as required. Brass cages perform better than steel cages, but are much more expensive.

Cages can be designed as "sliding" (land-riding) cages or as non-sliding cages (in which the balls slide). In the case of the sliding cages, cage sections are ■ with the inner one and outer race of the bearing in contact, which brings a vibration and shock-absorbing effect with it. A disadvantage the sliding cage is the friction on the sliding surface to the outer race. To reduce this friction were the cages - at least in the case of high-quality bearings - are made of brass instead of steel stampings. The cost of such Brass cages, however, are much larger than those of steel cages.

The invention, by means of which these disadvantages are to be avoided, is specified in claim 1. Advantageous embodiments of the Invention emerge from the subclaims.

According to the present invention there is thus a sliding cage for ball bearings made from stamped steel parts with a

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Cover made of thermoplastic nylon, for example "Nylon 11" be coated. The cage designed according to the invention has the advantages of brass cages, with increased service life under unfavorable lubrication conditions as well as with significantly reduced Manufacturing costs. It has been found that the nylon-coated steel cages practically none or only with very little wear continue to operate for a considerable period of time after the original lubrication has been used up Has.

The nylon can be applied as a powder to the steel stamping parts and is hardened by bringing it to a higher temperature is heated. The coating is on the order of 0.0635-1.27 mm, preferably 0.0635-0.203 mm, has a Melting temperature on the order of 235 ° C, a coefficient of friction in the order of 0.4 and a Shore D hardness in the order of 70 - 71.

An exemplary embodiment of the invention is illustrated with the aid of the drawing

explained. It shows:

Fig. 1 is a partially sectioned view of a ball bearing with a cage;

Fig. 2 is a perspective view of one designed according to the invention Cage;

FIG. 3 shows a cross section through the cage in the viewing direction of the arrows 3-3 in FIG. 2.

In the drawing and in particular in Fig. 1, a ball bearing 10 is shown, which has an inner race 12, an outer

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Has running ring 14 and a plurality of balls 16 arranged therebetween. The balls 16 are held in the bearing by a sliding cage 18 - at certain intervals; the cage 18 is made of equal parts 20 which are connected to one another by rivets 20.

The cage 18 is shown in more detail in FIGS. As already mentioned, the cage 18 is composed of two identical parts 20 which are held together by rivets 22 extending through openings 24. The parts are typically made from sheet metal by stamping. As shown, each part 20 is a ring with spaced apart curved walls 26 which, in the assembled state, form pockets 28 each for receiving a ball 16. Between the curved walls 26 there are further recesses 30 which are formed by the riveted wall 32 and an overlying wall 34; the wall 34 slides on the outer race 14 of the ball bearing 10. The recesses 30 serve to receive lubricant; Bearings as described are mostly pre-lubricated in the manufacturer's factory. The parts 20 are coated, that is to say covered with a coating 36 made of a thermoplastic polyamide, for example "nylon 11", which is manufactured, for example, by the Rilsan Corporation, Glen Rock, New Jersey 07452. The coating is applied as a powder in either an electrostatic process or a fluidized bed process to a thickness of from 0.0635 mm (0.0025 inches) to 1.27 mm (0.050 inches), and preferably between 0.0635 mm ( 0.0025 inch) and 0.2032 mm (0.008 inch), and is at a temperature in the range from 205 ⁰ C to 235 ° C (400-450 ⁰ F)

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melted. The data for the nylon 11 coating result from a prospectus from Rilsan Corporation as follows:

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characteristic

Functional

Engineering

Test mode

Particle size 60-200 60-200 - CO Flow bed 0-80 0-80 Alpine air jet CD
-F- Electrostatic Strainer A200 Minimum film thickness 0.203 mm 0/203 mm Flow bed 0.076 mm 0.076 mm ASTM D-1005 - Electrostatic S ■ Ni ^η 100% coating 160 185 J792 use 1728 χ 10 ³ (ft.Vmil / lb.) 62.4 χ 144 χ sp.gr. Spec. Weight 1.20 1.04 at 23 ° C 0.51 0.49 ASTM D-792 Apparent diqhte 182 ° -185 ° C 182 ° -185 ° C ASTM 1895-69 Melting point 0.9 - 1.2 0.9 - 1.2 ASTM D-: 17-64 Water absorption ACTM ϋ-'570-63

Hardness (Shore "D")

70

ASTM D-2 24 0

CO Cn Cn

characteristic

Abrasion resistance (Taber, Rad, CS-17, 1 kg load) Weight loss after 1000 revolutions

Functional

15 mg

Engineering

8 mg

Test method

ASTM D-1044-56

Coefficient of friction (coating on steel) Static Dynamic

tensile strenght

(psi) on cast plates

_i elongation to ....

0.289 0.190

6200

63%

0.382 0.277

5900

31%

ASTM D-1894-63

ASTM D-638

ASTM D-882

"■ 4
CO

Linear expansion coefficient

8.1x10 " ⁵ / ° C

8.8x10 " ⁵ / ° C

ASTM D-696

characteristic Functional Engineering

Test method

Shock resistance

(up to 160 in.-lbs.) Direct and inverted

excellent excellent

Gardner push procedure

Flammability
in./see.

0.4 at 19 mils 0.2 at 19 mils ASTM D-1433

Dielectric strength

I. <_ *
CJ at 20 ^° C well O
■ C /
O
KJ 65% RH mm I. well 0792 mm Coating thickness: τητη 0.076 0.127 0.203 0.432 0.712

4.62 KV

7.06 KV

9.93 KV

15.34 KV

22.92 KV 4.91 KV

7.51 KV

10.56 KV

16.32 KV

24.38 KV

CO O -Ο-

co σι σι

characteristic

Functional

Engineering

Test method

former resistance A. A = good, X = bad A. strong alkalis X weak " A. strong acids A. black Acids A. Fat, oil A. chlorinated lo
solvent A. Alcohols A. aromatic lo
solvent A. Sea water A. Weather conditions boiling water

A A X A A

A A

A A A A

ASTM D-543

Claims (5)

Patent to sayings .J cage for a ball bearing with an inner race, a outer race and a plurality of interposed balls that contact the inner and outer races and through the Cage are kept at a distance, consisting of two identical, substantially circular, connected to one another Parts made of steel and provided with spaced pockets for receiving the balls as well as recesses for receiving Lubricant for the bearing, characterized in that the cage (18) is provided with a coating (36) made of plastic. which has a thickness on the order of 0.0635-1.27 mm (0.0025-0.05 inches), a coefficient of friction less than 0.4 and a Shore D hardness of 70 - 71. 2. Cage according to claim 1, characterized in that the plastic (36) a thickness on the order of 0.0635 0.203 mm (0.0025 - 0.008 inch). 3. Cage according to claim 1 or 2, characterized in that the plastic (36) is a thermoplastic plastic. 4. Cage according to claim 3, characterized in that the thermoplastic Plastic (36) is a solidified nylon powder. 5. Cage according to claim 4, characterized in that the nylon (36) is nylon 11. 130021/0792