JPH07252490A - Nylon powder-containing liquid lubricating material - Google Patents

Abstract

PURPOSE:To obtain the subject material such as a lubricating oil or grease, to be used in machinery/equipment operating under high bearing level. CONSTITUTION:This material is e.g. a lubricating oil or grease; for the former, it is obtained by incorporating a conventional lubricating oil with 0.5-10wt.% of fine nylon powder <=20mum in particle size for the latter, it is obtained by incorporating a conventional grease with 3-20wt.% of fine nylon powder <=20mum m in particle size.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improving the performance of a liquid lubricant, that is, lubricating oil or grease, which is used to smoothly operate a gear device, a rotary shaft or a sliding device of a machine for a long time. .

[0002]

2. Description of the Related Art Lubricating a machine gear device, a rotary shaft or a sliding device for the purpose of preventing wear due to a large frictional resistance caused by direct contact of mechanical elements which are in relative contact with each other and which are in relative contact with each other. Fill with liquid lubricant such as oil or grease,
Or apply.

These liquid lubricants form an oil film on the contact surface between the mechanical elements that are in contact with each other and prevent direct contact of the mechanical elements,
Although the above-mentioned purpose is achieved, if the pressure applied to the contact surface (hereinafter abbreviated as surface pressure) is too large, the oil is expelled from the contact surface and the oil film disappears.

[0006] Even under a high surface pressure, a substance that intervenes on the contact surface and exhibits lubricity, such as molybdenum disulfide, has been mixed, but it has not been widely applied to lubricating oil except a part of grease. . The main reasons for this are that the density difference from the oil is too large and the oil precipitates, and the large increase in viscosity due to the addition of a large amount to show the effect.

[0005]

By adding a small amount to a liquid lubricant, it intervenes in the contact surface of a mechanical element that is in sliding contact under high surface pressure to prevent direct contact of the element and reduce friction or wear ( If it is possible to find a substance that exerts an anti-friction effect, it will inevitably contribute to improving the performance of the machine. However, if an additive substance that can be mixed with lubricating oil or grease to exert an anti-friction effect is used, The following conditions are required.

1) Fine particles that are well dispersed in an oily substance and can easily enter narrow gaps between mechanical elements,

2) Low friction with mechanical elements (mainly metals) in the presence of oily substances,

3) Being softer than steel, copper alloys, and aluminum alloys, which are the main constituents of machine elements, and not damaging machine elements,

4) Fine particles do not aggregate due to friction to form coarse particles,

5) Addition of a small amount shows the effect, and addition does not significantly change the physical properties of lubricating oil or grease.

6) Especially when added to a lubricating oil, there is little difference in density from the lubricating oil which is mainly a mineral oil, and even if the added and mixed lubricating oil is left for a long period of time, the added substance does not precipitate and is at least suspended. To maintain the state, without forcibly mixing in use,
Promptly and uniformly disperse and mix.

[0012] It is an important problem to be solved industrially to discover such a substance, experimentally determine an appropriate addition amount, and provide a liquid lubricant having a high lubricating effect under a high surface pressure.

[0013]

As a substance satisfying the conditions 1) to 6), a certain kind of plastic powder is expected. It is a plastic whose low friction is currently confirmed,
Fine powders on the market include Teflon, polyolefin, and nylon.The above plastic powders are added and mixed in various proportions in various lubricating oil qualities, applied to gear reduction gears, and the effects are compared and confirmed. The present invention has been completed by confirming that the effective plastic fine powder is nylon fine powder having a particle size of 20 μm or less and the appropriate addition amount range.

The fine nylon powder used in the present invention is obtained by finely pulverizing 12 nylon by a low temperature pulverization method and has substantially spherical irregular shaped particles. 12 nylon is
It is a fine nylon powder that is suitable for the present invention and easily available because it has little oxidative deterioration and has a relatively high melting point (180 ° C.).

However, other types of nylon (for example, 6-6 nylon) have also been confirmed to have an anti-friction effect, so that the effect of the present invention can be expected sufficiently.

[0016]

The nylon fine powder in the liquid lubricant according to the present invention, which is enclosed or applied in the machine / apparatus, is drawn into the contact surface together with the liquid lubricant as the mechanical element, for example, the gear wheel rotates while sliding, Although it prevents direct contact of elements, the elastic modulus of nylon is approximately 3000 [MPa]
Since it is as small as (70/70 of steel), it elastically deforms due to the contact surface pressure and creates an appropriate gap for allowing an oil film to exist between both elements. Furthermore, it is significantly softer than metals and has friction resistance between metals. Since it is 1/2 to 1/3, the anti-friction effect is exhibited without damaging the mechanical element or hindering the movement of the mechanical element.

[0017]

EXAMPLES Next, the present invention and comparative examples will be described. Examples 1 to 6 and Comparative Example 1 (

[Table 1]) For the commercially available mineral lubricating oil for speed reducers, the above-mentioned nylon fine powder and two types of average particle diameters of 20 μm and 5 μm are used, and 0.5 to
Examples 1-6 were made with 10 wt% addition. The original lubricating oil was used as Comparative Example 1.

The test equipment was a hypoid gear reducer made of a commercially available steel gear (distance between input and output shafts: 20 mm, large gear diameter: 6 mm).
3mm, reduction ratio 1/45), or a worm gear reducer made of steel worm / bronze worm gears (distance between input and output shafts 40mm, reduction ratio 1/50). . Input shaft is 100v, 100
w A single-phase motor (1400 rpm) was directly connected. Input power (watt) by connecting a power meter to the effective coil of a single-phase motor
The performance evaluation was performed by comparing the starting power by measuring.

[0019]

According to the test results of [Table 1], the addition amount of the nylon powder shows an effect at 0.5%, but the optimum addition amount is 2 to 5
%. If it is added in an amount of 10% or more, the fluidity of the lubricating oil is impaired and it is not practical.

Examples 11 to 16 and Comparative Examples 11 to 14 (

[Table 2]) Commercially available metallic soap base grease with the above nylon fine powder 2
Seeds and the addition amount of 3 to 20% by weight in Examples 11 to 1
Made 6. Comparative Examples 11 to 14 were the original grease, grease made by adding other plastic powder to the original grease, and commercially available grease containing molybdenum disulfide.

As the test apparatus, a commercially available worm gear reducer made of steel worm / aluminum alloy worm gear (distance between input and output shafts 30 mm, reduction ratio 1/40) was used.

Using the same apparatus as described above, the vertical motion of the weight was repeated continuously.

The performance comparison was based on the temperature rise of the worm shaft, the number of continuous vertical operations until it stopped due to overload due to oil shortage, and the tooth thickness reduction of the worm gear due to wear.

[0023]

According to the test results of [Table 2], the addition of 3% of nylon powder shows the effect, but the best addition amount is 5 to 15%.
If it is added in an amount of 20% or more, the viscosity of grease increases and the practicality decreases.

[0024]

As described above, the liquid lubricant in which the nylon fine powder of 20 μm or less is added / dispersed reduces the frictional force between the mechanical elements that are in contact with each other while sliding under high surface pressure, and reduces the wear. As a result, the mechanical efficiency is increased, and the excellent effect of extending the life is given.

Claims (2)

[Claims] 1. A lubricating oil containing a polyamide resin (commonly known as nylon) powder having a particle size of 20 μm or less in an amount of 0.5 to 10% by weight. 2. A grease containing 3 to 20% by weight of polyamide resin (commonly called nylon) powder having a particle size of 20 μm or less.