JP2008115955A - Pulley supporting bearing, and pulley supporting structure of electromagnetic clutch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pulley supporting bearing which appropriately support a load caused by the tension and the offset of an endless belt, and has a long life and high reliability. <P>SOLUTION: The pulley supporting bearing 11 is a sealed type double row angular ball bearing which comprises: an inner race 12 which has a double row inner race raceway surface 12a on its outside diameter surface, and has the inner diameter d<SB>1</SB>satisfying a following condition, d<SB>1</SB>≥30 mm; an outer race 13 which has a double row outer race raceway surface 13a on its inner diameter surface so as to face the inner race raceway surface 12a, has the outside diameter d<SB>2</SB>satisfying the following conditions, 45 mm≤d<SB>2</SB>≤65 mm, and has the axial width l satisfying the following conditions, l<18 mm, and 0.19≤l/d<SB>2</SB>≤0.39; a plurality of balls 14 to be arranged between the inner race raceway surface 12a and the outer race raceway surface 13a; and a sealing member 16 which is arranged between the inner race 12 and the outer race 13, and seals the internal space of the bearing. Further, in at least one of the outside diameter surface of the inner race 12 and the inner diameter surface of the outer race 13, the central region between the double row raceway surfaces is recessed than both end regions. <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 increases, the contact angle changes and the ball slip rate increases, resulting in a significant decrease in grease life.

  Further, along with the downsizing of the compressor, the bearing internal space volume of the rolling bearing used for the electromagnetic clutch is decreasing. As a result, the amount of grease filled inside the bearing is inevitably reduced. Furthermore, since the bearing temperature increases as the speed of the electromagnetic clutch increases, the lubrication life of the rolling bearing is reduced.

  Accordingly, an object of the present invention is to provide a long-life and reliable pulley support bearing by appropriately supporting a load caused by the tension and offset of an endless belt and extending a lubrication life, and such a pulley support bearing. It is providing the pulley support structure of the electromagnetic clutch which employ | adopted.

The pulley support bearing according to the present invention is a pulley support bearing that is fitted to the inner diameter surface of the pulley and rotatably supports the pulley. This pulley support bearing has a double-row inner ring raceway surface on the outer diameter surface, a double row outer ring raceway surface at a position facing the inner ring raceway surface of the inner ring having an inner diameter d ₁ of d ₁ ≧ 30 mm and d ₁ ≧ 30 mm. An outer ring having an outer diameter d ₂ of 45 mm ≦ d ₂ ≦ 65 mm, an axial dimension l of 1 <18 mm, and 0.19 ≦ l / d ₂ ≦ 0.39, and an inner ring raceway surface and an outer ring raceway surface. A sealed double-row angular contact ball bearing comprising a plurality of balls disposed therebetween and a sealing member disposed between an inner ring and an outer ring and sealing a bearing internal space. Furthermore, in at least one of the outer diameter surface of the inner ring and the inner diameter surface of the outer ring, the central region between the double-row raceway surfaces recedes from both end regions.

  With this configuration, it is possible to appropriately support a radial load resulting from the tension of the endless belt, and to obtain a long-life pulley support bearing even in an environment where a moment load resulting from offset is applied.

  Further, in at least one of the outer diameter surface of the inner ring and the inner diameter surface of the outer ring, the central region between the double-row raceway surfaces is retracted from both end regions. That is, on the outer diameter surface of the inner ring, the outer diameter size of the central region between the raceway surfaces is made smaller than the outer diameter size of both end regions. On the inner diameter surface of the outer ring, the inner diameter dimension of the central area between the raceway surfaces is made larger than the inner diameter dimensions of both end areas. Thereby, the bearing internal space volume which can enclose grease increases. Furthermore, the leakage of grease to the outside of the bearing can be effectively suppressed by expanding the bearing space between the double-row raceway surfaces.

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 has a double-row inner ring raceway surface on the outer diameter surface, an inner ring having an inner diameter dimension d ₁ of d ₁ ≧ 30 mm, and a double-row outer ring at a position facing the inner ring raceway surface of the inner diameter face. An outer ring having a raceway surface, an outer diameter d ₂ of 45 mm ≦ d ₂ ≦ 65 mm, an axial dimension l of 1 <18 mm, 0.19 ≦ l / d ₂ ≦ 0.39, an inner ring raceway surface, and an outer ring raceway A sealed double row angular contact ball bearing comprising a plurality of balls disposed between surfaces and a sealing member disposed between an inner ring and an outer ring for sealing a bearing internal space. Further, in at least one of the outer diameter surface of the inner ring and the inner diameter surface of the outer ring, the central region between the double row raceway surfaces is set back from both end regions of the double row raceway surfaces.

  By adopting the pulley support bearing having the above configuration, an electromagnetic clutch having a long life and high reliability can be obtained.

  According to the present invention, the radial load and the moment load can be appropriately supported by optimizing the relationship between the outer diameter dimension and the axial dimension of the bearing. Also, by expanding the bearing space between the double row raceway surfaces. The amount of grease filled can be increased and leakage of grease to the outside of the bearing can be prevented. As a result, a long-life and highly reliable pulley support bearing and a pulley support structure for an electromagnetic clutch can be obtained.

  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.

  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 28a.

  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 25 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.

  In the pulley support bearing 11 configured as described above, the outer diameter surface of the inner ring 12 has a central region 12b located between the double-row inner ring raceway surfaces 12a retracted from both end regions 12c. That is, the outer diameter dimension of the central area 12b is set smaller than the outer diameter dimension of both end areas 12c. On the other hand, as for the inner diameter surface of the outer ring 13, both end region 13c between the double row outer ring raceway surfaces 13a recedes from the central region 13b. That is, the inner diameter dimension of the central area 13b is set smaller than the inner diameter dimensions of both end areas 13c.

  Thus, the bearing inner space is increased by retracting a part of the inner diameter surface of the inner ring 12 and a part of the outer diameter surface of the outer ring 13 from the other parts. As a result, the amount of grease enclosed in the pulley support bearing 11 increases. Here, from the viewpoint of expanding the bearing internal space, it is considered that all of the outer diameter surface of the inner ring 12 and the inner diameter surface of the outer ring 13 except the raceway surfaces 12a and 13a may be retracted from the conventional bearing. It is done. However, when the thickness dimension of the inner ring 12 and the outer ring 13 is reduced, the rigidity of the pulley support bearing 11 is lowered.

Specifically, the pulley support bearing 11, the straight line L ₁ connecting the contact point between the ball 14 and the inner ring 12 and outer ring 13 at the right side of the raceway surface, the balls 14 and the inner ring 12 at the left side of the raceway surface shown in FIG. 1 and a angular contact ball bearing of the outward type (DB) that the point of intersection of the straight line L ₂ connecting the contact point between the outer ring 13 alpha is located outside the pitch circle.

That is, the load blown to the inner ring 12 and the outer ring 13 acts on the intersections between the raceway surfaces 12a and 13a and the straight lines L ₁ and L ₂ (hereinafter referred to as “load application points”). Therefore, from the viewpoint of appropriately supporting the load acting on the bearing, it is desirable to retreat the side far from the load acting point in the central region 12b, 13b and the both end regions 12c, 13c.

  In the pulley support bearing 11 shown in FIG. 1, the retraction amount of the central region 12 b of the inner ring 12 is larger than the retraction amounts of both end regions of the outer ring 13. Grease inside the bearing leaks mainly from the gap between the inner ring 12 and the sealing seal 16. Therefore, it is possible to effectively prevent leakage of grease to the outside of the bearing by expanding the bearing space in the center region between the double-row raceway surfaces.

  Note that the angular ball bearing has a shoulder on either the axially inner side or the axially outer side of the inner ring raceway surface 12a. That is, even in the conventional angular contact ball bearing, the outer diameter dimension differs between the left and right sides of the inner ring raceway surface. However, in the pulley support bearing 11 according to one embodiment of the present invention, a ring-shaped groove is formed in the central region 12b of the inner ring 12, and the outer diameter dimension is made smaller than the minimum diameter position of the inner ring raceway surface 12a. is doing. That is, the present invention differs from conventional angular contact ball bearings in that the ring-shaped groove is formed to actively expand the bearing space in the central region.

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 / d ₂ ≦ 0.39 is set. In this embodiment, the inner ring 12 and the outer ring 13 have the same axial dimension.

  Next, the operation of the compressor 21 configured as described above will be described with reference to FIGS. 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 rotor 33. 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, as a test for confirming the effect of the present invention, 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 11 (hereinafter referred to as “the product of the present invention”) as shown in FIG. ") Was used to test.

  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.

  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.

  In the above embodiment, an example of an outward-facing (DB) angular contact ball bearing has been described. However, the present invention is a straight line connecting the contact points of the rolling elements with the inner ring and the outer ring on each of the left and right raceways. The present invention can also be applied to an inward-facing (DF) angular contact ball bearing in which the intersection point is located inside the pitch circle. In this case, from the viewpoint of maintaining the rigidity of the bearing, it is desirable to retract the both end region of the inner ring and the central region of the outer ring from the other parts.

  In the above embodiment, an example in which both the central region 12b of the inner ring 12 and both end regions 13c of the outer ring 13 are retracted has been shown. However, in order to obtain the effects of the present invention, at least one of them is shown. Only need to retreat. For example, in order to avoid leakage of grease more reliably, it is only necessary to retract the central region.

  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.

Explanation of symbols

  11 pulley support bearing, 12 inner ring, 12a inner ring raceway surface, 12b, 13b central region, 12c, 13c both end regions, 13 outer ring, 13a outer ring raceway surface, 14 balls, 15 cage, 16 seal seal, 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 -44, driven pulley, 45 motor.

Claims (2)

A pulley support bearing that is fitted to the inner diameter surface of the pulley and rotatably supports the pulley,
An inner ring having double-row inner ring raceway surfaces on the outer diameter surface and an inner diameter d ₁ of d ₁ ≧ 30 mm;
A double row outer ring raceway surface is provided 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, 0.19 ≦ l / an outer ring with d ₂ ≦ 0.39;
A plurality of balls disposed between the inner ring raceway surface and the outer ring raceway surface;
A sealing member disposed between the inner ring and the outer ring and sealing a bearing internal space;
A pulley that is a sealed double-row angular ball bearing in which at least one of the outer diameter surface of the inner ring and the inner diameter surface of the outer ring has a central region between the double-row raceway surfaces set back from both end regions. Support bearing. 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 having double-row inner ring raceway surfaces on the outer diameter surface and an inner diameter d ₁ of d ₁ ≧ 30 mm;
A double row outer ring raceway surface is provided 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, 0.19 ≦ l / an outer ring with d ₂ ≦ 0.39;
A plurality of balls disposed between the inner ring raceway surface and the outer ring raceway surface;
A sealing member disposed between the inner ring and the outer ring and sealing a bearing internal space;
In at least one of the outer diameter surface of the inner ring and the inner diameter surface of the outer ring, the electromagnetic region is a sealed double-row angular contact ball bearing in which a central region between the double-row raceway surfaces recedes from both end regions. Clutch pulley support structure.

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