JP2014009738A - Rolling bearing with rust inhibitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing which is appropriately available for a food machine and uses a rust inhibitor in an outer ring.SOLUTION: A rolling bearing comprises an outer ring, an inner ring, and a plurality of rolling bodies which are disposed between the outer ring and the inner ring so as to freely roll. In the rolling bearing, the outer ring is comprised of steel containing Cr in 6 wt.% or less. The outer ring is coated with grease, as rust-preventive oil, containing any one or more components of liquid paraffin, white oil, poly-α olefin oil, and fatty acid ester as base oil and containing any one or more components of aluminum composite soap, calcium composite soap, polyuria, and inorganic salt as a thickener, or with oil containing any one or more components of liquid paraffin, white oil, poly-α olefin oil, and fatty acid ester as base oil and containing any one or more components of amine-based carboxylate and sorbitan fatty acid ester as an additive agent.

Description

  The present invention relates to a rolling bearing device to which a rust preventive agent is applied, for example, used in a food transport robot, such as a food, pharmaceutical, or cosmetic manufacturing apparatus or transport apparatus.

  Rolling bearings used for food production and conveyance are in direct or indirect contact with food raw materials and products (or semi-finished products) at the production site, and in particular may contact water and salt. Since it is necessary to prevent toxic components from flowing out into the human body and mixing them into foods, stainless steel that has corrosion resistance is usually used for food hygiene, with the exception of industrial lubricants and rust preventive oils. Is done. For example, Patent Document 1 discloses that stainless steel in which at least one of an outer ring, an inner ring, and a rolling element is activated by plasma surface treatment is used, and fluorine-based grease is applied and sealed as a lubricant. .

JP 2003-343579 A

  However, when stainless steel is used for the inner and outer rings and rolling elements of the bearing, there is a problem that the cost of the bearing increases.

On the other hand, H1 grade lubricant is a kind of chemical products used in food processing sites set by the USDA (US Department of Agriculture) Food Safety Audit Bureau, and all risks of accidental mixing into food are denied. It is known as a lubricant used in places where it cannot. In addition, since 2001, the NSF (International Foundation for Hygiene Science) has continued to work with USDA, and has registered and registered chemical substances other than foodstuffs used in food manufacturing plants, one of which is H1 grade lubricant. In Japan, certification / standards for lubricants for food machinery are currently undeveloped, but in the future there are international trends that consider food safety. High nature.
However, since the lubricating oil satisfying the H1 grade is certified only from the viewpoint of food safety and is generally used for food machinery lubrication, the lubrication performance when used in bearings varies depending on the composition, and rolling bearings. There was room for study in terms of usage conditions and rolling life of the steel.

  Then, this invention aims at providing the bearing which can be used conveniently for a food machine and uses a rust preventive agent for an outer ring | wheel.

The invention for solving the above-mentioned problems is directed to a rolling bearing comprising a plurality of rolling elements that are freely rollable between an outer ring, an inner ring, and an outer ring and an inner ring. It is made of a steel material containing the following, and the outer ring is made of liquid paraffin, white oil, poly-alpha olefin oil, fatty acid ester and any one or more of the base oil, aluminum composite soap, calcium composite soap, polyurea, inorganic salt A grease containing one or more of the above ingredients as a thickener, or one or more of liquid paraffin, white oil, poly-alpha olefin oil, fatty acid ester as a base oil, An oil containing one or more components of acid salt and sorbitan fatty acid ester as an additive is applied as a rust inhibitor.
The above grease contains a base oil and a thickener as main components, but a small amount of additives may be further added.
For the outer ring of the present invention, it is possible to employ bearing steel having Cr: 6% by weight or less, that is, having a Cr content that is smaller than that of stainless steel and relatively inferior in corrosion resistance. Depending on the conditions of use, the bearing of the present invention may use high carbon chrome steel such as SUJ1 or SUJ2, carburized steel, or the like.
Further, the grease and oil of the present invention are preferably used as a rust preventive agent, applied to the outer ring, and filled as a lubricant in a bearing space formed by the outer ring and the inner ring.
When the grease of the present invention and the oil of the present invention are used in a bearing for food production machines, those that have been certified for H1 grade are preferably employed.

  The rolling bearing of the present invention uses rust preventive grease and rust preventive oil that do not affect the human body due to accidental mixing. However, the influence on the human body due to leakage of harmful components inside the bearing can be prevented. In addition, the bearing of the present invention does not use a relatively expensive stainless steel, and can use a normal bearing steel material such as a high carbon chrome bearing steel or a carburized steel, thereby reducing the product cost.

1 is a sealed rolling bearing according to an embodiment of the present invention.

  In this embodiment, as shown in FIG. 1, the ball bearing A is sealed with grease in a bearing space formed by the outer ring 1, the inner ring 2, and the ball 3, and is sealed with rubber seals 4 on both sides of the bearing. The outer ring 1, the inner ring 2, and the ball 3 of the bearing A are made of high carbon chrome steel.

Since machines that process foods and pharmaceuticals often use water, as described above, it is necessary to improve the corrosion resistance by applying ordinary bearing steel with anti-rust oil. Therefore, in the present embodiment, the outer diameter surface 11 and the end surface 12 of the outer ring 1 are coated with a rust preventive grease, for example, Cassida grease RLS, which uses poly α-olefin oil as a base oil and aluminum composite soap as a thickener. doing. Preferably, food machine grease certified as H1 grade is employed.

  Also, since the same bearing grease as the anti-rust grease is sealed inside the ball bearing A, even if grease leakage inside the bearing occurs during use, it cannot cause a chemical reaction with the anti-rust grease. Even if a very small amount of food or medicine is mixed, it is safe.

  The rubber seal used for preventing grease leakage is preferably a contact seal. In the present embodiment, it is preferable to use a so-called outer contact type seal that makes a slight contact with the outside of the seal groove 13 of the outer ring 1.

  In the ball bearing of the present embodiment, rust preventive grease that can be used for food, pharmaceuticals, and cosmetics is applied to the outer ring. Therefore, even if a steel material other than the bearing steel having corrosion resistance such as stainless steel is used as the material of the outer ring, Is less likely to occur, and it is preferable to attach it to food, pharmaceuticals and cosmetics processing and conveying devices.

  In the embodiment, bearing steel is used for the rolling elements, but a ceramic material may be used in order to improve corrosion resistance, heat resistance, wear resistance, and the like.

  In addition, in this embodiment, the deep groove ball bearing has been described as an example, but a bearing embodiment such as an angular ball bearing may be used. Deep groove ball bearings and angular contact ball bearings can be used in a single row, and depending on the conditions of use, if the bearing requires rigidity, or if it is used with preload applied, use a double row ball bearing or angular contact ball bearing. May be. Further, when the bearings are used in a double row, the seal may be modified only on the outer side in the axial direction of the combined bearing. In this case, the grease can flow between the bearings.

1 outer ring 2 inner ring 3 ball

Claims (2)

  In a rolling bearing provided with an outer ring, an inner ring, and a plurality of rolling elements arranged so as to be freely rollable between the outer ring and the inner ring, the outer ring is made of a steel material containing Cr: 6% by weight or less, The outer ring is based on any one or more of liquid paraffin, white oil, poly-alpha olefin oil, and fatty acid ester, and is one of aluminum composite soap, calcium composite soap, polyurea, and inorganic salt. Grease containing the above ingredients as a thickener, or one or more of liquid paraffin, white oil, poly-alpha olefin oil, fatty acid ester, base oil, amine carboxylate, sorbitan fatty acid ester A rolling bearing characterized in that an oil containing any one or more components as an additive is applied as a rust inhibitor. The rolling bearing according to claim 1, wherein the grease or the oil is filled in a bearing space formed by the outer ring and the inner ring.

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