JP5459007B2 - Lubricant sealing method - Google Patents

Description

  The present invention relates to an improvement in manufacturing technology of double-row (for example, two-row) ball bearings (for example, double-row hub unit bearings for supporting wheels of various vehicles such as automobiles and railway vehicles). The present invention relates to an improvement in a method of enclosing a lubricant (for example, grease) into the inside of the double row ball bearing.

A double row (for example, two rows) ball bearing is applied as a component of the bearing portion in a hub unit that rotatably supports a wheel of an automobile, for example. Such double row ball bearings (hub unit bearings) that support the wheels of an automobile include, for example, an inner member (annular member having a raceway surface on the outer periphery) and an outer member (a raceway surface on the inner periphery). There are various types (types) depending on combinations such as whether or not the annular member has rotation, the presence or absence and number of flanges, or the separation configuration of the inner member, and any type depending on the use conditions and purpose of use. Are used properly. FIGS. 6 to 9 show examples of the configuration of such double row ball bearings (hub unit bearings). The bearings are composed of an inner member 2 and an outer member arranged so as to be relatively rotatable. One side member 4, a plurality of rolling elements (balls) 20 incorporated so as to be able to roll between the double-row raceway surfaces 6 and 8 of these members 2 and 4, and one rolling element (ball) 20 in each row. A retainer 22 is provided for rotatably holding, and the inner member 2 has a structure in which two inner ring structural bodies 2a and 2b are assembled into one.
FIG. 6 shows an example of a hub unit bearing in which neither the inner member 2 nor the outer member 4 has a flange. FIGS. 7 to 9 show a hub unit bearing in which the outer member 4 is provided with a flange 4f. An example of each is shown. FIG. 7 shows a bearing configuration in which the inner member 2 is a stationary ring and the outer member 4 is a rotating ring. FIGS. 8 and 9 are conversely, and the inner member 2 is a rotating wheel and the outer member 4. An example of a bearing configuration with a stationary ring is shown. The hub unit bearing shown in FIG. 7 is configured as a type that supports the driven wheel of an automobile, and FIGS. 6, 8, and 9 are configured as types that can support both the driven wheel and the driving wheel.

For these double row ball bearings (hub unit bearings), the friction between the inner member 2, the outer member 4, the rolling elements (balls) 20, and the retainer 22 are in contact with each other. Lubrication is performed for the purpose of reducing wear, preventing seizure, or extending the fatigue life. Such lubrication is performed by enclosing a lubricant inside the bearing, and can be roughly classified into oil lubrication and grease lubrication depending on the type of lubricant used.
In general, oil lubrication has the characteristics that the fluidity of the lubricant and the cooling effect on the bearing are high and the lubrication performance is superior to that of grease lubrication. Has a drawback that it easily leaks to the outside of the bearing. On the other hand, grease lubrication can suppress leakage to the outside of the bearing, can simplify the bearing and its peripheral structure, and is maintenance-free. For this reason, for example, in the case of a double row ball bearing (hub unit bearing) that supports the wheels of an automobile, grease lubrication is widely performed in consideration of its excellent maintainability (see Patent Document 1).

  Note that, regardless of whether oil lubrication or grease lubrication is performed on the double row ball bearing (hub unit bearing), the bearing is surrounded by the bearing (inner member 2 and outer member 4). Sealing device (various seals, shields, etc.) 24 is provided to seal the space) from the outside and keep it in a sealed state (airtight state and liquid-tight state), and the lubricating oil and grease enclosed in the bearing Is prevented from leaking (scattering) outside the bearing. Further, by providing such a sealing device 24, foreign matters (for example, muddy water, dust) are prevented from entering the inside from the outside of the bearing.

  When performing grease lubrication on a double row ball bearing (hub unit bearing), a nozzle portion (such as a grease discharge nozzle of a pump device) of a predetermined sealing means from an axial end surface portion (hereinafter referred to as a bearing flat portion) of the bearing. ) Grease the inside of the bearing. At this time, if the amount of grease is excessively large (for example, the amount of grease close to the dynamic space volume considering the rotation of the bearing is encapsulated), the encapsulated grease may leak to the outside of the bearing. For this reason, a little smaller amount of grease is sealed in the bearing than the dynamic space volume inside the bearing.

JP 2008-128421 A

Here, when the grease is sealed inside the bearing, if the sealing position is close to the bearing flat portion, grease leakage at the time of sealing tends to occur. The sealing device for the hub unit bearing (for example, a seal) is designed mainly to prevent the intrusion of foreign matter such as muddy water, so the effect of preventing grease leakage from the inside of the bearing to the outside (durability) It is not as high as the effect of preventing foreign material from entering from the outside. Therefore, if grease at the time of sealing adheres to the vicinity of the bearing flat surface portion, the grease may leak to the outside of the bearing even when the sealing device is mounted after the grease is sealed. In addition, grease does not reach the raceway surface sufficiently, resulting in deterioration of lubrication performance, or the amount of grease between the rows supplying lubricant (oil exuded from the grease) to the raceway surface is insufficient. There is a risk of lowering.
In place of such an enclosing means, for example, it is also possible to enclose grease inside the bearing by applying grease in advance to the surface of the bearing component and assembling the bearing using the component. In this case, however, the grease becomes an obstacle to the measurement of the axial gap and the acoustic inspection, which not only becomes a problem in terms of quality assurance of the bearing, but also deteriorates the working environment due to the scattered grease adhering to the assembly area. It is also assumed that inconveniences such as a decrease (insufficiency) of grease filling amount and the like occur.

  The present invention has been made to solve such problems, and its purpose is to evenly spread grease to the raceway surface while preventing external leakage of the lubricant (grease, for example) enclosed in the bearing. For double row ball bearings (hub unit bearings) that allow the lubricant to reach the space between the rows of lubricant that can be reliably supplied to the raceway surface The object is to provide a method of encapsulating a lubricant.

  In order to achieve such an object, the lubricant encapsulating method according to the present invention is formed on an inner member and an outer member, which are opposed to each other so as to be relatively rotatable, and the inner member and the outer member, respectively. In order to lubricate a double-row ball bearing having a plurality of balls incorporated so as to roll between the double-row raceways facing each other and a cage that rotatably holds the balls of each row, Enclose the lubricant inside. The retainer is provided with a plurality of pockets for accommodating the balls and rotatably holding them, and a plurality of column portions provided between adjacent pockets in the circumferential direction. It has a slanted shape with one side having a large diameter and the other side having a small diameter, and has a lubricant introduction groove that continues in a concave shape from the periphery on the large diameter side toward the small diameter side on the outer periphery thereof, and The nozzle portion of the lubricant enclosing means is connected to the large-diameter side end portion of the column portion while forming a space for introducing the lubricant between the raceway surface and the ball. The lubricant is sealed, and the lubricant is sealed from the nozzle part to the larger diameter side than the outer diameter part of the cage through the lubricant introduction groove.

  In the lubricant enclosing means, the nozzle portion has a cylindrical shape, and the annular end portion on the close contact side with the large-diameter side end portion of the pillar portion of the cage is the same number and the same interval as the pillar portion in the circumferential direction. A plurality of lubricant discharge ports arranged along the line are provided. When the lubricant is sealed inside the bearing, the lubricant is discharged from the lubricant discharge port in a state where the phases of the lubricant discharge port and the lubricant introduction groove of the column portion are matched.

  According to the method of encapsulating a lubricant according to the present invention, while preventing the external leakage of the lubricant encapsulated in the bearing (as an example, grease), the grease is evenly distributed over the raceway surface, and to the raceway surface. An amount of grease that can reliably supply the lubricating oil (oil exuded from the grease) can reach the inter-row portion. As a result, the raceway surface can be kept in a good lubrication state for a long time, the life of the grease can be extended, and the double row ball bearing (hub unit bearing) can be stably rotated with a certain accuracy. Is possible.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure for demonstrating the lubricant enclosure method which concerns on one Embodiment of this invention, Comprising: (a) assembles a double row ball bearing (hub unit bearing), and it is an exterior between an inner member and an outer member. FIG. 4B is a cross-sectional view of a main part showing a state opened to the state (a state in which the sealing device is not mounted); FIG. 5B shows a grease introduction space formed by pulling the inner member; Cross-sectional view of the principal part showing a state in which the grease is sealed inside the bearing, in close contact with the large-diameter side end part (the axial end face of the large-diameter annular part), (c) is the principal part showing the structure of the cage It is a perspective view. It is a figure which shows the structure of the nozzle part which opened the lubricant discharge port on the holder | retainer contact surface, Comprising: (a) is a perspective view which shows the contact | adherence side (lubricant discharge port) with a holder | retainer, (b) These are the longitudinal cross-sectional views of the same figure (a). It is a figure which shows the structure of the nozzle part which opened the lubricant discharge port to the recessed part (step part) of a cage contact surface, Comprising: (a) is a perspective view which shows the contact | adherence side (lubricant discharge port) with a cage FIG. 2B is a longitudinal sectional view of FIG. It is a figure which shows the structure of the nozzle part which opened the lubricant discharge port to the recessed part (groove) of a cage | basket contact surface, Comprising: (a) is a perspective view which shows the contact | adherence side (lubricant discharge port) with a cage | basket , (B) is a longitudinal sectional view of FIG. FIG. 6 is a diagram illustrating a configuration of a nozzle portion in which a lubricant discharge port is opened at a protruding portion of a cage contact surface, wherein (a) is a perspective view illustrating a contact side (lubricant discharge port) with a cage; b) is a longitudinal sectional view of FIG. FIG. 3 is a cross-sectional view of a principal part showing a configuration of a double row ball bearing (a hub unit bearing that does not have a flange and can support both a driven wheel and a driving wheel) to be encapsulated with lubricant according to the present invention. FIG. 3 is a cross-sectional view of a main part showing a configuration of a double row ball bearing (a hub unit bearing that supports a driven wheel with an inner member as a stationary ring and an outer member as a rotating wheel with a flange, which is a target for encapsulating a lubricant according to the present invention). . FIG. 2 shows a configuration of a double row ball bearing (a hub unit bearing capable of supporting both a driven wheel and a driving wheel with an inner member as a rotating wheel and an outer member as a stationary ring with a flange) to be filled with lubricant according to the present invention. It is principal part sectional drawing. FIG. 2 shows a configuration of a double row ball bearing (a hub unit bearing capable of supporting both a driven wheel and a driving wheel with an inner member as a rotating wheel and an outer member as a stationary ring with a flange) to be filled with lubricant according to the present invention. It is principal part sectional drawing.

  Hereinafter, the lubricant sealing method of the present invention will be described with reference to the accompanying drawings. Note that the method for encapsulating a lubricant according to the present invention can be applied as a method for encapsulating a lubricant in the interior thereof in order to lubricate various double-row ball bearings. As an example, in order to lubricate a hub unit bearing (hereinafter also simply referred to as a bearing) for rotatably supporting the wheel of an automobile as shown in FIG. explain. At that time, the lubricant encapsulated in the hub unit bearing may be either lubricating oil or grease. Here, a case where grease is encapsulated is assumed as an example.

  FIGS. 6 to 9 show an example of the configuration of a double row ball bearing (hub unit bearing) in which the lubricant is sealed by the lubricant sealing method of the present invention. As shown in each figure, these hub unit bearings are formed on the inner member 2 and the outer member 4 that are opposed to each other so as to be relatively rotatable, and are formed on the inner member 2 and the outer member 4 respectively. A plurality of balls 20 incorporated so as to roll between the opposing double-row raceway surfaces 6 and 8 and a cage 22 that rotatably holds the balls 20 in each row are provided.

  The inner member 2 is configured by assembling two separable annular bodies (hereinafter referred to as inner ring constituent bodies) 2a and 2b into one. In these inner ring structural bodies 2a and 2b, raceway surfaces 6 facing the double row (two rows) raceway surfaces 8 formed on the inner circumference of the outer member 4 are formed on the outer circumference, respectively. A recess formed by reducing the diameter of the inner periphery of the other inner ring constituent body (the inner ring constituent body 2b with respect to the inner ring constituent body 2a or the inner ring constituent body 2a with respect to the inner ring constituent body 2b) over the entire circumference (as an example) , Groove) 2c is provided. Note that the inner member 2 (inner ring components 2a, 2b) and the outer member 4 can both be configured as stationary members (so-called stationary wheels) or rotating members (so-called rotating wheels). The stationary wheel is fixed to a vehicle body component (e.g., a knuckle (not shown) of a suspension device) and maintained in a stationary state, whereas the rotating wheel is a wheel component (e.g., a wheel disc wheel (e.g., illustrated). Etc.) is fixed and rotates together with the wheel component.

  As shown in FIG. 1 (c), the retainer 22 includes a plurality of pockets 22p for receiving and rotating the balls 20 one by one and a plurality of column portions 22b provided between adjacent pockets 22p. Arranged in the circumferential direction, the column portion 22b has an inclined shape with one side having a large diameter and the other side having a small diameter with respect to the axial direction (left-right direction in FIGS. 6 to 9). The pocket 22p and the column portion 22b are connected by a pair of a large-diameter annular portion 22d and a small-diameter annular portion 22f that are opposed to each other with a predetermined interval, and the small-diameter annular portion 22f has an inner peripheral edge. A plurality of claw portions 22a protruding in the diameter reducing direction are provided. The retainer 22 has a small-diameter annular portion 22f (claw portion 22a) between the rows of the hub unit bearings (in other words, an assembly side of the two inner ring components 2a and 2b), a large-diameter circle. One ring is incorporated between the raceway surfaces 6 and 8 of each row so that the ring portion 22d is positioned on the opposite side, and rotates between the raceway surfaces 6 and 8 together with the balls 20 held in the pockets 22p.

  In this embodiment, a groove 22j (hereinafter referred to as a lubricant introduction groove) 22j is formed in the outer periphery of the pillar portion 22b so as to be concave from the peripheral edge on the large diameter side toward the small diameter side. By forming such a lubricant introduction groove 22j in the pillar portion 22b, when the lubricant (as an example, grease) is sealed inside the hub unit bearing, the lubricant introduction groove 22j serves as a guide, It is possible to smoothly enclose the hub unit bearings in the raceway surfaces 6 and 8 and the inter-row portion without adhering to the vicinity of the axial end surface portion (bearing flat portion). The configuration (size, cross-sectional shape, depth, etc.) of the lubricant introduction groove 22j is not particularly limited, and grease is smoothly enclosed in the raceway surfaces 6 and 8 and the inter-row portion without adhering to the vicinity of the bearing flat portion. If possible, any configuration may be used. For example, a lubricant introduction groove whose cross-sectional shape is substantially V-shaped, substantially U-shaped, rectangular or trapezoidal can be assumed.

  Further, as shown in FIG. 1A, the cage 22 is configured such that the axial end surface 22g of the large-diameter annular portion 22d is substantially flush with the spherical surface of the ball 20 held in the pocket 22p. In addition, the pocket 22p of the pocket 22p is formed in a concave spherical shape having a diameter that is slightly larger than the diameter of the ball 20. For this reason, the retainer 22 has a portion corresponding to each pocket 22p in the inner peripheral edge of the large-diameter annular portion 22d, which is thinned in a half-moon shape (the portion shown in FIG. ) 22c). Thereby, the ball 20 held in the pocket 22p can be smoothly rotated.

  By configuring the inner member 2 (inner ring constituent bodies 2a, 2b) and the cage 22 as described above, the claw portions 22a of the cage 22 are engaged with the recesses 2c of the inner ring constituent bodies 2a, 2b. Two inner ring components 2a and 2b are assembled. That is, when the hub unit bearing is assembled, the claw portion 22a of the retainer 22 is inserted into the recess 2c of the inner member 2 (inner ring components 2a, 2b) with respect to the set of the outer member 4, the ball 20 and the retainer 22. The inner ring components 2a and 2b are inserted into (inserted into) the set until they are engaged. Thereby, after the hub unit bearing is assembled, the concave portion 2c and the claw portion 22a are engaged, and the movement of the ball 20 is suppressed, so that the two inner ring components 2a and 2b can be assembled in a non-separated state. It is possible to prevent them from coming off.

Here, the number, size, arrangement interval, and the like of the claw portions 22a are not particularly limited, and can be arbitrarily set. Further, the number, size, and arrangement interval of the claw portions 22a may be the same or different in the two cages 22 incorporated in each row. Further, it does not matter whether the claw portion 22a is formed, or the body of the retainer 22 is integrated or separated. In addition, it is also conceivable that the claw portion 22a is formed as a continuous ridge over the entire circumference in the circumferential direction.
On the other hand, the configuration (size, shape, depth, etc.) of the recess (groove) 2c is not particularly limited as long as the claw portion 22a of the cage 22 can be engaged. That is, the claw portion 22a of the retainer 22 and the recess 2c of the inner member 2 (inner ring constituent bodies 2a, 2b) may have any configuration as long as they are configured to be able to engage with each other.
Further, the counter part having a diameter slightly larger than the groove bottom diameter of the raceway surface 6 of the inner member 2 (inner ring constituent bodies 2a, 2b) is caught on the ball 20 to prevent separation of the two inner ring constituent bodies 2a, 2b. The so-called knuckling method is also applicable.

  In the state where the two inner ring structural bodies 2a and 2b are assembled into one and the hub unit bearing is assembled, the balls 20 in the double row (two rows) form a predetermined contact angle with each other inward. The members 2 (inner ring constituent bodies 2a, 2b) and the raceway surfaces 6, 8 of the outer member 4 are incorporated so as to be able to roll while being in contact with each other. In this case, an action line (not shown) connecting the two contact points is perpendicular to the raceway surfaces 6 and 8, passes through the center of each rolling element 20, and is a point (action point) on the center line of the hub unit bearing. Cross at. That is, the hub unit bearing is configured as a rear combination (DB) bearing. As a result, it is possible to maintain high rigidity for applying various loads (radial load, axial load, moment load, etc.).

In the hub unit bearing having such a configuration, a lubricant (as an example, grease) is enclosed in its inside (the space surrounded by the inner member 2 (inner ring components 2a and 2b) and the outer member 4). The inner member 2 (inner ring components 2a and 2b), the outer member 4, the ball 20, and the retainer 22 are in contact with each other, reducing friction and wear, preventing seizure, or extending fatigue life. It is illustrated.
Hereinafter, with respect to a method of enclosing grease inside the bearing, grease is encapsulated in a double row ball bearing (hub unit bearing) in which neither the inner member 2 nor the outer member 4 has a flange as shown in FIG. The case is taken up as an example and explained. The present invention can be similarly applied to a double row ball bearing (hub unit bearing) as shown in FIGS.

  In addition, since the grease to be enclosed may be arbitrarily selected and used in accordance with the lubrication performance required for the hub unit bearing, the specific type is not particularly limited. For example, mineral oil or synthetic oil such as silicone oil and diester oil can be used as the base oil, and metal soap such as lithium soap, urea or fluorine compound can be used as the thickener. The base oil and the thickener may be arbitrarily combined to form a grease component. If necessary, various additives (for example, an antioxidant, a rust inhibitor, and an extreme pressure agent) may be added to the grease.

  To enclose such grease, first, the hub unit bearing is assembled by integrating the inner member 2 (inner ring components 2a, 2b), the outer member 4, and the balls 20 held by the cage 22. That is, the claw portion 22a of the retainer 22 is engaged with the recess 2c of the inner ring constituting bodies 2a and 2b, and the two inner ring constituting bodies 2a and 2b are assembled into one (state shown in FIG. 1 (a)). In this state, the sealing device 24 is not mounted, and the hub unit bearing is in a state where both sides between the inner member 2 (inner ring constituent bodies 2a, 2b) and the outer member 4 are open to the outside. The sealing device 24 may be attached after the completion of the grease filling.

  From this state, the inner member 2 (inner ring structure 2a in FIG. 1 (a)) is pulled outwardly from the bearing with respect to the axial direction (to the left in the figure (in the direction of the arrow)). The inner ring structure 2 a) is displaced in the tensile direction with respect to the outer member 4. At that time, the ball 20 is also displaced in the tensile direction with respect to the outer member 4 along the raceway surface 6 of the inner member 2 (inner ring structure 2a). Thus, a space (hereinafter referred to as a grease introduction space) S for introducing grease is formed between the raceway surfaces 6 and 8 and the balls 20 (state shown in FIG. 1B). As a method of pulling the inner member 2 (inner ring constituting body 2a), for example, a method of holding the inner member 2 (inner ring constituting body 2a) with a collet chuck can be assumed. However, magnetism is not used because it is not easy to demagnetize the finished bearing product (hub unit bearing after assembly is complete). The pulling force when pulling the inner member 2 (inner ring structure 2a) is greater than the pressing force applied from the nozzle portion 50 of the lubricant sealing means described later, and scratches the raceway surfaces 6 and 8 and the balls 20. What is necessary is just to set so that the nail | claw part 22a of the holder | retainer 22 engaged with the recessed part 2c of the inner ring structure 2a may not be damaged.

  Next, while forming the grease introduction space S, the nozzle portion 50 of the lubricant enclosing means is positioned in the open portion between the inner member 2 (inner ring constituting bodies 2a, 2b) and the outer member 4, and the nozzle portion 50 The nozzle portion 50 is inserted into the open portion until it is in close contact with the large-diameter side end portion of the column portion 22b of the cage 22 (in other words, the axial end surface 22g of the large-diameter annular portion 22d). .

Then, grease is sealed from the nozzle portion 50 to the larger diameter side than the outer diameter portion of the retainer 22 via the lubricant introduction groove 22j formed in the column portion 22b (see the arrow shown in FIG. 1B). The sealed grease flows inside the bearing with the lubricant introduction groove 22j as a guide. At this time, since the grease introduction space S is formed inside the bearing, the grease guided in the lubricant introduction groove 22j can freely flow in the grease introduction space S. 8 can be distributed evenly and smoothly, and the grease can surely reach the inter-row portion. As a result, an amount of grease that can reliably supply the lubricating oil (oil exuded from the grease) to the raceway surfaces 6 and 8 can be sealed between the rows.
When the grease is filled, the inside of the bearing is opened to the atmosphere, and the discharge amount is stabilized by preventing the bearing internal pressure from increasing due to the grease discharge. In this embodiment, however, the inner ring component 2a is moved outward from the bearing when the grease is filled. By pulling, a slight gap is formed between the other inner ring constituting body 2b assembled in one and the air is released through the gap, so that the bearing internal pressure does not increase even when grease is discharged. The grease is sealed inside the bearing in a state where the nozzle portion 50 is in close contact with the large-diameter side end portion of the column portion 22b (the axial end surface 22g of the large-diameter annular portion 22d) and the enclosed grease Is smoothly guided to the lubricant introduction groove 22j, so that the grease does not adhere to the vicinity of the axial end surface portion (bearing flat portion) of the hub unit bearing. If possible, by pulling out from the open part between the inner member 2 and the outer member 4 while rotating the nozzle portion 50, the grease can be cut off and the amount of grease charged can be stabilized. Therefore, after the grease is completely sealed, the sealed grease 24 is mounted between the inner member 2 (inner ring structure 2a) and the outer member 4 to ensure that the sealed grease leaks (scatters) outside the bearing. Can be prevented.

  As a result, the raceway surfaces 6 and 8 can be kept in a good lubrication state for a long time, the life of the grease can be extended, and the hub unit bearing can be stably rotated with a certain accuracy. Become.

  The above-described sealing of the grease inside the bearing is performed using a predetermined lubricant sealing means. As such a lubricant sealing means, for example, the amount of grease (discharge amount) can be set according to the size of the hub unit bearing, more specifically, the size of its internal space. What is necessary is just to apply the quantitative type pump apparatus etc. which can pressurize and discharge from the discharge outlet 52 of the nozzle part 50. FIG. The nozzle unit 50 functions as a connector with a hub unit bearing that encloses grease, and includes a supply pipe connected to a grease supply source of a lubricant enclosing means (pump device or the like), and discharges as an opening of the supply pipe. An outlet 52 is provided.

  FIGS. 2 to 5 show configuration examples of the nozzle portion 50. The nozzle portion 50 has a cylindrical shape, and has a large-diameter side end portion of the column portion 22b of the retainer 22 (another way of grasping). If this is done, the discharge for discharging a plurality of greases arranged along the circumferential direction to the annular end portion (hereinafter referred to as the annular portion) close to the axial end surface 22g) of the large-diameter annular portion 22d. An outlet (hereinafter referred to as a lubricant discharge port) 52 is provided. In this case, the nozzle portion 50 has an outer diameter slightly smaller than the inner diameter of the axial end portion of the outer member 4 (for example, the left end portion in FIG. 1B), and the inner diameter is the inner member 2. It is set slightly larger than the outer diameter of the axial end portion (for example, the left end portion in FIG. 1B, that is, the groove shoulder portion of the raceway surface 6) of the inner ring structural bodies 2a and 2b, Both the outer member 4 and the inner member 2 (inner ring constituent bodies 2a, 2b) are configured to be engageable with each other with a small gap therebetween in the axial direction. The grease is discharged from the lubricant discharge port 52. In this case, the same amount of grease may be discharged from each lubricant discharge port 52 at the same time. However, the grease discharge timing and the discharge amount do not have to be the same for all the lubricant discharge ports 52, and can be varied for each lubricant discharge port 52. By varying in this way, it becomes possible to manage the grease filling inside the bearing with higher accuracy, and to further contribute to the improvement of the lubrication performance of the hub unit bearing as described above.

  2 (a) and 2 (b), a flat surface (hereinafter, referred to as an annular portion) that can be in close contact with the large-diameter side end portion of the column portion 22b of the retainer 22 (the axial end surface 22g of the large-diameter annular portion 22d). As an example, a configuration of the nozzle portion 50 in which the lubricant discharge port 52 is opened on the cage contact surface 54 is shown. In such a nozzle 50, the same number of lubricant discharge ports 52 as the column portions 22b of the cage 22 are arranged along the circumferential direction at the same interval as the column portions 22b. In sealing the grease inside the bearing, for example, if the phase of the lubricant introduction groove 22j provided in the column portion 22b and the lubricant discharge port 52 is adjusted using a technique such as image processing, the lubricant discharge port 52 Grease can be directly discharged toward the lubricant introduction groove 22j, and the grease can freely flow in the grease introduction space S without adhering to the axial end surface portion (bearing flat portion) of the hub unit bearing. Is possible.

  FIGS. 3 and 4 show, as an example, the configuration of the nozzle portion 50 in which a concave portion 56 that is continuous over the entire circumference is formed in the cage contact surface 54 and the lubricant discharge port 52 is opened in the concave portion 56. 3 (a) and 3 (b), a stepped portion from the cage contact surface 54 continuous in the circumferential direction is formed as the recess 56, and a lubricant discharge port 52 is opened on the stepped surface. 4 (a) and 4 (b), a groove that is continuous in the circumferential direction is formed as a recess 56 in the cage contact surface 54, and a lubricant discharge port 52 is opened at the groove bottom. In this way, by forming the recess (step or groove) 56 on the cage contact surface 54, when grease is discharged from the lubricant discharge port 52, the grease passes along the recess (step or groove) 56. It is possible to wrap around. Therefore, it is possible to smoothly guide the grease to the lubricant introduction groove 22j without arranging the same number of lubricant discharge ports 52 as the pillar portions 22b of the cage 22 along the circumferential direction at the same interval as the pillar portions 22b. It becomes possible. That is, the number and arrangement interval of the lubricant discharge ports 52 can be freely set to some extent, and the phase alignment between the lubricant introduction groove 22j and the lubricant discharge port 52 is not particularly required.

  5 (a) and 5 (b), a nozzle portion 50 in which the outer peripheral edge portion of the cage contact surface 54 is continuously protruded over the entire circumference, and the lubricant discharge port 52 is opened in the protruding portion 58. The configuration of is shown as an example. In this case, the protruding portion 58 is an annular region having a larger diameter than the outer diameter of the large-diameter side end portion (the axial end surface 22g of the large-diameter annular portion 22d) of the column portion 22b of the retainer 22 on the retainer contact surface 54. Are projected from the other annular regions. As a result, the grease can be discharged into the bearing while the lubricant discharge port 52 is further closer to the grease introduction space S. Therefore, the protruding height of the protruding portion 58 may be adjusted so as to protrude to the maximum without contacting the outer member 4 (groove shoulder portion of the raceway surface 8) or the ball 20. Also in the nozzle 50, the same number of lubricant discharge ports 52 as the column portions 22b of the cage 22 are arranged along the circumferential direction at the same interval as the column portions 22b, and image processing or the like is performed when enclosing grease. It is preferable to perform phase alignment between the lubricant introduction groove 22j provided in the column portion 22b and the lubricant discharge port 52 using the above technique.

  In any of the nozzle portions 50 shown in FIGS. 2 to 5, the entire surface of the cage contact surface 54 is the large-diameter side end portion of the column portion 22b of the cage 22 (the axial end surface of the large-diameter annular portion 22d). 22g) need not be in close contact with each other, and at least the inner peripheral surface area may be in close contact with the large-diameter side end (axial end surface 22g). In FIGS. 2 to 5, it is assumed that the lubricant discharge port 52 and the cage contact surface 54 are configured as an integral cylindrical member (nozzle portion 50). The nozzle member 50 may be configured by separately forming the cylindrical member opened in the cylinder and the cylindrical member having the cage contact surface 54 with different diameters and combining these cylindrical members.

  And even if it is a case where grease is enclosed inside a bearing using any nozzle part 50 shown in FIGS. 2-5, after the completion of encapsulation, the inner member 2 and the outer side are rotated while the nozzle part 50 is rotated. By pulling out from the open part between the members 4, the grease from the lubricant discharge port 52 is easily cut off, and the grease is not attached in the vicinity of the axial end surface part (bearing flat part) of the hub unit bearing. Therefore, by mounting the sealing device 24 between the inner member 2 and the outer member 4, it is possible to more reliably prevent the sealed grease from leaking (scattering) to the outside of the bearing.

  As described above, according to the method for encapsulating the lubricant according to the present embodiment, the grease is evenly distributed to the raceway surfaces 6 and 8 while preventing external leakage of the grease encapsulated inside the bearing. The amount of grease that can reliably supply the lubricating oil (oil exuded from the grease) to 8 can reach the inter-row portion and can be sealed. As a result, the raceway surfaces 6 and 8 can be kept in a good lubrication state for a long period of time, the life of the grease can be extended, and the double row ball bearing (hub unit bearing) can be stably rotated with a certain accuracy. It will be possible to continue.

2 Inner members 2a, 2b Inner ring structure 4 Outer members 6, 8 Raceway surface 20 Ball 22 Retainer 22b Pillar portion 22d Retainer large diameter annular portion 22g Large diameter annular portion axial end surface 22j Lubricant introduction groove 22p Pocket 80 Nozzle part S Lubricant introduction space (grease introduction space)

Claims (2)

A plurality of inner members and outer members that are opposed to each other so as to be rotatable relative to each other, and a plurality of inner members and outer members that are formed on the inner members and the outer members, respectively, so as to be able to roll between two opposing raceway surfaces. In order to lubricate a ball and a double row ball bearing provided with a cage that rotatably holds the balls of each row, a lubricant encapsulating method for encapsulating the lubricant inside the bearing,
The retainer is provided with a plurality of pockets for accommodating the balls and rotatably holding them, and a plurality of column portions provided between adjacent pockets in the circumferential direction. It has an inclined shape with one side having a large diameter and the other side having a small diameter, and has a lubricant introduction groove that continues in a concave shape from the periphery on the large diameter side toward the small diameter side on its outer peripheral portion
Pulling the inner member outward in the axial direction with respect to the axial direction, forming a space for introducing a lubricant between the raceway surface and the ball, and the nozzle portion of the lubricant sealing means as the column portion A lubricant sealing method, wherein the lubricant is sealed from the nozzle portion to a larger diameter side than the outer diameter portion of the cage through the lubricant introduction groove. .   The nozzle portion of the lubricant enclosing means has a cylindrical shape, and the annular end portion on the close contact side with the large-diameter side end portion of the pillar portion of the cage has the same number and the same interval as the pillar portion along the circumferential direction. A plurality of lubricant outlets arranged in a row, and in a state where the phases of the lubricant outlet and the lubricant introduction groove of the column portion are matched, the lubricant is discharged from the lubricant outlet. The method for encapsulating a lubricant according to claim 1, wherein the lubricant is encapsulated.

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