JPH06294418A - Radial needle bearing - Google Patents

Abstract

PURPOSE:To regulate the flow of a lubricating oil running between a shaft and an outer ring to a small level by providing a cage with an outer diameter slightly smaller than the diameter of the raceway of the outer ring, and an inner diameter slightly larger than the diameter of the inscribing circle of a plurality or needles. CONSTITUTION:The outer diameter (d) of a cage 12 is slightly smaller than the diameter D of the raceway or an outer ring 11 (d<D). Otherwise, the inner diameter R of the cage 12 is slightly larger than the diameter of the inscribing circles of a plurality of needles 6, or than the outer diameter (r) of a shaft 2 (R>r). The thickness of the cage 12 is slightly smaller than the diameter of the needle 6. A very small outer gap 14 is formed between the outer peripheral surface of the cage 12 and the raceway 11 of the outer ring, and a very small gap 15 between the inner circumferential surface of the cage 12 and the outer peripheral surface of the shaft 2. The pressure of the oil existing in a gap 20 is smaller compared with that of the oil existing in the upstream of the cage 12 by the same degree of the passing resistance of the outer and inner gaps 14, 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION A radial needle bearing according to the present invention is incorporated in an automatic transmission for automobiles or various hydraulic equipment to support a rotary shaft inside a fixed portion such as a housing and to mount a bearing portion. It is used to control the amount of lubricating oil circulating.

[0002]

2. Description of the Related Art For example, a support bearing provided in an oil pump portion of an automatic transmission for an automobile has a function of rotatably supporting a shaft and also squeezes high-pressure oil flowing through the support bearing to flow downstream. It must also have the function of adjusting the amount of oil. Therefore, conventionally, as shown in FIG.
The support bearing is constructed by providing the slide bearing 3 between the inner peripheral surface of the housing 1 and the outer peripheral surface of the shaft 2.

However, the plain bearing 3 has a large torque loss when the shaft 2 rotates. Therefore, for the purpose of improving the power performance of the automobile and saving fuel consumption, it is considered that the above-mentioned support bearing is constituted by a needle bearing. However,
In the case of a commonly known needle bearing, the amount of oil penetrating in the axial direction is too large to be used as the support bearing.

[0004] In view of such a situation, the actual Kaihei 1-8392
No. 0 publication describes a needle bearing having a structure as shown in FIGS. First, in the case of the structure of the first example shown in FIG. 14, the seal ring 4 called a floating seal is provided between the inner peripheral surface of the outer ring 5 and the outer peripheral surface of the shaft 2 which form the needle bearing. This seal ring 4
Is made of synthetic resin or the like in an annular shape, and has an inner diameter slightly larger than the outer diameter of the shaft 2 and an outer diameter smaller than the inner diameter of the outer ring 5 and larger than the inner diameter of the inward flange portion 8a. Have. The seal ring 4 is mounted inside the outer ring 5 between the cage 7 holding the needle 6 and the inward flange portion 8a on the downstream side in the lubricating oil flow direction.

Such a seal ring 4 is pressed against the inner surface of the inward flange portion 8a by being pressed by the oil pressure in the operating state of the automatic transmission or the like. In this state, a slit-shaped gap 9 is formed between the inner peripheral edge of the seal ring 4 and the outer peripheral surface of the shaft 2, and the oil flows downstream through the gap 9.

Further, in the structure of the second example shown in FIG. 15, the seal ring 4a for adjusting the flow rate of oil is formed in an annular shape with a U-shaped cross section. The seal ring 4a has an inner diameter slightly larger than the outer diameter of the shaft 2 and an outer diameter smaller than the inner diameter of the outer ring 5 and larger than the inner diameter of the inward flange portion 8a. The seal ring 4a is mounted inside the outer ring 5 at a portion between the needle 6 and the inward flange portion 8a on the downstream side, with the opening side of the U-shaped cross section facing in the direction opposite to the needle 6. .

[0007]

However, the conventional radial needle bearing constructed and operating as described above still has the following problems to be solved.

First, in the structure of the first example shown in FIG.
It is difficult to reduce the width of the gap 9 or increase the length of the gap 9, and it is not possible to sufficiently reduce the oil flow rate. On the other hand, in the structure of the second example shown in FIG. 15, the length dimension of the gap 9a between the inner peripheral surface of the seal ring 4a and the outer peripheral surface of the shaft 2 can be increased to some extent, and the flow rate can be reduced. Things are possible for the time being. However, in order to obtain a sufficient drawing effect, the length dimension of the seal ring 4a must be considerably increased. The installation space of the support bearing in the oil pump part is limited,
It is not preferable that the length dimension is too large.

The radial needle bearing of the present invention has been invented in view of the above circumstances.

[0010]

The radial needle bearing of the present invention has an outer ring raceway on the inner peripheral surface and an inward flange portion bent inward in the diametrical direction at both end portions, similarly to the conventional radial needle bearing described above. , An outer ring each having the same, a cage having a plurality of pockets in the circumferential direction and rotatably provided inside the outer ring, and an end surface of the cage and an inner surface of the inward flange portion. A seal ring, which is provided between the pockets and serves as a resistance against the lubricating oil that flows in the axial direction inside the outer ring, and a plurality of needles that are rotatably held inside the pockets are provided.

Particularly, in the radial needle bearing of the present invention, the cage has an outer diameter slightly smaller than the diameter of the outer ring raceway and an inner diameter slightly larger than the diameter of the inscribed circle of the plurality of needles. Have and.

[0012]

In the radial needle bearing of the present invention constructed as described above, the oil flow in the axial direction is throttled not only by the retainer but also by the seal ring. Due to this kind of labyrinth effect, the amount of reduction of the entire radial needle bearing becomes sufficiently large. As a result, the flow rate of oil can be sufficiently reduced without increasing the length of the radial needle bearing in the axial direction.

[0013]

1 and 2 show a first embodiment of the present invention. A shaft 2 that rotates relative to the housing 1 is inserted into a circular hole 10 formed in the housing 1. A cylindrical outer ring 5 is internally fitted and fixed to the inner peripheral surface of the circular hole 10 by an interference fit. The outer ring 5 has an outer ring raceway 11 on its inner peripheral surface, and an inward flange portion 8a at both end openings.
8b respectively. A retainer 12 and a plurality of needles 6 rotatably retained by the retainer 12 are provided between the outer ring raceway 11 and the outer peripheral surface of the shaft 2.
The seal ring 13 is provided.

The cage 12 is called a cage cage, and is made of, for example, a heat-resistant synthetic resin by injection molding, or made of a metal such as copper or aluminum. The outer diameter d of the cage 12 is slightly smaller than the diameter D of the outer ring raceway 11 (d <D). The inner diameter R of the cage 12 is slightly larger than the diameter of the inscribed circle of the plurality of needles 6, that is, the outer diameter r of the shaft 2 (R> r). In other words, the thickness of the cage 12 is the same as the needle 6
Slightly smaller than the diameter dimension of. Therefore, this cage 1
A small outer gap 1 is formed between the outer peripheral surface 2 and the outer ring raceway 11.
4, a minute inner gap 15 is formed between the inner peripheral surface of the cage 12 and the outer peripheral surface of the shaft 2.

On the other hand, the seal ring 13 is made of metal and has a ring-shaped core 16 and is reinforced by the core 16.
The seal member 17 is made of an elastic material such as rubber. The seal ring 13 includes the inner surface of the inward flange portion 8a located on the downstream side (the right side in FIG. 1) in the oil flow direction, and the cage 1 described above.
It is mounted between the outer side surface of the two. Also, this sealing material 17
A short cylindrical seal lip 1 is provided on the inner surface of the outer periphery of the seal lip 1.
8 is formed, and the tip end portion of the seal lip 18 is made to enter the inside in the diametrical direction of the inward flange portion 8a.
The cage 12 and the seal ring 13 are inserted inside the outer ring 5 before the inward flange portion 8b formed to have a relatively thin wall is bent.

In the radial needle bearing of the present invention constructed as described above, the space 19 between the inner peripheral surface of the circular hole 10 and the outer peripheral surface of the shaft 2 is directed from left to right in FIG. The oil flowing all over is first throttled by the retainer 12.
That is, as shown by the arrow a in FIG. 1, the oil that has entered the space 19 passes through the outer gap 14 and the inner gap 15 existing on the outer peripheral side and the inner peripheral side of the retainer 12, and then the retainer. It is fed into the gap 20 existing on the downstream side of 12.
The pressure of the oil existing in this gap 20 is
Compared with the pressure of the oil existing on the upstream side, the passage resistance of both the outer and inner gaps 14 and 15 becomes lower.

Further, the oil reaching the gap 20 pushes the seal lip 18 outward in the diametrical direction as shown by a chain line in FIG. 2, and at the same time, the inner peripheral surface of the seal lip 18 and the shaft 2 are separated from each other. It flows through the gap 21 between the outer peripheral surface and the downstream side. The outer peripheral surface of the tip portion of the seal lip 18 faces the inner peripheral edge of the downstream inward flange portion 8a, and the deformation of the seal lip 18 is limited by the inward flange portion 8a. Therefore, the cross-sectional area of the gap 21 is limited. Moreover, since the pressure of the oil existing in the clearance 20 existing at the upstream end of the clearance 21 is lower than the pressure of the oil existing on the upstream side of the cage 12 as described above, the above-mentioned clearance is caused by a kind of labyrinth effect. The momentum of the oil flowing through 21 becomes weak.

As a result, the amount of oil flowing through from the upstream side to the downstream side of the radial needle bearing is sufficiently reduced. That is, in the radial needle bearing of the present invention, the flow rate of the oil can be sufficiently reduced without increasing the length dimension in the axial direction.

Next, FIG. 3 shows a second embodiment of the present invention. In the case of this embodiment, the metal core 16a constituting the seal ring 13a has an L-shaped cross section, and the seal ring 13a
In order to support the outer ring 5 on the outer ring 5, a part of the core metal 16a is fitted into the outer ring 5. Therefore, in the case of the present embodiment, the rigidity of the seal ring 13a in the radial direction and the thrust direction is improved, and the drawing performance by the seal ring 13a is further improved, as compared with the case of the first embodiment. Other configurations and operations are similar to those of the above-described first embodiment.

Next, FIG. 4 shows a third embodiment of the present invention. In the case of the present embodiment, the inner diameter of the portion where the seal ring 13a is mounted on the inner peripheral surface of the outer ring 5 is made slightly smaller than the inner diameter of the outer ring raceway 11 portion with which the needle 6 abuts. Therefore, in the case of the present embodiment, the work of internally fitting and fixing the core metal 16a of the seal ring 13a to the outer ring 5 can be performed easily and without damaging the outer ring raceway 11. Other configurations and operations are similar to those of the second embodiment described above.

Next, FIGS. 5 to 6 show a fourth embodiment of the present invention. In the case of this embodiment, a so-called self-sealing type seal ring 22 made of rubber and having an S-shaped cross section is used as the seal ring 22 provided on the downstream side of the cage 12. When a pressure is applied to the upstream side of the seal ring 22, the inner peripheral seal lip 23 is pressed against the outer peripheral surface of the shaft 2 by this pressure. A small notch 24 is formed on the inner peripheral edge of the seal lip 23 as shown in FIG. 6, and when the seal lip 23 is pressed against the outer peripheral surface of the shaft 2 as described above, the seal ring is formed. Oil flows between the upstream side and the downstream side of 22 only through the notch 24. Therefore, if the size of the notch 24 is regulated, the amount of oil flowing through from the upstream side to the downstream side of the radial needle bearing can be sufficiently reduced.

Next, FIG. 7 shows a fifth embodiment of the present invention. In the case of this embodiment, the rigidity of the seal ring 22a is improved by making the outer peripheral half of the seal ring 22a a solid body. Other configurations and operations are similar to those of the above-described fourth embodiment.

Next, FIGS. 8 to 10 show a sixth embodiment of the present invention. In the case of the present embodiment, the pair of ring elements 2 is used as the seal ring 25 provided on the downstream side of the cage 12.
It is used by stacking 6 and 27 in the thrust direction. Each of these ring elements 26, 27 is made of a slippery synthetic resin such as nylon, Delrin, or PTFE.

Among them, the ring element 27 on the inward flange portion 8a side has a split 2 at one location in the circumferential direction, as shown in FIG.
8 is provided, or a notch 29 is formed as shown in FIG. 10 to form an oil throttle channel. Alternatively, as shown in FIGS. 11 to 12, recessed grooves 30, 30 each extending in the diametrical direction are formed on both surfaces of the ring element 27. On the other hand, the ring element 26 on the retainer 12 side is internally fitted and supported by the interference fit on the outer ring 5 at the downstream side portion of the retainer 12. A gap, which is slightly larger than the thickness of the ring element 27, is formed between the ring element 26 and the inward flange portion 8a to prevent the ring elements 26 and 27 from strongly rubbing against each other. ing.

In the case of the present embodiment, the oil reaching the downstream side of the cage 12 has a crack 28 (in the case of the structure shown in FIG. 9) of the ring element 27 and a cutout 29 (in the inner peripheral edge of the ring element 27). (In the case of the structure shown in FIG. 10), or the concave grooves 30, 3
0 (in the case of the structure shown in FIGS. 11 to 12) only,
It is sent to the downstream side. Therefore, if the size (cross-sectional area) of the crack 28, the notch 29, and the concave grooves 30, 30 is regulated, the amount of oil flowing through from the upstream side to the downstream side of the radial needle bearing can be sufficiently reduced.

The ring elements 27 of the three examples shown in FIGS. 9 to 12 are different in the following effects. First, in the case of the structure of the first example shown in FIG. 9, the inner diameter of the ring element 27 can be adjusted based on the elastic deformation of the ring element 27. Therefore, even if the inner diameter and the outer diameter of the shaft 2 do not exactly match, the inner peripheral edge of the ring element 27 and the outer peripheral surface of the shaft 2 are brought into close contact with each other to form the inner peripheral edge and the outer peripheral surface. It is possible to prevent oil from flowing through the gap. However, when the ring element is elastically deformed based on hydraulic pressure or the like and the inner diameter is changed, oil may flow through the gap portion, and at the same time, the width dimension of the crack 28 is changed,
The oil squeezing amount changes. Therefore, it is not suitable for applications where the hydraulic pressure is particularly high.

Next, in the case of the structure of the second example shown in FIG. 10, the inner diameter of the ring element 27 and the outer diameter of the shaft 2 are strictly regulated in order to strictly regulate the oil throttle amount. However, it is not necessary to consider the change in the oil throttle amount due to the elastic deformation of the ring element 27. Therefore, it can be used even when the hydraulic pressure is high.

Further, in the case of the structure of the third example shown in FIGS. 11 to 12, in addition to the effect obtained by the structure of the second example, a large diaphragm effect can be easily obtained. That is, in order to obtain a large diaphragm effect with the structure of the second example, the cross-sectional area of the cutout 29 (FIG. 10) must be reduced. Although the work of forming the cutout 29 having a small cross-sectional area in a desired size is troublesome, in the case of the third example, the flow passage length becomes long, so that even if the cross-sectional area is made large, the throttling is sufficient. You can get the effect. Further, the concave grooves 30, 30 having a large cross-sectional area are less likely to be clogged with foreign matter than the cutouts 29 having a small cross-sectional area, and the flowability of lubricating oil can be sufficiently secured. Further, the oil flowing through the concave grooves 30, 30 is drawn between the side surface of the ring element 27 and the sliding surface in the thrust direction, which faces the side surface, and improves the slipperiness between these two surfaces. Therefore,
The effect of reducing the rotating torque is also obtained. Incidentally, the concave grooves 30, 30
It is easy to adjust the diaphragm effect by changing the number and depth.

[0029]

Since the radial needle bearing of the present invention is constructed and operates as described above, the flow rate of the lubricating oil flowing between the shaft and the outer ring is reduced without increasing the weight of the seal ring and the outer ring. It becomes possible to regulate. As a result, the weight of the transmission can be reduced and the inertial mass can be reduced to improve the performance of the device.

[Brief description of drawings]

FIG. 1 is a partial sectional view showing a first embodiment of the present invention.

FIG. 2 is also an enlarged cross-sectional view of a main part.

FIG. 3 is a partial sectional view showing a second embodiment of the present invention.

FIG. 4 is a partial sectional view showing the third embodiment.

FIG. 5 is a partial sectional view showing the fourth embodiment.

FIG. 6 is a view of the seal ring taken out from the left side of FIG.

FIG. 7 is a partial cross-sectional view showing a fifth embodiment of the present invention.

FIG. 8 is a partial cross-sectional view showing the sixth embodiment.

FIG. 9 is a front view showing a first example of a ring element on the inward flange portion side.

FIG. 10 is a front view showing the second example.

FIG. 11 is a front view showing the third example.

FIG. 12 is a view seen from above in FIG. 11.

FIG. 13 is a partial cross-sectional view showing a conventional structure using a slide bearing.

FIG. 14 is a partial cross-sectional view showing a first example of a conventional structure using a needle bearing.

FIG. 15 is a partial cross-sectional view showing the second example.

[Explanation of symbols]

 1 Housing 2 Shaft 3 Sliding Bearing 4, 4a Seal Ring 5 Outer Ring 6 Needle 7 Cages 8a, 8b Inward Flange 9, 9a Gap 10 Circular Hole 11 Outer Ring Track 12 Cage 13, 13a Seal Ring 14 Outer Gap 15 Inner Gap 16 , 16a Core bar 17 Sealing material 18 Seal lip 19 Space 20, 21 Gap 22, 22a Seal ring 23 Seal lip 24 Notch 25 Seal ring 26, 27 Ring element 28 Crack 29 Notch 30 Recessed groove

Claims (1)

[Claims] 1. An outer ring having an outer ring raceway on its inner peripheral surface and inward flange portions on both ends, and a plurality of pockets in the circumferential direction, which are rotatably provided inside the outer ring. A retainer, and a seal ring provided between the end surface of the retainer and the inner side surface of the inward flange portion, which serves as a resistance against the lubricating oil flowing in the inner side of the outer ring in the axial direction,
In a radial needle bearing having a plurality of needles rotatably held inside each of the pockets, the cage has an outer diameter slightly smaller than a diameter of the outer ring raceway and an inner diameter of the plurality of needles. A radial needle bearing having an inner diameter slightly larger than the diameter of the tangent circle.