JP2021067274A - Hub unit bearing - Google Patents

Abstract

To provide a hub unit bearing which can prevent the deformation of a column part in a state in which a plurality of cages is laminated on one another, and the bite-in of the cages.SOLUTION: A cage 20 has a large-diameter side circular disc part 21, a small-diameter side circular disc part 22 arranged coaxially with the large-diameter side circular disc part 21, and a plurality of column parts 23 for connecting the large-diameter side circular disc part 21 and the small-diameter side circular disc part 22 in an axial direction, and arranged in a peripheral direction with substantially-equal intervals. The column parts 23 of the cage 20 are formed while inclining toward the large-diameter side circular disc part 21 from the small-diameter side circular disc part 22, a circular arc-shaped notch 25 is formed at an internal diameter side of the large-diameter side circular disc part 21, dimensions of the column parts 23 in a radial direction become large as progressing toward the large-diameter side circular disc part 21 from the small-diameter side circular disc part 22 within a range in which the radial dimensions are superimposed on a tapered face 23a1 in the axial direction, and when setting the maximum width of the notch 25 in the peripheral direction as a, and setting widths of the column parts 23 in the peripheral direction in a position in the peripheral direction which are the same as the maximum width of the notch 25 in the peripheral direction as b, a<b is established.SELECTED DRAWING: Figure 2

Description

The present invention relates to a hub unit bearing, and more particularly to a hub unit bearing including a cage.

Conventionally, as a cage for a hub unit bearing, an inclined cage in which a column portion is inclined with respect to an axial direction is known (see, for example, Patent Document 1). As shown in FIG. 5, the cage 100 described in Patent Document 1 is formed of synthetic resin and is connected to a plurality of inclined pillars 102 provided between the pockets 101 and one end of the pillars 102 in the axial direction. It has a small-diameter annulus 103 and a large-diameter annulus 104 connected to the other end of the column 102 in the axial direction, and has a column 102, a small-diameter annulus 103, and a large-diameter annulus 104. A spherical pocket 101 is formed by the above.

Since the hub unit bearing carries a moment load due to the road surface reaction force, it is preferable to make the distance between the rows of the two rows of rolling elements as long as possible in order to improve durability and moment rigidity. Therefore, in the cage 100 of Patent Document 1, a circular notch 105 is provided on the inner diameter side of the pocket portion of the large diameter side annular portion 104 so that the distance between rows is as long as possible, and the large diameter side annular portion 104 is provided. The ball 110 can approach the vicinity of the end face of the ball 110.

Japanese Unexamined Patent Publication No. 2012-31924

By the way, in a bearing production line, a plurality of cages are set in a cage fixed distribution device (not shown) in a state of being stacked along the axial direction thereof. Therefore, as shown in FIG. 6, the plurality of cages 100a are packaged (bar-wrapped) in a stacked state before being set in the cage constant distribution device.

Here, since the inclined cage 100a is generally manufactured by injection molding of the axial draw method, the outer diameter of the small diameter side annular portion 103a is smaller than the inner diameter of the large diameter side annular portion 104a. When the cages 100a are stacked in a rod-shaped package or the like, the outer peripheral surface of the small diameter side annular portion 103a comes into contact with the thin portion on the inner peripheral surface of the tapered pillar portion 102a. Then, when a force acts in the axial direction of the cage 100a in this contacted state, the thin portion on the inner peripheral surface of the pillar portion 102a is deformed, or the thin portion on the inner peripheral surface of the pillar portion 102a has a small diameter side circle. The outer peripheral surface of the ring portion 103a may be fitted, and it may be difficult to separate the cage 100a in the cage regular distribution device.

Further, when the cages 100 described in Patent Document 1 are stacked, when the notch 105 of the large diameter side annular portion 104 and the outer peripheral surface of the pillar portion 102 are fitted, the thin circular notch 105 is fitted. In addition to the problems of deformation and breakage, the stacking height changes at the part where the fitting occurs, so that the cutting with the fixed distribution device becomes more unstable.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to prevent notches, deformation of pillars, and fitting of cages in a state where a plurality of cages are stacked. To provide hub unit bearings.

The above object of the present invention is achieved by the following configuration.
(1) A hub unit including an outer ring member, an inner ring member rotatably provided with respect to the outer ring member via a plurality of rolling elements, and a cage for holding the plurality of rolling elements at substantially equal intervals in the circumferential direction. It ’s a bearing,
The cage connects the large-diameter annulus, the small-diameter annulus concentrically with the large-diameter annulus, the large-diameter annulus, and the small-diameter annulus in the axial direction. It has a plurality of pillars provided at substantially equal intervals in the circumferential direction, and has.
Pockets are formed between the pillars adjacent to each other in the circumferential direction to hold the rolling elements so that they can roll.
The pillar portion is formed so as to be inclined from the small diameter side annular portion toward the large diameter side annular portion, and the outer peripheral surface of the pillar portion extends from the small diameter side annular portion toward the large diameter side annular portion. It is formed by a tapered surface and a cylindrical surface having the same outer diameter as the large diameter side annulus.
On the inner diameter side of the large diameter side ring portion, an arc-shaped notch is formed in which the ridge line formed by the axial end surface of the large diameter side ring portion and the inner surface of the pocket enters the outer diameter side.
The radial dimension of the pillar portion increases from the small diameter side annulus to the large diameter annulus in the range where it overlaps the tapered surface in the axial direction.
A hub unit bearing in which a <b, where a is the maximum circumferential width of the notch and b is the circumferential width of the outer peripheral surface of the column at the same radial position as the maximum circumferential width of the notch.

According to the present invention, the radial dimension of the pillar portion increases from the small diameter side annular portion to the large diameter side annular portion in the range where the column portion overlaps the tapered surface in the axial direction. In the stacked state, the outer peripheral surfaces and the inner peripheral surfaces of adjacent cages do not come into surface contact with each other and fit into each other. Further, even if the notch of the large-diameter annulus portion comes into contact with the vicinity of the axial center of the outer peripheral surface of the pillar portion in the state where the cages are stacked, the pillar portion is in the notch of the large-diameter side annulus portion. The outer peripheral surface of the is not fitted. As a result, notches and deformation or breakage of the pillars can be prevented, and cutting with a fixed distribution device can be easily performed.

It is sectional drawing explaining one Embodiment of the hub unit bearing which concerns on this invention. It is sectional drawing explaining the cage shown in FIG. It is a side view of the cage seen from the direction III of FIG. It is sectional drawing explaining the state in which a plurality of cages shown in FIG. 1 are stacked. (A) is a cross-sectional view of a conventional hub unit bearing, and (b) is a side view of the cage as seen from the V direction of (a). It is sectional drawing explaining the state in which a plurality of conventional cages are stacked.

Hereinafter, an embodiment of the hub unit bearing according to the present invention will be described in detail with reference to the drawings.

The hub unit bearing 10 of the present embodiment is for a drive wheel, and as shown in FIG. 1, the outer ring member 11, the hub ring 12 which is an inner ring member, and the hub ring 12 are separate inner ring members. A plurality of balls (rolling) arranged in two rows so as to be rollable between the inner ring 13 integrally fixed to the hub ring 12 and the outer peripheral surface of the hub ring 12 and the inner ring 13 and the inner peripheral surface of the outer ring member 11. A moving body) 14, a pair of cages 20 that hold the plurality of balls 14 in the two rows at substantially equal intervals in the circumferential direction, and a pair of sealing devices 15 that close the openings at both ends of the bearing internal space 10a. ..

The hub ring 12 is a member having a substantially cylindrical shape, and a flange portion 12b extending radially outward from the outer peripheral surface is formed at an outboard side end portion (left side in the drawing). A plurality of hub bolts 31 for fastening a tire wheel, a brake rotor, etc. (not shown) are provided on the flange portion 12b at substantially equal intervals in the circumferential direction.

A small diameter step portion 12c is formed at the inboard side end portion (right side in the drawing) of the hub ring 12, and after the inner ring 13 is externally fitted to the small diameter step portion 12c, the end portion of the small diameter step portion 12c has a diameter. The inner ring 13 is fixed to the hub ring 12 by caulking outward in the direction. Further, by pressing the inner ring 13 by caulking, an appropriate preload is applied.

Two rows of outer ring raceway surfaces 11a and 11a parallel to each other are formed on the inner peripheral surface of the outer ring member 11 so as to be separated from each other. Further, on the outer peripheral surfaces of the hub ring 12 and the inner ring 13, inner ring raceway surfaces 12a and 13a are formed corresponding to the outer ring raceway surfaces 11a and 11a of the outer ring member 11, respectively. A plurality of balls 14 rotatably held by the cage 20 are arranged at equal intervals in the circumferential direction on the two rows of orbits composed of the inner ring raceway surfaces 12a and 13a and the outer ring raceway surfaces 11a and 11a. There is.

The plurality of balls 14 are arranged in a back surface combination in contact with the outer ring raceway surfaces 11a and 11a and the inner ring raceway surfaces 12a and 13a at a predetermined contact angle with each other. As a result, the hub ring 12 and the inner ring 13 can rotate with respect to the outer ring member 11.

As shown in FIGS. 2 and 3, the cage 20 is made of synthetic resin and is formed in a substantially conical trapezoidal shape by injection molding of the axial draw method, and has a large diameter side annular portion 21 and a large diameter side circle. A plurality of small-diameter ring portions 22 arranged concentrically with the ring portion 21, and a plurality of large-diameter ring portions 21 and small-diameter ring portions 22 connected in the axial direction and provided at substantially equal intervals in the circumferential direction. It has a pillar portion 23 and. Then, a pocket 24 for rotatably holding the ball 14 is formed between the pillar portions 23 adjacent to each other in the circumferential direction. In the present embodiment, the pair of cages 20 are symmetrically arranged so that the small diameter side annular portions 22 face each other in the axial direction.

The pillar portion 23 is formed so as to be inclined so as to increase in diameter from the small diameter side annular portion 22 toward the large diameter side annular portion 21. Further, the pocket 24 is formed in a space surrounded by an adjacent column portion 23, a small diameter side annular portion 22 and a large diameter side annular portion 21, and the large diameter side annular portion 21 side of the pocket 24 is on the small diameter side. Inserted from the ring portion 22 side, the large diameter side ring portion 21 side is a spherical shape that follows the outer shape of the ball 14 and the root side is a cylindrical mold, and the small diameter side ring portion 22 side of the pocket 24 is a large diameter side circle. Inserted from the ring portion 21 side, the small diameter side annular portion 22 side is formed by combining a spherical molding mold that follows the outer diameter of the ball 14 and the root side is a cylindrical molding mold, and the mating surfaces of the two molding molds are parted. The line PL remains. Therefore, the outer diameter surface side of the pillar portion 23 becomes thinner as it goes toward the small diameter side annular portion 22, and the inner diameter surface side of the pillar portion 23 becomes thinner as it goes toward the large diameter side annular portion 21 side. It has become.

As shown in FIG. 2, the large-diameter side annular portion 21 has an outer peripheral surface 21a formed on a single cylindrical surface having a constant outer diameter along the axial direction, and the axial end surface 21b is on the central axis X. It is formed by a vertical plane. Further, the axial end surface 21b of the large diameter side annular portion 21 is directly connected to the inclined inner peripheral surface 23b of the pillar portion 23, and is formed by the outer diameter surface of the molding die inserted from the large diameter side annular portion 21 side. A ridgeline is formed with the slope to be formed, that is, the inner surface of the pocket 24.

The small diameter side annular portion 22 is formed on a tapered surface (partial conical surface) whose outer peripheral surface 22a expands in diameter toward the large diameter side annular portion 21, and the axial end surface 22b is formed by a plane perpendicular to the central axis X. Has been done. Further, the inner peripheral surface 22c of the small diameter side annular portion 22 is formed as a single cylindrical surface having a constant inner diameter along the axial direction.

The pillar portion 23 is a cylindrical surface having the same outer diameter as the tapered surface 23a1 whose outer diameter surface 23a expands toward the large diameter side annular portion 21 and the outer peripheral surface 21a of the large diameter side annular portion 21. It is composed of 23a2. Further, the inner peripheral surface 23b of the pillar portion 23 is also formed in a tapered shape whose diameter increases toward the large diameter side annular portion 21.

Further, the radial dimension r of the pillar portion 23 increases from the small diameter side annular portion 22 toward the large diameter side annular portion 21 in the range where the column portion 23 overlaps the tapered surface 23a1 in the axial direction. Therefore, in the pillar portion 23, the inclination of the tapered outer peripheral surface (tapered surface 23a1) with respect to the central axis X is larger than that of the tapered inner peripheral surface 23b.
In the present embodiment, the ridge line formed by the axial end surface 21b of the large diameter side annular portion 21 and the inner surface of the pocket 24 is on the outer diameter side of the center O of the ball 14, and the small diameter side annular portion 22. The outer peripheral surface 22a has a smaller diameter than the center O of the ball 14.

On the inner diameter side of the large-diameter ring portion 21, ridge lines formed by the axial end surface 21b of the large-diameter ring portion 21 and the inner surface of the pocket 24 are formed on both sides in the circumferential direction. An arcuate notch 25 that enters the outer diameter side from the inner peripheral surface 21c of the ring portion 21 is formed. As a result, the balls 14 are arranged so as to project axially from the axial end surface 21b of the large-diameter ring portion 21, and the distance between rows of the hub unit bearing 10 can be increased.
In the present embodiment, as shown in FIG. 2, the inner peripheral surface 21c of the large diameter side annular portion 21 is divided in the circumferential direction at the position of the ridgeline, and the inner peripheral surface of the extending pillar portion 23 is extended. It is formed in a stepped shape by 23b.

Further, as shown in FIG. 3, the maximum circumferential width of the notch 25 is a, and the outer peripheral surface 23a of the pillar portion 23 (small diameter side annular ring of the tapered surface 23a1) at the same radial position as the maximum circumferential width of the notch 25. When the circumferential width of the portion 22 side) is b, a <b is set. As a result, when a plurality of cages 20 are stacked and the phases of the notch 25 of one adjacent cage 20 and the pillar portion 23 of the other cage 20 match, the pillar portion 23 becomes the notch 25. In that case, the pillar portion 23 can be prevented from being fitted into the notch 25.

Next, with reference to FIG. 4, a state in which a plurality of cages 20 of the present embodiment are stacked will be described.

As shown in FIG. 4, a plurality of cages 20 are stacked along the axial direction so as to be concentric with each other before being set in a cage regular distribution device (not shown) in the production line of the hub unit bearing 10. , It is wrapped in a bar in that state.

Here, the radial dimension r of the pillar portion 23 increases from the small diameter side annular portion 22 toward the large diameter side annular portion 21 in the range where the column portion 23 overlaps the tapered surface 23a1 in the axial direction. In the state where the vessels 20 are stacked, the ridges of the inner peripheral surface 23b of the pillar portion 23 of the cage 20 located below and the axial end surface 21b of the large diameter side annular portion 21 are located above the cage 20. Since the contact is made only near the center of the outer peripheral surface 23a of the pillar portion 23 in the axial direction, the adjacent cages 20 do not come into surface contact with each other and fit into each other. Further, in the state where the cages 20 are stacked, the notch 25 formed in the large-diameter side annular portion 21 of the cages 20 located below is held above by the phase of the adjacent cages 20. It may come into contact with the outer peripheral surface 23a of the pillar portion 23 of the vessel 20. However, since the maximum circumferential width a of the notch 25 <the circumferential width b of the pillar 23, it is possible to prevent the pillar 23 from being fitted into the notch 25, and the large diameter side around the notch 25. It is possible to prevent the annular portion 21 from being deformed.

Further, in the present embodiment, the outer peripheral surface 22a of the small diameter side annular portion 22 is formed as a tapered surface whose diameter increases toward the large diameter side annular portion 21 as shown in FIGS. 2 and 4. When the cages 20 are stacked, they are configured so as not to come into contact with the inner peripheral surface 23b of the pillar portion 23.

Further, in the present embodiment, the outer peripheral surface 21a of the large diameter side annular portion 21, a part of the outer peripheral surface 23a of the pillar portion 23 (cylindrical surface 23a2), and the inner peripheral surface 22c of the small diameter side annular portion 22 are in the axial direction. It is formed on each cylindrical surface along the above. Therefore, for example, the cage 20 is set in the cage regular distribution device with the outer peripheral surface 21a of the large diameter side annular portion 21 and the cylindrical surface 23a2 of the pillar portion 23, or the inner peripheral surface 22c of the small diameter side annular portion 22. By using it as a guide surface in the case, bar-wound packaging can be easily performed, and by centering the cage 20, the cage 20 can be reliably cut out by the hooking / unhanging claw of the cage setting device. be able to.

Further, in the present embodiment, the outer peripheral surface 21a of the large diameter side annular portion 21, a part of the outer peripheral surface 23a of the pillar portion 23 (cylindrical surface 23a2), and the inner peripheral surface 22c of the small diameter side annular portion 22 are in the axial direction. The cross-sectional area of the cage 20 is small because it is formed on each of the cylindrical surfaces along the above. Therefore, the contact angle of the ball is large, and it can be used as a cage for a bearing having a high shoulder adjacent to the raceway groove.

As described above, according to the hub unit bearing 10 of the present embodiment, the pillar portion 23 is formed so as to be inclined from the small diameter side annular portion 22 toward the large diameter side annular portion 21 and is formed. The outer peripheral surface of the 23 is formed by a tapered surface 23a1 extending from the small diameter side annular portion 22 toward the large diameter side annular portion 21 and a cylindrical surface 23a2 having the same outer diameter as the large diameter side annular portion 22. On the inner diameter side of the large diameter side annular portion 21, an arc-shaped notch 25 is formed in which the ridge line formed by the axial end surface 21b of the large diameter side annular portion 21 and the inner surface of the pocket 24 enters the outer diameter side. The radial dimension r of the pillar portion 23 increases from the small diameter side annular portion 22 toward the large diameter side annular portion 21 in the range where the column portion 23 overlaps the tapered surface 23a1 in the axial direction. Further, when the maximum circumferential width of the notch 25 is a and the circumferential width of the column portion 23 at the same radial position as the maximum circumferential width of the notch 25 is b, a <b. As a result, when the cages 20 are stacked, the ridgeline between the axial end surface 21b of the large-diameter ring portion 21 and the inner peripheral surface 23b of the pillar portion 23 is near the axial center of the outer peripheral surface 23a of the pillar portion 23. Since the outer peripheral surface 23a of the pillar portion 23 does not fit into the notch 25 of the large diameter side annular portion 21, the notch 25 and the pillar portion 23 are prevented from being deformed or damaged. In addition, cutting with a fixed distribution device can be easily performed.

Further, according to the hub unit bearing 10 of the present embodiment, the radial dimension r of the column portion 23 is from the small diameter side annular portion 22 to the large diameter side annular portion 21 in the range where it overlaps with the tapered surface 23a1 in the axial direction. When the cages 20 are stacked, the length of the pillars 23 of the cages 20 overlapping with the pillars 23 of the adjacent cages 20 in the radial direction becomes longer, and the rod-wound packaging state. The number of cages 20 in the cage 20 can be increased. As a result, in the bearing assembly process, the frequency of replenishing the cage to the cage constant distribution device can be reduced, and the work man-hours can be reduced.

The present invention is not limited to those exemplified in the above embodiments, and can be appropriately modified without departing from the gist of the present invention.

10 Hub unit bearing 11 Outer ring member 12 Hub ring (inner ring member)
13 Inner ring (inner ring member)
14 balls (rolling body)
15 Sealing device 20 Cage 21 Large diameter side annular part 21a Outer peripheral surface 22 Small diameter side annular part 22a Outer peripheral surface 22b Axial end surface 22c Inner peripheral surface 23 Pillar part 23a Outer peripheral surface 23b Inner peripheral surface 24 Pocket 25 Notch

Claims (1)

A hub unit bearing including an outer ring member, an inner ring member rotatably provided with respect to the outer ring member via a plurality of rolling elements, and a cage for holding the plurality of rolling elements at substantially equal intervals in the circumferential direction. And
The cage has a large-diameter annulus portion, a small-diameter annulus portion concentrically arranged with the large-diameter annulus portion, a large-diameter annulus portion, and a small-diameter annulus portion in the axial direction. It has a plurality of pillars which are connected to each other and are provided at substantially equal intervals in the circumferential direction.
Pockets for holding the rolling elements so as to be rollable are formed between the pillars adjacent to each other in the circumferential direction.
The pillar portion is formed so as to be inclined from the small diameter side annular portion toward the large diameter side annular portion, and the outer peripheral surface of the pillar portion is formed from the small diameter side annular portion to the large diameter side circle. It is formed by a tapered surface extending toward the ring portion and a cylindrical surface having the same outer diameter as the large diameter side annular portion.
On the inner diameter side of the large diameter side annular portion, an arc-shaped notch is formed in which the ridge line formed by the axial end surface of the large diameter side annular portion and the inner surface of the pocket enters the outer diameter side.
The radial dimension of the pillar portion increases from the small diameter side annular portion toward the large diameter side annular portion in the range of overlapping with the tapered surface in the axial direction.
A hub unit bearing where a <b, where a is the maximum circumferential width of the notch and b is the circumferential width of the outer peripheral surface of the pillar at the same radial position as the maximum circumferential width of the notch. ..

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