JP3152828B2 - Seal structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seal structure, and more particularly to, for example, a driven gear device for a speedometer. An apparatus can be provided. Further, a preferred embodiment of the present invention relates to a driven gear device for a speedometer, in which the driven gear can stably rotate for a long period of time.

[0002]

2. Description of the Related Art As a device for transmitting the rotation speed of a transmission of an automobile to a meter portion of a driver's seat, there is a driven gear device D for a speedometer as shown in FIG. This driven gear device D, as shown in FIG.
Gear part 11 driven by rotation of transmission
And a shaft 12 to which a cable for operating a speedometer is connected is rotatably inserted into a cylindrical sleeve 2, and the sleeve 2 seals between the driven gear 1 and the sleeve 2. The configuration is such that a seal portion 3 and a seal 4 for an attachment portion to the transmission are provided.

[0003] In the conventional driven gear device as described above, the shaft and the sleeve of the driven gear are usually made of metal such as iron or aluminum. However, the metal shaft or sleeve is heavy. In addition, transmission vibration and noise are easily transmitted,
In addition, since the production thereof requires steps such as die casting and cutting, the use of resin for these shafts and sleeves is being studied.

However, when the shaft and / or the sleeve are made of resin, the sliding between the sealing portion and the shaft causes wear and creep deformation of the sliding portion, thereby losing the sealing function. Has caused problems such as seizure, wear and the like on the sliding portion, oil leakage and difficulty in rotating the shaft, and it has been difficult to put the sliding portion into practical use.

In order to solve the above-mentioned problem, as shown in FIG.
It is conceivable to dispose 1 and thereby prevent abrasion and creep deformation in a sliding portion.

[0006]

However, in general, when the driven gear device is used, the temperature inside the transmission is about 120 ° C. or higher. Therefore, when the metal pipe 21 is provided on the resin shaft 12 as described above. As shown in FIG. 9, the resin of the shaft 12 undergoes dimensional shrinkage due to recrystallization or the like, and a clearance is created between the resin and the metal pipe 21 that does not shrink, so that the metal pipe 21 rotates together with the seal portion 3. The present inventors have found that there is a problem that the sealing function is lost due to oil leakage from the clearance or the clearance.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and to provide a highly reliable sealing structure in which a sealing function is maintained for a long period of time even if at least the driven gear shaft and further the sleeve are essentially made of resin. More specifically, it is to provide a driven gear device.

[0008]

SUMMARY OF THE INVENTION The object of the present invention is to provide the present invention, that is, a cylindrical sleeve, and at least a shaft rotatably inserted in the sleeve, which is made of a resin, and a driven gear made of resin. A seal structure in which a seal portion that slidably contacts the inner peripheral surface of the sleeve and seals between the sleeve and the shaft of the driven gear is provided, and a metal portion is provided at least at a portion of the sleeve where the seal portion contacts. Is achieved by

[0009]

According to the seal structure of the present invention, at least the shaft of the driven gear and further the sleeve can be made of resin, so that it is lightweight and hardly transmits vibration and noise. Further, since the sliding portion of the seal portion is a metal portion on the inner peripheral surface of the sleeve, particularly a metal layer, when the resin shrinks in size at a high temperature during use, the sleeve 2 has an inner diameter as shown by an arrow in FIG. , The sleeve 2 and the metal layer 21 are in closer contact with each other, and due to the difference between the outer diameter and the inner diameter of the metal layer 21, the outer peripheral surface of the metal layer 21 is closer to the inner peripheral surface. Since the rotation resistance is larger than the rotation resistance, the metal layer does not rotate together with the seal portion 3. Therefore, there is no clearance between the sleeve 2 and the metal layer 21. Further, the inner peripheral surface of the sleeve on which the metal layer is provided is suppressed from abrasion due to sliding with the seal portion, for a long period of time. A sealing effect is exhibited.

Hereinafter, the seal structure of the present invention will be described in more detail with reference to the drawings, taking a driven gear device for a speedometer as an example.

FIG. 1 is a schematic sectional view showing an embodiment of the present invention. In the figure, D is a driven gear device for a speedometer, which comprises a resin sleeve 2 and a sleeve 2.
And a driven gear 1 rotatably inserted therein. The driven gear 1 is provided with a seal portion 3 and a metal portion (metal layer) 21 is formed on an inner peripheral surface of the sleeve 2. I have. 5 is an O-ring.

In the example shown in FIG. 1, the driven gear 1 has a gear portion 11 formed with teeth that mesh with a transmission gear and a slit for connecting a cable (not shown) for operating a speedometer. Reference numeral 121 denotes the shaft 12 formed at the end. In the present invention, at least the shaft 12 is made of resin. Of course, the gear portion 11 may also be made of resin. In the present invention, the gear portion 11 and the shaft 12 can be integrally formed. According to this, the gear portion 11 and the shaft 12 can be manufactured simultaneously, thereby simplifying the manufacturing process. At the same time, manufacturing costs (processing costs) are reduced.

The resin is not particularly limited, but is preferably a resin having excellent oil resistance, heat resistance, mechanical strength and the like. Further, at least the outer peripheral surface of the shaft of the driven gear 1 is preferably made of a resin having excellent oil resistance and heat resistance and a small friction coefficient. Examples of such a resin include a resin selected from a polyamide resin, a saturated polyester resin, polyphenylene sulfide, polyether ether ketone, and a liquid crystal polymer. Preferable specific examples of these resins include 6-nylon, 6,6-nylon, aromatic nylon, polybutylene terephthalate, polyethylene terephthalate and the like. Among these resins, polyamide resins are particularly preferable, and nylon (specifically, 6,6-nylon or the like) is particularly preferably used. It is preferable that a filler such as a glass fiber, a carbon fiber, and an inorganic filler be mixed with the resin in order to improve mechanical strength. The filler is generally blended in an amount of 1 to 60 parts by weight, preferably 15 to 40 parts by weight, based on 100 parts by weight of the resin.

The shaft 12 of the driven gear 1 has
A seal portion 3 for sealing a gap S between the shaft 12 and the sleeve 2 is provided.

The form of the seal portion 3 is not particularly limited as long as it can prevent oil from leaking from the gap S between the shaft 12 and the sleeve 2.
2 and 3 are preferable because the sealing function of the sealing portion 3 is further improved (FIG. 2 is a schematic cross-sectional view showing a free state of the sealing portion 3, and FIG. FIG. 4 is a schematic partial cross-sectional view showing a state where a part is mounted on a shaft of a driven gear device). In FIG. 3, an annular groove 13 is formed on the outer peripheral surface of the driven gear 1, and a cylindrical main body 31 that fits into the annular groove 13 and a sleeve 2 that extends from the cylindrical main body 31 in the outer radial direction and is The lip portion 32 slidably in contact with the metal portion 21 constitutes the seal portion 3.

It is preferable that at least the lip portion 32 of the seal portion 3 is formed of an elastic material so that the lip portion 32 can slidably contact the metal portion 21 of the sleeve 2. Is preferably a rubber having excellent oil resistance, heat resistance, mechanical strength, and the like, and examples thereof include acrylonitrile-butadiene rubber, acrylic rubber, fluorine rubber, and hydrogenated nitrile rubber. Preferably, the lip portion 32 is formed integrally with the cylindrical main body portion 31. According to this, the lip portion 32 and the cylindrical main body portion 3 are formed.
1 is prevented from being poorly joined.

The cross-sectional shapes of the annular groove 13 and the cylindrical body 31 are not particularly limited. For example, as shown in FIGS. 2 and 3, the cylindrical body 31 can be stably held in the annular groove 13. , The cylindrical main body 31 with the groove 13
It is preferable to have a rectangular shape that can be easily fitted to the horn. In addition,
In the case where the cylindrical main body 31 has a certain degree of elasticity, if the inner diameter is set to be equal to or smaller than the diameter of the bottom of the annular groove 13 by about 20% or less, the elasticity is utilized. The cylindrical main body 31 can be fitted and fixed in the annular groove 13 and the cylindrical main body 31
This is preferable because the restraining force (stretching force) of the ring becomes large and the adhesion to the annular groove 13 is improved.

The lip 32 extends from the cylindrical main body 31 in the outer diameter direction, but preferably extends so as to be inclined toward the side where oil is present.
According to this, even when pressure is applied by the oil, the lip portion 32 is pressed against the metal portion 21 of the sleeve 2, so that the oil does not leak to the outside (hereinafter, referred to as the lip portion 32).
This property is called "self-sealing property"). Also, due to the difference between the outer diameter and the inner diameter of the seal portion 3, the outer peripheral portion of the seal portion 3 usually has a larger rotational resistance than the inner peripheral portion. Although it is easy to slide in the peripheral portion, if the lip portion 32 is extended so as to be inclined as described above, the crushing force of the lip portion 32 is absorbed by its bending elasticity, and the lip portion 32 is directly applied to the cylindrical main body 31. Since it is not transmitted,
Since the rotation resistance of the outer peripheral portion of the seal portion 3 is reduced, the seal portion 3 slides on the outer peripheral portion. Further, when the sealing portion 3 is configured so that the binding force of the cylindrical main body portion 31 is larger than the crushing force of the lip portion 32,
The rotation resistance of the inner peripheral portion of the seal portion 3 becomes large, and the shaft 1
2 is more reliably maintained, so that the sealing portion 3 does not slide on the inner peripheral portion to lose the sealing function, and the sealing portion 3 and the shaft 12 No wear due to rotation.

The inclination angle θ of the lip portion 32 is 20 °
<Θ <90 °, preferably 20 ° <θ <60 °. The lip 32
Is less than 20 °, the self-sealing property tends to be insufficient due to the above-mentioned inclination, while if it is more than 90 °, the lip portion 32 is pushed out so as to warp outward due to oil pressure. It tends to cause oil leakage. The axial width w of the cylindrical main body 31
_It is preferable that ₂ is set to be larger than the axial width w ₁ of the lip portion 32 forming portion in terms of the stability of the cylindrical main body portion 31.

The lip portion 32 is preferably formed so as to have a thin or substantially uniform thickness toward the outer peripheral end. When the thickness of the lip portion 32 is increased toward the outer peripheral end portion, stress is concentrated near the boundary portion between the lip portion 32 and the cylindrical main body portion 31, and the portion is easily damaged. Therefore, the seal part 3
Is not preferred in terms of life.

Further, as shown in FIG. 2, the outer peripheral end of the lip portion 32 is preferably formed so as to have a mountain-shaped cross-sectional shape projecting in the outer diameter direction. Since the portion can sufficiently cut off the oil film, the sealing function of the seal portion 3 is improved. It is desirable that the crossing angle α of the oblique side forming the mountain-shaped projection is set in the range of 90 ° ≦ α ≦ 150 °, preferably 100 ° ≦ α ≦ 120 °. When the crossing angle α is less than 90 °, the outer peripheral end of the lip 32 has a cross-sectional shape protruding at an acute angle as shown in FIG. When the angle exceeds °, as shown in FIG. 5, the protrusion of the end portion becomes insufficient, so that the oil film cannot be cut off sufficiently and oil may leak.

The driven gear 1 is rotatably inserted into a cylindrical sleeve 2 having a metal portion 21 formed at least in a portion in contact with the seal portion. The metal part 21
Is preferably made of a metal having excellent abrasion resistance, heat resistance, etc., for sliding with the lip portion 32,
Examples of such a metal include carbon steel, stainless steel, and copper alloy. Among them, carbon steel is preferably used.

As a form of the metal portion 21, a form formed as a metal layer as shown in FIG. 1 is preferable. According to this, the sleeve 2 other than the metal layer can be made of resin. The thickness of the metal layer varies depending on the type of metal, but is preferably about 1 to 2 mm.
When the thickness of the metal layer is within the above range, sufficient wear resistance and heat resistance can be obtained, and the sleeve 2 does not become excessively heavy. The metal layer is formed at least in a portion of the sleeve 2 where the seal portion 3 comes into contact.
If the metal layer is formed over the area where the contact is made, the seizure due to the sliding of the sleeve 2 and the shaft 12 as described above is suppressed, so that the driven gear can stably rotate for a long period of time. . In this case, FIG.
As shown in (1), it is more preferable that a metal layer is formed on the portion of the sleeve 2 that comes into contact with the gear portion 11, since the seizure caused by sliding between the sleeve 2 and the gear portion 11 is suppressed. The sleeve 2 may be entirely made of metal, but is inferior in weight reduction.

The metal layer may be formed, for example, by fixing a metal pipe or the like to the inner peripheral surface of the sleeve 2 by an ultrasonic insert or the like, but is formed by integrally molding the sleeve 2 with the metal pipe or the like. Then, the connection between the sleeve 2 and the metal layer becomes stronger, which is preferable.

In the present invention, as described above, the metal part 2
1 is preferably formed as a metal layer, and the sleeve 2 other than the metal portion 21 is preferably formed of a resin. As the resin forming the sleeve 2, the same resin as that of the driven gear 1 is used. However, when the metal part 21 is partially formed on the inner peripheral surface of the sleeve 2, at least the inner peripheral surface of the sleeve 2, and a portion other than the metal part 21 is the outer peripheral surface of the driven gear 1. It is preferable to be made of a resin having the same oil resistance and heat resistance as described above and having a small coefficient of friction. In this case,
It is more preferable that the portion of the sleeve 2 that comes into contact with the gear portion 11 is also made of the same resin having a small friction coefficient. An outer peripheral surface of the sleeve 2 is provided with an annular groove 22 for holding the O-ring 5 and an external thread portion 2.
3 is formed.

The driven gear 1 and the sleeve 2 are
It is molded by conventionally known means such as injection molding, and its size is arbitrarily determined according to the space in which the driven gear device is provided.

[0027]

【Example】

Example 1 A sleeve 2 and a driven gear 1 having the shape shown in FIG. 1 were manufactured using 6,6-nylon containing 30% of glass fiber, and a position of the inner peripheral surface of the sleeve 2 where a seal portion was to be brought into contact. A metal part 21 is provided by fixing a pipe made of carbon steel. On the other hand, the driven gear 1 is provided with a seal part having the same shape as the seal part 3 shown in FIG. However, this seal portion has an inclination angle (θ in FIG. 2) of 30.
°, the crossing angle (α) of the oblique side forming the mountain-shaped protruding shape at the outer peripheral end is 100 °, and the material is acrylic rubber. The driven gear 1 was loaded on the sleeve 2 to produce a driven gear device having the configuration shown in FIG.

The driven gear device obtained in Example 1 was mounted on a transmission, and the temperature was set to 120 ° C.
When the shaft of the driven gear was rotated under the condition of a rotation speed of 2,000 rpm, no oil leakage or the like from the device occurred even after 1000 hours or more (corresponding to 100,000 km running or more in an actual vehicle test) after the rotation started.

Comparative Example 1 A driven gear device having the structure shown in FIG. 8 was manufactured using the same materials as in Example 1 described above. However, the cross-sectional shape, the inclination angle (θ), and the intersection angle (α) of the seal portion are the same as in the first embodiment.

When the driven gear shaft was rotated using the driven gear device obtained in Comparative Example 1 under the same conditions as in Example 1, oil leakage occurred from the device within 100 hours after the start of rotation. It was confirmed that.

Embodiment 2 In Embodiment 1, a metal layer as the metal portion 21 is formed over the portion of the sleeve 2 where the driven gear 1 comes into contact, and the structure is exactly the same as that of FIG. A driven gear device was manufactured.

When the driven gear shaft was rotated under the same conditions as in the first embodiment using the driven gear device obtained in the second embodiment, a sealing function equivalent to that in the first embodiment (a function to prevent oil leakage) was obtained. ) Was obtained,
Wear on the inner peripheral surface of the sleeve and the outer peripheral surface of the shaft was reduced, and the stability of gear rotation was maintained in a favorable state.

Hereinafter, examples of embodiments of the present invention will be listed. (1) An embodiment in which the gear portion and the shaft of the driven gear are integrally formed of resin. (2) An embodiment in which the metal portion is formed over a portion of the sleeve that comes into contact with the shaft and the gear portion. (3) At least the outer peripheral surface of the shaft of the driven gear
An embodiment comprising a resin selected from nylon, 6,6-nylon, aromatic nylon, polybutylene terephthalate, and polyethylene terephthalate. (4) An aspect in which at least the inner peripheral surface of the sleeve other than the metal part is made of a resin selected from 6-nylon, 6,6-nylon, aromatic nylon, polybutylene terephthalate, and polyethylene terephthalate. (5) An embodiment in which at least one filler selected from glass fibers, carbon fibers, and inorganic fillers is blended with the resin constituting the driven gear and / or the sleeve. (6) The embodiment according to the above (5), wherein the filler is mixed in an amount of 1 to 60 parts by weight with respect to 100 parts by weight of the resin. (7) An aspect in which at least the lip portion of the seal portion is formed of an elastic body. (8) The embodiment according to the above (7), wherein the elastic body is a rubber selected from acrylonitrile-butadiene rubber, acrylic rubber, fluorine rubber and hydrogenated nitrile rubber. (9) A mode in which the lip is formed integrally with the cylindrical main body. (10) An aspect in which the cross-sectional shapes of the annular groove and the cylindrical main body are rectangular. (11) A mode in which the inner diameter of the cylindrical main body is set to be equal to or smaller than the diameter of the bottom of the annular groove by about 20% or less. (12) An aspect in which the lip portion is extended so as to be inclined toward the side where oil is present. (13) A mode in which the restraining force (stretching force) of the cylindrical body is greater than the crushing force of the lip. (14) A mode in which the inclination angle θ of the lip portion is set in the range of 20 ° <θ <90 °. (15) the axial width w ₂ of the cylindrical body portion, is set to be larger than the axial width w ₁ of the lip forming portion aspects. (16) A mode in which the lip portion is formed so as to be thin or substantially uniform in thickness toward the outer peripheral end. (17) A mode in which the outer peripheral end of the lip is formed to have a mountain-shaped cross-sectional shape protruding in the outer radial direction. (18) The crossing angle α of the hypotenuse forming the mountain-shaped protruding shape is 90 ° ≦
The embodiment according to (17), wherein the angle is set within a range of α ≦ 150 °. (19) An embodiment in which the metal part is made of a metal selected from carbon steel, stainless steel and copper alloy.

[0034]

According to the seal structure of the present invention, since the seal portion is provided on the shaft of the driven gear to eliminate the seal sliding portion of the shaft, the shaft is made of resin but does not wear. In addition, since the shaft and the sleeve of the driven gear can be made of resin, the weight and weight of the driven gear are hardly transmitted, so that the vibration and noise of the entire driven gear device are reduced. Further, the sleeve and the metal portion are more closely contacted with each other, the metal portion does not rotate together with the seal portion, and no clearance is generated between the sleeve and the metal portion.
In addition, there is an effect that wear of the inner peripheral surface of the sleeve is suppressed, and the sealing function is maintained for a long period of time.

Moreover, as shown in a preferred embodiment shown in FIG.
In the case where the metal portion 21 is formed over the portion that comes into contact with 1, seizure, wear, etc. due to sliding between the sleeve 2 and the shaft 12 are suppressed, so that oil leakage does not occur and the driven gear is This has the effect that it can rotate stably for a long time.

Further, since the seal portion slides on the metal portion as described above, wear and creep deformation of the sleeve are prevented. Therefore, the driven gear device has a longer life.

Further, since the shaft of the driven gear and the sleeve can be made of resin as described above, it is possible to easily manufacture the driven gear device and to reduce the manufacturing cost.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an example of a driven gear device for a speedometer showing a seal structure of the present invention.

FIG. 2 is a schematic partial cross-sectional view illustrating an example of a seal portion.

FIG. 3 is a schematic partial cross-sectional view showing a state where the seal portion of FIG. 2 is mounted on a shaft of a driven gear device.

FIG. 4 is a schematic partial cross-sectional view showing another example of a seal portion mounted on a shaft of a driven gear device.

FIG. 5 is a schematic partial cross-sectional view showing another example of a seal portion mounted on a shaft of a driven gear device.

FIG. 6 is a schematic sectional view showing another example of the driven gear device for a speedometer showing the seal structure of the present invention.

FIG. 7 is a schematic sectional view showing an example of a conventional driven gear device for a speedometer.

FIG. 8 is a schematic sectional view showing another example of a conventional driven gear device for a speedometer.

FIG. 9 is a schematic partial cross-sectional view showing a state in which a clearance has occurred between a shaft and a metal pipe in the apparatus of FIG. 8;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Driven gear 11 Gear part 12 Shaft 121 Slit 2 Sleeve 21 Metal layer 22 Annular groove 23 Male screw part 3 Seal part 5 O-ring S Gap D Driven gear device for speedometer

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazumasa Nishida 663 Minoshima, Arita City, Wakayama Prefecture Mitsubishi Cable Industries, Ltd. Mishima Works (56) References Japanese Utility Model No. 2-125248 (JP, U) (58) Field (Int.Cl. ⁷ , DB name) F16J 15/32 311

Claims (7)

(57) [Claims] 1. A cylindrical sleeve, and at least a shaft rotatably inserted in the sleeve has a driven gear made of resin, and the driven gear is slidably in contact with an inner peripheral surface of the sleeve. A sealing portion for sealing between the sleeve and the shaft of the driven gear, and a metal portion in at least a portion of the sleeve where the sealing portion contacts. 2. The seal structure according to claim 1, wherein the sleeve is made of resin. 3. The method according to claim 1, wherein the metal part is a metal layer.
The described seal structure. 4. The seal structure according to claim 1, wherein the metal portion is formed over at least a portion of the sleeve that contacts the shaft. 5. The driven gear, wherein at least the outer peripheral surface of the shaft is made of a resin selected from a polyamide resin, a saturated polyester resin, polyphenylene sulfide, polyether ether ketone, and a liquid crystal polymer.
4. The seal structure according to 2 or 3. 6. At least the inner peripheral surface of the sleeve,
4. The seal structure according to claim 1, wherein the portion other than the metal portion is made of a resin selected from a polyamide resin, a saturated polyester resin, polyphenylene sulfide, polyether ether ketone, and a liquid crystal polymer. 7. A cylindrical body fitted into an annular groove formed on the outer peripheral surface of the driven gear, and a seal extending from the cylindrical main body in an outer radial direction to a metal part on an inner peripheral surface of the sleeve. 4. The seal structure according to claim 1, wherein the seal structure comprises a lip portion that movably contacts.