JP2006132740A - Roller bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a roller bearing which intends to apply low torque by securing durability and simultaneously which is capable of enhancing acoustic performance under high temperature environment. <P>SOLUTION: The roller bearing is provided with an inner ring 11 which includes inner ring track 12 on outer peripheral face, an outer ring 13 which includes outer ring track 14 on inner peripheral face and a plurality of rolling elements 15 which are relatively rotatably arranged between the inner 12 and outer ring tracks 14. The roller bearing is formed with the rolling element 15 made of a ceramic material and is configured so as to satisfy 0.53< R<SB>0</SB>/D<SB>b</SB>≤0.65, 0.52<R<SB>i</SB>/D<SB>b</SB>≤0.65, where D<SB>b</SB>is diameter of the rolling element, R<SB>o</SB>is radius of curvature of the outer ring track 14 and R<SB>i</SB>is radius of curvature of the inner ring track 12 and furthermore to satisfy D<SB>p</SB><(d+D)/2, 10<SP>3</SP>≥D<SB>p</SB>≥2, where D is outer diameter of the outer ring 13, d is inner diameter of the inner ring 11 and D<SB>p</SB>is pitch circle diameter of the rolling element 15 and is established so that the D<SB>p</SB>amounts to 10mm- 40mm or less. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rolling bearing used to rotatably support a rotating shaft that rotates at a low load at a high speed with respect to a housing, such as a fan motor such as a household vacuum cleaner or an air conditioner blower. About.

  As an example of a conventional rolling bearing, an outer ring having an outer ring raceway on an inner peripheral surface, an inner ring having an inner ring raceway on an outer peripheral surface, and a plurality of balls provided in a freely rollable manner between the outer ring raceway and the inner ring raceway There are known rolling bearings with

  As shown in FIG. 6, the rolling bearing 100 includes a deep groove type outer ring raceway in which an inner ring 101, an outer ring 102, and a ball 103 are formed of bearing steel such as SUJ2 and M50, and the cross-sectional shape is an arc shape. Balls 103 incorporated between 104 and an inner ring raceway 105 having a circular cross-sectional shape are held by a cage 106 so as to roll freely in a state of being spaced apart from each other. Further, the outer peripheral edge portions of the seal members 107 and 107 are locked to the inner peripheral surfaces of both ends of the outer ring 102, and the inner peripheral edges of the seal members 107 and 107 are opposed to the outer peripheral surfaces of both end portions of the inner ring 101.

In such a rolling bearing 100, when the diameter of the ball 103 is D _b , the radius of curvature of the cross-sectional shape of the outer ring raceway 104 is R _o ′, and the radius of curvature of the cross-sectional shape of the inner ring raceway 105 is R _i ′, It was 0.50 <R _o ′ / D _b ≦ 0.53 and 0.50 <R _i ′ / D _b ≦ 0.52. Further, when the outer diameter of the outer ring 102 is D, the inner diameter of the inner ring 101 is d, and the pitch circle diameter (PCD) of the balls 103 is D _p ′, D _p ′ ≈ (D + d) / 2. In other words, with D _p ′ / {(D + d) / 2} ≈1, the ball 103 is arranged in the substantially central portion between the outer peripheral surface of the outer ring 102 and the inner peripheral surface of the inner ring 101 in the diameter direction of the rolling bearing 100. It was.

  As an example of a conventional rolling bearing, the outer ring is thick, the pitch circle diameter of the ball is shifted to the inner diameter side, and the radius of curvature of the cross-sectional shape of the outer ring raceway and the inner ring raceway is increased in relation to the ball diameter. Is known (see, for example, Patent Document 1).

Rolling bearing disclosed in Patent Document 1, the diameter of the ball and D _b, the radius of curvature of the cross-sectional shape of the outer ring raceway and R _o, the radius of curvature of the cross-sectional shape of the inner raceway when the R _i, 0 .53 <R _o / D _b ≦ 0.65, 0.52 <R _i / D _b ≦ 0.65, further, the outer diameter of the outer ring is D, the inner diameter of the inner ring is d, and the pitch circle diameter of the ball Is _Dp , x = _Db / {(D−d) / 2}, and y = _Dp / {(D + d) / 2}, x ≧ 0.3 and y <1.0. ing.
Japanese Patent Laid-Open No. 2001-090736 (page 3-4, FIG. 1)

By the way, in recent years, fan motors used in exhaust applications for hot water heaters have long acoustic lifespan of over 20,000 hours under energy saving (low torque), high temperature and high speed conditions of 100 ° C. or higher and 5000 min ⁻¹ or higher. Is starting to be needed.
However, in the rolling bearing 100 including the outer ring having the outer ring raceway on the inner peripheral surface, the inner ring having the inner ring raceway on the outer peripheral surface, and a plurality of balls between the outer ring raceway and the inner ring raceway, Since it is a general-purpose structure considering the incorporation and not the structure considering the low load, the rotational torque (rotational resistance) is not necessarily low. Therefore, if the rotational torque of the rotational support portion is simply reduced by changing the bearing specifications at a low load, the torque can be reduced to some extent by using a lower diameter series. However, it is necessary to reduce the inner diameter of the housing to which the outer ring 102 is to be fixed, and this is not preferable because it is necessary to change the design of other components of the rotation support portion. In addition, there is a case where a sufficient reduction in torque cannot be achieved by simply lowering the diameter series. In addition, since the ball 103 is formed of bearing steel, at the high temperature (100 ° C. or higher), the deterioration of the webiness occurs at an early stage, and the acoustic durability performance is deteriorated earlier than that caused by normal surface roughness. There was also a problem of end.
Further, in the rolling bearing disclosed in Patent Document 1, although a certain degree of durability can be secured and the torque can be reduced without reducing the outer diameter of the outer ring, the ball is made of bearing steel. At times (over 100 ° C.), the deterioration of the webiness occurs early on the surface of the ball, and the sound durability may be deteriorated earlier than that caused by normal surface roughness.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a rolling bearing capable of ensuring durability and reducing torque and improving acoustic performance in a high temperature environment. It is in.

1) A rolling bearing according to the present invention includes an inner ring having an inner ring raceway on an outer peripheral surface, an outer ring having an outer ring raceway on an inner peripheral surface, and a plurality of rolling bearings disposed between the inner ring raceway and the outer ring raceway so as to be relatively rotatable. a rolling bearing comprising: a moving object, wherein the rolling element is formed by a ceramic material, the diameter of the rolling element and D _b, the radius of curvature of the cross-sectional shape of the outer ring raceway and R _o, of the inner ring raceway the radius of curvature of the cross-sectional shape when the _{R i, 0.53 <R o /} D b ≦ 0.65,0.52 < a R i / _{D b} ≦ 0.65 and, an outer diameter of the outer ring When D is D, the inner diameter of the inner ring is d, and the pitch circle diameter of the rolling elements is D _p , D _p <(d + D) / 2, 10 ³ ≧ D _p ≧ 2, and D _p is 10 mm to 40 mm or less. It is characterized by being.

According to the invention described in the above 1), the diameter D _b of the rolling elements, and the radius of curvature R _i of the cross-sectional shape of the inner ring raceway, a radius of curvature R _o of the cross-sectional shape of the outer ring raceway, the relationship, 0.53 <R _o / D _b ≦ 0.65, 0.52 <R _i / D _b ≦ 0.65 is set at the contact portion between the rolling surface of the rolling element and the inner ring raceway and the outer ring raceway. The contact ellipse can be reduced, and the rolling resistance and spin generated at the contact ellipse during rotation can be reduced to reduce the torque. If the values of R _o / D _b and R _i / D _b exceed 0.65, the area of the contact ellipse becomes too small, and it becomes difficult to ensure the rolling fatigue life of each track. Brinell impressions are likely to occur with respect to the track. Therefore, the upper limit value of each ratio R _o / D _b and R _i / D _b is set to 0.65 or less. Further, the relationship between the inner diameter d of the inner ring, the outer diameter D of the outer ring, and the pitch circle diameter D _p of the rolling element is D _p <(d + D) / 2, 10 ³ ≧ D _p ≧ 2, and D _p is 10 mm. By setting it to ˜40 mm or less, it is possible to reduce the internal rolling friction and reduce the torque by reducing the pitch circle diameter of the rolling element and the diameter of the rolling element without reducing the outer diameter of the outer ring. it can. Furthermore, since the rolling elements are made of ceramic, deterioration of acoustic performance can be eliminated over a long period of time even in a high temperature environment. As a result, durability can be ensured and torque can be reduced, and acoustic performance in a high temperature environment can be improved.

  According to the rolling bearing of the present invention, it is possible to solve the problems that sufficient torque reduction cannot be achieved, and that the deterioration of sound durability performance is deteriorated due to early deterioration of webiness at high temperatures, thereby ensuring durability. As a result, the torque can be reduced and the acoustic performance in a high temperature environment can be improved.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the drawings.
FIG. 1 is a cross-sectional view of an embodiment of a rolling bearing according to the present invention, FIG. 2 is a dynamic torque value result table of the example, FIG. 3 is a dynamic torque value result table of the example, and FIG. FIG. 5 is a result table of the sound durability test.

  As shown in FIG. 1, a rolling bearing 10 according to an embodiment of the present invention includes an inner ring 11 having an inner ring raceway 12 having an arc shape in cross section on an outer peripheral surface, and an arc shape in cross section on an inner peripheral surface. And an outer ring 13 having a deep groove type outer ring raceway 14 and a plurality of balls 15 as rolling elements provided between the inner ring raceway 12 and the outer ring raceway 14 so as to roll freely. And the ball | bowl 15 is hold | maintained so that rolling is possible in the state which opened the space | interval with the holder | retainer 16. FIG.

  In the rolling bearing 10, the outer peripheral edge portions of the seal members 17, 17 are engaged with the inner peripheral surfaces of both ends of the outer ring 13, and the inner peripheral edges of the seal members 17, 17 are closely opposed to the outer peripheral surfaces of both ends of the inner ring 11. Has been. Then, grease is sealed in a bearing space surrounded by the seal members 17 and 17. The ball 15 is formed of a ceramic material (a composite material containing silicon nitride).

  When the rolling bearing 10 supports a rotating shaft of a fan motor for a vacuum cleaner, the outer ring 13 is fitted and fixed to the housing, and the inner ring 11 is fitted and fixed to the rotating shaft. In this way, the rolling bearing 10 is used at a low load and high speed rotation by supporting the rotating shaft of a household vacuum cleaner or a blower of a domestic air conditioner on the housing.

Then, the rolling bearing 10, the diameter of the ball 15 and D _b, the radius of curvature of the cross-sectional shape of the inner ring raceway 12 and R _i, the radius of curvature of the cross-sectional shape of the outer ring raceway 14 when the R _o, the balls 15 the diameter _{D b,} and the radius of curvature _{R i} of the inner ring raceway 12, and the radius of curvature _{R o} of the outer ring raceway 14, the _{relationship, 0.53 <R o / D b} ≦ 0.65,0.52 <R _i / D _b ≦ 0.65 is set. At this time, _if the values of R _o / D _b and R _i / D _b exceed 0.65, the area of the contact ellipse becomes too small, and it becomes difficult to secure the rolling fatigue life of each track. As for the outer ring raceway, the Brinell impression is likely to occur. Therefore, the upper limit value of each ratio R _o / D _b and R _i / D _b is set to 0.65 or less. The ratio of the diameter _{D b} of the ball 15, and the radius of curvature _{R i} of the cross-sectional shape of the inner ring raceway _12, with respect to R i / _{D b,} as the fan motor of the blower such as an air conditioner, 10000 min ^-1 ( when used in r.p.m.) or less, 0.52 _<although the R i / _{D b} ≦ 0.65, as the fan motor of the suction device such as a vacuum cleaner, 20,000 min ^{- In} the case of using ¹ or more, it is preferable to satisfy 0.53 <R _i / D _b ≦ 0.65.

Furthermore, the rolling bearing 10, the outer diameter of the outer ring 13 is D, the inner diameter of the inner ring 11 is d, the pitch circle diameter of the ball 15 when the D _p, the outer diameter D of the outer ring 13, the inner diameter of the inner ring 11 and d, the pitch circle diameter _{D p} of the ball 15, the _{relationship,} and at D p <(d + D) / 2, and at 10 ³ ≧ _{D p} ≧ 2, _{D p} is set below 10mm~40mm . The relationship between the outer diameter D of the outer ring 13, the inner diameter d of the inner ring 11, and the pitch circle diameter D _p of the balls 15 is D _p <(d + D) / 2, and 10 ³ ≧ D _p ≧ 2. , D _p is set to 10 mm to 40 mm or less, and in the conventional rolling bearing, D is a relationship among the outer diameter D of the outer ring, the inner diameter d of the inner ring, and the pitch circle diameter D _p ′ of the balls. _For p′≈ (D + d) / 2, the pitch circle diameter can be reduced. Thereby, compared with the conventional rolling bearing, the ball 15 can be disposed at a position offset from the outer peripheral surface of the outer ring 12 to the inner peripheral surface side of the inner ring 11 with respect to the diameter direction of the rolling bearing 10.

  In such a rolling bearing 10, the outer ring 13 is fitted and fixed to a housing of a fan motor for a vacuum cleaner, and the inner ring 11 is fitted and fixed to a rotating shaft of the fan motor. When the fan motor is rotated, since the internal rolling friction is reduced, the fan motor is rotated with a low torque. Further, since the balls 15 are made of ceramic, the rotation of the fan motor is supported without causing deterioration of acoustic performance for a long time even in a high temperature environment.

According to the rolling bearing 10 described above, the diameter _{D b} of the ball 15, and the radius of curvature _{R i} of the cross-sectional shape of the inner ring raceway 12, and the radius of curvature _{R o} of the cross-sectional shape of the outer ring raceway 14, the relationship, 0.53 By setting <R _o / D _b ≦ 0.65, 0.52 <R _i / D _b ≦ 0.65, the contact portion between the rolling surface of the ball 15 and the inner ring raceway 12 and the outer ring raceway 14 The contact ellipse formed on the contact ellipse can be made smaller, and the rolling resistance and spin generated at the contact ellipse portion during rotation can be reduced to reduce the torque. Further, the relationship between the outer diameter d of the inner ring 11, the inner diameter D of the outer ring 13, and the pitch circle diameter D _p of the balls 15 is such that D _p <(d + D) / 2, 10 ³ ≧ D _p ≧ 2, and D _p. By setting it to 10 mm to 40 mm or less, the pitch diameter of the balls 15 and the diameter of the balls 15 are reduced without reducing the outer diameter of the outer ring 13, thereby reducing the internal rolling friction and reducing the torque. be able to. Furthermore, since the balls 15 are made of ceramic, deterioration of acoustic performance can be eliminated over a long time even in a high temperature environment. As a result, durability can be ensured and torque can be reduced, and acoustic performance in a high temperature environment can be improved.

Next, with reference to FIG. 2 to FIG. 5, description will be given of an embodiment performed for confirming the function and effect of the rolling bearing 10 according to the present invention.
First, the dynamic torque values shown in FIGS. 2 and 3 were measured. For the measurement of dynamic torque, the rolling bearing 10 of the present invention and the rolling bearing of the comparative example are prepared, the operating condition is a rotational speed of 1,800 min ⁻¹ , and the amount of grease charged is the space volume inside the bearing. To 30%.

As shown in FIG. 2, if the pitch circle diameter _{D p} of the ball is 23 mm, the minimum value is 1078 (mN · m), the maximum value of 1332.8 (mN · m), and the average value is 1225 (mN · m ) In contrast, when the pitch circle diameter _{D p} of the ball to 21.5 mm, the minimum value is 686 (mN · m), the maximum value is 735 (mN · m), and the average value of 705.6 (mN · m )

As shown in FIG. 3, if the pitch circle diameter _{D p} of the ball is 15 mm, the minimum value is 156.8 (mN · m), the maximum value is 196 (mN · m), and the average value of 176.4 (mN・ M). In contrast, when the pitch circle diameter _{D p} of the ball to 13 mm, the minimum value is 58.5 (mN · m), the maximum value is 107.8 (mN · m), and the average value is 88.2 (mN・ M).

Figure 2, as evidenced by FIG. 3, by decreasing the pitch circle diameter D _p of the ball, regardless of the size of the rolling bearing, it can be seen that small torque.

  Next, the change in the webiness when left at a high temperature as shown in FIG. 4 was examined. A webiness tester was used to measure the change in webiness. The waveness tester presses the ball against the arbor mounted on the spindle of the drive unit, the ball is rotated at a constant speed, and the contact type speed sensor's teeth are brought into contact with the surface of the rotating ball. The displacement speed in the radial direction of the ball is detected by the type speed sensor, and a voltage signal proportional to the displacement speed is output. Then, the output voltage signal is processed, and the waveness, which is the undulation (unevenness) of the surface of the ball, is converted into a numerical value and displayed, and the waveness waveform is displayed on the CRT. In this case, the case where it was allowed to stand for 100 hours at 25 ° C., 50 ° C., 75 ° C., 100 ° C., 125 ° C., 150 ° C. and 175 ° C. was measured.

  As shown in FIG. 4, as a result of the webiness test, in the steel balls used as a comparative example, when the standing temperature fluctuates to 100 ° C., 125 ° C., 150 ° C., and 175 ° C., the webiness value is 0.18 μpc, It was found that the values rose to 0.3 μpc, 0.55 μpc, and 0.82 μpc. On the other hand, in the ceramic ball of the present invention, even if the standing temperature fluctuates to 25 ° C., 50 ° C., 75 ° C., 100 ° C., 125 ° C., 150 ° C., and 175 ° C., there is a large fluctuation in the webiness value It was found that a stable webiness value was exhibited.

  Next, an acoustic durability test was conducted to examine the influence on the Anderon value (High-Band) and motor noise shown in FIG. In the sound durability test, 200 hours, 400 hours, 800 hours, 1000 hours, 1500 hours, 2000 hours, 3000 hours, 4000 hours, 5000 hours, 6000 hours, 7000 hours, 8000 hours, 9000 hours, 10000 hours, 11000 hours, The Anderon values of 12000 hours, 13000 hours, 14000 hours, and 15000 hours were examined.

As shown in FIG. 5, in the rolling bearing of the conventional structure used as a comparative example, the Anderon value is 3 to 4 H.S. at 2000 hours, 3000 hours, 5000 hours, 6000 hours, and 7000 hours. B. However, by the time of 8000 hours, 9000 hours, and 10000 hours, the Anderon value is 20H. B. Reached. On the other hand, in the rolling bearing having the structure of the present invention, it was found that there was no great variation in the Anderon value between 200 hours and 15000 hours. This reduces the pitch circle diameter D _p of the ball, by reducing the diameter D _b of the ball with it, because anderon value is improved. The reason is considered to be the result of the ball's kinetic energy being reduced and the ball's excitation force becoming smaller.

Results of such an embodiment, the rolling bearing 10 of the present invention, the diameter D _b of the ball 15, and the radius of curvature R _i of the cross-sectional shape of the inner ring raceway 12, and the radius of curvature R _o of the cross-sectional shape of the outer ring raceway 14 , the _{relationship, 0.53 <R o / D b} ≦ 0.65,0.52 < by setting the R i / _{D b} ≦ 0.65, the rolling surface of the ball 15 and the inner ring raceway 12 and the outer ring This is because the contact ellipse formed at the contact portion with the track 14 is reduced, and the rolling resistance and spin generated in the contact ellipse portion during rotation are reduced. Further, the relationship between the inner diameter d of the inner ring, the outer diameter D of the outer ring, and the pitch circle diameter D _p of the rolling elements is expressed as D _p <(d + D) / 2, 10 ³ ≧ D _p ≧ 2, and D _p is 10 mm. This is because by setting it to ˜40 mm or less, it was possible to reduce the internal rolling friction by reducing the pitch circle diameter of the rolling element and the diameter of the rolling element without reducing the outer diameter of the outer ring. Furthermore, because the balls 15 are made of ceramic, it is possible to eliminate deterioration of acoustic performance over a long period of time even in a high temperature environment.

  In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably. For example, the seal member is not limited to the illustrated non-contact type, and may be a contact type having a lip that is in sliding contact with the outer peripheral surface of the inner ring.

  Further, the rolling bearing is not limited to the illustrated one, and the present invention may be applied to various bearings such as a type without a cage.

It is sectional drawing of one Embodiment of the rolling bearing which concerns on this invention. It is a dynamic torque value result table of an example. It is a dynamic torque value result table of an example. It is a graph showing the change of the webiness at the time of leaving at high temperature. It is a result table of an endurance test. It is sectional drawing of the conventional rolling bearing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Rolling bearing 11 Inner ring 12 Inner ring track 13 Outer ring 14 Outer ring track 15 Ball (rolling element)

Claims (1)

A rolling bearing comprising: an inner ring having an inner ring raceway on an outer peripheral surface; an outer ring having an outer ring raceway on an inner peripheral surface; and a plurality of rolling elements arranged to be relatively rotatable between the inner ring raceway and the outer ring raceway. And
The rolling element is formed of a ceramic material,
The diameter of the rolling element and D _b, the radius of curvature of the cross-sectional shape of the outer ring raceway and R _o, the radius of curvature of the cross-sectional shape of the inner ring raceway in the case of the _{R i, 0.53 <R o /} D b ≦ 0.65, 0.52 <R _i / D _b ≦ 0.65, and
When the outer diameter of the outer ring is D, the inner diameter of the inner ring is d, and the pitch circle diameter of the rolling elements is D _p , D _p <(d + D) / 2, 10 ³ ≧ D _p ≧ 2, D A rolling bearing, wherein _p is 10 mm to 40 mm or less.

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