JPH10246233A - Composite coating sliding product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain abrasive injury and insure lubricating performance by forming a ceramics layer on the surface of a sliding product, and baking a coating layer of fluororesin on the outer surface so that one part of this is penetrated into the ceramics layer. SOLUTION: This sliding member 5 uses metal such as cast iron or steel as a base material 6, ceramics synthetic material as a non-oxide material such as almina, powder of silicon nitride, or the like is formed into a fixed shape on the outer circumferential surface, and baked so as to form a ceramics layer 7. Liquid suspended with fine particles of fluororesin is sprayed on the outer surface of the layer 7 by means of a spray into a proper film thickness, dried, baked in a baking furnace, and a coating layer 8 of which one part is penetrated into the layer 7 is formed on the outer surface of the layer 7. The layer 8 is made of material of low friction coefficient and excellent lubricity, and favorable lubricating performance is exhibited even at no feed of oil. The layer 8 is gradually abraded, but because the layer 8 is protected by the layer 7 of high abrasion resistance when the abrasion is progressed over a fixed depth, abrasive injury of the layer 8 is restrained thereafter, and hence favorable lubricating performance can be maintained for a long term.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is mainly applied to a sliding portion such as a bearing portion, a key portion and a ball joint portion of a movable blade pump.
The present invention relates to a composite coated sliding product that can be applied to various types of mechanical parts using a metal as a base material.

[0002]

2. Description of the Related Art In a sliding product of this type, taking a movable blade pump as an example, as shown in FIG. The coating layer 11 made of a material having excellent heat resistance and chemical resistance such as ethylene fluoride resin (PTFE: generally referred to as Teflon) or fluorine resin, and having a low friction coefficient and excellent lubricity is used. Oil-free lubrication was realized by coating with a film thickness of about 0.2 to 0.3 mm.

[0003]

However, in the case of a conventional sliding product in which lubrication-free lubrication is realized only by the coating layer 11 made of the above-mentioned ethylene tetrafluoride resin or fluororesin material, the film is formed by a film. Due to the low thickness and lack of wear resistance, the coating layer 11 is susceptible to wear damage in a short-term operation, as shown in FIG. 5, and as a result, the friction coefficient increases due to the contact between the metal base materials 10, Furthermore, when it is applied to a pump that causes burning, the pumping liquid penetrates into the coating layer 11 from the damaged portion, thereby further shortening the service life. There was a problem of being forced.

The present invention has been made in view of the above circumstances, and suppresses a certain level of wear damage of a coating layer made of a material having a low coefficient of friction to ensure a predetermined lubricating performance for a long period of time. It is an object of the present invention to provide a composite coated sliding product that can be made.

[0005]

According to a first aspect of the present invention, there is provided a composite coated sliding product having a ceramic layer formed on a surface of a metal-based sliding product. And a coating layer made of fluororesin or ethylene tetrafluoride resin formed on the outer surface of the ceramic layer by baking so that a part thereof penetrates into the ceramic layer. Things.

According to the first aspect of the present invention, the outermost coating layer is made of a fluororesin or an ethylene tetrafluoride resin having a low coefficient of friction and excellent lubricity. Therefore, it is possible to exhibit good lubrication performance even without lubrication. At this time, the coating layer on the outermost surface gradually wears and damages with use, but when the wear damage exceeds a certain level, the coating layer baked in the ceramic layer in a penetrated state has high wear resistance. Since the coating is protected by the ceramic layer, the subsequent wear and damage of the coating layer is suppressed, thereby increasing the coefficient of friction due to the contact between the metal base materials and further prolonging the occurrence of seizure. It is possible to maintain good lubrication performance over a long period of time in combination with the inherent heat resistance.

[0007] In particular, as an object of the composite coated sliding product according to the first aspect of the present invention, as described in the second aspect, the present invention is applied to a bearing portion or a sliding portion of a movable blade pump or a general bearing. By doing so, their service life can be greatly extended as compared with conventional products.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partially sectional perspective view showing a main part of a mechanical movable vane pump which is one of application examples of the composite coating sliding product according to the present invention. The movable vane pump has a pump discharge passage (not shown). A movable wing 2 which is supported by a support shaft 1 so as to be able to change its angle is moved inside a fixed cylindrical member 4 in the axial direction by the operation of a motor 3 and a sliding member 5. The discharge water amount is changed by driving and rotating the support shaft 1 around the support shaft 1 through a crosshead 6 fixed to the tip of the crosshead 6 and an arm 7 linked to the movement of the crosshead 6 to change the angle. ing.

As shown in FIG. 2, the sliding member 5 of the movable vane pump having the above-described structure has a base material 6 made of a metal such as cast iron or steel.
A ceramic layer 7 is formed by forming a ceramic synthesis raw material, which is a non-oxide material such as alumina (aluminum oxide), silicon nitride powder, or silicon carbide, into a predetermined shape and simultaneously sintering the same.

A liquid in which fine powder of fluororesin is suspended on the outer surface of the ceramic layer 7 is sprayed to an appropriate film thickness by a spray, dried, and baked in a firing furnace, so that a part of the fluororesin is partially baked. The coating layer 8 penetrating into the ceramic layer 7 is formed on the outer surface of the ceramic layer 7.

As described above, in the sliding member 5 in which the ceramic layer 7 and the coating layer 8 made of fluororesin are formed on the outer surface of the metal base material 6, the coating layer 8 on the outermost surface is made of fluororesin. Because it is made of a material having a low coefficient of friction and excellent lubricity, good lubrication performance is exhibited even without lubrication. The outermost surface of the coating layer 8 is gradually worn and damaged as the sliding member 5 slides in the axial direction in the fixed cylindrical member 4 during use, that is, during operation of the movable blade pump. As shown in FIG. 3, when the wear damage progresses to a certain level or more, the coating layer 8a of the remaining fluororesin which is baked in the ceramic layer 7 in a penetrating state is protected by the ceramic layer 7 having high wear resistance. Therefore, abrasion damage of the coating layer 8a thereafter is suppressed, and good lubrication performance is maintained even during long-term pump operation.

In the above-described embodiment, a description has been given of the case where a fluororesin is used as a material for forming the coating layer 8 outside the ceramic layer 7, but an ethylene tetrafluoride resin (PTFE) may be used. . This ethylene tetrafluoride resin needs to be sintered by powder metallurgy and is inferior to fluororesin in terms of workability, but its coefficient of friction is very small, 0.2 to 0.04. It is superior in terms of lubrication performance. In addition, these fluororesins and ethylene tetrafluoride resins are both excellent in heat resistance and chemical resistance, and from this aspect, the service life can be extended.

In the above embodiment, the present invention is applied to the composite coating of the sliding member 5 in the movable blade pump.
In addition, the present invention may be applied to the composite coating of the inner peripheral surface of the fixed cylindrical member 4 in the movable vane pump, and various mechanical parts other than the movable vane pump, such as a bearing for a vehicle, using a metal as a base material. Is also applicable.

[0014]

As described above, according to the first aspect of the present invention, the ceramic layer and the outside of the ceramic layer are formed of a material having a low coefficient of friction and excellent lubricity, such as a fluororesin or an ethylene tetrafluoride resin. In the early stage of use, the oil-free lubrication performance is well exhibited while allowing the wear of the coating layer, and
After the coating layer is damaged beyond a certain level, the coating layer that has been baked in the ceramic layer in a penetrating state is protected by the highly wear-resistant ceramic layer. Damage can be minimized. Therefore, the use of a very short period of time increases the coefficient of friction due to the contact between the metal base materials and eliminates the occurrence of seizure, and, in combination with the inherent heat resistance of the ceramic layer, provides good lubrication performance. This can be maintained over a period of time, and it is possible to significantly increase the service life of the sliding product.

In particular, when the present invention is applied to a bearing or a sliding portion of a movable vane pump or a general bearing as described in claim 2, operation shutdown, disassembly, parts replacement, etc. due to performance degradation or occurrence of failure, etc. Cycle can be greatly extended as compared with the conventional product.

[Brief description of the drawings]

FIG. 1 is a partially sectional perspective view showing a main part of a mechanical movable vane pump which is one of application examples of a composite coated sliding product according to the present invention.

FIG. 2 is an enlarged sectional view of a composite coating section.

FIG. 3 is an enlarged cross-sectional view illustrating the progress of wear of the composite coating portion.

FIG. 4 is an enlarged sectional view of a coating part in a conventional sliding product.

FIG. 5 is an enlarged cross-sectional view for explaining the progress of wear of the coating part.

[Explanation of symbols]

 5 Sliding member (an example of a sliding product) 6 Metal base material 7 Ceramic layer 8 Coating layer

Claims (2)

[Claims] A ceramic layer is formed on a surface of a sliding product having a metal as a base material, and a coating layer made of a fluororesin or an ethylene tetrafluoride resin is formed on an outer surface of the ceramic layer. A composite coated sliding product characterized in that a part is baked and formed so as to penetrate into the ceramic layer. 2. The composite coated sliding product according to claim 1, wherein the target product is a bearing portion or a sliding portion of a movable blade pump or a general bearing.