JP2010121755A - Retainer for ball bearing and ball bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a retainer for a ball bearing capable of achieving grease-leak proof and space saving simultaneously and at a low cost, and the ball bearing. <P>SOLUTION: In the crown-shaped retainer 5 for the ball bearing having a pocket 11 a part of which is opened on one side face of an annular body to retain a ball 4 inside in a plurality of circumferential points of the annular body, a recessed part extending from a pocket opening edge on the retainer internal diameter side to the retainer external diameter side is provided on the inner face of each pocket 11, grease for a food machine is enclosed, the recessed part is provided, thereby reducing the amount in which the grease adhering to the ball 4 is scratched by the internal diameter face of the retainer 5, and grease adhesion to the external diameter part of an inner ring 2 is prevented. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a ball bearing retainer and a ball bearing, for example, to a technique for solving grease leakage of a bearing used in a rotating part and a conveyance system of a food manufacturing apparatus or the like.

Bearings used in food production equipment are required to have grease leakage resistance, low torque, corrosion resistance, and the like. Among these requirements, there are some which provide a plurality of slinger (for example, Patent Document 1) and a plurality of seals (for example, Patent Document 2) in order to improve grease leakage resistance.
JP 2003-262234 A JP 2003-254343 A

The one disclosed in Patent Document 1 or 2 requires a space for providing a slinger or the like in the axial direction of the bearing, which increases the number of parts and increases the manufacturing cost.
In some cases, grease may leak and plant-based grease that does not cause any problems even when mixed into food is used. However, when this vegetable grease is used, it has a shorter life compared to mineral oil and chemically synthesized greases. Moreover, it is desirable that even plant grease should not be mixed into food.

  An object of the present invention is to provide a ball bearing retainer and a ball bearing that can achieve grease leakage resistance and space saving at the same time and at low cost.

  The cage for ball bearings according to the present invention is a crown-shaped cage for ball bearings having pockets that are partially opened on one side surface of the annular body to hold the balls therein at a plurality of locations in the circumferential direction of the annular body. In the invention, the inner surface of each pocket is provided with a recessed portion extending from the pocket opening edge on the inner diameter side of the cage toward the outer diameter side of the cage, and filled with grease for food machinery.

  According to this configuration, a crown-shaped cage for ball bearings is applied, and a concave portion that extends from the pocket opening edge on the inner diameter side of the cage to the outer diameter side of the cage is provided on the inner surface of the pocket. The amount of food machine grease scraped by the inner surface of the cage is reduced. Thereby, grease leakage from the back side of the cage pocket can be suppressed, and adhesion of grease to the outer diameter portion of the inner ring can be prevented. Therefore, it is possible to prevent the grease from flowing into the seal groove of the inner ring, thereby preventing the grease leakage from the ball bearing. Thereby, grease does not leak and does not mix with food.

  Therefore, mineral oil-based or chemically synthesized oil-based grease can be used, and the ball bearing has a longer life compared to the case of using food machine grease. Since the ball bearing retainer can prevent grease leakage, it is not necessary to design and deform the shape of the seal groove of the inner ring, and it is not necessary to provide a slinger or the like in the axial direction of the ball bearing. Therefore, it is not necessary to increase the number of parts, and space saving can be achieved. The manufacturing cost can be reduced by reducing the number of parts compared to the conventional one.

In the food machine grease, the base oil may be at least one oil selected from liquid paraffin oil, polyalphaolefin oil, vegetable oil, animal oil, fluorine oil, ester oil, silicone oil, and alkylene glycol oil.
The thickener for the food machine grease may be at least one compound selected from aluminum composite soap, calcium hydrostearate, polyurea, clay, and fluororesin.

The grease filling ratio may be less than 100% with respect to the static space between the inner and outer rings. The space surrounded by the inner and outer rings of the ball bearing seal plate is defined as the total space volume.From this total space volume, the space excluding the space where the ball and cage perform rotational motion when the ball bearing rotates is defined as `` stationary. “Space”.
When the grease filling rate is less than 100% with respect to the static space, it is possible to suppress undesired leakage of the sealed grease from the outside of the ball bearing from the radial gap between the inner surface of the sealing plate and the outer surface of the inner ring.

The position in the axial direction of the recessed portion of the pocket may be a position that substantially coincides with the shoulder portion of the raceway surface of the inner ring in a state where the cage is incorporated in the bearing. In this case, the amount of the grease adhering to the ball scraped off by the inner diameter surface of the cage is effectively reduced.
The said recessed part may be provided in multiple places located in the both sides of the center of the holder circumferential direction in the opening edge of the said pocket. As described above, the recesses are provided at a plurality of positions on both sides of the center in the circumferential direction of the cage, thereby reducing the amount of grease scraping on the surface of the ball regardless of the rotation direction of the bearing. it can.

  The recessed portion is provided at one position so as to spread from the center in the cage circumferential direction at the opening edge of the pocket and has a width larger than half of the width in the cage circumferential direction of the pocket. Also good. In this case, since the amount of grease scraping on the surface of the ball can be reduced by one recess, the cage structure can be simplified. Therefore, it is possible to simplify the mold structure for forming the recess and to reduce the amount of grease accumulated on the inner diameter surface of the cage. When post-processing the dents on the inner surface of each pocket with a grindstone or the like, man-hours can be reduced as compared to the case where a plurality of dents are formed. Therefore, it is possible to reduce the manufacturing cost.

The concave portion may extend from the opening edge on the inner diameter side of the cage to the vicinity of the ball arrangement pitch circle, and may gradually become shallower and narrower as it approaches the ball arrangement pitch circle from the inner diameter edge of the cage.
You may provide the recessed part extended in the back surface of each said pocket from the inner diameter edge of a holder to the outer diameter side of a holder. Thereby, the area of the internal diameter surface in a pocket can be reduced, and the effect of grease leakage prevention can be improved.
A pair of claws facing in the circumferential direction are provided on the open side of each pocket so as to protrude in the axial direction, and the outer diameter of the cage is larger than the distance between the tips on the inner diameter side of the pair of claws of each pocket. You may narrow the space | interval between the front-end | tips on the side. In this case, the grease from the outer ring is scraped off by the outer diameter portion of the claw portion on the outer diameter side of the cage, and the grease does not adhere to the inner ring. Grease from the inner ring is also scraped off by the inner diameter portion of the claw portion on the outer diameter side of the cage, and the amount of grease adhering to the ball can be reduced. Since the scraped grease is located far from the outer diameter surface of the inner ring, it does not adhere to the outer diameter surface of the inner ring.
The tips on the inner diameter side of the pair of claws of each pocket may be opened, and the tips on the outer diameter side of the cage may be connected.
The interval between the tips of the pair of claws of each pocket may be reduced stepwise from the inner diameter side of the cage toward the outer diameter side of the cage.
You may make the space | interval between the front-end | tips of a pair of nail | claw of each said pocket infinitely narrow toward a cage outer diameter side from a cage inner diameter side.
When the total width of the claw projected onto the straight line in the radial direction of the cage passing through the center in the circumferential direction of the cage in the pocket is defined as It, the width Ie of the claw portion on the holding outer diameter side of the claw projected onto the straight line is 2 It is preferable to set the width of the claw portion on the outer diameter side of the cage so that it becomes / 3 It or less.

According to the ball bearing in which the ball bearing cage according to any one of claims 1 to 9 is incorporated, grease leakage can be prevented by the cage. For this reason, the amount of grease filled can be increased as compared with the conventional one, and the life can be extended.
In the ball bearing, a plurality of balls interposed between inner and outer rings are held by a cage, and the inner and outer rings and the plurality of balls may be made of stainless steel. In this case, it is possible to suppress the occurrence of rust without applying rust preventive oil to bearing parts such as inner and outer rings. Moreover, since it is not necessary to apply | coat rust prevention oil, the versatility which can be used for a foodstuff manufacturing apparatus as a bearing increases.

  The cage for ball bearings according to the present invention is a crown-shaped cage for ball bearings having pockets that are partially opened on one side surface of the annular body to hold the balls therein at a plurality of locations in the circumferential direction of the annular body. In the above, the inner surface of each pocket is provided with a recess that extends from the pocket opening edge on the inner diameter side of the cage to the outer diameter side of the cage and encloses the grease for food machinery. Can be achieved.

  An embodiment of the present invention will be described with reference to FIGS. FIG. 1A is a cross-sectional view of a food manufacturing apparatus to which a ball bearing according to this embodiment is applied, and FIG. 1B is an enlarged cross-sectional view of a main part thereof. The ball bearing 1 is a sealed deep groove ball bearing. As shown in FIG. 1A, a kneading rotary shaft J1 provided in a casing KS of a food production apparatus, for example, a food production apparatus for kneading food is provided. Used for supporting rotating parts. However, you may use the ball bearing 1 for the conveyance system of a foodstuff manufacturing apparatus, etc.

The food production apparatus KS shown in FIG. 1 (A) transfers the food raw material introduced into the casing KS from the introduction port TG to one axial direction indicated by an arrow A1 while kneading with the screw blade SB. Thereafter, the food manufacturing apparatus KS discharges the kneaded food from the outlet HG. The screw blade SB is spirally provided on the rotation shaft J1, and the rotation shaft J1 is configured to be rotationally driven by a motor (not shown).
Bearing boxes JB and JB are provided at one end and the other end of the casing KS, and the outer ring 3 of the ball bearing 1 is fitted into each bearing box JB. The outer ring end face is retained by the retaining ring TW. Both ends of the rotating shaft J1 are fitted into the inner ring 2 of these ball bearings 1. Thereby, the ball bearing 1 supports the both ends of the rotating shaft J1 rotatably.

The ball bearing 1 will be described.
As shown in FIG. 1B, the ball bearing 1 includes a plurality of balls 4 interposed between the raceway surfaces 2a and 3a of the inner ring 2 and the outer ring 3, and a cage 5 for holding these balls 4 is provided. Both ends of the annular space formed between the rings 2 and 3 are sealed with contact seals 6 respectively. The food machine grease described later is enclosed inside the ball bearing. The inner and outer rings 2, 3 are made of bearing steel, for example. The balls 4 are generally made of steel balls. In the ball bearing 1 used in the food manufacturing apparatus, the inner and outer rings 2, 3 and the ball 4 are made of martensitic stainless steel (Japanese Industrial Standard SUS440C) in particular. It is preferable in terms of the antirust surface. For example, when the inner and outer rings 2 and 3 and the balls 4 made of stainless steel are applied under severe use conditions in which salt water or the like enters the ball bearing, it is not necessary to apply rust preventive oil to these bearing components. It becomes possible to suppress the occurrence of rust. Moreover, since it is not necessary to apply | coat rust prevention oil, the versatility which can be used for a foodstuff manufacturing apparatus as a bearing increases. A ball 4 made of ceramic balls may be applied instead of the steel balls. The contact seal 6 is composed of an annular cored bar 7 and a rubber-like member 8 fixed integrally to the cored bar 7, and the outer peripheral part is fitted in a seal mounting groove 9 formed on the inner peripheral surface of the outer ring 3. Fixed to state. The inner ring 2 has a seal groove 10 formed of a circumferential groove at a position corresponding to the inner peripheral portion of each contact seal 6, and a seal lip 6 a formed at an inner peripheral side end of the contact seal 6 is a seal groove of the inner ring 2. 10 is in sliding contact.

  As shown in FIG. 2, the retainer 5 has a crown shape having pockets 11 for retaining the balls 4 (FIG. 1B) therein at a plurality of locations in the circumferential direction of the annular body 12. Each pocket 11 is partially opened on one side surface of the annular body 12. The inner surface of each pocket 11 has a concave spherical curved surface shape along the outer surface of the ball 4. A portion between the adjacent pockets 11, 11 of the annular body 12 serves as a connecting portion 13. On the open side of each pocket 11, a pair of claws 14, 14 facing in the circumferential direction of the cage are provided protruding in the axial direction. In this specification, the pocket opening side in the bearing axial direction is called the pocket side, and the opposite side is called the back side.

As shown in FIGS. 2 and 3, the inner surface of the pocket 11 of the cage 5 is provided with a plurality of recesses 16 extending from the pocket opening edge on the cage inner diameter side to the cage outer diameter side. By providing the recess 16, the amount of grease adhered to the ball 4 is scraped off by the inner diameter surface of the cage 5, and adhesion of grease to the outer diameter portion of the inner ring 2 is prevented. In this example, the recessed portions 16 are two locations located on both sides of the center OW11 in the cage circumferential direction at the opening edge of the pocket 11. The inner surface shape of each recess 16 is such that the cross-sectional shape along the circumferential direction of the cage (that is, the cross-sectional shape taken along a plane perpendicular to the cage central axis) is larger than the radius of curvature Ra of the concave spherical surface serving as the inner surface of the pocket 11. The arcuate shape has a small radius of curvature Rb. More specifically, as shown in FIG. 3 (B), the retainer 5 has a cylindrical surface shape substantially along the surface of each virtual cylinder V centered on a straight line L in the radial direction. is there. The recessed portion 16 extends from the pocket opening edge on the cage inner diameter side to the vicinity of the ball arrangement pitch circle PCD in the radial direction of the cage, and gradually decreases from the cage inner diameter edge toward the ball arrangement pitch circle PCD. That is, the shape gradually becomes shallower and narrower. The ball arrangement pitch circle PCD is also called a pocket PCD.
The positions of the two recessed portions 16 are, for example, two symmetrical places where the orientation angle in the circumferential direction with respect to the center OW11 in the circumferential direction of the cage at the opening edge of the pocket 11 is 40 ° ± 15 °. The depth of the recessed portion 16 is preferably such that the distance Rc from the center O11 of the recessed spherical surface of the pocket inner surface to the deepest position of the recessed portion 16 is 1.05 times or more the radius of the ball 4 (just. It may be 1.05 times).
In this embodiment, the number of the recessed portions 16 is two, but may be three or more.

  In still another example of the inner surface of the pocket in FIG. 4, the cross-sectional shape of the recess 16 (cross-sectional shape along the circumferential direction of the cage) is a polygonal shape. Specifically, as shown in FIG. 5B, the polygonal shape substantially follows the surface of each polygonal column (regular decagonal column in the illustrated example) VA around the radial line LA of the cage 5. . The concave portion 16 extends from the opening edge on the inner diameter side of the cage to the vicinity of the ball arrangement pitch circle PCD in the radial direction of the cage, and gradually decreases as the ball arrangement pitch circle PCD approaches from the inner diameter edge of the cage. The shape gradually becomes shallower and narrower. Other configurations in the embodiment of FIG. 4 are the same as those of the example of FIG.

  In another example of FIG. 5, the recessed portions 16 provided on the inner surface of the pocket 11 are provided at two locations on both sides of the center OW11 in the cage circumferential direction at the opening edge of the pocket 11, and The recessed portion 16 extends to the vicinity of the outer diameter edge of the cage. The cross-sectional shape along the circumferential direction of the cage of the inner surface of the recessed portion 16 is an arc shape having a radius of curvature RBb smaller than the radius of curvature Ra of the concave spherical surface serving as the inner surface of the pocket 11, and is shown in detail in FIG. As shown, the shape is substantially along the surface of one virtual ring VB. The virtual ring VB may be an outer peripheral surface of a grindstone that processes the recess 16. The virtual ring VB has a ring outer diameter that fits in the pocket 11 and has a donut shape with a circular cross-sectional shape at an arbitrary circumferential position, and the ring center OVB is placed on the cage center axis O as shown in FIG. It has an inclination to it. As described above, since the virtual ring VB is inclined toward the inner diameter side, the dent depth of the outer diameter side dent portion in each dent portion 16 is shallower than the inner diameter side dent portion. In other words, the degree of the dent in each of the dent portions 16 decreases from the dent portion on the inner diameter side toward the dent portion on the outer diameter side. Thereby, the grease leakage preventing effect is obtained.

In addition, in this invention, the cross-sectional shape along the cage circumferential direction of the recessed portion 16 is not limited to the shape of each example of FIGS. 3 to 5, but is a partial oval shape, a rectangular groove shape, a trapezoidal groove shape, and others. Any cross-sectional shape may be used. The cross-sectional shape of the recess 16 may be asymmetric with respect to the center of the recess.
The inner surface shape of the pocket 11 is not limited to a spherical shape, and may be any shape as long as the inner diameter side of the ball arrangement pitch circle PCD becomes a smaller diameter as it approaches the opening diameter of the cage inner diameter side. For example, the ball arrangement pitch circle PCD Further, the outer diameter side portion may be a cylindrical surface shape, and the inner diameter side portion may be a conical surface shape.

The ball bearing cage 5 in the example of FIG. 7 is obtained by deleting the back side of the inner diameter surface of the connecting portion 13 in the embodiment shown in FIGS. Thereby, in the pocket 11, the back side becomes a shape surrounded by the arc-shaped shell portion 11a.
In the example of FIGS. 3 to 5, the amount of grease that adheres to the balls 4 can be reduced by the recess 16 on the inner diameter surface of the cage 5. If it increases, it will lead to grease leakage. That is, in this case, grease adheres to the inner diameter surface of the connecting portion 13 and the grease in this portion can move only in the axial direction. When the axial range of the connecting portion 13 overlaps with the region where the outer diameter portion of the inner ring 2 exists, that is, when the inner diameter surface of the connecting portion 13 is located closer to the bearing end surface than the raceway surface 2a of the inner ring 2, Grease leaks out of the bearing from the inner diameter surface of the connecting portion 13. Therefore, as shown in FIG. 7, if the back surface side of the inner diameter surface of the connecting portion 13 is deleted, the grease can be prevented from leaking out of the bearing from the inner diameter surface of the connecting portion 13.

In the example of FIG. 7, an example is shown in which the back side of the connecting portion 13 is deleted from the inner diameter surface to the outer diameter surface. However, when considering the strength of the cage 5, it is desirable that the deleted amount is small. In order to suppress the adhesion of grease to the outer diameter portion of the inner ring 2, it is also effective to increase the distance between the outer diameter surface of the inner ring 2 and the inner diameter surface of the cage 5. A part of the wall may be deleted and a conventional wall surface may be left on the outer diameter side. That is, in the cross-section at the circumferential center position of the connecting portion 13 between the adjacent pockets 11, 11, the axial position on the back side of the inner diameter surface left without being deleted of the connecting portion 13 is defined as the raceway surface of the inner ring 2. Positioning on the center side of the raceway surface 2a rather than the shoulder portion of 2a is important for preventing grease leakage. This is shown in FIG. 12 as a schematic diagram of the positional relationship in the axial direction Y, with the sectional view of the inner ring 2 indicated by the phantom line superimposed on the cage 5 of FIG. That is, in the same figure, the axial position Yb of the connecting portion 13 may be on the center side (Yb <Ya) of the track surface 2a relative to the axial position Ya of the shoulder portion of the track surface 2a of the inner ring 2.
Further, the position of Yb in the figure is a position on the back side where the inner diameter surface of the connecting portion 13 may exist, and extends to the same position as the axial position on the back side of the central portion of the pocket 11 on the outer diameter side. There may be an outer wall. Similarly, the axial thickness of the connecting portion 13 from the Yb position toward the outer diameter side may be gradually or gradually increased toward the back side.

  The ball bearing cage 5 of the example of FIG. 8 shows an example in which the thickness of the shell 11a of the pocket 11 is relatively thick in the embodiment of FIG. In this case, the increase in the thickness of the shell portion 11a leads to an increase in the area of the inner diameter surface of the cage 5, and therefore tends to promote grease leakage. In particular, on the inner diameter surface of the cage 5, the position where a large amount of grease accumulates is in the vicinity of the axial position (indicated by symbol P) that coincides with the shoulder of the raceway surface 2a of the inner ring 2 in FIG. It is important to reduce the area of the inner diameter surface of the cage 5 in the vicinity of this axial position. Therefore, in this embodiment, the recessed portion 26 is also provided on the outer surface of the shell portion 11a of the pocket 11 to reduce the area of the inner diameter surface of the pocket 11. Thereby, the reduction | decrease of the grease deposit amount to the internal diameter surface of the holder | retainer 5 and the strength improvement of a holder | retainer single-piece | unit can be made to make compatible.

In order to reduce the area of the inner diameter surface of the cage 5, the recessed portion 16 provided on the inner surface of the pocket 11 may be enlarged as shown in a partially enlarged perspective view in FIG. 9.
As shown in a partially enlarged perspective view in FIG. 10, the annular body 12 constituting the cage 5 is held in a shape in which the axial thickness on the inner diameter side is thin and gradually increases toward the outer diameter side. The area of the inner diameter surface of the vessel 5 may be reduced. Similarly, the axial thickness of the annular body 12 may be increased stepwise from the inner diameter side to the outer diameter side.

  The ball bearing retainer 5 in the example of FIG. 11 is obtained by reducing the weight by deleting a part of the pair of tip portions 14 protruding to the open side of the pocket 11 in the embodiment of FIG. When the ball bearing 1 is used at high speed rotation, the influence of centrifugal force acting on the cage 5 becomes large. In order to reduce the stress of the cage 5 due to the centrifugal force, it is effective to reduce the weight of the cage 5. Thus, in this embodiment, the outer diameter side of the tip portion 14 is partially deleted. At the time of high speed rotation, the distal end portion 14 of the cage 5 is deformed so as to be inclined toward the outer diameter side with respect to the central portion of the pocket 11, so that the ball 4 is guided on the inner diameter side of the distal end portion 14. Therefore, even if a part of the outer diameter side of the tip end portion 14 is deleted as in this embodiment, there is no adverse effect on the bearing function.

  FIG. 13 and FIG. 14 show test results for confirming the grease adhesion state. In this test, a ball bearing incorporating the cage 5 of the example of FIG. 7 and a ball bearing incorporating a general crown-shaped cage were operated and compared under the same conditions. FIG. 13 shows a grease adhesion state of a ball bearing using the cage 5 of the example of FIG. 7, and FIG. 14 shows a grease adhesion state of a ball bearing using a general crown-shaped cage.

  From this test result, in a ball bearing incorporating a general crown-shaped cage (FIG. 14), there is a large amount of grease between the cage inner diameter surface and the outer diameter portion of the inner ring. Grease is leaking toward the groove. If the ball bearing is provided with a seal, grease flows between the seal groove and the seal tip, and leaks to the outside of the bearing as the temperature inside the bearing rises. In the ball bearing (FIG. 13) in which the cage 5 of the embodiment is incorporated, it can be seen that a very small amount of grease adheres to the inner diameter portion of the cage 5, but not to the inner ring outer diameter portion.

  As can be seen from the test results, in the ball bearing cage 5 of this embodiment, the inner surface of each pocket 11 is provided with a recess 16 extending from the pocket opening edge on the cage inner diameter side to the cage outer diameter side. The amount of grease adhering to the balls 4 is scraped off by the inner diameter surface of the cage 5 is reduced. Thereby, adhesion of grease to the outer diameter portion of the inner ring 2 can be prevented. If no grease adheres to the outer diameter portion of the inner ring 2, the grease can be prevented from flowing into the seal groove 10 (FIG. 1B) of the inner ring 2, and as a result, grease leakage from the ball bearing 1 can be prevented.

  In each of the above-described embodiments, the preferred position of the recess 16 on the inner surface of the pocket 11 is the position indicated by the symbol P in FIG. That is, the position in the bearing axial direction of the recessed portion 16 is a place that substantially coincides with the shoulder portion of the inner ring raceway surface 2 a when the cage 5 is incorporated into the ball bearing 1. This is because a large amount of grease accumulates on the inner diameter surface of the cage 5 due to contact between the balls 4 and the inner ring raceway surface 2a and in the vicinity of the axial position that coincides with the shoulder portion of the raceway surface.

The ball bearing cage 5 of the example of FIG. 15 is obtained by replacing the two recessed portions 16 provided on the inner surface of the pocket 11 with one recessed portion 16 in the embodiment of FIGS. The recess 16 also extends from the opening edge on the inner diameter side of the cage to the outer diameter side of the cage, and the sectional shape of the inner surface of the recess 16 along the circumferential direction of the cage (that is, perpendicular to the central axis of the cage). The cross-sectional shape obtained by cross-section with a flat surface is an arc having a radius of curvature RCb smaller than the radius of curvature Ra of the concave spherical surface serving as the inner surface of the pocket 11.
The recessed portion 16 is provided at one location so as to spread from the center OW11 in the cage circumferential direction at the opening edge of the pocket 11 to one side, and the width W16 of the recessed portion 16 is the width W11 of the pocket 11 in the cage circumferential direction. The width is almost the whole. The width W16 of the recess 13 is preferably larger than half of the width W11 of the pocket 11, and more preferably 2/3 or more, or 3/4 or more.
As shown in FIG. 15B, the inner surface shape of the recessed portion 16 is a cylindrical surface shape substantially along the surface of the virtual cylinder VC centered on the straight line LC in the radial direction of the cage 5. The virtual cylinder VC may be the surface of a grindstone that processes the recess 16. The recessed portion 16 extends from the opening edge on the cage inner diameter side to the ball arrangement pitch circle PCD in the radial direction of the cage, and gradually decreases, that is, gradually, from the cage inner diameter edge to the ball arrangement pitch circle PCD. The shape is shallow and narrow. In this embodiment, the dent 16 extends just to the ball arrangement pitch circle PCD, but may slightly extend to the outer diameter side of the cage with respect to the ball arrangement pitch circle PCD, or slightly to the ball arrangement pitch circle PCD. You may not reach it.

  The depth of the concave portion 16 is such that the distance RCc from the center O11 of the concave spherical surface of the pocket inner surface to the deepest position of the concave portion 16 is 1.05 times or more the radius of the ball 4 (just 1.05 times). Preferably). The radius of curvature Ra of the concave spherical surface serving as the inner surface of the pocket 11 is slightly larger than the radius of the ball 4 and is less than 1.05 of the radius of the ball 4.

The ball bearing cage 5 in the example of FIG. 16 has a crown-shaped ball bearing cage in which a pair of claws 14 and 14 facing the circumferential direction are provided on the open side of each pocket 11 so as to protrude in the axial direction. In each pocket 11, the interval between the tips of the claw portions 14b, 14b on the outer diameter side of the cage is set narrower than the interval between the tips of the claw portions 14a, 14a on the cage inner diameter side. Further, a recess 16 is provided on the inner surface of each pocket 11.
The protruding length of the claw portion 14a is the same as the protruding length of the claw in a general crown-shaped cage, and the protruding length of the claw portion 14b is longer than that of the claw portion 14a. As shown in FIG. 19 showing a cross-section along the circumferential direction of the cage of the claw 14 (cross-section along the pitch circle PCD of the ball arrangement), the circumferential direction of the cage facing the front end of the claw 14a and the front end of the claw 14b from the pocket center O11. It is preferable that the angles θa and θb are set to 1.5 times or more (θb ≧ 1.5θa) that the angle θb facing the tip of the claw portion 14b faces the angle θa facing the tip of the claw portion 14a.

  As shown in FIG. 20, the width of the claw portion 14b on the cage outer diameter side in the cage radial direction is such that the projection of the claw 14 projected on a straight line N in the cage radial direction passing through the center of the cage 11 in the circumferential direction of the cage. When the total width (pocket width) is It, it is preferable that the width Ie of the claw portion 14b projected on the straight line N is set to 2/3 or less (Ie ≦ 2 / 3It) of the total width It.

  In this embodiment, the ball bearing cage 5 is manufactured by the steps shown in FIGS. 17 and 18. As shown in FIG. 17A, a claw component 14ba having a claw tip portion protruding from the claw portion 14a on the cage inner diameter side of the claw portion 14b on the cage outer diameter side is separated from the cage body 5A. To form. Then, after the cage body 5A is incorporated into the inner and outer rings 2, 3 (FIG. 1B) and the ball 4, the claw part 14ba is bonded to the cage body 5A as shown in FIG. Weld by hot press or fit. Thereby, it is possible to avoid whitening or breakage at the base of the nail 14 when the cage is incorporated. The claw component 14ba may be not only the claw tip portion protruding from the claw portion 14a on the cage inner diameter side but also the most or the whole claw portion 14b on the cage outer diameter side.

  In the manufacturing method of FIG. 18, as shown in FIG. 18A, the retainer 14 b of the claw portion 14 b that protrudes from the claw portion 14 a has an open posture in which the claw tip portion 14 ba is farther away from the pocket center O 11 than when completed. Semi-finished product 5B is manufactured. Then, after the cage semi-finished product 5B is incorporated in the inner and outer rings 2 and 3 (FIG. 1B) and the ball 4, the claw tip portion 14ba is closed along the surface of the ball 4 as shown in FIG. In addition, it is bent while applying heat to cause thermal deformation or secondary processing. Thereby, it is possible to avoid whitening or breakage at the base of the claw 14 when the cage is incorporated.

  In the ball bearing cage 5 in the example of FIG. 16, the grease from the outer ring 3 (FIG. 1B) is scraped off at the outer diameter portion of the claw portion 14 b on the outer diameter side of the cage. Does not adhere. Grease from the inner ring 2 is also scraped off by the inner diameter part of the claw part 14b on the outer diameter side of the cage, the amount of grease adhering to the ball 4 is reduced, and the grease deposited on the pole part of the ball 4 is suppressed. Since the scraped grease is located far from the outer diameter surface of the inner ring 2, the scraped grease does not adhere to the outer diameter surface of the inner ring 2. Furthermore, by providing the recess 16 on the inner surface of each pocket 11, the amount of the grease adhering to the balls 4 scraped off by the inner diameter surface of the cage 5 is reduced. Thereby, grease adhesion to the outer diameter part of the inner ring 2 can be prevented more reliably.

As another example of a ball bearing cage, if the projection length of the claw tip on the cage outer diameter side is longer than the claw tip on the cage inner diameter side, the claw shape is c 3 and the contact seal 6 (FIG. 1B) may be in any shape as long as they are not in contact with each other.
In another example of FIG. 21, the interval between the tips of the pair of claws 14, 14 of each pocket 11 is infinitely narrowed from the cage inner diameter side toward the cage outer diameter side. Furthermore, the recessed part 16 (FIGS. 3-5 etc.) is provided in the inner surface of each pocket 11. FIG.
In another example of FIG. 22, the tips on the cage inner diameter side of the pair of claws 14 and 14 of each pocket 11 are opened, and the tips on the cage outer diameter side are connected. Furthermore, the recessed part 16 (FIGS. 3-5 etc.) is provided in the inner surface of each pocket 11. FIG.

The grease for food machinery will be described.
Food machinery is used for processing food ingredients and edible products (hereinafter referred to as “food ingredients, etc.”), as well as bearings and other sliding parts mounted on food machines as well as parts that directly contact food ingredients. Food hygiene law, which is a legal hygiene standard for various materials in food applications, even if the material does not come into direct contact with food ingredients, etc. The following greases for food machinery are applied in accordance with the approval standards such as food, additives, etc., FDA standards and USDA H-1 standards.

As the base oil of the grease for food machinery that can be used in the present invention, at least one oil selected from liquid paraffin oil, polyalphaolefin oil, vegetable oil, animal oil, fluorine oil, ester oil, silicone oil and alkylene glycol oil is used.
The oil selected from the liquid paraffin oil, poly-alpha olefin oil, vegetable oil, and animal oil has passed the USDA H-1 standard and the FDA standard as a substance harmless to the human body. Liquid paraffin oil is a hydrocarbon oil obtained by highly purifying a relatively light lubricating oil fraction by washing with sulfuric acid. It is mainly composed of alkyl naphthenes and is listed in the “Food Additives Official Declaration” or “Japan Pharmacopoeia”. It is described as medicinal liquid paraffin. This also corresponds to food liquid paraffin oil and pharmacopoeia liquid paraffin oil in the United States, England and Germany.
The poly α-olefin oil that can be used in the present invention has obtained an evaluation standard that it is completely harmless to the human body even if it is brought into direct contact with food according to the USDA H-1 standard. It is a synthetic hydrocarbon oil that does not contain impurities such as compounds. The vegetable oil that can be used in the present invention is a well-known natural oil that can be used as a food or food additive. For example, camellia oil, olive oil, peanut oil, castor oil, rapeseed oil, and the like can be used. Animal oils that can be used in the present invention are well-known natural oils that can be used as foods or food additives, such as sanagi oil, beef leg oil, lard (pig fat), or aquatic animal oils such as sardine oil and herring oil. There may be.

The fluorine oil that can be used in the present invention passes the above-mentioned USDA H-1, and consists of three atoms of carbon, fluorine, and oxygen. For example, the following formula (1) and formula (2) in Chemical Formula 1 below: It is of the molecular structure shown.

（式中、Ｒはメチル基、フェニル基の単体または混合された基である。）
このようなシリコーン油（オルガノポリシロキサン油）の具体例としては、ジメチルシリコーン油等のアルキルメチルシリコーン油、フェニルメチルシリコーン油等が挙げられる。
本発明に使用できるポリアルキレングリコール油は、合成潤滑油として周知のポリエチレングリコール油、ポリプロピレングリコール油などであり、これらは前述のＦＤＡで規定された合成潤滑油である。 The base oil selected from the ester oil, silicone oil, and polyalkylene glycol oil is one that has passed the USDA H-1 standard or FDA standard as a substance that does not harm the human body if it is less than a predetermined concentration. The ester oil that can be used in the present invention is a well-known ester oil having a —COO— structure, such as dibasic acid ester oil, polyol ester oil, phosphoric ester oil, and silicic acid ester oil. It is a synthetic lubricating oil composed of the compounds specified as additives (Indirect Food Additive). Specific examples of ester oils designated by the FDA include monohydrogen phosphate ester oil and dihydrogen phosphate ester oil.
The silicone oil used in the present invention is designated as the FDA among silicone oils known as polymer type synthetic lubricating oils, and is represented by the following chemical formula 2 (for example, dimethylpolysiloxane oil) Can be adopted.

(In the formula, R represents a single group or a mixed group of a methyl group and a phenyl group.)
Specific examples of such silicone oil (organopolysiloxane oil) include alkylmethyl silicone oil such as dimethyl silicone oil, phenylmethyl silicone oil, and the like.
Examples of the polyalkylene glycol oil that can be used in the present invention include polyethylene glycol oil and polypropylene glycol oil, which are well-known as synthetic lubricating oils. These are synthetic lubricating oils defined by the aforementioned FDA.

In the grease for food machinery, a compound is added to the base oil as a thickener. This compound is at least one compound selected from aluminum composite soap, calcium hydrostearate, polyurea, clay, and fluororesin.
Since the grease leakage can be prevented by the ball bearing retainer 5 according to the present embodiment, the amount of grease filled can be increased and the life can be extended compared to the conventional one.
Those using aluminum composite soap as a thickener can suppress the occurrence of peculiar peeling due to hydrogen embrittlement. Therefore, it is possible to extend the life of the ball bearing 1 filled with the food machine grease.
The grease for food machinery is not limited to plant-based grease, and mineral oil-based or chemically synthesized oil-based grease can be used. In this case, the ball bearing 1 has a longer life compared to the case where plant-based grease is used.

The grease filling rate is less than 100% with respect to the static space between the inner and outer rings 2 and 3. A space surrounded by the inner side of the contact seal of the ball bearing 1 and the inner and outer rings 2 and 3 is defined as a total space volume, and from this total space volume, a space in which the ball 4 and the cage 5 perform rotational motion when the ball bearing rotates. The excluded space is called “static space”.
When the grease sealing rate is less than 100% with respect to the static space, it is possible to suppress the undesired leakage of the sealed grease from the outside of the ball bearing from the radial gap between the inner surface of the contact seal and the outer surface of the inner ring.

  If the back side of any one of the ball bearing retainers 5 in the embodiment described above is assembled toward the side where it is desired to take measures against grease, the grease sealing function of the final product can be maintained. In the food manufacturing apparatus of FIG. 1 (A), as shown in FIG. 1 (B), the ball bearing 1 with the back side of each cage 5 facing into the casing KS and the pocket side facing outward in the axial direction is provided. Fit into the bearing box JB. Thereby, grease leakage from the back side of the pocket can be suppressed, and adhesion of grease to the inner ring outer diameter portion can be prevented. Therefore, it is possible to prevent the grease from flowing into the seal groove 10 in the axial direction in the inner ring 2, and thus the radial clearance δ1 between the casing KS and the rotary shaft J1 (from FIG. 1B) It is possible to prevent the grease from leaking into the casing KS, thereby preventing the grease from being mixed into the food.

  Since the grease leakage can be prevented by the ball bearing retainer 5, it is not necessary to change the design of the shape of the seal groove 10 of the inner ring 2, and it is not necessary to provide a slinger or the like in the axial direction of the ball bearing 1. . Therefore, it is not necessary to increase the number of parts, and space saving can be achieved. The manufacturing cost can be reduced by reducing the number of parts compared to the conventional one.

The ball bearing cage 5 according to the present embodiment may be applied to an angular ball bearing.
In the single row angular contact ball bearing shown in FIG. 23, the seal groove 10 is formed on the right side of the inner ring 2, and the seal member 6 is provided only on the right end. A seal member fixing groove 9 is formed at the right end of the inner surface of the outer ring corresponding to the right seal groove 10. The counter bore portion CB forming the inner ring outer diameter surface on the left side of FIG. 23 is formed to have a smaller diameter than the outer diameter portion 2D on the right side of the same drawing. Thereby, the inner ring 2 can be easily incorporated into the outer ring 3 and the ball 4 from the counter bore portion CB on the left side. Furthermore, the distance δ2 between the inner diameter surface of the cage 5 on the back side of the pocket and the counter bore portion CB can be increased. In this case, due to the synergistic effect of reducing the amount of the grease adhering to the balls 4 scraped by the inner diameter surface of the cage 5 by the recessed portion 16 of the cage, the adhesion of the grease to the counter bore portion CB on the left side is prevented. It becomes possible.

In the other example shown in FIG. 24, the amount of grease that adheres to the balls 4 on the inner surface 5d of the cage 5 is reduced by the recess 16 with respect to the grease pushed out from the raceway surface 2a and the like to the left side of the drawing. Thereby, adhesion of grease to the outer diameter portion 2D of the inner ring 2 can be prevented, and grease flow to the seal groove 10 can be prevented.
As in another example of FIG. 25, seal members 6 and 6 may be provided on both sides of the inner and outer rings. Grease pushed out from the raceway surface 2a and the like to the right side of the figure can be prevented from leaking by the seal member 6 on the right side. With respect to the grease pushed out from the raceway surface 2a and the like to the left side of the figure, the amount of the grease adhering to the balls 4 scraped by the inner surface 5d is reduced by the recess 16 of the cage 5.

  In the double-row angular ball bearing shown in FIG. 26, double-row balls 4 are interposed between raceway surfaces 2a and 3a, and cages 5 in each row hold a plurality of balls 4 in each row. The pocket open side of the cages 5 in each row is directed inward in the axial direction, and the back side of the pocket faces the seal member 6 with a slight distance. In other words, it arrange | positions so that the pocket surface of the two holder | retainers 5 and 5 may face each other. The aforementioned grease for food machinery is enclosed in the bearing space. These angular ball bearings also have the same effects as the deep groove ball bearing described above.

(A) is sectional drawing of the foodstuff manufacturing apparatus with which the ball bearing which concerns on this embodiment is applied, (B) is the principal part expanded sectional view. It is a perspective view of the cage for ball bearings. (A) is a partial enlarged perspective view of an example of the cage, and (B) is a perspective view showing a state in which a virtual cylinder is added to the perspective view. (A) is a partial enlarged perspective view of another example of the cage, (B) is a perspective view showing a state in which a virtual polygonal column is added to the perspective view. (A) is a partial enlarged perspective view of still another example of the cage, and (B) is a perspective view showing a state in which a virtual ring is added to the perspective view. It is explanatory drawing which shows the relationship between the pocket of the holder | retainer, and a virtual ring in a cross section. It is a perspective view of the cage for ball bearings concerning other embodiments of this invention. It is a perspective view of the cage for ball bearings concerning further another embodiment of this invention. It is a partial expansion perspective view of the cage for ball bearings concerning further another embodiment of this invention. It is a partial expansion perspective view of the cage for ball bearings concerning further another embodiment of this invention. It is a partial expansion perspective view of the cage for ball bearings concerning further another embodiment of this invention. It is explanatory drawing of the relationship of the axial direction position between the pocket of a cage for ball bearings, and an inner ring raceway surface. (A) is explanatory drawing of the result of the grease leak test of the ball bearing incorporating the cage | basket of the structure shown in FIG. 3, (B) is the elements on larger scale of (A). (A) is explanatory drawing of the result of the grease leak test of the ball bearing incorporating the general crown-shaped cage, (B) is the elements on larger scale of (A). (A) is the elements on larger scale of the ball bearing retainer concerning other embodiment of this invention, (B) is a perspective view which shows the state which added the virtual cylinder to the perspective view. It is a perspective view of the cage for ball bearings of other embodiments of this invention. It is explanatory drawing of the manufacturing method of the ball bearing retainer. It is explanatory drawing of the other manufacturing method of the ball bearing retainer. It is explanatory drawing of the angle from the pocket center of the nail | claw tip of the ball bearing retainer. It is explanatory drawing of the width | variety of the nail | claw of the ball bearing retainer. It is a side view which shows the other example of a shape of the nail | claw of the ball bearing cage. It is a side view which shows the further another example of a shape of the nail | claw of the ball bearing cage. It is a principal part expanded sectional view of the angular ball bearing concerning further another embodiment of this invention. It is a principal part expanded sectional view of the angular ball bearing concerning further another embodiment of this invention. It is a principal part expanded sectional view of the angular ball bearing concerning further another embodiment of this invention. It is a principal part expanded sectional view of the double row angular contact ball bearing concerning other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Ball bearing 2 ... Inner ring 4 ... Ball 5 ... Ball bearing retainer 11 ... Pocket 12 ... Ring body 14 ... Claw 16 ... Recessed part

Claims (16)

In a crown-shaped ball bearing retainer having pockets that are partially opened on one side surface of an annular body and hold a ball inside the annular body at a plurality of locations in the circumferential direction of the annular body.
Provided on the inner surface of each pocket is a recess extending from the pocket opening edge on the inner diameter side of the cage to the outer diameter side of the cage,
Filled with grease for food machinery,
A ball bearing retainer characterized by that.   The grease for food machinery according to claim 1, wherein the base oil is at least one oil selected from liquid paraffin oil, polyalphaolefin oil, vegetable oil, animal oil, fluorine oil, ester oil, silicone oil and alkylene glycol oil. Bearing cage.   The ball bearing retainer according to claim 1, wherein the thickener of the food machine grease is at least one compound selected from aluminum composite soap, calcium hydrostearate, polyurea, clay, and fluororesin.   The ball bearing retainer according to any one of claims 1 to 3, wherein a grease filling rate is less than 100% with respect to a stationary space between the inner and outer rings.   5. The ball according to claim 1, wherein an axial position of the pocket recess is substantially coincident with a shoulder of the raceway surface of the inner ring in a state where the cage is incorporated in the bearing. Bearing cage.   The ball bearing retainer according to any one of claims 1 to 5, wherein the recessed portion is provided at a plurality of positions on both sides of a circumferential direction of the retainer in the opening edge of the pocket.   7. The pocket retainer circumferential direction according to claim 1, wherein the recessed portion is provided at one position so as to spread from the center in the cage circumferential direction at the opening edge of the pocket to both sides. A ball bearing retainer having a width larger than half of the width.   In claim 6 or claim 7, the recess extends from the opening edge on the inner diameter side of the cage to the vicinity of the ball arrangement pitch circle, and gradually becomes shallower as it approaches the ball arrangement pitch circle from the cage inner diameter edge. Ball bearing cage with a narrow shape.   The ball bearing retainer according to any one of claims 1 to 8, wherein a concave portion extending from a cage inner diameter edge to a cage outer diameter side on a back surface of each pocket is provided.   10. The pair of claw holders according to claim 1, wherein a pair of claws facing each other in the circumferential direction are provided on the open side of each pocket so as to protrude in the axial direction. A ball bearing retainer in which the distance between the tips on the outer diameter side of the cage is narrower than the distance between the tips on the inner diameter side.   The ball bearing retainer according to claim 10, wherein a gap between the tips on the inner diameter side of the pair of claws of each pocket is opened and the tips on the outer diameter side of the cage are connected.   The ball bearing retainer according to claim 10, wherein the distance between the tips of the pair of claws of each pocket is gradually reduced from the cage inner diameter side toward the cage outer diameter side.   The ball bearing retainer according to claim 10, wherein the interval between the tips of the pair of claws of each pocket is steplessly narrowed from the cage inner diameter side toward the cage outer diameter side.   The holding outer diameter of the nail projected on the straight line according to claim 11 or 12, wherein the total width of the claw projected onto a straight line in the radial direction of the cage passing through the center in the circumferential direction of the cage in the pocket is defined as It. A ball bearing retainer in which the width of the claw portion on the outer diameter side of the cage is set so that the width Ie of the claw portion on the side is 2/3 It or less.   A ball bearing incorporating the ball bearing cage according to any one of claims 1 to 9.   The ball bearing according to claim 15, wherein a plurality of balls interposed between inner and outer rings are held by a cage, and the inner and outer rings and the plurality of balls are each made of stainless steel.

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