JP2008163998A - Pulley supporting bearing and pulley supporting structure of electromagnetic clutch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pulley supporting bearing capable of increasing its bearing life. <P>SOLUTION: The pulley supporting bearing 11 is a sealing type multiple row angular ball bearing consisting of a metal inner ring 12 of which inner diameter d<SB>1</SB>is equal to or longer than 30 mm, a metal outer ring 13 of which outer diameter dimension d<SB>2</SB>is equal to or longer than 45 mm and equal to or shorter than 65 mm and of which axial direction dimension l is shorter than 18 mm and satisfies 0.19≤l/d<SB>2</SB>≤0.39, a plurality of metal balls 14 provided between an inner ring raceway surface 12a and an outer ring raceway surface 13a and a tight seal 16 provided between the inner ring 12 and the outer ring 13 for tightly sealing a bearing inner space. Phosphoric acid metallic salt coating films are formed on the inner ring raceway surface 12a, the outer ring raceway surface 13a and rolling surfaces 14a of the balls 14. A grease composition 17 is sealed in the bearing inner space. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a pulley support bearing, and more particularly to a bearing that supports a pulley of an electromagnetic clutch.

  A conventional compressor that compresses a refrigerant by being incorporated in an air conditioner for an automobile is described in, for example, Japanese Patent Application Laid-Open No. 11-280644 (Patent Document 1). Moreover, since the compressor described in the publication rotates the rotating shaft by the driving force of the engine, an electromagnetic clutch is often employed as a device for controlling the mechanical connection between the engine and the compressor.

  The electromagnetic clutch is rotatably supported by a rolling bearing, and is arranged with a pulley connected to the engine by an endless belt, a predetermined clearance from one end surface of the pulley, and fixed to the rotating shaft of the compressor. A plate and a solenoid fixed at a position facing the magnetic annular plate across the pulley. Further, as a rolling bearing that rotatably supports a pulley, a deep groove ball bearing, a three-point contact ball bearing, a four-point contact ball bearing, and the like are often used.

In the electromagnetic clutch having the above configuration, when the solenoid is not energized, the pulley and the magnetic annular plate are separated from each other, and the rotation of the pulley is not transmitted to the rotating shaft. On the other hand, when the solenoid is energized, the magnetic annular plate comes into contact with the pulley by the attraction force of the solenoid, and the rotation of the pulley is transmitted to the rotating shaft.
JP-A-11-280644

  In the electromagnetic clutch having the above-described configuration, the rolling bearing that supports the pulley includes a radial load caused by the tension of the endless belt, an imaginary line that passes through the axial center portion of the pulley, and an imaginary line that passes through the axial center portion of the rolling bearing. A moment load due to the distance (hereinafter referred to as “offset”) is applied. In particular, with the recent reduction in weight, compactness, and speed of compressors, the speed of electromagnetic clutches has increased, and the load applied to rolling bearings has also increased.

  Here, the single row deep groove ball bearing has low rigidity against moment load. In addition, although the three-point contact ball bearing and the four-point contact ball bearing have higher rigidity against moment load than the single row deep groove ball bearing, it may not always be sufficient. As a result, vibration and noise are easily generated during operation, and durability is difficult to ensure. Further, in a single row four-point contact ball bearing, when the offset is increased, the contact angle changes and the ball slip rate increases, and the grease life is significantly reduced. If it does so, a lubrication defect will be caused, and a raceway surface will generate | occur | produce and there exists a possibility that a bearing life may become short.

  Further, the rolling bearing described above is in a state of boundary lubrication during rolling, and an oil film is present partially or temporarily on the raceway surface or rolling surface, that is, the friction surface between the ball and the inner ring or outer ring. The interface lubrication condition is not likely to occur. Here, there is also a problem that due to the heat generation at that time and the generation of wear powder due to sliding between metals, the lubricant such as grease deteriorates and the bearing life cannot be extended sufficiently.

  Further, when the rolling bearing described above is used under severe conditions such as high-speed rotation at high temperatures, specific peeling accompanied with white structure change occurs at an early stage on the raceway surface of the rolling bearing, which causes a problem. Such specific exfoliation is considered to be exfoliation due to hydrogen embrittlement caused by hydrogen. Since such peeling may shorten the bearing life, it is necessary to take measures.

  An object of the present invention is to provide a pulley support bearing capable of extending the bearing life.

  Another object of the present invention is to provide a pulley support structure for an electromagnetic clutch having a long life.

The pulley support bearing according to the present invention is fitted to the inner diameter surface of the pulley and rotatably supports the pulley. Further, the pulley support bearing is made of metal and has a double row inner ring raceway surface on the outer diameter surface, and an inner ring whose inner diameter dimension d ₁ is d ₁ ≧ 30 mm, and is made of metal and has an inner diameter surface. There are double-row outer ring raceway surfaces at positions facing the inner ring raceway surface, the outer diameter dimension d ₂ is 45 mm ≦ d ₂ ≦ 65 mm, the axial dimension l is l <18 mm, 0.19 ≦ l / d ₂ ≦ 0. .39 outer ring, a plurality of balls made of metal and disposed between the inner ring raceway surface and the outer ring raceway surface, and a sealing member disposed between the inner ring and the outer ring to seal the bearing internal space. This is a sealed double row angular contact ball bearing. Here, a metal phosphate coating is formed on the inner ring raceway surface, the outer ring raceway surface and the ball rolling surface. In addition, a grease composition is sealed in the bearing internal space, and the grease composition is a grease composition obtained by adding an additive to a base grease composed of a base oil and a thickener. The additive contains at least one aluminum-based additive selected from aluminum powder and an aluminum compound, and the mixing ratio of the aluminum-based additive is 0.05 to 100 parts by weight with respect to 100 parts by weight of the base grease. .

  By adopting the above configuration, the change in the contact angle and the slip ratio of the balls can be reduced to prevent the grease life from being reduced. Even in the case of boundary lubrication in which the oil film is interrupted on the friction surfaces of the outer ring, inner ring, and balls, the metals do not come into contact with each other and there is no risk of metal wear powder being generated. In addition, peeling due to hydrogen embrittlement can be reduced. Therefore, the bearing life can be extended.

  Preferably, the inner ring, the outer ring, and the ball are immersed in a phosphate triester solution to form a metal phosphate salt film on the surface thereof. By doing so, a metal phosphate coating can be easily formed on the friction surfaces of the inner ring, the outer ring and the balls.

A pulley support structure for an electromagnetic clutch according to the present invention includes a pulley, a magnetic annular plate disposed on one side in the axial direction of the pulley and fixedly connected to the rotating shaft, and a position facing the magnetic annular plate on the other side of the pulley. And a pulley support bearing that rotatably supports the pulley. The pulley support bearing is made of metal and has a double row inner ring raceway surface on the outer diameter surface, and an inner ring whose inner diameter dimension d ₁ is d ₁ ≧ 30 mm, and is made of metal and has an inner diameter raceway surface. There are double-row outer ring raceway surfaces facing the surface, the outer diameter dimension d ₂ is 45 mm ≦ d ₂ ≦ 65 mm, the axial dimension l is l <18 mm, 0.19 ≦ l / d ₂ ≦ 0.39. The outer ring, the metal, a plurality of balls disposed between the inner ring raceway surface and the outer ring raceway surface, and a sealing member disposed between the inner ring and the outer ring and sealing the bearing inner space. This is a double-row angular contact ball bearing. Here, a metal phosphate coating is formed on the inner ring raceway surface, the outer ring raceway surface and the ball rolling surface. In addition, a grease composition is sealed in the bearing internal space, and the grease composition is a grease composition obtained by adding an additive to a base grease composed of a base oil and a thickener. The additive contains at least one aluminum-based additive selected from aluminum powder and an aluminum compound, and the mixing ratio of the aluminum-based additive is 0.05 to 100 parts by weight with respect to 100 parts by weight of the base grease. .

  By adopting the pulley support bearing configured as described above, it is possible to reduce the separation of the raceway surface, and thus it is possible to obtain an electromagnetic clutch having a long life.

  Preferably, a distance δ between an imaginary line passing through the axial central portion of the pulley and an imaginary line passing through the axial central portion of the pulley support bearing satisfies δ ≦ 4 mm. By setting the offset within this range, the life of the pulley support bearing can be extended.

  According to this invention, the change in the contact angle and the slip ratio of the balls can be reduced to prevent the grease life from decreasing. Further, even in the case of boundary lubrication in which the oil film is interrupted on the friction surfaces of the outer ring, inner ring, and balls, the metals do not come into contact with each other, and there is no possibility of generating metal wear powder. In addition, peeling due to hydrogen embrittlement can be reduced. Therefore, the bearing life can be extended.

  Moreover, since the pulley support structure of an electromagnetic clutch provided with such a pulley support bearing can reduce peeling of a raceway surface, it can lengthen a lifetime.

  With reference to FIGS. 1-4, the pulley support bearing which concerns on one Embodiment of this invention is demonstrated. 1 is a view showing the pulley support bearing 11, FIG. 2 is a view showing a compressor 21 employing the pulley support bearing 11, and FIGS. 3 and 4 are partially enlarged views of the electromagnetic clutch 32. FIG. In addition, the pulley support bearing 11 in FIGS. 2-4 is simplified and shown.

  First, referring to FIG. 2, the compressor 21 includes a casing 22, a rotating shaft 29, a swash plate 30, a piston 31, and an electromagnetic clutch 32. The compressor 21 is incorporated in a vapor compression refrigerator of an automobile air conditioner.

  The casing 22 includes a head case 23 having a low-pressure chamber 26 and a high-pressure chamber 27, a cylinder case 24 having a plurality of cylinders 28 in which pistons 31 reciprocate, and a swash plate case 25 that houses a swash plate 30. (Omitted).

  The low-pressure chamber 26 includes a suction port (not shown) provided in the head case 23, a suction hole 26a communicating with each cylinder 28, and a valve 26b for preventing the reverse flow of the refrigerant vapor from the suction hole 26a. The suction port communicates with the outlet of an evaporator (not shown) that constitutes the vapor compression refrigerator. Then, the refrigerant vapor sucked from the suction port is supplied to the cylinder 28 through the suction hole 26a.

  On the other hand, the high-pressure chamber 27 has a discharge port (not shown) provided in the head case 23, a discharge port 27a communicating with the cylinder 28, and a valve 27b for preventing the reverse flow of the refrigerant vapor from the discharge port 27a. The discharge port communicates with an inlet of a condenser (not shown) that constitutes the vapor compression refrigerator. Then, the refrigerant vapor inside the cylinder 28 compressed by the piston 31 is supplied to the high pressure chamber 27 through the discharge port 27a.

  The rotating shaft 29 communicates with the casing 22 and the electromagnetic clutch 32, and is rotatably supported at two locations of the cylinder case 24 and the swash plate case 25 by a radial needle roller bearing 29a and a thrust needle roller bearing 29b. Further, the swash plate 30 is held inside the swash plate case 25.

  The swash plate 30 is fixedly connected to the rotating shaft 29 in a state where it is inclined at a predetermined angle with respect to a plane orthogonal to the rotating axis of the rotating shaft 29. Further, pistons 31 are connected to a plurality of locations on the circumference by a sliding shoe 30a.

  The piston 31 is connected to the swash plate 30, and reciprocates in the axial direction (left-right direction in FIG. 2) in the cylinder 28 as the rotary shaft 29 rotates. A compression chamber 28 a for compressing the refrigerant vapor is formed in a region surrounded by the cylinder 28 and the piston 31.

  The electromagnetic clutch 32 includes a pulley 33, a solenoid 34, a magnetic annular plate 35, and a pulley support bearing 11.

  The pulley 33 has a groove 33b for holding the endless belt 33a on the outer diameter surface and a recess 33c for housing the solenoid 34 on one end surface, and is rotatably supported by the casing 22 by the pulley support bearing 11.

  The solenoid 34 is disposed in a state where a predetermined gap is provided inside the recess 33 c and is fixed to the casing 22. The magnetic annular plate 35 is an annular member formed of a magnetic material, and is disposed so as to face the solenoid 34 with the pulley 33 interposed therebetween. Moreover, it is being fixed to the rotating shaft 29 by the leaf | plate spring 35a. The leaf spring 35 a biases the magnetic annular plate 35 in a direction away from the pulley 33.

  Next, referring to FIG. 1, the pulley support bearing 11 includes an inner ring 12 having a double row inner ring raceway surface 12a on the outer diameter surface, and a double row outer ring raceway surface at a position facing the inner ring raceway surface 12a on the inner diameter surface. An outer ring 13 having 13a, a plurality of balls 14 disposed between the inner ring raceway surface 12a and the outer ring raceway surface 13a, a retainer 15 for holding a space between adjacent balls 14, and a bearing inner space ("inner ring 12 of This is a sealed double-row angular contact ball bearing provided with a sealing seal 16 as a sealing member for sealing a space between the outer diameter surface and the inner diameter surface of the outer ring 13. A grease composition 17 is enclosed in the pulley support bearing 11. The inner ring 12, the outer ring 13 and the ball 14 are all made of metal.

The pulley support bearing 11 has an inner diameter d ₁ of the inner ring 12 of d ₁ ≧ 30 mm, an outer diameter d ₂ of the outer ring 13 of 45 mm ≦ d ₂ ≦ 65 mm, an axial dimension l of 1 <18 mm, 0.19. ≦ l / d2 ≦ 0.39 is set. In this embodiment, the inner ring 12 and the outer ring 13 have the same axial dimension.

Here, a metal phosphate salt film is formed on the surface of the inner ring 12 including the inner ring raceway surface 12a, the surface of the outer ring 13 including the outer ring raceway surface 13a, and the surface of the ball 14 including the rolling surface 14a of the ball 14. Yes. A method for forming the metal phosphate coating on the surface of the inner ring 12 and the like will be briefly described. First, a solution of a phosphate triester ((RO) ₃ P═O) such as tricresyl phosphate ((CH ₃ C ₆ H ₄ O) ₃ PO) is prepared. In the formula, R represents an aryl group, an aliphatic hydrocarbon group, or an alicyclic hydrocarbon group. The inner ring 12 and the like described above are immersed in this solution. In this way, the inner ring 12 and the like are reacted with the phosphoric acid triester to form a metal phosphate film on the surface.

  Here, the phosphoric acid triester is an organic phosphoric acid compound represented by the formula, and a commercially available industrial material can be used as the plasticizer or the like. From the viewpoint of handleability, it may be diluted with an organic solvent as necessary. Further, in order to increase the reaction rate, the reaction may be carried out by heating. For example, if immersed for 1 to 2 hours at 60 ° C., a desired metal phosphate film can be obtained.

  By doing so, a metal phosphate coating is applied to the inner ring raceway surface 12a of the inner ring 12, the outer ring raceway surface 13a of the outer ring 13, and the rolling surface 14a of the ball 14, that is, the friction surface between the inner ring 12 and the outer ring 13 and the ball 14. Can be formed. Then, even in the case of boundary lubrication in which the oil film is interrupted, the metals do not contact each other, and generation of metal wear powder can be prevented. Therefore, the separation of the raceway surface and the like can be reduced and the bearing life can be extended.

  Next, the operation of the compressor 21 configured as described above will be described with reference to FIGS. 2, 3 and 4. First, the endless belt 33a is stretched around a driving pulley (not shown) that is rotationally driven by an engine (not shown). Therefore, the pulley 33 rotates with the rotation of the engine.

  Referring to FIG. 3, a gap is formed between pulley 33 and magnetic annular plate 35 when solenoid 34 is not energized. As a result, the rotation of the pulley 33 is not transmitted to the rotating shaft 29. On the other hand, referring to FIG. 4, when the solenoid 34 is energized, the magnetic annular plate 35 abuts against the pulley 33 against the leaf spring 35 a by the attractive force of the solenoid 34. As a result, the rotation of the pulley 33 is transmitted to the rotating shaft 29 via the magnetic annular plate 35. 3 and FIG. 4 indicates a rotating portion.

  When the rotary shaft 29 rotates, the piston 31 attached to the swash plate 30 reciprocates inside the cylinder 28. When the piston 31 moves in the direction of increasing the volume of the compression chamber 28a (leftward in FIG. 2), the valve 26b is opened, and the refrigerant vapor moves from the low pressure chamber 26 to the compression chamber 28a through the suction hole 26a. At this time, the valve 27b is closed to prevent the refrigerant vapor in the high pressure chamber 27 from flowing back to the compression chamber 28a.

  Next, when the piston 31 moves in the direction of reducing the volume of the compression chamber 28a (right direction in FIG. 2), the piston 31 compresses the refrigerant vapor in the compression chamber 28a, and the valve 27b is opened and compressed. The refrigerant vapor thus moved moves to the high-pressure chamber 27 through the discharge port 27a. At this time, the valve 26 b is closed to prevent the refrigerant vapor in the compression chamber 28 a from flowing back to the low pressure chamber 26.

  With the above configuration, the refrigerant vapor can be compressed using the driving force of the engine. Here, the electromagnetic clutch 32 increases the tension of the endless belt 33a in order to prevent slippage between the endless belt 33a and the pulley 33 and reliably transmit power. Therefore, the pulley support bearing 11 that supports the pulley 33 is loaded with a radial load due to the tension of the endless belt 33a or a moment load due to offset. Therefore, by using the pulley support bearing 11 as a double row angular ball bearing having a dimensional relationship as shown in FIG.

  Here, since the rotation speed of the rotating shaft 29 depends on the outer diameter dimension of the pulley 33, the outer diameter dimension of the pulley 33 cannot be freely set from the viewpoint of securing the rotation speed necessary for the compressor 21. Further, since the inner diameter dimension of the pulley 33 is determined in consideration of the strength of the pulley 33 and the like, the inner diameter dimension is naturally determined when the outer diameter dimension is determined.

As a result, the pulley support bearing 11 has a larger restriction on the outer diameter of the outer ring 13 fitted into the pulley 33 than the inner diameter of the inner ring 12 fitted into the casing 22 at the time of design. Therefore, by optimizing the relationship between the outer diameter d ₂ and the axial dimension l of the larger outer ring 13 of the restriction, it is possible to maximize the bearing function.

  Next, the grease composition 17 enclosed in the pulley support bearing 11 will be described. The grease composition 17 is a grease composition formed by adding an additive to a base grease composed of a base oil and a thickener. The additive contains at least one aluminum-based additive selected from aluminum powder and an aluminum compound.

  Aluminum compounds include aluminum carbonate, aluminum sulfide, aluminum chloride, aluminum nitrate and its hydrate, aluminum sulfate, aluminum fluoride, aluminum bromide, aluminum iodide, aluminum oxide and its hydrate, aluminum hydroxide, selenium Aluminum fluoride, aluminum telluride, aluminum phosphate, aluminum phosphide, lithium aluminate, magnesium aluminate, aluminum selenate, aluminum titanate, aluminum zirconate and other inorganic aluminum, aluminum benzoate, aluminum citrate and other organic aluminum Is mentioned. These aluminum-based additives may be added to grease by mixing one type or two types. Particularly preferred is an aluminum powder having a high extreme pressure effect because it has excellent heat resistance and resistance to thermal decomposition.

  The compounding ratio of the aluminum-based additive is 0.05 to 10 parts by weight with respect to 100 parts by weight of the base grease. That is, when the aluminum-based additive is only aluminum powder, 0.05 to 10 parts by weight of aluminum powder with respect to 100 parts by weight of the base grease, and when the aluminum-based additive is only aluminum compound, 100 parts by weight of the base grease When the aluminum compound is 0.05 to 10 parts by weight relative to the base grease and the aluminum-based additive is aluminum powder and aluminum compound, the total amount of the aluminum powder and aluminum compound is 0.05 to 100 parts by weight of the base grease. -10 weight part is mix | blended.

  If the blending ratio of the aluminum-based additive is less than this blending range, peeling on the raceway surface due to hydrogen embrittlement cannot be effectively prevented. Moreover, even if it exceeds the said range, the peeling prevention effect does not improve any more.

  Here, as base oil, mineral oil such as spindle oil, refrigerating machine oil, turbine oil, machine oil, dynamo oil, highly refined mineral oil, liquid paraffin, polybutene, GTL oil synthesized by Fischer-Tropsch method, poly α-olefin Oils, hydrocarbon synthetic oils such as alkyl naphthalene and alicyclic compounds, or natural oils, polyol ester oils, phosphate ester oils, polymer ester oils, aromatic ester oils, carbonate ester oils, diester oils, polyglycol oils And non-hydrocarbon synthetic oils such as silicone oil, polyphenyl ether oil, alkyl diphenyl ether oil, alkyl benzene oil, and fluorinated oil. Among these, it is preferable to use an alkyl diphenyl ether oil or a poly α-olefin oil excellent in heat resistance and lubricity.

  In addition, as thickeners, urea compounds such as benton, silica gel, fluorine compound, lithium soap, lithium complex soap, calcium soap, calcium complex soap, aluminum soap, aluminum complex soap, diurea compound, polyurea compound, etc. Is mentioned.

  A urea compound is obtained by reacting an isocyanate compound and an amine compound. Since it is not preferable to leave a reactive free radical, it is preferable to mix the isocyanate group of the isocyanate compound and the amino group of the amine compound so as to be approximately equivalent.

  A diurea compound is obtained by reaction of a diisocyanate and a monoamine, for example. Diisocyanates include phenylene diisocyanate, tolylene diisocyanate, diphenyl diisocyanate, diphenylmethane diisocyanate, octadecane diisocyanate, decane diisocyanate, hexane diisocyanate, and monoamines include octylamine, dodecylamine, hexadecylamine, atarylamine, oleylamine, aniline. , P-toluidine, cyclohexylamine and the like. The polyurea compound is obtained, for example, by reaction of diisocyanate with monoamine or diamine. Examples of the diisocyanate and monoamine include those similar to those used for the production of the diurea compound. Examples of the diamine include ethylenediamine, propanediamine, butanediamine, hexanediamine, octanediamine, phenylenediamine, tolylenediamine, xylenediamine, And diaminodiphenylmethane.

  By adding a thickener such as a urea compound to the base oil, a base grease for blending the aluminum additive and the like can be obtained. A base grease using a urea compound as a thickener is prepared by reacting an isocyanate compound and an amine compound in a base oil.

  The blending ratio of the thickener in 100 parts by weight of the base grease is 1 to 40 parts by weight, preferably 3 to 25 parts by weight. If the content of the thickener is less than 1 part by weight, the thickening effect is reduced, making it difficult to form a grease, and if it exceeds 40 parts by weight, the obtained base grease becomes too hard and it is difficult to obtain the desired effect. Become.

  In addition to the aluminum-based additive, a known grease additive may be included as necessary. Examples of the additives include antioxidants such as organic zinc compounds, amines, and phenolic compounds, metal deactivators such as benzotriazole, viscosity index improvers such as polymethacrylate and polystyrene, molybdenum disulfide, and graphite. Examples thereof include solid lubricants, metal sulfonates, antirust agents such as polyhydric alcohol esters, friction reducing agents such as organic molybdenum, oily agents such as esters and alcohols, and antiwear agents such as phosphorus compounds. These can be added alone or in combination of two or more.

  As described above, the pulley support bearing configured as described above, that is, the constituent members of the pulley support bearing have the dimensional relationship described above, and the metal phosphate salt coating is formed on the inner ring raceway surface, the outer ring raceway surface and the ball rolling surface. The pulley support bearing in which the grease composition sealed inside has the above-described configuration can prevent a decrease in grease life by reducing a change in contact angle and a sliding ratio of balls. If it does so, poor lubrication can be controlled and peeling of a raceway surface can be reduced. Further, even under a boundary lubrication environment, the generation of metal wear powder can be prevented, and the raceway surface can be reduced. Further, peeling due to hydrogen embrittlement can be reduced. Therefore, the bearing life can be extended.

  Further, by adopting the pulley support bearing having the above-described configuration, it is possible to reduce the separation of the raceway surface, so that an electromagnetic clutch having a long life can be obtained.

  Next, a test for measuring the grease life was performed. The test method and test results will be described with reference to FIGS. 5 and 6 are diagrams showing the test apparatus 41, and FIG. 7 is a graph showing the test results.

  First, the test apparatus 41 includes a drive pulley 42, a driven pulley 44 connected to the drive pulley 42 by an endless belt 43, and a motor 45 that rotationally drives the drive pulley 42. Further, as a bearing for supporting the driven pulley 44, a double-row angular contact ball bearing (hereinafter referred to as “the product of the present invention”) as a pulley support bearing 11 as shown in FIG. 1 and a four-point contact single-row ball bearing as a comparative example. (Hereinafter referred to as “conventional product”).

  As test conditions, the rotational speed of the driven pulley 44 is 7000 rpm, the radial load applied to the bearing by the tension of the endless belt 43, etc. is 1470 N, and the offset amount δ is 0.5 mm and 4 mm. The atmosphere and the temperature of the bearing at the time of the test are managed by a heater.

  Referring to FIG. 7, it was confirmed that when the product of the present invention is adopted as a bearing for supporting the driven pulley 44, a bearing life of 500 hours or more can be obtained even when the offset amount δ is 4 mm. On the other hand, when a conventional product is used, a bearing life of about 350 to 520 hours can be obtained if the offset amount δ is 0.5 mm. However, if the offset amount δ is 4 mm, the cage was damaged immediately after the start of the test. Accordingly, it is confirmed that the pulley support bearing 11 according to one embodiment of the present invention as shown in FIG. 1 can be used for a long period of time if the offset amount δ when incorporated in the pulley is δ ≦ 4 mm. It was done.

  Moreover, it tested about what formed the phosphate metal salt film and what did not form. As Example 1, 7.36 g of tricresyl phosphate was diluted with 2-propanol to prepare 200 ml of a phosphate triester solution, and a bearing 5115 (made by NTN: thrust ball bearing, made of bearing steel) was added to this solution. Both wheels were immersed for 2 hours at a solution temperature of 60 ° C. to form iron phosphate and other metal phosphate metal salt coatings on the surface.

  Next, a commercially available mineral oil grease (manufactured by Nippon Grease Co., Ltd .: Nigue WR-S) was applied to the raceway surface of this bearing, and the state of oil film formation during use of the bearing was examined by the following test method.

  (A) Oil film forming ability test: The rolling bearing of Example 1 was loaded with a thrust load of 16.4 kg and rotated at a speed of 1200 rpm for 60 minutes. The electrical resistance (Ω) (hereinafter referred to as bearing internal resistance) between the rotating shaft attached to the rotating wheel and the fixed wheel was measured over time, and the result is shown in FIG. Here, the bearing internal resistance increases as the oil film becomes thicker as the oil film forming ability of the lubricating grease increases.

  As Comparative Example 1, a bearing 5115 in which a metal phosphate salt film is not formed is used, and a commercially available mineral oil-based grease (manufactured by Nippon Grease Co., Ltd .: Nigues WR-S) is applied to the raceway surface as Comparative Example 1. This was subjected to an oil film formation ability test in exactly the same manner as in Example 1, and the results are also shown in FIG.

  As is apparent from the results of FIG. 8, in Example 1 in which an iron phosphate or other metal phosphate salt film was formed on the surface, the internal resistance value (Ω) increased until 45 minutes had passed, and then a substantially constant value. It can be seen that the ability to form a lubricating oil film is excellent. On the other hand, Comparative Example 1 was inferior in the ability to form a lubricating oil film.

  As Example 2, 7.36 g of tricresyl phosphate was diluted with 2-propanol to prepare 200 ml of a phosphate triester, and a bearing 6204 (manufactured by NTN: radial ball bearing (single row deep groove ball bearing)) was added to this solution. Both bearing wheels and rolling elements were immersed at a solution temperature of 60 ° C. for 2 hours to form iron phosphate and other metal phosphate metal salt coatings on the surface.

  Next, 0.23 to 0.25 g of a commercially available mineral oil grease (Nippon Grease Co., Ltd .: Nigace WR-S) was sealed on the bearing surface of this bearing, and an iron non-contact seal was attached to the bearing side surface, and the following test was performed. The life of rolling bearings was investigated by this method.

  (B) Life test for rolling bearings: Three examples 2 were used, and a rotating shaft with a transmission was attached to these inner rings to apply a thrust load of 6.8 kgf, and radial against the outer ring that stopped rotating. A load of 6.8 kgf was applied, and the inner ring was rotated through a rotating shaft at a speed of 10,000 rotations per minute in an atmosphere of 150 ° C. Then, the rotation torque of these bearings increases, and the rotation of the motor driving the rotating shaft exceeds the limit current (that is, when the rotation torque becomes more than twice the starting torque). The results are shown in the graph of FIG.

  As Comparative Example 2, a comparison was made using three bearings 6204 not formed with a metal phosphate salt coating, and applying the same amount of commercially available mineral oil grease (Nippon Grease Co., Ltd .: Nigues WR-S) on the raceway surface. A life measurement test of a rolling bearing was conducted in the same manner as in Example 2 for Example 2, and the results are shown in FIG.

  As is apparent from the results of FIG. 9, Example 2 in which a metal phosphate film is formed on the inner ring, outer ring and rolling elements of the bearing is a comparative example having no metal phosphate film on the surface of the same part. The bearing life (time) was 5 to 10 times longer than 2.

  Next, examples of the above-described grease composition will be shown. In half of the base oil shown in Table 1, 4,4-diphenylmethane diisocyanate (trade name Millionate MT manufactured by Nippon Polyurethane Industry Co., Ltd., hereinafter referred to as MDI) is dissolved in the proportion shown in Table 1, and the remaining half In this base oil, a monoamine that was twice the equivalent of MDI was dissolved. The respective blending ratios and types are shown in Table 1.

  A solution in which monoamine was dissolved was added while stirring the solution in which MDI was dissolved, and then the reaction was continued at 100 to 120 ° C. for 30 minutes to produce a diurea compound in the base oil.

  To this, an aluminum-based additive and an antioxidant were added at the blending ratio shown in Table 1, and the mixture was further stirred at 100 to 120 ° C. for 10 minutes. Thereafter, the mixture was cooled and homogenized with three rolls to obtain a grease composition.

In Table 1, the synthetic hydrocarbon oil used as the base oil is Shinflud 601 manufactured by Nippon Steel Chemical Co., Ltd. having a kinematic viscosity of 30 mm ² / sec at 40 ° C., and the alkyl diphenyl ether oil is a kinematic viscosity of 97 mm ² / sec at 40 ° C. Moresco HighLube LB100 manufactured by Matsumura Oil Co., Ltd. was used. Moreover, the hindered phenol by Sumitomo Chemical Co., Ltd. was used for antioxidant.

  The obtained grease composition was subjected to a rapid acceleration / deceleration test. Test methods and test conditions are shown below. The results are shown in Table 1.

<Rapid acceleration / deceleration test>
An alternator, which is an example of an electrical accessory, was simulated, and the grease composition was sealed in a rolling bearing for rotating an inner ring that supports a rotating shaft, and a rapid acceleration / deceleration test was performed. The rapid acceleration / deceleration test conditions are as follows: the load is applied to the pulley attached to the tip of the rotating shaft at 1960 N, the rotational speed is set to 0 to 18000 rpm, and the test is performed with a current of 0.1 A flowing in the test bearing. Carried out. Then, abnormal peeling occurred in the bearing, and the time when the vibration of the vibration detector exceeded the set value and the generator stopped (peeling life time, h) was measured. The test was terminated after 500 hours.

Comparative Examples 3-5
In the method according to Example 3, the thickener and base oil were selected at the blending ratio shown in Table 1 to adjust the base grease, and the additives were further blended to obtain a grease composition. The obtained grease composition was evaluated by conducting the same test as in Example 3. The results are shown in Table 1.

  As shown in Table 1, in each Example, all the rapid acceleration / deceleration tests showed excellent results of 400 hours or more (peeling life time). This is considered to be because the specific exfoliation accompanied by the white texture change that occurs on the rolling surface can be effectively prevented by adding the aluminum-based additive at a predetermined ratio.

  In addition, although the pulley support bearing 11 in said embodiment showed the example which has the holder | retainer 15 which hold | maintains the space | interval of the adjacent ball | bowl 14, it is not limited to this but is a full complement roller bearing which abbreviate | omitted the holder | retainer 15. May be.

  Moreover, although the electromagnetic clutch 32 in said embodiment showed the example used in order to control mechanical connection with an engine and the compressor 21, it can use for arbitrary uses, without restricting to this. . Furthermore, although the example in which the pulley support bearing 11 in the above-described embodiment is used to support the pulley 33 of the electromagnetic clutch 32 has been shown, the invention is not limited to this, and an arbitrary transmission such as a continuously variable transmission (CVT) is shown. Can be used for applications.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to the thing of embodiment shown in figure. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

  The present invention is advantageously used for a bearing that supports a pulley such as an electromagnetic clutch.

It is a figure which shows the pulley support bearing which concerns on one Embodiment of this invention. It is a figure which shows the compressor which employ | adopted the pulley support bearing shown in FIG. It is a figure which shows the non-transmission state of the electromagnetic clutch shown in FIG. It is a figure which shows the transmission state of the electromagnetic clutch shown in FIG. It is a figure which shows the test device for confirming the effect of this invention. It is the elements on larger scale of the driven pulley of the test apparatus shown in FIG. It is a figure which shows the result of an effect confirmation test. It is a figure which shows the result of the formation capability test of the oil film of Example 1 and Comparative Example 1, and shows the relationship between elapsed time and an electrical resistance value. It is a figure which shows the lifetime of Example 2 and Comparative Example 2.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 Pulley support bearing, 12 Inner ring, 12a Inner ring raceway surface, 13 Outer ring, 13a Outer ring raceway surface, 14 Ball, 14a Rolling surface, 15 Cage, 16 Seal seal, 17 Grease composition, 21 Compressor, 22 Casing, 23 Head Case, 24 Cylinder case, 25 Swash plate case, 26 Low pressure chamber, 26a Suction hole, 26b, 27b Valve, 27 High pressure chamber, 27a Discharge port, 28 Cylinder, 28a Compression chamber, 29 Rotating shaft, 29a Radial needle roller bearing, 29b Thrust needle roller bearing, 30 swash plate, 30a sliding shoe, 31 piston, 32 electromagnetic clutch, 33 pulley, 33a, 43 endless belt, 33b groove, 33c recess, 34 solenoid, 35 magnetic annular plate, 35a leaf spring, 41 Test equipment, 42 drive pulley, 44 driven pulley Li, 45 motor.

Claims (4)

A pulley support bearing that is fitted to the inner diameter surface of the pulley and rotatably supports the pulley,
The pulley support bearing is
An inner ring made of metal, having double-row inner ring raceway surfaces on the outer diameter surface, and an inner diameter dimension d ₁ of d ₁ ≧ 30 mm;
It is made of metal and has a double row outer ring raceway surface at a position facing the inner ring raceway surface of the inner diameter surface, the outer diameter dimension d ₂ is 45 mm ≦ d ₂ ≦ 65 mm, the axial dimension l is l <18 mm, An outer ring of 0.19 ≦ l / d ₂ ≦ 0.39;
A plurality of balls made of metal and disposed between the inner ring raceway surface and the outer ring raceway surface;
A sealed double-row angular contact ball bearing comprising a sealing member disposed between the inner ring and the outer ring and sealing a bearing internal space;
A metal phosphate coating is formed on the inner ring raceway surface, the outer ring raceway surface, and the rolling surface of the ball,
In the bearing internal space, a grease composition is enclosed,
The grease composition is a grease composition obtained by adding an additive to a base grease composed of a base oil and a thickener,
The additive contains at least one aluminum-based additive selected from aluminum powder and an aluminum compound,
The pulley support bearing is a blending ratio of the aluminum-based additive that is 0.05 to 100 parts by weight with respect to 100 parts by weight of the base grease.   The pulley support bearing according to claim 1, wherein the inner ring, the outer ring, and the ball are immersed in a phosphate triester solution to form the metal phosphate salt film on a surface thereof. Pulley,
A magnetic annular plate disposed on one side of the pulley in the axial direction and fixedly connected to the rotating shaft;
A solenoid fixed at a position facing the magnetic annular plate on the other side of the pulley;
A pulley support bearing for rotatably supporting the pulley,
The pulley support bearing is
An inner ring made of metal, having double-row inner ring raceway surfaces on the outer diameter surface, and an inner diameter dimension d ₁ of d ₁ ≧ 30 mm;
It is made of metal and has a double row outer ring raceway surface at a position facing the inner ring raceway surface of the inner diameter surface, the outer diameter dimension d ₂ is 45 mm ≦ d ₂ ≦ 65 mm, the axial dimension l is l <18 mm, An outer ring of 0.19 ≦ l / d ₂ ≦ 0.39;
A plurality of balls made of metal and disposed between the inner ring raceway surface and the outer ring raceway surface;
A sealed double-row angular contact ball bearing comprising a sealing member disposed between the inner ring and the outer ring and sealing a bearing internal space;
A metal phosphate coating is formed on the inner ring raceway surface, the outer ring raceway surface, and the rolling surface of the ball,
In the bearing internal space, a grease composition is enclosed,
The grease composition is a grease composition obtained by adding an additive to a base grease composed of a base oil and a thickener,
The additive contains at least one aluminum-based additive selected from aluminum powder and an aluminum compound,
The aluminum clutch additive blending ratio is 0.05 to 100 parts by weight with respect to 100 parts by weight of the base grease. A distance δ between an imaginary line passing through the central portion in the axial direction of the pulley and a virtual line passing through the central portion in the axial direction of the pulley support bearing is:
The pulley support structure for an electromagnetic clutch according to claim 3, wherein δ ≦ 4 mm is satisfied.

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