KR20200014766A - Double Row Angular Contact Ball Bearing - Google Patents

Abstract

The present invention, bearing inner ring; A concave first inner rolling element raceway formed in the outer circumferential region of the bearing inner ring; A concave second inner rolling element raceway axially offset relative to the first inner rolling element raceway and likewise formed in the outer circumferential region of the bearing inner ring; Bearing outer ring; A concave first outer rolling element raceway formed in the inner circumferential region of the bearing outer ring; A concave second outer rolling element raceway axially offset relative to the first outer rolling element raceway and formed in the bearing outer ring; A first ball / cage assembly having a first ball received in a first track space extending between the first inner rolling element track and the first outer rolling element track; And a second ball / cage assembly having a second ball received in a second track space extending between the second inner rolling element track and the second outer rolling element track. . In this case, the central trajectory of the two ball / cage assemblies takes on specific axial and radial relative positions.

Description

Double Row Angular Contact Ball Bearing

The present invention relates to a double row angular contact ball bearing according to the preamble of patent claim 1.

From DE 10 2009 057 192 A1, with reference to FIG. 1 included in this document, a double row angular contact ball bearing is known which is considered as prior art. According to this document, it is proposed to design balls of a ball-cage assembly with a smaller diameter than those of a ball / cage assembly with an axially adjacent and relatively larger diameter. . The angular contact ball bearing is also configured such that the end faces of the bearing ring lie on each bearing side in one common plane. The centers of the balls with a larger diameter move on a central track having a diameter larger than the maximum track diameter of the outer track that surrounds the relatively smaller ball / cage assembly.

From WO 85/03 749 A1, balls of two axially adjacent ball / cage assemblies have the same ball diameter or balls of a relatively smaller diameter ball / cage assembly are balls of the other ball / cage assembly. Double-row angular contact ball bearings with larger ball diameters are known.

From WO 85/03 749 A1 a wheel bearing arrangement is known, in which a wheel hub is supported via two angular contact ball bearings arranged in opposite directions. The balls of the individual angular contact ball bearings are guided in one cage device, which in each angular contact ball bearing has relatively larger diameter balls as well as balls of smaller diameter ball / cage assemblies. Guide the balls in the cage assembly. The track and ball are designed such that the balls of two adjacent ball / cage assemblies alternately enter into the space between the balls of the individual ball / cage assemblies.

From DE 10 2008 024 316 A1 a bearing arrangement for supporting the pinion shaft is known, in which case the bearing arrangement comprises two rolling bearings which are pressed against one another in the axial direction, each of which is a double row It is implemented as an angular contact ball bearing. The balls form first and second ball / cage assemblies and slide over first and second inner rolling element tracks having different diameters. The cages of the individual ball / cage assemblies circulate the individual cage circulation chambers at different angular velocities, in the category of operation of the bearing arrangement.

The object of the present invention is to provide an angular contact ball bearing of the type mentioned in the foreword, which is characterized by a high carrying capacity and which can be produced with a reduced manufacturing cost compared to the structural shape up to now with a corresponding carrying capacity. It is.

This problem is solved by an angular contact ball bearing having the features specified in patent claim 1 of the present invention.

This makes it possible to provide a double row angular contact ball bearing which, in a preferred manner, is characterized by high axial and radial support capabilities and which can be manufactured under reduced material demand. In addition, through the angular contact ball bearings, the required support capacity can be realized under reduced axial and radial installation space requirements as a whole. In addition, the concept according to the invention results in a higher stiffness with respect to the structural mechanical coupling of the track pair in the individual bearing rings and a more advantageous distribution of the bearing forces which are guided through the ball within a wide axial force range. In a preferred manner the lifetimes of the trajectories are mutually adjusted with increased statistical probability over a wide load spectrum.

In this case the diameter of the first ball is preferably smaller than the diameter of the second ball. At this time, the diameter of the smaller ball is preferably in the range of 0.75 times to 0.95 times the diameter of the larger ball.

According to another aspect of the invention, the angular contact ball bearing according to the invention preferably has a minimum orbital radius (inner vertex radius) of the first inner rolling element raceway and a minimum orbital radius (inner vertex) of the second inner rolling element raceway. Radius). Furthermore, the minimum trajectory radius of the second inner rolling element trajectory is preferably smaller than the radius of the first central trajectory of the first ball.

Furthermore, the axial spacing of the balls can also be adjusted to be smaller than the arithmetic mean of small and large ball diameters. This gap may also be smaller than the diameter of the smaller balls. This concept is particularly suitable for bearing structure shapes in which the diameter difference of the balls is relatively small.

The rolling element trajectory is preferably implemented such that the distance of the intersection of the bearing axis of the adjacent end plane of the bearing inner ring with the vertical line is less than half the diameter of the second ball, in which case the vertical line is between the ball centers in the bearing axial cross section. It is a straight line which divides the section of in the center and stands vertically on the section. Said intersection of the bearing axis and the perpendicular line preferably lies in an axial intermediate region extending continuously in the bearing in the axial direction, ie between the end faces of the bearing inner ring, according to another aspect of the invention.

The first set of balls is preferably guided in the first cage device. The cage arrangement may be embodied in a preferred manner as a pocket cage or snap cage with a continuous annular web extending from the side facing away from the second set of angular contact ball bearings. The second set of balls is likewise preferably guided in the second cage device. The cage arrangement may again be embodied in a preferred manner as a pocket cage or snap cage with a continuous annular web extending on the side facing away from the first set of balls of angular contact ball bearings. At least one or both of the cages may be embodied as pocket cages in which balls are mounted radially from the inside, and the pocket cages are then subjected to their ball package under temporary elastic expansion, depending on the situation. ball package) to the bearing inner ring.

The second cage and the second balls guided in the second cage are driven by the first cage and the balls guided in the first cage until the bearing assembly is complete, so that the bearing outer ring rests on the two ball / cage assemblies. It can be fixed on the bearing inner ring until it rests on it. This concept is in a particularly preferred manner a gentle shoulder (so-called S3 shoulder) which allows the first balls to bounce shortly in the radial direction as they slide, and to be able to escape axially from the bearing inner ring only when the cage is radially expanded. Can be realized by being formed at least in the first trajectory. According to one particular aspect of the invention, it is possible to prevent the axial movement of the ball of the second ball / cage assembly, especially under the temporary radial fixation action of the second cage and then after the bearing outer ring action after assembly of the bearing. A gentle shoulder is also formed in the second trajectory. The central shoulder of this second rolling element track (so-called S4- shoulder) makes it possible to realize the narrowest adjacent axial space of the balls of the two ball / cage assemblies, for example axial bearing compressive stress. This temporary deficiency prevents the bearing inner ring from being axially loaded and the center shoulder in which the balls of the second ball / cage assembly are axially centered even when the bearing inner ring moves against the bearing direction. This is because (S4 shoulder) prevents collision with the balls of the first ball / cage assembly.

The first inner rolling element raceway is preferably designed to form a groove profile in the axial cross section. The groove profile includes an area with a later minimum orbital diameter and includes an orbital area with a larger orbital diameter protruding from both sides in the axial cross section and into the area. Thus, the first set of first balls is axially guided in the first inner rolling element track groove. Corresponding groove shaped designs can also be carried out in the second inner rolling element raceway in a preferred manner.

As mentioned above, the double row angular contact ball bearings according to the invention are preferably designed such that the axial spacing between the individual rows is less than the maximum rolling body diameter installed. The bearing ring can be designed such that a bearing outer diameter to bearing inner diameter ratio, smaller than 2.26, in particular equal to or smaller than 2.15, can be achieved. Furthermore, the bearing according to the invention can be realized at a ratio of bearing axial total length to bearing height (0.5 x Da-Di) smaller than 1.46, in particular equal to or smaller than 1.38.

The balls are preferably guided in an N-profile cage with one side open, in which case the cage is also preferably installed so that the open sides face each other, that is, facing the bearing area lying inside in the axial direction. . This continues to support the collection of lubricants.

The ratio of the inlet width of the cage to the nominal diameter of the balls assigned to the individual cages is preferably in the range of 0.6 to 0.8 times the ball diameter, preferably in the range of 0.6 to 0.68 times. This requires less axial installation space than a closed N-profile cage, as the inner web is omitted, as in the so-called snap cage. For such snap cages, the inlet width can typically be snapped to the last ball when filling the ball / cage assembly from the axial direction; Thereby less balls per row are used; For example, it may be more easily lost in pivotal assembly typical of the bearings; It is as big as it is. In this case, preferably the pocket of the inserted N-profile cage is preferably designed such that the rolling body can be mounted only from one direction (radially from the inside or radially from the outside), because the inlet width This is because it is preferably small. The rolling body holder peculiar to the N-profile prevents the loss of the rolling body in the mounted state.

Further, preferably, the outer height of the smaller outer ball raceway is such that the radial height H of the apex of the larger outer ball raceway of the outer ring is at least 0.4 times the large ball diameter and 0.8 times the nominal diameter of the large ball. It lies above the vertex of.

The concept according to the invention results in a significant improvement over the prior art in terms of bearing weight and bearing structure size. Thus, the bearing according to the invention is also characterized in particular by the increase in power density. In addition, the concept according to the invention improves the distribution of the removed loads per bearing row and approximates the overall life of both bearing rows.

Due to the increased power density, cost savings by material savings can be realized. Since the surface to be machined is smaller and the component weight is reduced, the manufacture of bearings can also be achieved under process cost savings.

Bearings according to the invention are characterized by increased power density. Preferably, a new cage structure shape is provided. This enables weight and material savings without degrading bearing performance (ie without loss of life and functional safety).

By reducing the bearing row spacing by the concept according to the invention, the row gap can take a value equal to or smaller than the diameter of the maximum rolling body installed in the bearing.

As already mentioned above, the bearing according to the invention can also be realized with a three- or four-shoulder design [in other words, a first raceway is formed as a groove in the bearing inner ring (3S design), or a second The trajectory is also formed as a groove (4S design)], in which case the sub-shoulder height is preferably much lower than each main shoulder which acts axially.

At least one of the ball / cage assembly rows can be guided in a cage with one side open, in particular in an N-profile cage, which will be described further below. The term shoulder design here means that the corresponding ball trajectory has one vertex and the trajectory is lifted back in the direction of the ball under the formation of the shoulder.

In the bearings according to the invention the ball / cage assembly fastening function can be realized in particular in at least smaller bearing rows in a preferred manner. When using a four-shoulder design in the bearing inner ring, ball / cage assembly fastening for two ball rows can be achieved.

The cage design proposed in accordance with the present invention ensures high ball density and easy mounting possibilities with an excellent ball / cage assembly fastening function in the inner ring. The cage structure shape can be realized as a cage structure shape with an outer holder, in which case the outer holder is preferably matched to the orbital ridge of the inner ring.

The cage used for the individual rolling body rows is preferably formed so that the cage board of the cage is formed so as to provide an end face having a matched dimension such that, although reduced but still sufficient, the oil flow through the bearing is achieved. The oil churning loss of the oil is reduced. According to another aspect of the invention, the contact angles of the two bearing rows are adjusted such that they are substantially the same. These contact angles may be different and according to one particular aspect of the invention these contact angles preferably lie in the range of 25 ° to 40 °.

In the bearing according to the present invention, as described above, the pitch circle diameters (diameters of the circular orbits in which the center of the ball moves) are preferably different in the two ball rows. The ball diameters of the two ball rows are the same, or preferably different, and if the ball diameters are different, preferably a ball with a smaller diameter is also used in a ball row with a smaller diameter of the ball center orbit.

The number of balls is preferably adjusted so that the maximum ball mounting per bearing row is achieved according to the solution: ((TK-DM ^* Pi) / (WK-DM + 1.3)), in which the result is rounded to an integer and TK -DM = pitch circle diameter, Pi = 3.14159; WK-DM = rolling body diameter.

According to another particular aspect of the invention, the axial annular end faces of the bearing ring are designed to have shoulder zones to ensure a smaller but more accurate connection surface for the attachment element. This also leads to a reduction in the grinding complexity for side grinding.

The bearing according to the invention can be implemented in accordance with another particular aspect of the invention such that the outer ring is freely disassembled and mounted on two rows of balls without any fixing. In this case, the 4S design is preferably realized in the bearing inner ring, ie two rows of balls slide in the groove of the bearing inner ring. In this case, the cage is preferably implemented to radially fix the ball on the groove of the bearing inner ring.

The bearings according to the invention are particularly suitable for realizing so-called adjusted shaft bearings, which are capable of supporting the shaft structure as rigidly as possible without friction. The bearings according to the invention can in particular be used in passenger car transaxles, FQ transmissions as differential bearings, and angular gear arrangements for pinion and ring gear support. It is also suitable as an alternative bearing for bearing points where tapered roller bearings have been used until now. Another large field of use of bearings according to the invention is in industrial applications. As a bearing for agricultural machinery, pumps, compressors and off-road vehicles, it is also suitable for two-wheeled cardan shafts.

The bearing according to the invention is a double row angular contact ball bearing, also referred to as a tandem angular contact ball bearing. The novel tandem angular contact ball bearings (TBB) according to the invention have a shallow axial depth, small radial height and require less installation space than conventional tandem angular contact ball bearings at comparable support strength.

Axial overall height reduction compared to conventional structural shapes is realized, in particular by using two new types of plastic cages, which in this way cover two rows of balls of bearings, in particular in the direction of the bearing axis of the bearings. The axial spacing of the ball centers measured by means can be narrowed to each other such that it is equal to or smaller than the diameter of the maximum installed ball.

With the new cage structure shape, each without a second cage board, the rows of balls can be arranged at minimum intervals relative to one another. This allows the entire bearing to be configured narrower in the axial direction.

The narrowing of the two bearing rows from each other produces a positive side effect. Thus, the bearing better distributes the load to be supported in two rows of balls, and with this improved and more uniform bearing thermal load distribution in the bearing according to the invention, the bearing according to the invention has been It provides a longer life compared to the result, which can be "downsized" again. Bearing friction torque is also reduced by downsizing (reduced rolling body quantity, reduced pitch circle diameter). The narrower structure saves bearing ring material and reduces bearing cost.

The bearings are preferably designed such that, as described, the axial spacing between the individual rows is less than the maximum rolling body diameter installed. The axial gap may be slightly larger than the maximum rolling body diameter installed. Thus, as long as rolling bodies of different diameters are used for the two ball rows, the axial spacing can also be adjusted to be less than the maximum ball diameter plus the difference of the balls.

In the bearings according to the invention, preferably open N-profile cages are used, which, unlike conventional N-profile cages, save axial installation space and provide higher mounting capacity than conventional snap cages. Make it possible. The pocket of the N-profile cage is designed such that the rolling body can be mounted only from one direction (from inside or from outside). The rolling body holders unique to the N-profile prevent the loss of the rolling body in the mounted state (ie two ball / cage assemblies with their respective individual cages).

According to another aspect of the invention, the problem specified in the introduction is in accordance with the invention:

-Bearing inner ring,

A first inner rolling element raceway formed in the outer circumferential region of the bearing inner ring,

A second inner rolling element raceway axially offset with respect to the first inner rolling element raceway and formed in the outer circumferential region of the bearing inner ring,

Bearing outer ring having a first outer rolling element raceway formed in the inner circumferential region of the bearing outer ring

A second outer rolling element raceway axially offset relative to the first outer rolling element raceway, formed in the bearing outer ring,

A first set with first balls received in a first track space extending between the first inner rolling element track and the first outer rolling element track, and

With a second set with second balls received in a second track space extending between the second inner rolling element track and the second outer rolling element track,

Solved by angular contact ball bearings,

In this case the center of the first ball circulates around the bearing axis on the first center track having a smaller diameter, and the center of the second ball circulates around the bearing axis on a second center track having a larger diameter, The axial spacing of the two center tracks and the diameter of the center track measured in the direction of the bearing axis are such that the conical surface line defined by the centers of the first and second balls in the bearing shaft section including the bearing axis together with the bearing axis. mutually adjusted to form an angle equal to or greater than arctan ((RB2-RB1) / (k × BD2)). RB2 = radius of the central trajectory of the second ball; RB1 = radius of the central trajectory of the first ball; k = displacement coefficient; BD2 = diameter of the second ball, BD1 = diameter of the first ball. The displacement coefficient k in this case is less than 1.22, in particular less than (BD2 / BD1) or less than the value "1".

Further details and features of the present invention refer to the following detailed description in conjunction with the drawings.
1 is a schematic diagram illustrating the structure of a double row angular contact ball bearing according to the present invention.
FIG. 2 is another schematic diagram illustrating the structure of a double row angular contact ball bearing according to the present invention with respect to the position of the ball track center and the adjustment of the two ball / cage assemblies thus achieved.
3 is a schematic diagram illustrating the structure of a double row angular contact ball bearing according to the present invention in relation to another design feature of the bearing ring and the position of the ball track center.
4 is a schematic view for explaining the structure of a double row angular contact ball bearing according to the present invention with respect to the axial position of the ball track center.
5 is a schematic diagram illustrating the structure of a double row angular contact ball bearing according to the present invention in connection with the formation of a shoulder in the bearing inner ring.

The view according to FIG. 1 is an angular according to the invention with a bearing inner ring RI, a first inner ring end face RI1, a second inner ring end face RI2, and a cylindrical inner ring seat face RI3. An example of the first embodiment of a contact ball bearing is shown.

In addition, the angular contact ball bearing is concavely curved in the axial cross section, similarly to the first inner rolling element raceway RI4 formed in the outer circumferential region of the bearing inner ring RI and concavely curved in the axial cross section. And a second inner rolling element raceway RI5 axially offset relative to the first inner rolling element raceway RI4 and formed in the outer circumferential region of the bearing inner ring RI.

The bearing comprises a bearing outer ring RA having a first outer ring end face RA1, a second outer ring end face RA2, and a cylindrical outer ring seat face RA3. In the inner circumferential region of the bearing outer ring RA a first outer rolling element raceway RA4 is formed which is concavely curved in the axial cross section, and in addition, the bearing outer ring RA is also concave in the axial cross section. A second outer rolling element raceway RA5 is also formed which is curved and axially offset with respect to the first outer rolling element raceway RA4.

The bearing has a first ball / cage with first balls B1 housed in a first track space SB1 extending between a first inner rolling element track RI4 and a first outer rolling element track RA4. The assembly KB1 is included. The bearing has a first cage device C1 for guiding the first ball B1 of the first ball / cage assembly KB1, and a second inner rolling element raceway RI5 and a second outer rolling element raceway RA5. It further comprises a second cage (C2) for guiding the second ball (B2) of the second ball / cage assembly (KB2) accommodated in the second track space (SB2) extending between.

In the double row angular contact ball bearing according to the invention, the centers ZB1 of the first balls B1 circulate about the bearing axis X on the first center track Z1. Centers Z2 of the second balls B2 circulate around the bearing axis X on the second central trajectory ZB2. The center trajectories ZB1, ZB2 have different radii RB1, RB2.

The first and second cage devices C1, C2 are manufactured as separate cages C1, C2 and can take different angular velocities during the relative rotation of the bearing inner ring RI with respect to the bearing outer ring RA. . The orbital spaces SB1 and SB2 are most narrowly adjacent, but these orbital spaces RB1 and RB2 do not intersect, but rather, in the state where the balls B1 and B2 do not penetrate into the different ball orbital spaces, respectively, Overlaid only in relation to the direction final positions.

The distance of the second center raceway ZB2 from the outer ring seat surface RA3 of the bearing outer ring RA is the second center raceway ZB2 from the inner ring seat surface RI3 of the bearing inner ring RI. Is less than the interval of. Further, the axial spacing S of the two center tracks ZB1, ZB2 measured in the direction of the bearing axis X is the ball B2 of one of the ball / cage assemblies, here ball / cage assembly KB2. Is smaller than the maximum diameter (BD2).

In the embodiment of the bearing according to the invention shown in this figure, the balls B1 and B2 have different diameters BD1 and BD2 from each other. The spacing S of the center tracks ZB1, ZB2 measured in the direction of the bearing axis X is smaller than the diameter BD2 of the relatively larger balls B2. In particular, the spacing here is smaller than the arithmetic mean of the ball diameters BD1 and BD2.

In addition, in the bearing according to the present invention shown in the figure, the radius RB1 of the first center raceway ZB1 of the first balls B1 is equal to the radius RB2 of the center raceway ZB2 of the second balls B2. It is designed to be smaller than). The diameter BD1 of the first balls B1 of the first ball / cage assembly KB1 is smaller than the diameter BD2 of the second balls B2 of the second ball / cage assembly KB2.

The minimum orbital radius of the first inner rolling element raceway RI4 is smaller than the minimum orbital radius of the second inner rolling element raceway RI5. In addition, the minimum trajectory radius of the second inner rolling element trajectory RI5 is smaller than the radius RB1 of the first central trajectory ZB1 of the first balls B1.

Double-row angular contact ball bearings according to the invention are, in accordance with a particular aspect of the invention, bearing lines X and vertical lines L1 from adjacent end planes of the bearing inner ring RI defined by the end face RI2. The distance X1 of the intersection point P1 of is designed to be smaller than half of the diameter DB2 of the second ball B2, in which case the vertical line L1 is the ball centers Z1, Z2 in the bearing axial cross section. Is a straight line which divides the section between the centers and stands vertically on the section.

The section comprising the ball centers Z1, Z2 extends on a straight line g. The straight line g intersects the bearing axis X at point C. The distance from the end plane defined by the end face RA1 of the bearing outer ring RA to the point C lies in the range of 1.7 to 2.4 times the axial overall width BB of the bearing, in particular 2.1 times.

In the case of the angle α formed between the straight line g and the bearing axis X, the point is applied at which the angle is equal to or greater than "arctan ((RB2-RB1) / (k x BD2))". RB2 = radius of the central trajectory of the second balls; RB1 = radius of the central trajectory of the first balls; k = displacement coefficient; BD2 = diameter of the second balls. In this case, the displacement coefficient k is smaller than 1.22, in particular smaller than (BD2 / BD1) or smaller than the value "1".

In this embodiment, the ball / cage assembly KB1 of the first ball B1 has a ball number different from the number of balls of the ball / cage assembly KB2 of the second ball B2. In the illustrated bearing, the first ball / cage assembly includes thirteen balls having a diameter BD1 of 12.7 mm, and the second ball / cage assembly KB2 has fourteen balls having a diameter BD2 of 13.5 mm. It includes. In this embodiment, the total diameter RAD of the bearing outer ring is 88 mm. The inner diameter RID of the bearing inner ring RI is 40.98 mm. In this embodiment, the width BB is 32.5 mm. The first inner end face RI1 is axially offset with respect to the first end face RA1 of the bearing outer ring in the axial direction towards the bearing center region. The offset dimension O2 is preferably larger than the offset X1 of the intersection point P1 with respect to the end plane defined by the end face RI2. The end face RI2 is also axially offset relative to the end face RA2 of the bearing outer ring such that the end face is dimensioned in a direction away from the axial bearing center from the plane defined by the outer ring end face RA2. Protrudes by (03). The dimension 03 preferably corresponds to half of the diameter BD2 of the second ball and is larger than the offset dimension 02.

The figure according to FIG. 2 further shows the structure of a double row angular contact ball bearing according to the invention in the form of a detailed view. As already mentioned above, the distance X1 from the adjacent end plane of the bearing inner ring RI defined by the end face RI2 to the intersection point P1 of the bearing axis X and the vertical line L1 is equal to the second. It is smaller than half of the diameter DB2 of the ball B2, in which case the vertical line L1 represents a section between the ball centers Z1, Z2 in the present bearing axial section including the bearing axis X. It is a straight line that divides in the center and stands vertically on the interval.

The section extends on a straight line g. The straight line g intersects the bearing axis X at point C. The distance X3 from the end plane defined by the end face RA1 of the bearing outer ring RA to the point C lies within a range of 1.7 to 2.4 times the axial overall width BB of the bearing. Especially 2.1 times. The axial spacing X7 of the second central raceway ZB2 from the second end face RI2 of the bearing inner ring RI is smaller than the diameter DB2 of the second ball B2.

In the case of the angle α formed between the straight line g and the bearing axis x, it is applied that the angle α is equal to arctan (01 / (k × BD2)). O1 = (RB2-RB1); RB2 = radius of the central trajectory of the second ball; RB1 = radius of the central trajectory of the first ball; k = displacement coefficient; BD2 = diameter of the second ball. In this case the displacement coefficient k is less than 1.22, in particular less than (BD2 / BD1) or less than the value "1".

The intersection point P3 of the radial plane E1 and the vertical line defined by the circumferential trajectory ZB1 of the ball centers Z1 of the first balls B1 is the outer peripheral surface RA3 of the bearing outer ring RA. ) On the radial level from the outside. The intersection point P2 of the circumferential plane of the second ball centers Z2 and the vertical line L1 lies inside the bore surrounded by the inner seat surface RI3 of the bearing inner ring RI, in particular with respect to the bearing axis. It lies in the range of 0.7 to 0.8 times at the radial level, in particular 0.75 times the inner radius (0.5 x RID) of the bearing inner ring (RI).

The drawing according to FIG. 3 is used to show and explain the ratio of bearing width BB to bearing height BH. In the embodiment shown in this figure, the ratio of bearing width BB to bearing height BH lies in the range of 1.2 to 1.5, in particular 1.36. The ratio of the inner diameter RID to the overall bearing width BB lies in the range of 1.0 to 1.4, in particular 1.21, as specifically shown in this figure. The radial spacing X4 of the second central raceway ZB2 of the centers Z2 of the second balls B2 to the outer circumferential surface RA3 is formed from the inner circumferential surface RI3 of the bearing inner ring RI. It is smaller than the distance X5 to two center track | orbit ZB2. The orbital radius difference between the radial offset O1, that is, the radius of the track of the second center track ZB2 and the radius of the track of the first center track ZB1 is smaller than the half diameter DB2 of the second balls B2. Further, the distance X5 from the inner peripheral surface RI3 of the bearing inner ring RI to the second center trajectory ZB2 is preferably in the range of 0.8 to 1.2 times the diameter DB2 of the second balls B2. Lies within, especially 1.05. Thus, the radial thickness of the bearing inner ring RI in the region of the inner raceway vertex P4 substantially corresponds to the half diameter DB2 of the second balls. The axial spacing X7 from the second front face RI2 of the bearing inner ring RI to the second center track ZB2 is smaller than the diameter DB2 of the second balls B2.

The drawing according to FIG. 4 is used to show and explain the axial positions of the center tracks ZB1, ZB2 and the axial spacing S between the center tracks ZB1, ZB2. The axial spacing S of the center tracks ZB1, ZB2 is such that, in a preferred embodiment of the double row angular contact ball bearing according to the invention shown in this figure, the spacing S is equal to or equal to the diameter DB2. Matches to the diameter DB2 of the second ball B2 to be smaller. Axial spacing X6 from the first end face RA1 of the bearing outer ring to the first center raceway ZB1 and from the second front face RI2 of the bearing inner ring RI to the second center raceway ZB2. The axial spacing X7 of is matched so that "(BD1 / X6) = q (BD2 / X7)" applies, in which case q preferably lies within the range of 0.85 to 1.2, in particular 1 or larger diameter ( DB2) to small diameter DB1.

The drawing according to FIG. 5 is used to show and explain the shape of the bearing inner ring (RI), in a so-called three-shoulder design, or in a four-shoulder design which will now be complementary to this figure. As can be seen from the figure, the two trajectories RI4 and RI5 are formed as concave grooves in the axial cross section. The trajectory RI4 of the first balls B1 comprises a shoulder S3 flat in its area adjacent to the first inner ring end surface RI1, as shown in the figures already described above. The shoulder causes an axial fixation action of the ball B1 as soon as the ball B1 is inserted into the first cage C1 and slides over the bearing inner ring RI under a temporary elastic deformation of the first cage C1. do.

In the region of the bearing inner ring RI lying axially between the centers Z1, Z2 of the balls B1, B2, the radial level of the orbital vertex P4 radially outward in this embodiment. Another shoulder S4 is formed to rise up. The ridge of the shoulder S4 may be adjusted to protrude to the height level of the first central trajectory ZB1 of the first ball or to lie just below the radial level. The shoulder may be formed in a rounded state in the exit area of the wall portion RI4 in contact with the second ball B2, so that the shoulder smoothly rounds on its side facing the first ball B1. It goes to orbit RI4.

According to the concept according to the invention, the spacing S of the ball / cage assembly centers Z1, Z2, in other words the bearing rows, is reduced so that the spacing is equal to the diameter of the maximum rolling body B1, B2 installed in the bearing. It can take the same or less value.

The bearing according to the invention can be realized either as a three-shoulder design or as a four-shoulder design, as already mentioned above [in other words, the first raceway RI4 in the bearing inner ring is formed as a groove (3S). Design, additionally the second trajectory RI5 is also formed as a groove (4S design)], in which case the auxiliary shoulder height is much lower than the individual main shoulders S1 and S2, which preferably serve in the axial direction.

At least one of the ball / cage assembly rows KB1, KB2 may be guided in a cage C1, C2 with one side open, in particular in an N-profile cage, further described below. The term shoulder design here means that the corresponding ball trajectories RI4 and RI5 have vertices P5 and P4 and lift the trajectory again under the formation of the shoulder in the direction of the balls B1 and B2.

In the bearings according to the invention, the ball / cage assembly fixing function can be realized in a preferred manner, in particular at least in a relatively smaller bearing row KB1. When using a four shoulder design in the bearing inner ring (RI), the ball / cage assembly fixing function for the two ball rows KB1, KB2 can be achieved.

The shape of the cages C1 and C2 proposed in accordance with the present invention ensures high ball density and easy mounting possibilities with good ball / cage assembly fastening function in the inner ring RI. The cages C1 and C2 can be realized as cages with external fixings, in which case the external fixings preferably match the orbital ridges of the inner ring RI. The cages C1 and C2 used for the individual rolling body rows KB1 and KB2 are preferably such that the cage boards CB1 and CB2 of the cage are reduced but still sufficient to achieve oil flow through the bearing. By forming to provide end faces with matched dimensions, oil churning losses in the bearings are reduced. According to another aspect of the invention, the contact angles of the two bearing rows KB1, KB2 are adjusted such that they are substantially the same. These contact angles may be different and according to one particular aspect of the invention these contact angles preferably lie in the range of 25 ° to 40 °. In the case of the bearing according to the present invention, as described above, the pitch circle diameters (the centers Z1 and Z2 of the balls B1 and B2) of the two rows of balls KB1 and KB2 are preferably moved. Diameter of ZB2) is different. The ball diameters BD1 and BD2 (see FIG. 1) of the two ball rows KB1 and KB2 are the same or different as shown in the drawing, where the ball diameters BD1 and BD2 are different. The ball B1 having a smaller diameter BD1 is preferably also used in the ball row KB1 having a smaller raceway radius RB1 of the ball center raceway ZB1.

The number of balls is preferably adjusted such that the maximum ball mounting per bearing row KB1, KB2 is achieved according to the solution: ((TK-DM ^* Pi) / (WK-DM), where the result is rounded to an integer TK-DM = pitch circle diameter [2 × center orbit radius (RB1 or RB2)], and Pi = 3.14159; WK-DM = rolling body diameter (BD1, BD2).

Claims (5)

As angular contact ball bearing,
Bearing inner ring (RI) having a first inner ring end face (RI1), a second inner ring end face (RI2), and a cylindrical inner ring seat face (RI3),
A first inner rolling element raceway RI4 formed in the outer circumferential region of the bearing inner ring RI and curved concave in the axial cross section,
A second inner rolling element raceway RI5 axially offset relative to the first inner rolling element raceway RI4 and formed in the outer circumferential region of the bearing inner ring RI and concavely curved in the axial cross section; ,
Bearing outer ring RA, having a first outer ring end face RA1, a second outer ring end face RA2, and a cylindrical outer ring seat face RA3,
A first outer rolling element raceway RA4 formed in the inner circumferential region of the bearing outer ring RA and curved concave in the axial cross section,
A second outer rolling element raceway RA5 which is axially offset with respect to the first outer rolling element raceway RA4 and is formed in the bearing outer ring RA and curved concave in the axial cross section,
A first ball / cage assembly having a first ball B1 housed in a first track space SB1 extending between a first inner rolling element track RI4 and a first outer rolling element track RA4. KB1),
A first cage device C1 for guiding the first ball B1 of the first ball / cage assembly KB1,
A second ball / cage assembly having a second ball B2 housed in a second track space SB2 extending between a second inner rolling element track RI5 and a second outer rolling element track RA5. KB2),
A second cage device C2 for guiding the second ball B2 of the second ball / cage assembly KB2,
in this case,
The center Z1 of the first ball B1 circulates around the bearing axis X on the first center trajectory ZB1, and the center Z2 of the second ball B2 is the second center trajectory ZB2. Circulating around the bearing axis (X) on
The central trajectories ZB1, ZB2 have different radii RB1, RB2,
The radius RB1 of the first center trajectory ZB1 of the first ball B1 is smaller than the radius RB2 of the center trajectory ZB2 of the second ball B2,
When the bearing inner ring (RI) makes relative rotation with respect to the bearing outer ring (RA), the first and second cage devices (C1, C2) can take different angular velocities,
The distance X4 of the second center raceway ZB2 from the outer ring seat face RA3 of the bearing outer ring RA is the second center from the inner ring seat face RI3 of the bearing inner ring RI. Less than the interval X5 of the track ZB2,
The axial spacing S of the two central tracks ZB1, ZB2 measured in the direction of the bearing axis X is the maximum diameter of the balls B1, B2 of one of the ball / cage assemblies KB1, KB2. Less than BD1, BD2)
The diameter BD1 of the first ball B1 is smaller than the diameter BD2 of the second ball B2,
In angular contact ball bearings,
The difference in orbit radius O1 between the radius of the raceway of the second center raceway ZB2 and the radius of raceway of the first center raceway ZB1 is smaller than the half diameter DB2 of the second ball B2,
The distance X5 of the second central raceway ZB2 from the inner peripheral surface RI3 of the bearing inner ring R1 lies in the range of 0.8 to 1.2 times the diameter DB2 of the second ball B2. An angular contact ball bearing characterized by the above-mentioned. Angular contact ball bearing according to claim 1, characterized in that the spacing (S) is smaller than the arithmetic mean of the ball diameters (BD1, BD2). Angular contact ball bearing according to claim 1, characterized in that the spacing (S) is smaller than the diameter (BD1) of the relatively smaller ball (B1). The distance from the adjacent end plane of the bearing inner ring RI to the intersection point P1 of the bearing axis X and the vertical line L1 is the second ball B2. It is smaller than the half diameter BD2, and the vertical line L1 is a straight line which divides the section between the ball centers Z1 and Z2 at the center in the bearing axial section and stands vertically on the section. Angular contact ball bearing. The angular of claim 1, wherein at least one of the ball / cage assemblies KB1, KB2 is guided in a cage device C1, C2 with one side open. Contact ball bearings.

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