JPS5911398A - Lubrication - Google Patents

Abstract

PURPOSE:To make long-term lubrication possible with low temp. increase and prolonged life almost without leakage, by using grease together with lubricating gel and applying them as two layers. CONSTITUTION:In applying a lubricant to a place to be lubricated, a grease with a hardness ranging from JIS consistency No.000 to No.1 is applied and then a lubricant (hereinafter referred to as lubricating gel) made semisolid as solid with a gelling agent with a consisting harder than that of the grease is applied. Since said grease and lubricating gel are quite different from each other in compositional and rheological properties, they are immiscible at the interface, forming two layers if shear is given to them by operating a machine. Therefore, little heat is developed by agitation, and the lubricant is slightly deteriorated and given a prolonged life. Additionally, the lubricant touching the outside is hard, foreign matter hardly enters from the outside, at the same time scarcely any lubricant flows out, and the lubricant in the place to be lubricated is highly fluid during revolution and is successfully supplied to a surface to be lubricated, so that good lubricating properties are obtd.

Description

[Detailed description of the invention] The present invention relates to a new lubrication direction.

Grease lubrication has many advantages over lubricating oils and is widely used.

The advantages of grease include:

(1) Less scattering, spillage, and dripping, preventing contamination of peripheral equipment, and allowing lubrication without replenishment for a long period of time.

(2) Since the grease itself acts as a seal,
``It prevents foreign matter from entering, and the sealing device for the lubricating part is simple and easy to design.

(3) Can be used in a wider temperature range than oil alone.

(4) It has better water resistance than oil and can be used in areas where water is present.

(5) Withstands harsh conditions such as high pressure loads, low speeds, impact loads, sliding, and intermittent operation.

(6) It can be stored for a long time, and the 54 oil film is maintained even in lubricated parts that are not operated for a long time, preventing rust and corrosion.

However, lubrication with grease has the following disadvantages compared to lubricating oil.

(1) Replacement, oiling, cleaning, and filling require experience.

(2) If foreign matter such as water or dust gets mixed in, it is difficult to carry out p-filtration. -, 1° (3) The cooling effect is small and the heat generation due to stirring resistance is large.

(4) Not suitable for ultra-high speeds.

Grease lubrication is carried out in a wide range of locations, and the conditions at the locations vary widely, such as operating temperatures, loads, speeds, environments, etc., and the type of grease used is tailored to the purpose of use. Many greases with significantly different compositions have been developed.

In recent years, as part of efforts to conserve resources, energy, and labor, demands have been made for greases to have longer lifespans, lower torque, maintenance and non-recurrence, and the use of lubricating oil to lubricate parts. Conventional greases cannot satisfy all of these requirements and demands.

In order to satisfy these needs and demands, the inventors of the present invention have conducted research aimed at correcting the drawbacks that conventional greases should have, but which are still insufficient and unresolved. The disadvantages of grease are a problem in response to requests and requests, but to solve the disadvantages, the advantages of grease would have to be halved or even 1 degree, so it is difficult to solve with a single grease. I confirmed it.

Regarding this, it is easy to think that it would be sufficient to use two types of grease together, or a combination of grease and oil, but it is difficult to do so in practice. For combinations of hard grease and soft grease, or combinations of hard grease and oil, when a machine works and rotation or sliding is applied to the lubricant, it will be relatively short for lubricants of similar composition or similar properties. The mixture becomes homogeneous over time, and is no different from the one that was mixed and supplied in advance, making it impossible to achieve the initial purpose. Therefore, these methods have not been put to practical use. If we consider that they are not mixed, and if there is hard grease surrounding soft grease in the actual lubricated part, the heat generation due to stirring, which is a disadvantage of grease, can be suppressed to a minimum of 1°, and the deterioration caused by heat generation will be small and the service life will be shortened. It can be extended, torque can be reduced, and the sealing performance, which is an advantage of grease, can be maintained and strengthened. However, in reality, this is more impossible than the above.

The present inventors have conducted various studies in order to maintain the advantages of the lubrication method using a two-layer lubricant for a long period of time, and have achieved the present invention.

To explain in more detail, the feature of the present invention is to use grease and a semi-solid lubricant (referred to as lubricating gel, lubricating gel, or gelb, hereinafter referred to as lubricating gel) with a gelling agent to supply lubrication as two layers. The purpose is to use two lubricants, grease and lubricating gel, which are compositionally different and have different rheological properties.

Conventionally, grease is defined as a semi-solid or solid lubricant in which a thickener is dispersed in a liquid lubricant, and includes lubricants with other ingredients added to improve special performance.
From a microscopic perspective, thickeners (various types ranging from spherical particles to stranded fibers with length and width) are dispersed in the lubricating oil as micelles, and the thickener retains the oil. is taking. For this reason, the grease used for ball bearings, roller bearings, and the grease used for parts without anti-scattering devices can be lubricated with grease in the parts that can be used for 1 degree, so when grease lubrication is mixed, In other words, it is necessary that the consistency (hardness) does not soften, that is, it is necessary to stabilize the mixture, and it is desirable that the torque is hobbed. A grease accumulation part is formed outside the bearing lubricating part, and it is necessary to form a protective film for the entire grease. Since the oil in grease is retained by a thickener, the oil that overflows from the thickener due to shearing etc. does not have the hardness of a grease and does not have the original performance of a grease. When strong shear is applied, the micelle structure created by the thickener is destroyed, and the thickener itself is also destroyed, and even if the shear is removed, the grease does not return to its original properties1. becomes.

It is said that the lubricity of grease is due to its thixotropic property (thixotropy), which causes the entire surface to become soft and lubricated, and then return to its original hardness when the grease stops moving. This phenomenon occurs, and it is hard to stiffen by 1°. Therefore, it is better to use gel fdan, which has strong thixotropic properties, but unlike grease hardened with a thickener, a grease-like material hardened with a gelling agent easily softens with heat or shearing.
Cannot be used continuously.

The thickening agent used in the present invention has a micellar structure that thickens a liquid (in the case of the present invention, lubricating oil), and most of them have a network structure of fibers to retain oil. It requires a relatively large amount of thickener to maintain its structure and is relatively resistant to shear. Furthermore, it is not necessarily necessary to dissolve or uniformly disperse in the liquid.

On the other hand, a gelling agent is almost the same as a thickening agent in its action of solidifying a liquid (in the present invention, a non-aqueous liquid).
Compared to thickeners, it has the ability to thicken a single liquid with a small amount, and exhibits high static hardness, but is easily softened by heat and/or shearing. Also, unlike thickeners, gelling agents can solidify liquids by solubilizing or stably dispersing them in liquids. Therefore 1. .

It is difficult or insufficient to prepare and use greases with gelling agents alone.

As mentioned above, grease and lubricating gel have completely different compositional and rheological properties, so even if a machine is operated and shear is applied to the lubricant, their behavior in response to shear differs, and they may mix at the interface. They found that there was no such phenomenon and established the lubrication method of the present invention by effectively utilizing this phenomenon.

The lubrication method of the present invention was achieved for the first time by discovering the above points, and is a novel lubrication method that cannot be easily achieved using conventional techniques.

The method of the present invention includes (1) a method in which soft grease is applied to the slippery part and lubricating gel is applied around it to form a two-layer lubricant of 1 m; There are two methods: applying lubricating gel to the area to be lubricated, and applying hard spike lease around it to form a two-layer lubricant layer.

The grease used in the present invention may be any conventionally used grease, but since the lubrication points to which this @cleaning method is applied are often subject to harsh conditions such as high loads, high speeds, and high temperatures. Preferably, 'lithium grease,
Multi-purpose grease with high dropping point such as urea grease, aluminum complex grease, lithium complex grease, etc. The gelling agent must have the ability to solidify non-aqueous liquids. Also included in the present invention are those that do not have a gelling effect when used as a - component, but exhibit the ability to work with a gelling agent when used as two or more than two components. For example, xanthan polymers, low density polyethylene, isotactic polypropylene, polycarboxylic acid esters, polycarboxylic acid derivatives and their salts, esters of carboxylic acid and hydroxypropyl hydrocarbons, unsaturated higher fatty acid esters, aluminum oftate, aluminum alcohol rate, alkoxides of group IA of the periodic table and ll
A-group crafts Tostil, I- and IA-group alkoxides,
K-acylglutamic acid diamide, N, N', N'-)
Realkylhydroxyaspartic acid amide, amide having a tetrahydrofuran group, alkylated derivative of glucose, heterocyclic compound having -0(OR)-N-...
and dibenzylidene sorbitol. l Preferred are N-acylglutamic acid diamide, N,N',N"-trialkylhydroxyaspartic acid amide, dibenzylidene sorbitol, which dissolve in lubricating oil at high temperatures. N-acylglutamic acid diamide and N
, N', N"-trialkylhydroxyaspartic acid amide shows similar gelation ability. In method (2), N-acylglutamic acid diamide, N, N', N'-)real Kylhydroxyaspartic acid amide is preferable.As lubricating oil 1U,
Mineral oil, ester synthetic oil, P, A, O oils and fats, synthetic hydrocarbons, etc., preferably mineral oil, ester synthetic oil, P, A,
It is O.

The grease in the above method (1) has a consistency grade of 000 to N11, preferably N[100 to 01
・It is. If it is over 1, it will be too hard and the torque will be too large, and N[
If it is less than LOOO, the two-layer structure cannot be maintained, which is inappropriate.

The hardness of the lubricating gel needs to be harder than that of the grease, and the OW (zero work) penetration of the grease is applied, and the
12 to 5 is appropriate. Below floors 2 and 2, the sealing function is insufficient, and IJ and Nα6 and above are inconvenient and unsuitable for lubricant supply.

The hardness of the lubricating gel in method (2) needs to be softer than that of the grease described below, and the OW consistency of the grease is applied.
o~Na2 is suitable. At N112 or higher (d), the torque at the start of lubrication becomes large, and at 0 or lower, the two-layer structure cannot be maintained, which is inappropriate.Grease grades 2 to 5 are appropriate.N
[With L2 or less, the sealing function is insufficient, and with NFL5 or more, greasing is inconvenient and unsuitable.

The scope of application of the lubrication method of the present invention is not particularly limited, but it is suitable for various open bearings, various sealed bearings, various joints, etc.

, t-) Near M roller bearings, the lubricant filling method of the present invention is explained with reference to FIG. 1. In method (1), roller 1, retainer 2, inner race 8, outer race 4 (part a) v Fill with grease.

After that, between the outside of the grease and the housing 5 (part b)
Fill with lubricating gel. In method (2), part a-2°VC
Lubricating gel, fill part b with grease. In FIG. 1, although the grease and the lubricating gel are shown without space for the sake of illustration, there may actually be a space between them.

Figure 2 shows a shielded ball bearing.The advantages of the present invention are as described above, but they are also common to methods (1), 3 (2), and are listed as follows: (1) Less heat generation due to M stirring (2) Lubricant deteriorates less due to heat generation and has a long life (8)
The lubricant that comes into contact with the outside is hard, so there is almost no foreign matter coming in from the outside. (4) The lubricant on the outside is hard, so there is almost no leakage or dripping of the lubricant. (5) The lubricant on the parts to be lubricated is It has high fluidity and good ability to intervene on lubricated surfaces, resulting in good lubricity.

The present invention will be explained by the following examples and comparative examples.

Example 1 N[lO lithium grease was used as the grease, and paraffinic mineral oil (ViSloo, 8C6t) was used as the lubricating gel.
The following tests were conducted using a Na8(OW) lubricating gel prepared by adding 5% by weight of dibenzylidene sorbitol and 5% by weight of PAN O to 94.5% by weight (@40°C), melting with heating, and cooling. The results obtained are shown in Table 1.

(a) Life test 680 according to ASTM D1741
6. Fill the ball, retate, and race parts of the oven bearing with grease 89 using a grease dispenser, and fill the outside (the part shown in Figure 1) with 8 g of lubricating gel.
1741, the grease life and grease leakage amount were investigated.

(b) Temperature rise test due to rotation (a) ,! : At the same time, a 6806 open bearing was filled with grease and lubricating gel, and a thermocouple was placed in contact with the outside of the outer race of the bearing, and it was set in an ASTM DI 741 test machine that was able to measure the temperature rise, without using a heater. Driving, ah.

The temperature is determined by rotation by a thermocouple on the outside of the outer race.

The increase was investigated and its steady-state value was measured.

Examples 2 to 4 Tests were conducted in the same manner as in Example 1, but with different types of grease and lubricating gel. In Example 2, the filling method is “Method (1)”
In Examples 8 and 4, method (2) is used.

Table 1 shows the greases, lubricating gels used, and test results.

Example 5 6202VV sealed bearing installed l+1
Rotation tests were carried out by filling the ball, retainer, and race surfaces with 0.7 g of the same grease used in Example 1 using a syringe, and replacing the motor bearing with 0.29 g of lubricating gel evenly applied to the shield plate. I did it. The operating conditions were compared with conventional grease lubrication. The results were as follows.

The temperature of the outer cover without load was 85°C.

In contrast, with conventional grease lubrication, the temperature was 40°C. Even under various conditions with different radial loads, a temperature reduction of 5 to 10 degrees Celsius was observed compared to conventional grease lubrication! 11 I was attacked.

In addition, no abnormal sounds, lubricant leakage, or other abnormalities were observed.

Example 6 For the bearing of a motor equipped with a 6202 VV sealed bearing, the same lubricating gel 0.72 as used in Example 4 was filled with a syringe into the balls, retainer, and race surface, and lubricating grease 0.29 was applied. A rotation test was conducted by replacing the coating with one that was evenly applied to the shield plate. The operating conditions were compared with conventional grease lubrication. The results were as follows.

The temperature of the outer cover under no load was 38°C.

In contrast, with conventional grease lubrication, the temperature was 40°C.

Even under various conditions where the radial load was changed, a decrease in temperature of 5 to 10°C was observed compared to conventional grease lubrication.

Also, no unusual noises, lubricant leaks, or other abnormalities were observed.

Comparative Example 1 Same base as used in the example with conventional grease lubrication.
The entire ring was filled with grease and the same test as in Example 1 was conducted. Table 1 shows the greases used and the test results.

Comparative Examples 2 and 8 The same test as in Example 1 was conducted using the same conventional grease as used in Example 1, with part a filled with soft grease and part b filled with hard grease. Table 1 shows the greases used and the test results.

As a result of the above test, the amount of grease leaked gradually increased with the passage of time in the case of the comparative example, whereas in the case of the example, almost no leakage was observed at the end of the service life.

In the case of the example, the temperature rise due to the rotation of the casing is temporarily suspended,
The results were almost the same even after restarting, and the temperature rise was kept low compared to the comparative example, which led to less deterioration of the lubricant, and life tests showed that the lifespan was significantly longer.

[Brief explanation of drawings]

Figure 1A is an explanatory diagram showing the oven-type roller bearing installed in machine 1, Figure 1B is an enlarged view of the bearing part circled in Figure 1A, and Figure 2 is a shielded type. FIG. 8 is an explanatory diagram showing the lubrication state near the pole of the ball bearing. FIG. 8 is an explanatory diagram of the lubrication state of the constant velocity joint. 1...Roller 2...Retainer 3...Inner race 4...Outer race 6...Housing 6...Hole 7,...Shield plate 8...
Gauge 9: Inner ring 10: Outer ring. Patent applicant Kyodo Yushi Co., Ltd.

Claims (1)

[Claims] L: When applying lubricant to a lubricated part, apply grease having a hardness in the range of JIS consistency Nl1ooo to N [Ll (7), and then A lubrication method characterized by supplying semi-solid or solid lubricant with a gelling agent having a harder consistency to form two lubricant layers. 2. When applying lubricant to lubricated parts, apply semi-solid or solid lubricant to the parts to be lubricated using a gelling agent that has a softer consistency than the grease described later, and then apply JI.
A lubrication method characterized by supplying a grease having a hardness in the range of S consistency 111 [L2 to 5 to form two lubricant layers.