JPH01153810A - Angular ball bearing for high speed rotation - Google Patents

Abstract

PURPOSE:To eliminate seizure so as to aim at prevention of temperature rise by forming a counter-bored part of an outer ring in which the radius of the groove of the outer ring track is smaller than that of the groove of the inner ring track and the steel ball holding ratio of the counter-bored part of inner ring to that the outer ring is smaller than 20%. CONSTITUTION:The shoulder 4a of an inner ring 3 is counter-bored toward the track 7i of the inner ring, the ratio of the size T of a bearing section to the diameter Do of a steel ball 6 is made less than 50%. A contact angle of the steel ball 6 toward the outer ring 1 is made nearly 15 degree so as to decrease a temperature rise. The radius De of the groove of the track 7e of the outer ring 1 is made smaller than the radius De of the groove of the inner ring 3, the shoulder 8b of the outer ring 1 opposite to the counter-bored part of the inner ring 3 is boared so as to form the holding ratio less than 20%. Accordingly, the majar axis of the contact oval of the outer ring never exceeds the effective track width of the outer ring 1, so as that seizure does not occur, temperature rise of a bearing is prevented and the bearing is formed preferably for a high speed rotation.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an angular contact ball bearing that is used, for example, in high-speed rotating parts such as machine tools.

(Prior Art) Angular contact ball bearings developed for high-speed rotation have various structures. There are roughly two categories. 1st
As shown in Figure 4, this type has a counterbore (2) formed on the outer ring (1), and the inner ring (3) has both shoulders (4a) + (
One of 4b) (4a) has shoulder thickness NFC. Further, the cage (5) is of the outer ring (1) guided type, and the ft steel balls (6) evenly distributed by the cage are smaller than the standard size. As shown in Fig. 5, the second type is a normal deep groove type with a counterbore formed on the inner diameter side of the outer ring (1), and the inner ring (3) ■ shoulders (4a), (4b).
) and drop one shoulder (4a) of the retainer (5).
The diameter of the steel ball (6) is smaller than the standard size or the diameter of the steel ball (6). Mayu, both types have outer rings (1
) has a contact angle (αe) of 15°, and the groove diameter of the raceway is the same for both the inner and outer rings.

(Problem to be solved by the invention) When an angular contact ball bearing rotates at high speed, the contact angle between the outer ring (1) and the inner ring (2) gradually shifts from the initial contact angle due to the centrifugal force of the steel balls, and the outer ring The contact angle (αθ) is an extremely small angle. Contrary to this, the contact angle (α1) of the inner ring (3) gradually becomes larger than the initial contact angle force (α1>ae).

On the other hand, in a bearing that rotates at high speed, due to centrifugal force acting on the steel balls, if both the outer and inner rings have the same curvature, the life of the outer ring will be significantly shorter than that of the inner ring. In order to solve this problem, a method is adopted in which the curvature of the outer ring is set small, but in this case, as shown in Fig. 4, the major axis (ae) of the contact ellipse on the outer ring (1) side is Steel ball in (7e) (6)■ The distance C from the contact point (Pa ) to the shallower side of the steel ball is called the outer ring effective raceway width)
(Ae) exceeds e (ae>Ae), resulting in edge load occurring on the outer ring and causing seizure. Note that (a
l) is the major axis of the contact ellipse on the inner ring (3) side, and (A1) is the part of the inner ring that corresponds to the outer ring effective raceway width (Ae), but it is easy to maintain the relationship (ai<Ai) on the inner ring side. Therefore, the possibility of such problems occurring is relatively low.!%
In the first type, a counterbore (2) is formed in the outer ring (11), so the distance (Ae) itself is small, and even when rotating with great force, the long axis (ae) of the contact ellipse is effective for the outer ring. The raceway width (Ae) was exceeded and the inner ring (3)
With 9Ill, even if there is a margin, seizure will occur on the outer ring (1) side.

As a result, no matter how small the contact angle of the outer ring becomes or how large the contact ellipse becomes, the contact ellipse will never protrude beyond the outer ring effective raceway width (Ae), so problems like the first type will occur. does not occur. However, as shown in FIG. 5, the lubricating oil discharge function does not function sufficiently, and due to this, the temperature of the lubricating oil itself rises, causing the entire bearing to become hot. In order to solve the problem of force and force, it was possible to weld lubricating oil to the outer ring's raceway force and end without drilling a hole, but this required more man-hours and was not necessarily effective in preventing temperature rise. .

(Means for Solving the Problems) The present invention provides a means for resolving the problem by shouldering one side of the inner ring and reducing the size of the cross section of the bearing (
Regarding angular contact ball bearings where Do/T, the ratio between T) and steel ball diameter (Do), is 50% or less, in order to equalize the life of the outer and inner rings at high speeds, the groove radius of the outer ring raceway is changed to the groove radius of the inner ring raceway. By making the steel ball holding ratio (K) of the shoulder of the outer ring on the opposite side of the shoulder of the inner ring slightly smaller than the addition, the major axis of the contact ellipse of the outer ring becomes smaller than that of the outer ring during high-speed rotation. This prevents the effective raceway width from exceeding the width of the bearing, thereby preventing edge load and bearing temperature.

(Function) When the angular contact ball bearing according to the present invention is used at high speed rotation, the contact angle (
ae) gradually becomes smaller than the contact angle [αi] of the inner ring (3) and begins to move toward the shoulder (8b). However, the outer ring's raceway groove radius (De) is smaller than the inner ring's groove radius (Di), and the embrace ratio (z) of one shoulder of the outer ring is less than 20%, so the effective raceway depression of the outer ring ( he) does not cause the major axis (ae) of the contact ellipse. Also, the lubricating oil flows as shown by the arrow (G) to ensure good discharge and prevent the bearing from becoming too hot. Incidentally, a comparison of the temperature rise of the outer ring with conventional products is shown in Figure 2 (jet lubrication) and Figure 3 (oil-air temperature).

(Example) Next, embodiments of the present invention will be described with reference to the drawings.

In Figure 1, the raceway (7e) of the outer ring (1), the inner ring (3)
A large number of steel balls (6) are interposed in the zero orbit (71) so as to be freely removable, and each pole is equally spaced by a retainer (5). Further, the cage is of an outer ring guided type. Inner circle (3
) of the shoulders (4a) and (4b), one shoulder (4a) is bent towards the inner ring raceway (71).The size (T) of the bearing cross section is as shown in the figure. It is expressed as the difference (m-n) between the outer diameter Gn) and the bearing inner diameter (n), but the ratio between this diameter and the diameter (Do) of the steel ball (6), that is, Do/T, is 50% or less. However, with conventional angular contact ball bearings, this
0% or more, but it is set small. Further, the contact angle (ae) of the steel ball (6) with respect to the outer ring f1 is approximately 15°, which is set smaller than that of an ordinary angular contact ball bearing. By reducing the steel ball diameter relative to the bearing cross section and reducing the contact angle (ae) with respect to the outer ring, the frictional moment or gyro moment is reduced, and the temperature rise of the bearing is reduced.

Note that (ai) indicates the contact angle on the inner ring side.

Furthermore, the groove radius (De) of the orbit (7θ) of the outer ring (1) is smaller than the groove radius (Dl) of the inner ring (3).
(Do) and the outer ring shoulder (8) opposite to the inner ring shoulder.
b) It is formed small enough to be dropped. ship table==i(Oe
) indicates the center of the groove radius (Do) of the outer ring, and (○i) also indicates the center of the groove radius (Di) of the inner ring. In this case, the above-mentioned inclusion ratio (2) is expressed as .

Note that (Ae) is the effective raceway width of the outer ring, (ae) is the major axis of the contact ellipse of the outer ring, and (Ai) is the effective raceway width of the inner ring, and (ai) is the major axis of the contact ellipse of the inner ring. In this embodiment, the groove radius (Do) of the outer ring is the same value as the conventional product, and the groove radius (Di) of the inner ring is t - large.

(Effects) Since the present invention has the above structure, the major axis of the contact ellipse of the outer ring does not exceed the effective raceway width of the outer ring, so there is no occurrence of burning. Since the discharge is good, the temperature rise of the bearing is prevented, making it suitable for high-speed rotation, and has many excellent NFL effects.

[Brief explanation of the drawing]

Fig. 1 is a half longitudinal sectional view of an embodiment of the present invention, Fig. 2 is a comparison with a conventional product using jet lubrication, Fig. 3 is a comparison with a conventional product using oil-air lubrication and a beak, and Fig. 4 is a comparison with a conventional product using oil-air lubrication. A vertical cross-sectional view of a conventional product. FIG. 5 is a vertical cross-sectional view of another conventional product. 1...Outer ring 3...Inner ring 4a...Shoulder of inner ring 4b...6...Steel ball 7e...Outer ring raceway 71...
・Inner raceway 8a...Outer ring shoulder 8b...Outer ring counterbore E...Steel ball holding ratio Do...Steel ball diameter De...
Outer ring raceway groove radius Di... Inner ring raceway groove radius T... Size of bearing cross section m... Outer diameter of bearing n... Inner diameter of bearing R...
Outer ring raceway diameter r... Inner ring inner diameter Agent Patent attorney
Jun Kawachi 2nd Part 1 Part 2 Figure 4th Procedural Amendment 7th month of 1988

Claims (1)

[Claims] In an angular contact ball bearing in which one of the inner rings is off-shoulder and the ratio (D/T) between the bearing cross-sectional size (T) and the steel ball diameter (Do) is 50% or less, the outer ring raceway A counterbore with a groove radius (De) smaller than the groove radius (Di) of the inner ring raceway, and a steel ball embrace ratio (E) of the outer ring shoulder on the opposite side of the inner ring shoulder drop to slightly smaller than 20%. An angular contact ball bearing for high-speed rotation characterized by the following: However, cross-sectional size (T) = [bearing outer diameter W - bearing inner diameter (n)]/2 Enclosing ratio (E) = [outer ring raceway diameter (R) - outer ring inner diameter (r)]/2 × [1/Steel ball diameter (Do)