JP2008069848A - Grease filled universal coupling - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a grease filled universal coupling keeping grease at a necessary part (place) and reducing quantity of filled grease. <P>SOLUTION: The grease filled universal coupling is provided with an outer ring 1, a shaft 9, an inner ring 2 fitted to the shaft 9, an outer ring inside space 12 surrounded by rolling elements 5 put between the inner ring 2 and the outer ring 1, and a boot inside space 11 surrounded by the shaft 9 and a boot 10 sealing a connecting space of the shaft 9 and the outer ring 1, and transmits torque to the outer ring 1 from the shaft 9. The grease filled universal coupling provided with a partition plate 13 between the outer ring inside space 12 and the boot inside space 11 and filled with grease in the outer ring inside space 12 is used for a constant velocity universal coupling transmitting torque by engagement of a track groove and rolling elements. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a grease-filled universal joint in which a partition plate is provided inside a universal joint (joint) that transmits rotational torque and grease is sealed.

  In recent years, technical improvements for higher performance, compactness, and weight reduction of automobiles have progressed, and there is a demand for miniaturization, higher performance, and longer life of universal joints used for drive transmission of automobile parts and industrial machines. It is growing. In other words, if the size and weight of the universal joint is required, as with the entire machine, a high load will be applied, and it may be difficult to achieve a long life with the conventional lubrication method using lubricating oil or grease. It is desired that the universal joint has a long life with simple maintenance even under severe conditions such as high temperature and high load.

  Conventionally, universal joints are filled with grease that is 70% or more of the internal space volume as a lubricant. Actually, grease is required as a lubricant for the sliding part composed of the outer ring, rolling element, cage, and inner ring, which is housed inside the outer ring. Originally, if grease exists only in the outer ring, Contributes to lubrication, and grease is sealed in more than 70% of the space volume consisting of the outer ring inner space surrounded by the outer ring, the sliding part, and the shaft, the boot, and the boot inner space surrounded by the shaft. There is no need. However, the grease sealed on the outer ring side also moves to the boot side during rotation of the universal joint. Therefore, when grease is sealed only in the outer ring, the grease moves to the boot side, and a phenomenon that the grease is depleted at an important sliding portion occurs, resulting in a problem that the life is shortened. In order to prevent this, the grease is filled with more grease than necessary for lubrication.

As a method of retaining the sealed grease at the sealed site, for example, mixing ultra-high molecular weight polyolefin or urethane resin and its curing agent with lubricating oil or grease, and holding a liquid lubricating component between the resin molecules. A method of using a solid lubricant having physical properties that gradually exudes is known (see Patent Documents 1 to 3). A self-lubricating polyurethane elastomer obtained by reacting a polyol, which is a polyurethane raw material, and a diisocyanate in a lubricating component in the presence of a lubricant is also known (see Patent Document 4).
When such solid lubricant is sealed in a bearing and solidified, it gradually exudes lubricating oil. If this is used, maintenance for replenishing the lubricating oil becomes unnecessary, and there is a lot of moisture. It is often useful for extending the life of bearings even in environments where they are used or where strong inertial forces are applied.

However, if such a solid lubricant is used at a site where external stress such as compression or bending is repeatedly applied at a high frequency such as a drive part of a universal joint, it is very large to deform following the compression and bending. A force is required, or a very large stress is applied to the solid lubricant, and a mechanical strength is also required in a portion holding the solid lubricant. Since the strength and the filling rate of the solid lubricant are usually contradictory, it is difficult to keep the lubricant at a high filling rate, which may hinder the extension of the service life.
JP-A-6-41569 JP-A-6-172770 JP 2000-319681 A JP-A-11-286601

  The present invention has been made to address such problems, and an object of the present invention is to provide a grease-filled universal joint that can retain grease at a necessary portion (place) and reduce the amount of grease to be filled.

  The grease-filled universal joint of the present invention includes an outer ring, a shaft, an inner ring fitted to the shaft, an outer ring inner space surrounded by the rolling elements interposed between the inner ring and the outer ring, the shaft, A grease-filled universal joint comprising a boot inner space surrounded by a shaft and a boot for sealing a connection space between the outer ring and a rotary torque transmitted from the shaft to the outer ring via the rolling element. A partition plate is provided between the outer ring inner space and the boot inner space, and grease is sealed in the outer ring inner space.

Further, the grease-filled universal joint is used for a constant velocity universal joint in which rotational torque is transmitted by engagement with a track groove and a rolling element, and is fitted to the outer ring and the inner ring having the track groove and the inner ring. A partition plate is provided between the inner space of the outer ring surrounded by the shaft to be closed and the inner space of the boot surrounded by the shaft and the boot for sealing the connection space between the shaft and the outer ring. To do.
The universal joint is a constant velocity universal joint.

In the grease-filled universal joint of the present invention, a partition plate is provided between the outer ring inner space and the boot inner space, and grease is sealed in the outer ring inner space, so that the lubricating grease is less likely to move and flow out into the boot inner space. As a result, the amount of grease to be enclosed can be reduced while maintaining the presence of grease in the sliding portion of the outer ring, the rolling element, the cage, and the inner ring, which are necessary for lubrication, and the weight and cost of the lubricant can be reduced. You can go down.
In addition, since it is difficult for grease to be present in the boot, it is possible to prevent damage to the boot due to rotational expansion, damage to the boot at the start-up in a low-temperature state, and displacement of the boot band, and improve durability. .
In addition, when the boot is damaged, the partition plate also serves as a seal against dust and moisture entering from the outside of the universal joint, so that entry of dust and moisture into the sliding portion can be prevented. .

The grease-filled universal joint of the present invention includes an outer ring, a shaft, an inner ring fitted to the shaft, an inner space surrounded by a rolling element interposed between the inner ring and the outer ring, a shaft, a shaft, and an outer ring. A boot inner space surrounded by a boot for sealing the connection space of the outer ring, and a partition plate is provided between the outer ring inner space and the boot inner space, and grease is sealed in the outer ring inner space. is there.
Moreover, the grease-filled universal joint of the present invention can be used for a constant velocity universal joint in which rotational torque is transmitted by engagement between a track groove and a rolling element. In this case, the inside of the boot surrounded by the outer ring and the inner ring having the track groove, the outer ring inner space surrounded by the shaft fitted to the inner ring, and the boot sealing the connection space between the shaft and the shaft and the outer ring. A partition plate is provided between the space.
The partition plate provided in the grease-filled universal joint of the present invention keeps the grease sealed in the outer ring inner space in the outer ring inner space so as not to move to the boot side, and the grease exists near the sliding surface that requires lubricant. To play a role. Even if the boot is damaged, the partition plate also serves as a seal against entry of dust, moisture, etc. into the sliding portion from the outside.

The partition plate used in the present invention is a material having flexibility and rubber-like elasticity capable of smoothly responding to the operation of the shaft even when the penetrating shaft is displaced at an operating angle, and a material having oil resistance to grease If it can be used, there is no particular limitation. For example, the thermoplastic elastomer and rubber generally used can be mentioned. These can be used alone or can be used by alloying.
Thermoplastic elastomers and rubbers can give flexibility while maintaining the strength of the structure, so when used in areas where external stresses such as compression and bending are frequently applied repeatedly, they easily deform following the compression and bending. Become.

Examples of elastomers that can be used in the present invention include polyolefin-based (TPO) (for example, Miralastomer manufactured by Mitsui Chemicals), polystyrene-based (TPS) (for example, Lavalon manufactured by Mitsubishi Chemical), and polyvinyl chloride-based (TPV) (for example, , Apco Sunplane), polyester (TPEE) (for example, Hytrel manufactured by Toray DuPont), polyurethane (TPU) (for example, Elastollan manufactured by BASF), polyamide (TPEA) (for example, Pebaks manufactured by Arkema) And the like.
In the case of rubber, various rubbers such as natural rubber, butadiene rubber, styrene butadiene rubber, chloroprene rubber, butyl rubber, nitrile rubber, ethylene propylene rubber, silicone rubber, urethane elastomer, fluorine rubber, and chlorosulfone rubber can be employed.

  The grease used in the present invention can be used without particular limitation as long as it is a commonly used grease. Base oils include commonly used lubricating oils such as paraffinic and naphthenic mineral oils, ester synthetic oils, ether synthetic oils, hydrocarbon synthetic oils, GTL base oils, fluorine oils, silicone oils, etc. Those mixed oils are mentioned. Examples of the thickener include lithium soaps, lithium complex soaps, calcium soaps, calcium complex soaps, aluminum soaps, aluminum complex soaps, and other urea compounds such as diurea compounds and polyurea compounds. It is not a thing.

  Grease also includes solid lubricants such as molybdenum disulfide and graphite, friction modifiers such as organic molybdenum, oily agents such as amines, fatty acids, and fats, antioxidants such as amines and phenols, petroleum sulfonates, disulfides. Antirust agents such as nonyl naphthalene sulfonate and sorbitan ester, extreme pressure agents such as sulfur and sulfur-phosphorus, antiwear agents such as organic zinc and phosphorus, metal deactivators such as benzotriazole and sodium nitrite, Various additives such as viscosity index improvers such as polymethacrylate and polystyrene may be included.

Examples of using the grease-filled universal joint of the present invention for a constant velocity universal joint include a ball fixed joint (hereinafter referred to as BJ) and an undercut free joint (hereinafter referred to as UJ). The number of balls of such BJ and UJ may be 6 or 8.
When the grease-filled universal joint of the present invention is used for BJ and UJ, the lubricant is filled only in necessary portions, which can contribute to cost reduction and weight reduction.
Examples of the sliding constant velocity universal joint include a double offset joint (hereinafter referred to as DOJ), a tripod joint (hereinafter referred to as TJ), and a cross groove joint.
Moreover, a cross joint etc. are mentioned as an inconstant velocity universal joint.

Since sliding universal joints such as TJ and DOJ require a sliding margin in the axial direction, the grease-filled space volume is larger than that of fixed universal joints such as BJ.
However, the grease-filled universal joint of the present invention can be provided with a partition plate between the outer ring inner space and the boot inner space so that the grease can be sealed only in the outer ring inner space where grease is required. When applying a sealed universal joint to a DOJ or TJ to enclose grease, the contribution to cost reduction and weight reduction becomes greater.

An embodiment in which the grease-filled universal joint of the present invention is applied to a constant velocity universal joint will be described with reference to FIGS. FIG. 1 is a cross-sectional view of a double offset joint according to an embodiment of the present invention. FIG. 2 is a view showing a partition plate as viewed from the A side with the boot of FIG. 1 removed.
As shown in FIG. 1, the double offset joint has six track grooves 3, 4 in the axial direction formed at equal angles on the inner surface of the outer ring 1 and the outer surface of the spherical inner ring 2, and is assembled between the track grooves 3, 4. The ball 5 is supported by a cage 6, the outer periphery of the cage 6 is a spherical surface 7, the inner periphery is a spherical surface 8 that fits the outer periphery of the inner ring 2, and the outer periphery of the outer ring 1 and the outer periphery of the shaft 9 are covered with a boot 10. Yes.

  The space existing in the universal joint includes a boot 10, a boot inner space 11 surrounded by the outer periphery of the shaft 9, an outer ring 1, an inner ring 2, track grooves 3 and 4, balls 5, and a cage 6. The outer ring inner space 12 surrounded by the shaft 9. A partition plate 13 penetrating the shaft 9 is attached between the boot inner space 11 and the outer ring inner space 12. Grease is enclosed in the outer ring inner space 12 and nothing is enclosed in the boot inner space 11. The partition plate 13 prevents the grease enclosed in the outer ring inner space 12 from moving to the boot inner space 11 and retains the grease in the outer ring inner space 12.

  Further, the partition plate 13 is manufactured from a flexible material that can smoothly correspond to the operating angle of the shaft 9, but in the case where the operating angle of the shaft 9 cannot be responded smoothly only by material properties. As shown in FIG. 2, by providing the cut 14 on the shaft 9 side, the flexibility corresponding to the operating angle of the shaft 9 can be enhanced.

  In the grease-filled universal joint of the present invention, the grease sealed in the outer ring inner space remains in the outer ring inner space without moving to the boot inner space by the partition plate, and the grease can be efficiently present on the sliding surface. As a result, it is possible to obtain a universal joint that requires a minimum amount of grease and that has a long service life and little deterioration of the rubber boot. Therefore, it can be suitably used as a universal joint for various industrial machines, particularly as a constant velocity universal joint for automobiles.

It is sectional drawing of the double offset joint which concerns on one Example of this invention. It is drawing which removes the boot of FIG. 1 and shows the partition plate seen from the A side.

Explanation of symbols

1 outer ring 2 inner ring 3 track groove 4 track groove 5 ball (rolling element)
6 Cage (Retainer)
7 Spherical surface 8 Spherical surface 9 Shaft 10 Boot 11 Space inside boot 12 Space inside outer ring 13 Partition plate 14 Notch

Claims (3)

An outer ring inner space surrounded by an outer ring, a shaft, an inner ring fitted to the shaft, and a rolling element interposed between the inner ring and the outer ring, and a connection space between the shaft and the shaft and the outer ring. A grease-filled universal joint comprising a boot inner space surrounded by a boot to be sealed, wherein rotational torque is transmitted from the shaft to the outer ring via the rolling elements,
A grease-filled universal joint, wherein a partition plate is provided between the outer ring inner space and the boot inner space, and grease is sealed in the outer ring inner space. The grease-filled universal joint is used for a constant velocity universal joint in which rotational torque is transmitted by engagement between a track groove and a rolling element,
A boot surrounded by an outer ring and an inner ring having track grooves, an outer ring inner space surrounded by a shaft fitted to the inner ring, and a boot that seals a connection space between the shaft and the shaft and the outer ring. 2. The grease-filled universal joint according to claim 1, wherein a partition plate is provided between the inner space and the inner space.   The universal joint according to claim 1, wherein the universal joint is a constant velocity universal joint.

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