JPH0416A - High torque rolling bearing - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Industrial Application Field) The high-torque rolling bearing according to the present invention is incorporated into, for example, a steering device of an automobile and used to rotatably support a steering shaft inside the steering device. .

(Prior Art) In the case of a 3° automobile steering device, a steering shaft is rotatably supported inside a cylindrical steering column supported by a vehicle body, and is rotated in a torsional direction by operation of a steering wheel.

When the steering shaft is rotatably supported inside the steering column in this way, a deep groove ball bearing or the like is installed between the inner peripheral surface of the steering column and the outer peripheral surface of the steering shaft as shown in FIG. A rolling bearing is provided to ensure smooth rotation of the steering shaft within the steering column.

This rolling bearing has an inner ring 2 having an inner ring raceway 1 on the outer peripheral surface.
, an outer ring 4 having an outer ring raceway 3 on its inner peripheral surface, and an inner ring raceway 1
A plurality of rolling elements 5.5 are rotatably provided between the outer ring raceway 3 and the outer ring raceway 3, a retainer 6 that holds the plurality of rolling elements 5.5, and a respective outer ring on the inner circumferential surface of the outer ring 4. By supporting the peripheral edge and slidingly contacting each inner peripheral edge with the outer peripheral surface of the inner ring 2, the plurality of rolling elements 5.
5 and a pair of seal members 8a and 8b that close both ends of the cylindrical space 7.

When the steering shaft is rotatably supported inside the steering column using such a rolling bearing, the outer ring 4 is fitted inside the steering column, and the inner ring 2 is fitted outside the steering shaft.

(Problem to be solved by the invention) By the way, in order to ensure straight-line stability of the automobile, the gearbox that constitutes the steering device is provided with some play, so that even if the steering wheel turns a little, the front wheels do not have a steering angle. is not granted.

Due to the presence of this play, the force required to rotate the steering wheel a small amount (within the range of play) is small, or in this case, if the steering wheel is rotated with too little force, the steering wheel The operation feeling becomes worse.

In order to appropriately increase the force required to rotate the steering wheel within the range of play, it is necessary to increase the torque required to rotate the rolling bearing that supports the steering shaft, which rotates with the steering wheel, inside the steering column. It is possible to make it bigger.

In order to increase the torque required to rotate a rolling bearing,
Generally, it is considered to increase the amount of grease sealed in the cylindrical space 7 of the rolling bearing for lubrication, but it is difficult to stably obtain high torque by simply sealing a large amount of grease.

The high torque rolling bearing of the present invention was designed to solve the above-mentioned problems.

(Means for Solving the Problems) The high-torque rolling bearing of the present invention has an inner ring having an inner ring raceway on the outer peripheral surface, an outer ring having an outer ring raceway on the inner peripheral surface, and an inner ring, similar to the conventional rolling bearing described above. A plurality of rolling elements provided in a freely rolling manner between the raceway and the outer ring raceway, a cage holding the plurality of rolling elements, and one of the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring. By supporting one peripheral edge of each on the surface and bringing the other peripheral edge into sliding contact with the other of the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring, the outer peripheral surface and the inner peripheral surface are and a pair of sealing members that close the openings at both ends of a cylindrical space that exists between the cylindrical space and the plurality of rolling elements.

Furthermore, in the high torque rolling bearing of the present invention, the above 1.
In the cylindrical space located between the pair of seal members, the viscosity is 100,000 to 2 million cSt (centistokes).
A viscous substance is enclosed such that the volume of this viscous substance occupies 70% or more of the gap volume obtained by subtracting the volume of the plurality of rolling elements and the volume of the cage from the volume of the cylindrical space.

(Function) In the case of the high-torque rolling bearing of the present invention configured as described above, the cage rotates in a highly viscous substance, so the torque required to rotate the cage increases, causing damage to the cage. The torque required to rotate the outer ring and the inner ring, which rotate relative to each other as the plurality of held rolling elements roll, increases.

(Example) Next, the present invention will be explained in more detail while explaining the illustrated embodiment.

1 and 2 show a first embodiment of the present invention, FIG. 1 is a partial sectional view, and FIG. 2 is a view from above of FIG. 1, comparing the cage and the rolling elements. It is.

As shown in FIG. 1, the high-torque rolling bearing of the present invention, like the conventional rolling bearing described above, has an inner ring 2 having an inner ring raceway 1 on its outer circumferential surface, and an outer ring 4 having an outer ring raceway 3 on its inner circumferential surface. , a plurality of rolling elements 5 that are rotatably provided between the inner ring raceway 1 and the outer ring raceway 3, a retainer 6a that holds the plurality of rolling elements 5, and a respective outer ring on the inner peripheral surface of the outer ring 4. 1 supporting the peripheral edge and having each inner peripheral edge slidably contact the outer peripheral surface of the inner ring 2
It is composed of a pair of seal members 8a and 8b. The pair of sealing members 8a18b steams the openings at both ends of the cylindrical space 7, which exists between the outer peripheral surface and the inner peripheral surface, and in which the plurality of rolling elements 5 are provided.

However, in the case of the high torque rolling bearing of the present invention, the cage 6a
The shape is different from the shape of the retainer 6 incorporated in the conventional rolling bearing described above.

That is, the cage 6a is a so-called crown-shaped cage, which is made entirely in an annular shape by injection molding synthetic resin. The depth H of the approximately U-shaped pockets 9.9, each of which rotatably holds the rolling elements 5.5, is
Sufficiently thicker than the outer diameter of each rolling element 5.5 (HAD
) are doing. As a result, both edges of the opening of each pocket 9.9 protrude more toward the inner surface of one of the sealing members 8a than the outer surface of each rolling element 5.5.

Further, the other side edge of the retainer 6a located on the opposite side to the opening side of the pocket 9.9 also projects toward the inner surface of the other seal member 8b.

As a result, the left and right edges of the retainer 6a are in close proximity to the inner surfaces of the seal members 8a and 8b, respectively. Preferably, the left and right edges of the retainer 6a and the seal member 8
Gaps 10a and 10b existing between the inner surfaces of a and 8b
The thickness dimension jlxt2 is set to 1/1 of the outer diameter of the rolling element 5.
1o or less (tl, t2≦D/10).

Also, the thickness of the cage 6a is made larger than the thickness of the cage 6 constituting the conventional rolling bearing, so that the outer peripheral surface of the cage 6a is aligned with the inner peripheral surface of the outer ring 4. 6a
The inner circumferential surfaces of the inner ring 2 and the outer circumferential surface of the inner ring 2 are respectively made close to each other.

Preferably, the inner and outer peripheral surfaces of the retainer 6a and the inner ring 2
A gap 11 exists between the outer peripheral surface of the outer ring 4 and the inner peripheral surface of the outer ring 4.
The thickness dimensions t3 and t4 of a and llb are set to 1/10 or less of the outer diameter of the rolling element 5 (ts, ta≦D/10).

If there is a partial protrusion in the width direction or thickness direction of the cage 6a, the thickness of the gap (minimum gap) in this protrusion is determined by the outer diameter of the rolling element 5. less than 1/10 of that.

Further, in the cylindrical space 7 located between the pair of sealing members 8a and 8b, a high viscosity substance such as silicone oil, grease, etc. having a viscosity of 10,000 to 2,000,000 cSt is sealed. are doing. In addition, when using grease as the viscous substance, the viscosity of the base oil of the grease is within the above range.

The amount of the viscous substance sealed is such that the volume S of the viscous substance is calculated from the total volume St of the cylindrical space 7 to the volume S of the plurality of rolling elements 5.
The gap volume So excluding s and the volume Sem of the cage 6a
(s-(0,7-1.0)So) is determined so as to occupy 70-100% of (=Sy 15!-8em).

In the case of the high-torque rolling bearing of the present invention configured as described above, since the cage 6a rotates in a highly viscous substance, the torque required to rotate the cage 6a becomes large, and the cage 6a is held in place. The torque required to rotate the outer ring 4 and the inner ring 2, which rotate relative to each other as the plurality of rolling elements 5 roll, increases.

In particular, in the case of the illustrated embodiment, the left and right edges of the cage 6a are on the inner surfaces of the sealing members 8a and 8b, the outer circumferential surface of the cage 6a is on the inner circumferential surface of the outer ring 4, and the inner circumferential surface of the cage 6a is on the inner circumferential surface of the outer ring 4. Gaps 10a, 10b, lla, and llb are provided on the outer peripheral surface of the inner ring 2, respectively.
Since the cage 6 is placed close to the cage 6 within the cylindrical space 7,
When rotating a, each gap 10a, 10b, lla
, 11b is subjected to a large shearing force.

This shearing force becomes a large resistance to rotating the cage 6a. At the same time, the opening of the pocket 9.9 functions as a concavo-convex portion extending in the circumferential direction, and stirs the viscous substance sealed in the cylindrical space 7.
Generates resistance to rotation. As a result,
The torque required for relative rotation between the outer ring 4 and the inner ring 2 becomes sufficiently large and stable.

Next, a second embodiment of the present invention shown in FIGS. 3 and 4 will be described.

In this embodiment, the pocket 9. is located on the other side edge of the retainer 6a.
A concavo-convex portion 12 extending in the circumferential direction is formed in a portion located on the opposite side from the opening of the concave portion 9 .

As a result, in the case of this embodiment, as the cage 6a rotates, the viscous substance sealed in the cylindrical space 7 becomes violently agitated, and the resistance to rotation of the cage 6a becomes more pronounced. The torque required for relative rotation between the outer ring 4 and the inner ring 2 can be increased.

In each embodiment, in order to adjust the torque required for relative rotation between the outer ring 4 and the inner ring 2, in addition to changing the viscosity and amount of the viscous substance sealed in the cylindrical space 7, the cage 6a By changing the width and thickness of the gaps 10a and 10
The dimensions of b, lla, and llb are changed, and the depth and pitch of the uneven portions 12 are also changed.

By employing these means alone or in combination, the desired torque can be stably obtained.

(Effects of the Invention) The high-torque rolling bearing of the present invention is configured and operates as described above, and because it can stably obtain large rotational torque, it can improve the operability of steering devices, etc. 8 coming.

[Brief explanation of the drawing]

1 and 2 show a first embodiment of the present invention, FIG. 1 is a partial sectional view, FIG. 2 is a view from above of FIG. 1 with the cage and rolling elements taken out, and FIG. 3-4 are views similar to FIGS. 1-2, showing a second embodiment of the present invention, and FIG. 5 is a sectional view showing an example of a conventional rolling bearing. 1: Inner raceway, 2: Inner raceway, 3: Outer raceway, 4: Outer raceway, 5
: rolling element, 6.6a: cage, 7: cylindrical space, 8a,
8b: Seal member, 9: Pocket, 10a, 10b, l
between la and Ilb+1597, 12: uneven portion. Figure 1

Claims (4)

[Claims] (1) An inner ring having an inner ring raceway on the outer peripheral surface, an outer ring having an outer ring raceway on the inner peripheral surface, a plurality of rolling elements rotatably provided between the inner ring raceway and the outer ring raceway, and the plurality of rolling elements. A retainer that holds a moving body, one peripheral edge of each of the outer circumferential surface of the inner ring and the inner circumferential surface of the outer ring is supported, and the other circumferential edge of each is supported on the outer circumferential surface of the inner ring and the inner circumferential surface of the outer ring. By slidingly contacting the other circumferential surface of the inner circumferential surface, the cylindrical space existing between the outer circumferential surface and the inner circumferential surface and provided with the plurality of rolling elements,
A rolling bearing consisting of a pair of seal members whose openings at both ends are closed, in which a viscous substance having a viscosity of 100,000 to 2,000,000 cSt is placed in a cylindrical space located between the pair of seal members. A high torque rolling bearing in which the volume of this viscous substance is enclosed so as to occupy 70% or more of the gap volume obtained by excluding the volume of the plurality of rolling elements and the volume of the cage from the volume of the cylindrical space. (2) The high-torque rolling bearing according to claim 1, wherein a portion of the retainer that is immersed in the liquid has irregularities extending in the circumferential direction. (3) Claim 1 or Claim 2, wherein the dimension of the smallest part of the gap existing between at least one side surface of the cage and the inner surface of the sealing member is 10% or less of the outer diameter dimension of the rolling element.
High torque rolling bearings as described in . (4) The minimum value of the gap between the outer circumference of the cage and the inner circumference of the outer ring is 10% or less of the outer diameter of the rolling element, and the inner circumference of the cage and the outer circumference of the inner ring 4. The high-torque rolling bearing according to claim 1, wherein the minimum value of the gap between the surfaces is 10% or less of the outer diameter of the rolling element.