JP4888403B2 - Double row roller bearing unit - Google Patents

Description

  The present invention relates to lubrication of various double row roller bearing units (e.g., hub unit bearings for supporting automobile wheels, etc.), and in particular, improves the method of encapsulating lubricant inside the unit and improves lubrication performance. The present invention relates to a double row roller bearing unit.

  Conventionally, for bearings, the bearing ring (rotating ring and stationary ring), rolling elements (balls and rollers) and the cage where the bearings are in contact with each other, friction and wear are reduced, seizure prevention, or Lubrication is performed for the purpose of 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 equipment are high, and that it has better lubrication performance than 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 hub unit bearing that supports the wheels of an automobile (hereinafter referred to as a wheel support bearing unit), grease lubrication is widely performed in consideration of its excellent maintainability. The improvement of the reliability of the wheel support bearing unit is achieved.

  In order to increase the load capacity against various loads (radial load, axial load, moment load, etc.), such a wheel support bearing unit is normally configured in a double row configuration in which a plurality of rolling element raceways (track grooves) are formed. Depending on the type of rolling elements incorporated in the double row raceway grooves, they are roughly divided into ball bearing units (for example, angular contact ball bearing units) and roller bearing units (same, tapered roller bearing units). Among these, the double row tapered roller bearing unit as shown in FIGS. 2 to 4 can increase the load capacity and rigidity of the bearing unit by increasing the length of the roller. It is also used when the axle structure requires that the sectional height ((outer diameter dimension−inner diameter dimension) / 2) of the bearing unit be kept low.

  By the way, in the double row tapered roller bearing unit (hereinafter referred to as bearing unit A) as shown in FIGS. 2 to 4, the tapered rollers 22 are held and guided on both shoulder portions of the raceway surface 10 r formed on the rotating wheel 10. For this purpose, flanges 10a and 10b are provided. In this case, the raceway surface 10r is formed to be inclined along the inclined rolling surface of the tapered roller 22 which is a rolling element, and has a large diameter on the outer side of the bearing unit A (hereinafter referred to as the unit outer side). A collar portion (referred to as the large diameter collar portion 10a) is disposed, and a small diameter collar portion (referred to as the small diameter collar portion 10b) is disposed on the inner side (referred to as the inside of the unit). .

  The large-diameter flange portion 10a, more specifically, the surface inside the unit (hereinafter referred to as a contact surface 10s) is in contact with the head (end portion on the large-diameter side) 22h of the tapered roller 22. The contact is a sliding contact. For this reason, for example, when the grease is not sufficiently supplied to the contact portion when the lubricant (as an example, grease) is sealed inside the unit, the contact surface 10s of the large-diameter flange portion 10a and the head of the tapered roller 22 are provided. The portion 22h does not come into contact smoothly, and problems such as burn-in occur at these contact portions.

When the grease is sealed inside the bearing unit A, a grease sealing jig (not shown) is usually inserted from the open part between the rotating wheel 10 and the stationary wheel 12 to discharge the grease, and the unit is sequentially The method of pushing the grease into is taken.
However, the contact portion between the large-diameter flange 10a (contact surface 10s) and the tapered roller 22 (head 22h) is a unit of the large-diameter flange 10a when viewed from the bearing plane side (unit exterior side). Since it is located on the inner side (behind the large diameter flange 10a), it has been difficult to sufficiently enclose the grease in the contact portion (near the contact surface 10s of the large diameter flange 10a).

Therefore, various measures have been conventionally taken in order to easily and sufficiently enclose grease in the contact portion and to keep the contact portion in a good lubricating state. For example, Patent Document 1 discloses a bearing unit structure example for sufficiently enclosing grease in the vicinity of the contact surface 10s of the large-diameter flange portion 10a. However, in the above structural example, it is necessary to remove the stationary wheels (outer race and axle hub), expose the contact portion to the outside, and perform a grease replenishment operation (enclosure operation) on the contact portion. For this reason, the grease replenishment operation (encapsulation operation) itself can be easily performed, but the previous operation at that time is very time-consuming and cannot be an effective measure in practice.
Japanese Utility Model Publication No. 6-32747

  Here, the double row tapered roller bearing unit (bearing unit A) as shown in FIGS. 2 to 4 has a large ratio of the length dimension of the tapered roller 22 to the entire width (dimension in the left-right direction in each figure), and the raceway The area (space) between the grooves is small. In such a bearing unit A with a small inter-groove region, as a result, the dynamic space volume of grease is small, and the amount of grease that can be sealed inside the unit is limited. For this reason, if grease is concentrated in the vicinity of the contact portion between the large diameter flange 10a (contact surface 10s) and the tapered roller 22 (head 22h), the amount of grease charged in the vicinity of the small diameter flange 10b decreases. Or the sealed grease may not reach the vicinity of the small diameter flange 10b sufficiently. As a result, the lubricating state in the vicinity of the small-diameter flange portion 10b is deteriorated, and in some cases, the grease in the inter-groove region may be lost.

  Further, the bearing unit A is configured as a so-called back-combined (DB) bearing, and this increases the rigidity. On the other hand, the bearing inner space increases in diameter toward the outside of the unit. Conical shape (tapered taper). For this reason, it is preferable to accumulate grease in the inter-groove region and move the accumulated grease to the raceway surface 10r little by little.

  The present invention has been made to solve such problems, and its purpose is to allow a limited amount of lubricant (e.g., grease or lubricating oil) to be enclosed in the unit efficiently and in a balanced manner. Is to provide a simple double row roller bearing unit.

  In order to achieve such an object, a double row roller bearing unit according to the present invention is formed on at least a pair of stationary wheels and rotating wheels, which are opposed to each other so as to be relatively rotatable, and the stationary wheels and the rotating wheels, respectively. And a plurality of rollers which are incorporated into the double row raceway grooves so as to be able to roll, and lubrication is performed by enclosing a lubricant inside the unit. In such a double row roller bearing unit, the roller is composed of a hollow roller having a through hole formed along a rotation axis thereof to form a hollow structure, and a solid roller having no through hole. Among the grooves, a plurality of the hollow rollers and the solid rollers are mixed and incorporated in at least one of the raceway grooves, and the hollow rollers sandwich at least one solid roller in the circumferential direction. It arrange | positions at intervals and the lubricant is enclosed by the area | region between the said track grooves inside a unit by letting the through-hole of the said hollow roller pass.

In this case, the number of hollow rollers incorporated in the one raceway groove is approximately the total number of built-in rollers calculated by adding the number of hollow rollers incorporated in the raceway groove and the number of solid rollers. Set to a number.
In addition, the number of solid rollers incorporated between adjacent hollow rollers along the circumferential direction of the one raceway groove is the number of solid rollers incorporated in the raceway groove by the number of hollow rollers. The quotient may be set to an integer calculated by rounding up or down.

  According to the double-row roller bearing unit according to the present invention, a limited amount of lubricant (for example, grease or lubricating oil) can be sealed in the unit efficiently and in a balanced manner. It is possible to ensure that the agent is evenly distributed throughout the unit. As a result, even when the amount of lubricant enclosed must be limited to a small amount, the double row roller bearing unit can be kept in a good lubricating state over a long period of time, and the bearing unit can be kept constant. It is possible to continue to rotate stably with accuracy, that is, to improve durability.

  Hereinafter, the double row roller bearing unit of the present invention will be described with reference to the accompanying drawings. The double-row roller bearing unit according to the present invention can be used in various applications and unit configurations. Here, the double-row roller bearing unit is for supporting a vehicle wheel as shown in FIGS. 1 (a) and 1 (b). A configuration of the bearing unit X will be described assuming a hub unit bearing, specifically, a double row tapered roller bearing unit (hereinafter referred to as a bearing unit X) as an example. The bearing unit X is lubricated by encapsulating a lubricant inside the unit. In this case, the encapsulated lubricant may be either lubricating oil or grease. Is assumed as an example.

  In this case, the bearing unit X includes the driving wheels of the automobile (the front wheels of the front engine rear wheel drive (FR) car and the rear engine rear wheel drive (RR) car, the front wheels of the front engine front wheel drive (FF) car, and Hub unit bearings that support four-wheel drive (all wheels of a 4WD) vehicle, or hub unit bearings that support driven wheels of automobiles (front wheels of FR and RR vehicles, rear wheels of FF vehicles) You may comprise as.

The type (type) of the hub unit bearing is not particularly limited to the types shown in FIGS. 1 (a) and 1 (b). ) May be provided by integral molding or the like, and the rotating wheel may be provided with a hub flange to which a wheel component member (not shown) (for example, a disc wheel) is fixed by integral molding or the like. Also good. Further, the rotating wheel may have a divided configuration of the first inner ring 16p and the second inner ring 16q as shown in FIGS. 1A and 1B, or may be configured by a hub and an inner ring structure not shown. It may be. The inner ring constituting body refers to a member that forms a raceway surface that is opposed to a raceway surface on the inner side of a vehicle body (not shown) of a stationary wheel and that is externally fitted to the hub and forms a rotating wheel together with the hub.
In addition to the tapered roller 18 as shown in FIGS. 1 (a) and 1 (b), the rolling elements include various types of rollers such as cylindrical rollers and spherical rollers depending on the usage conditions and purpose of the bearing unit X. You may select and use arbitrarily.

Here, in the configuration shown in FIGS. 1A and 1B, the outer member (outer raceway) is the stationary ring 2, and the inner member (inner raceway) is the rotating wheel 4 (inner rings 16p, 16q). On the contrary, a hub unit bearing having a configuration in which the outer member (outer raceway ring) is a rotating ring and the inner member (inner raceway ring) is a stationary ring may be used.
In any of the hub unit bearings (bearing unit X) described above, the stationary wheel is fixed to a vehicle body component (for example, a knuckle (not shown) of a suspension device) and maintained in a stationary state. A wheel component (for example, a disc wheel (not shown)) is fixed to the rotating wheel and rotates together with the wheel component.

  1 (a) and 1 (b) show a bearing unit X according to an embodiment of the present invention. The bearing unit X includes a stationary wheel 2 and a rotating wheel that are opposed to each other so as to be relatively rotatable. 4 and a plurality of rolling elements (conical rollers) 18 which are incorporated in a raceway groove formed between the stationary wheel 2 and the rotating wheel 4 so as to be able to roll.

  Specifically, the stationary wheel 2 is fixed to a vehicle body component (for example, a knuckle (not shown) of a suspension device) and is always kept in a non-rotating state, whereas the rotating wheel 4 is a wheel component. (For example, a disc wheel (not shown)) is fixed and rotating together with the wheel constituent member, and is formed between the raceway surfaces 21 and 41 (hereinafter referred to as the following) formed on the stationary wheel 2 and the rotating wheel 4 respectively. A plurality of rolling elements (conical rollers) 18 are rotatably incorporated in the raceway groove a) and between the raceway surfaces 23 and 43 (same as the raceway groove b) to constitute the bearing unit X.

  In this case, the rolling elements (conical rollers) 18 are rotatably held one by one in pockets formed in the annular cage 8, and the raceway groove a (between the raceway surfaces 21 and 41), and Rolling on the raceway b (between the raceway surfaces 23 and 43). Thereby, each rolling element (conical roller) 18 can roll the raceway grooves a and b at a predetermined interval (for example, equal intervals) without the rolling surfaces being in contact with each other. It is possible to prevent an increase in rotational resistance or seizure due to friction between the rolling elements (conical rollers) 18 that come into contact with each other. In the configuration shown in FIGS. 1 (a) and 1 (b), a so-called slanted rice bran type is applied as the cage 8. However, the usage conditions and purpose of the bearing unit X and the rolling elements of the rolling element are used. Any type such as a comb type or a cage type may be used depending on the type.

  Moreover, in this embodiment, the rolling element (conical roller) 18 is comprised by two types, the hollow roller 18a and the solid roller 18b. The hollow roller 18a has a hollow structure in which a through hole 18h is formed along its rotation axis, whereas the solid roller 18b has a structure (so-called tapered roller) that does not have the through hole 18h. It is made.

  Of the double row raceway grooves a and b (between the raceway surfaces 21 and 41 and between the raceway surfaces 23 and 43) formed in the bearing unit X, at least one raceway groove (one raceway row) includes: A plurality of hollow rollers 18a and solid rollers 18b are mixed and incorporated. 1A and 1B show, as an example, a configuration of a bearing unit X in which hollow rollers 18a and solid rollers 18b are mixed and incorporated only in the raceway groove a (between the raceway surfaces 21 and 41). Has been. In this case, the hollow roller 18a is not incorporated in the other raceway groove b (between the raceway surfaces 23 and 43), and only the solid roller 18b is incorporated.

  However, not only the raceway groove a (between the raceway surfaces 21 and 41) but also the raceway groove b (between the raceway surfaces 23 and 43) may be configured by mixing hollow rollers 18a and solid rollers 18b together. A configuration in which these rollers 18a and 18b are mixed and incorporated only in the raceway groove b may be employed.

  Further, a plurality of hollow rollers 18a and solid rollers 18b mixed and incorporated in one raceway groove (the raceway groove a (between the raceway surfaces 21 and 41)), the hollow roller 18a is in the circumferential direction of the raceway groove a. They are arranged at substantially equal intervals across the solid roller 18b. At that time, the number of hollow rollers 18a incorporated in the raceway groove a (between the raceway surfaces 21 and 41), that is, the hollow rollers 18a mixed with the solid roller 18b in the raceway groove a (between the raceway surfaces 21 and 41). The number is not particularly limited here because it may be arbitrarily set according to the size of the bearing unit X, for example.

  However, since the hollow roller 18a has a hollow structure in which a through hole 18h is formed along its rotation axis, the weight of the hollow roller 18a when it is made of the same material (for example, the same steel material) as the solid roller 18b. Is smaller than the solid roller 18b. Therefore, when mixed with the solid roller 18b, it is substantially evenly distributed without biasing the weight balance of one raceway groove (the raceway groove a (between the raceway surfaces 21 and 41)) and the bearing unit X. It is preferable to incorporate two or more hollow rollers 18a into the one track groove (track groove a) in order to maintain and prevent vibration. At that time, the hollow roller 18a is made of a material having a specific gravity greater than that of the solid roller 18b, and the weight balance between the hollow roller 18a and the solid roller 18b is eliminated, so that the weight balance is kept substantially uniform. Occurrence may be prevented.

Furthermore, the number of hollow rollers 18a incorporated into one raceway groove (the raceway groove a (between the raceway surfaces 21 and 41)) (the number of hollow rollers 18a mixed with the solid roller 18b) is equal to the raceway groove a (the raceway). It is preferable to set to a divisor of the total number of built-in rollers calculated by adding the number of assembled hollow rollers 18a and the number of assembled solid rollers 18b between the surfaces 21 and 41).
For example, when the total number of built-in rollers in the raceway groove a (between the raceway surfaces 21 and 41) is 9, the number of hollow rollers 18a is set to 3 and the number of solid rollers 18b is 6 It is sufficient to set the number. Then, the three hollow rollers 18a may be arranged at equal intervals in the circumferential direction of the raceway groove a by incorporating the three hollow rollers 18a one by one with two solid rollers 18b interposed therebetween. .

  Further, instead of adopting a configuration in which the number of hollow rollers 18a incorporated in one raceway groove (track groove a (between raceway surfaces 21 and 41)) is set to a divisor of the total number of built-in rollers described above, such raceway grooves The number of solid rollers 18b incorporated between the hollow rollers 18a adjacent in the circumferential direction a (between the raceway surfaces 21 and 41) is hollow, and the number of solid rollers 18b incorporated into the raceway groove a is hollow. It is good also as a structure which divided | segmented by the number of incorporation of the roller 18a, and set to the integer calculated by rounding up or rounding down the quotient. Thereby, the hollow rollers 18a can be arranged at substantially equal intervals in the circumferential direction of the raceway groove a.

  For example, when the number of solid rollers 18b incorporated into the raceway groove a (between the raceway surfaces 21 and 41) (ie, the total number of assemblies) is 7, and the number of hollow rollers 18a is 3 (in this case) , The total number of built-in rollers is 10), two between the adjacent hollow rollers 18a along the circumferential direction of the raceway groove a (when the quotient is rounded up), or three (when the same is rounded down) ), The hollow rollers 18a can be arranged at substantially equal intervals in the circumferential direction of the raceway groove a. Specifically, in the raceway groove a, two portions where the two solid rollers 18b are incorporated between the hollow rollers 18a adjacent to each other in the circumferential direction are incorporated in three places, and the three solid rollers 18b are incorporated. One part is configured.

  As described above, the bearing unit X in which the hollow roller 18a and the solid roller 18b are arranged (incorporated) in one raceway groove (the raceway groove a (between the raceway surfaces 21 and 41)) is lubricated with grease as described above. Thus, in the bearing unit X, the stationary wheel 2 and the rotating wheel 4 (inner rings 16p, 16q), the rolling elements 18 (hollow rollers 18a and solid rollers 18b), and the cage 8 are in contact with each other. Reduction of friction and wear of parts, prevention of seizure, or extension of fatigue life is achieved. At that time, the grease G may be sealed inside the unit by the following procedure.

  In addition, since the grease G to be enclosed may be arbitrarily selected and used according to the lubrication performance required for the bearing unit X, 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 grease G may be configured by arbitrarily combining the base oil and the thickener. Note that various additives (for example, an antioxidant, a rust inhibitor, and an extreme pressure agent) may be added to the grease G as necessary.

  When the grease G is sealed, as shown in FIG. 1A, the rolling element 18 (hollow roller) held by the stationary wheel 2, the rotating wheel 4 (inner rings 16p, 16q), and the cage 8 is used. 18a and solid roller 18b) are integrally assembled, and the bearing unit X is in a state in which both sides (the left side and the right side in the figure) between the stationary wheel 2 and the rotating wheel 4 (inner rings 16p, 16q) are opened. (The state shown in the figure).

  The grease G is sealed using a grease filling machine (not shown). At that time, the amount of grease G filled (discharge amount) is set in the grease filling machine in advance, and the set amount of grease G is set. Pressurized by the grease filling machine. Nozzles 30a and 30b for discharging grease G are connected to such a grease filling machine, and grease G is discharged from the nozzles 30a and 30b into the unit so that grease G is applied to the bearing unit X. Is enclosed. In this case, the discharge amount of the grease G may be arbitrarily set according to, for example, the size of the bearing unit X, more specifically, the size of the unit internal space.

  In the present embodiment, as an example, a nozzle for discharging grease G to the region between the raceway grooves a and b (hereinafter referred to as an inter-row portion S) inside the unit via the hollow roller 18a (the inter-row nozzle 30a). And a nozzle for discharging the grease G to the vicinity of the large diameter flange 4a of the rotating wheel 4 (inner ring 16q) (referred to as the flange nozzle 30b). The large diameter flange 4a is provided on both shoulders of the raceway surfaces 41 and 43 of the rotating wheel 4 (inner rings 16p and 16q) in order to hold and guide the rolling elements 18 (hollow rollers 18a and solid rollers 18b). Of the flanges 4a and 4b provided respectively, the flanges disposed on the outer side of the bearing unit X (hereinafter referred to as the unit outer side) and disposed on the inner side (hereinafter referred to as the unit inner side). , Referred to as a small-diameter collar portion 4b).

  In the configuration shown in FIG. 1 (a), as an example, the inter-row nozzle 30a is disposed on one side between the stationary wheel 2 and the rotating wheel 4 of the bearing unit X (open portion on the inner ring 16p side (in FIG. The discharge port 32a of the inter-row nozzle 30a is open toward the inside of the bearing unit X (left side in the figure). In addition, the collar nozzle 30b is positioned at the other open portion between the stationary wheel 2 and the rotating wheel 4 (inner ring 16q) (the open portion on the inner ring 16q side (the left end portion in the figure)). The discharge port 32b of the nozzle 30b is open toward the inside of the bearing unit X (to the right in the figure).

  FIG. 1 (a) shows a state in which one inter-row nozzle 30a and one collar nozzle 30b are provided, but a plurality of these nozzles 30a and 30b are preferably provided. . At that time, the inter-row nozzles 30a are provided in the same number as the number of hollow rollers 18a incorporated in the raceway groove (for example, the raceway groove a (between the raceway surfaces 21 and 41)) through which the grease G is discharged. The nozzles 30a are arranged one by one so as to have the same phase along the circumferential direction as a predetermined hollow roller 18a. Specifically, the inter-row nozzles 30a may be arranged such that the discharge ports 32a open toward the through holes 18h of the hollow rollers 18a.

  By disposing the plurality of inter-row nozzles 30a in this way, the grease G pressurized by the grease filling machine is discharged from the discharge ports 32a of the inter-row nozzles 30a to the hollow rollers 18a facing each of the discharge ports 32a. Each can be discharged individually toward the through hole 18h. As a result, the discharged grease G can smoothly reach the inter-row portion S of the bearing unit X through the through-holes 18h of the hollow rollers 18a, so that the grease G is surely sealed in the inter-row portion S. Can be accumulated.

  In this case, as shown in FIG. 1 (b), the inter-row nozzle 30a (FIG. 1 (a)) may have a structure in which a delivery pipe 34a provided therein is extended and exposed to the outside. With the inter-row nozzle 30a having such a structure, the delivery pipe 34a is inserted into the through hole 18h of the hollow roller 18a, and the discharge port 32a is positioned (opened) in the vicinity of the inter-row portion S of the bearing unit X. The grease G can be directly discharged to the inter-row portion S. Accordingly, the grease G can be more reliably sealed in the inter-row portion S, and a sufficient amount of the grease S can be accumulated more effectively.

  On the other hand, a predetermined number of flange nozzles 30b may be arranged at predetermined intervals (for example, equal intervals) along the circumferential direction according to the size of the bearing unit X, for example. In addition, when arrange | positioning the collar part nozzle 30b to the open part between the stationary wheel 2 and the rotary wheel 4 on the same side as the nozzle 30a between rows, the collar nozzle 30b of the nozzle 30a of the said row | line | column is along the circumferential direction. These flange nozzles 30b may be positioned so as to be sandwiched between them (for example, a state where these are alternately arranged one by one).

  By disposing the plurality of flange nozzles 30b in this manner, the grease G pressurized by the grease filler is discharged from the discharge port 32b of each flange nozzle 30b to the large diameter of the rotating wheel 4 (inner rings 16p, 16q). More specifically, it can be individually discharged toward the vicinity of the flange portion 4a toward the contact portion between the large-diameter flange portion 4a and the rolling element 18 (hollow roller 18a or solid roller 18b). . As a result, the discharged grease G can be sufficiently sealed in the vicinity of the large diameter flange 4a (the contact portion between the large diameter flange 4a and the hollow roller 18a or the solid roller 18b).

  Note that the amount of grease G discharged from the inter-row nozzle 30a and the collar nozzle 30b may be arbitrarily set according to the size of the bearing unit X, more specifically, the size of the unit internal space, for example. Although it is good, it is not particularly limited, but the amount of discharge from the collar nozzle 30b is kept to the minimum necessary so that a sufficient amount of grease G is enclosed and accumulated in the inter-row portion S of the bearing unit X. It is preferable to increase the discharge amount from the nozzle 30a as much as possible. In this case, for example, the discharge amount of the inter-row nozzle 30a and the collar nozzle 30b may be set in advance for the grease filling machine. At this time, the discharge amounts from the inter-row nozzles 30a may be different from each other, but are preferably equal. Similarly, the discharge amounts from the collar nozzle 30b may be different from each other, but are preferably equal.

  By setting the discharge amount from the inter-row nozzle 30a and the collar nozzle 30b to such a setting, the inter-row portion S of the bearing unit X can be maintained in a good lubrication state for a long period of time. In addition, by sufficiently accumulating the grease S in the inter-row portion S, the accumulated grease S is applied to the rotating wheel 4 (inner rings 16p, 16q) as the rotating wheel 4 (inner rings 16p, 16q) rotates. It can be moved along the raceway surfaces 41 and 43 toward the large-diameter flange portion 4a. As a result, a limited amount of grease G is allowed to flow inside the unit, and not only the inter-row portion S but also the entire inside of the unit can be kept in a good lubricating state over a long period of time.

  As described above, according to the bearing unit X according to the present embodiment, a limited amount of grease G can be easily and efficiently balanced in the unit, and the sealed grease G can be reliably supplied to the unit. The entire interior can be spread evenly. As a result, even when the amount of grease G to be filled is limited to a small amount, the bearing unit X can be kept in a good lubrication state for a long period of time, and the bearing unit X can be maintained with a certain degree of accuracy. Thus, it is possible to continue to rotate stably, that is, to improve durability.

  After the grease G is sealed in the bearing unit X, various sealing devices (for example, contact type) for shielding the inside of the unit from the outside and keeping it in a sealed state (airtight state and liquid tight state) What is necessary is just to assemble a seal | sticker or a non-contact-type seal | sticker, a shield, etc.) in the open part between the stationary wheel 2 and the rotating wheel 4 (inner ring | wheel 16p, 16q). As a result, leakage of the enclosed grease G to the outside of the unit can be prevented, and entry of foreign matter (for example, muddy water, dust, etc.) into the unit can be prevented.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure for demonstrating the structure of the double row roller bearing unit which concerns on one Embodiment of this invention, Comprising: (a) mixed and incorporated the hollow roller and the solid roller in one raceway groove | channel, and the said hollow roller Sectional view showing a state in which grease is sealed (discharged) into the unit (inter-row part) through the through-hole of the nozzle and sealed in the vicinity of the large-diameter collar, (b) is an extension of the delivery pipe of the inter-row nozzle FIG. 5 is a cross-sectional view showing a state in which grease is directly enclosed (discharged) between the rows. Sectional drawing which shows the structural example of the conventional double row tapered roller bearing unit. Sectional drawing which shows the structural example of the conventional double row tapered roller bearing unit. Sectional drawing which shows the structural example of the conventional double row tapered roller bearing unit.

Explanation of symbols

2 Stationary wheel 4 Rotating wheel 16p, 16q Inner ring 18 Rolling element (conical roller)
18a Hollow roller 18b Solid roller 18h Through-hole 21, 23, 41, 43 Raceway X Bearing unit (Double-row tapered roller bearing unit)

Claims (3)

And at least a pair of stationary wheels and rotating wheels opposed to each other so as to be rotatable relative to each other, and a plurality of rollers incorporated so as to be able to roll into double row raceway grooves respectively formed on the stationary wheels and the rotating wheels, A double row roller bearing unit lubricated by enclosing a lubricant inside the unit,
The roller is constituted by a hollow roller having a hollow structure with a through hole formed along the rotation axis thereof and a solid roller having no through hole,
Among the double row raceway grooves, a plurality of the hollow rollers and the solid rollers are mixedly incorporated in at least one raceway groove, and the hollow rollers are at least one solid roller in the circumferential direction. Are arranged at approximately equal intervals across the
A double row roller bearing unit, wherein a lubricant is sealed in a region between the raceway grooves inside the unit by passing through a through hole of the hollow roller.   The number of hollow rollers incorporated in the one raceway groove is set to a divisor of the total number of incorporated rollers calculated by adding the number of hollow rollers incorporated in the raceway groove and the number of solid rollers. The double row roller bearing unit according to claim 1, wherein the double row roller bearing unit is provided.   The number of solid rollers assembled between adjacent hollow rollers along the circumferential direction of the one raceway groove is obtained by dividing the number of solid rollers incorporated in the raceway groove by the number of hollow rollers. The double row roller bearing unit according to claim 1, wherein the double row roller bearing unit is set to an integer calculated by rounding up or down the quotient.

Images