JP2018150953A - Rolling bearing with seal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling bearing with a seal in which stirring resistance does not increase even when more oil than necessary enters the inside of the bearing. SOLUTION: An outer ring 2, an inner ring 3, an outer diameter portion 11 fitted in a pair of seal fitting grooves 8 provided at both ends of an inner diameter surface of the outer ring 2, and a seal lip 13 facing the inner ring 3. A seal member 10 having an inner diameter portion including 14 is provided, and oil passages 16 and 18 communicating the inside of the bearing and the outside of the bearing are formed between the seal lip 10 and the inner ring 3, and at least one of the seal members 10 is formed. An oil relief groove 12 that communicates the inside of the bearing and the outside of the bearing is formed on the outer diameter portion 11 side of the above. [Selection diagram] Fig. 4

Description

  The present invention relates to a rolling bearing with a seal, and relates to a rolling bearing with a seal used in a transmission mounted on a vehicle such as an automobile or various construction machines.

  In the transmission, foreign matters such as gear wear powder are mixed. This foreign matter causes early separation of the rolling surface of the bearing. For this reason, the sealing member is used to prevent foreign matter from entering the bearing internal space and prevent the rolling surface from being peeled off early.

  A general seal member has a seal lip formed of a rubber material or the like. A bearing surface that rotates in the circumferential direction with respect to the seal member is formed with a sliding surface that is in sliding contact with the seal lip. Since the seal lip and the sliding surface are in sliding contact over the entire circumference, the bearing torque increases due to the drag resistance (seal torque) of the seal lip.

  In order to suppress such an increase in bearing torque, Patent Document 1 discloses that a seal lip is provided on the sliding portion of the seal lip, and the oil penetrates into the sliding portion due to the wedge film effect. It has been proposed to reduce the torque in a fluid lubricating oil state.

  In addition, if there is more oil than necessary for lubrication inside the bearing, the stirring resistance increases, which also causes an increase in bearing torque. However, in the above-mentioned Patent Document 1, no consideration is given to the case where more oil than necessary enters the bearing.

International Publication No. 2016/143786

  An object of the present invention is to provide a rolling bearing with a seal that does not increase the stirring resistance even when more oil than necessary enters the bearing.

  In order to solve the above-mentioned problems, the present invention is directed to an outer ring, an inner ring, an outer diameter portion fitted in a pair of seal fitting grooves provided at both ends of an inner diameter surface of the outer ring, and the inner ring. A seal member having an inner diameter portion including a seal lip that forms an oil passage that communicates between the inside of the bearing and the outside of the bearing between the seal lip and the inner ring, and the at least one of the seal members An oil relief groove for communicating the inside of the bearing and the outside of the bearing is formed on the outer diameter side.

  The oil relief grooves may be arranged at equal intervals over the entire circumference in the circumferential direction of the outer diameter portion. Further, the oil relief groove can be provided obliquely with respect to the axial direction. And the said oil relief groove | channel can be provided in circular arc shape seeing from an axial direction.

  Further, the seal lip is in sliding contact with the sliding surface of the inner ring, the sliding portion of the seal lip is provided with a plurality of protrusions, and the oil passage is formed between the plurality of protrusions. be able to.

  The outer diameter portion may be formed of a rubber material.

  As described above, according to the present invention, in the rolling bearing with seal, an oil relief groove that communicates the inside of the bearing and the outside of the bearing is formed on the outer diameter side of at least one of the seal members. The entered lubricating oil can be discharged from the oil relief groove to the outside of the bearing, and an increase in stirring resistance can be prevented.

It is a perspective view of the state where a part of outer ring of a rolling bearing with seal concerning an embodiment of this invention was notched, and a cage is omitted. It is a side view of the state where a part of outer ring of a rolling bearing with seal concerning an embodiment of this invention was notched, and a cage is omitted. It is a longitudinal front view which expands and shows a part of rolling bearing with a seal | sticker which concerns on embodiment of this invention. It is sectional drawing which expands and shows the sealing member part of the rolling bearing with a seal | sticker which concerns on embodiment of this invention. It is sectional drawing which expands and shows the inward lip | rip of the rolling bearing with a seal | sticker which concerns on embodiment of this invention, and the sliding surface part of an inner ring | wheel. It is a perspective view which shows the sealing member used for embodiment of this invention. It is a front view which shows the sealing member used for embodiment of this invention. It is a typical sectional view expanding and showing a seal member used for an embodiment of this invention. It is sectional drawing which expands and shows the sealing member part of the rolling bearing with a seal | sticker which concerns on other embodiment of this invention. It is the schematic which shows the example which used the rolling bearing with a seal | sticker which concerns on embodiment of this invention for the transmission.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
As shown in FIG. 1 to FIG. 3, a rolling bearing with a seal (hereinafter sometimes simply referred to as a rolling bearing) 1 includes an outer ring 2, an inner ring 3, and a raceway groove 4 formed on an inner diameter surface of the outer ring 2. And a plurality of balls 6 assembled between raceway grooves 5 formed on the outer diameter surface of the inner ring 3 and a cage 7 for holding the balls 6. That is, the rolling bearing 1 of this embodiment is a ball bearing.

  Hereinafter, a direction along the bearing central axis of the rolling bearing 1 is referred to as an axial direction, and a direction orthogonal to the axial direction is referred to as a radial direction. The circumferential direction around the bearing central axis is referred to as the circumferential direction.

  Lubricating oil is supplied into the annular bearing formed by the outer ring 2 and the inner ring 3 by appropriate means such as grease and an oil bath.

  A rolling bearing 1 with a seal according to an embodiment of the present invention is used, for example, in an automobile transmission. FIG. 10 is a schematic view showing an example of incorporation in an automobile transmission. The figure is an example of an automatic transmission. The outer rings 2 of the rolling bearings 1 and 1 with seals are fitted to both ends in the axial direction of the case 23, and both ends of the main shaft 24 are rotatably supported by the inner rings 3 of the bearings 1 and 1, respectively. A counter shaft 25 is provided in the case 23 in parallel with the main shaft 24. The counter shaft 25 has a gear portion that meshes with the gear portion of the main shaft 24, and is rotatably supported by the case 23 via a bearing.

  The rolling bearing 1 with seal according to the embodiment of the present invention is used for bearings for differentials, constant velocity joints, propeller shafts, turbochargers, machine tools, and the like, in addition to the transmission of the vehicle, and is attached to these rotating shafts.

  As described above, the inner ring 3 is attached to the main shaft 24 (see FIG. 10) and rotates integrally with the main shaft 24. The outer ring 2 is attached to the case 23 (see FIG. 10).

  A pair of seal fitting grooves 8 are formed at both ends in the axial direction on the inner diameter surface of the outer ring 2, while the outer diameter surfaces of the inner ring 3 face the pair of seal fitting grooves 8 in the radial direction. A seal groove 9 is formed at the position.

  An outer diameter portion 11 of a rubber seal member 10 is fitted into each of the pair of seal fitting grooves 8 formed in the outer ring 2. The seal member 10 includes a cored bar 10b and a rubber portion 10a that covers the cored bar 10b. Specifically, the rubber portion 10a covers the entire core metal 10b except for the axially inner side surface of the core metal 10b. The rubber portion 10a is made of rubber having excellent oil resistance and heat resistance, such as nitrile rubber, heat-resistant nitrile rubber, hydrogenated nitrile rubber, acrylic rubber, and fluorine rubber.

  This seal member 10 divides the inside of the bearing from the outside of the bearing. On the outside side with the seal member 10 as a boundary, there are foreign matters according to the assembly destination of the rolling bearing 1, such as gear wear powder, clutch wear powder, and fine quarrying. Such powdery foreign matter reaches the vicinity of the rolling bearing 1 by the flow of lubricating oil or atmosphere. The seal member 10 prevents foreign matter from entering the bearing from the outside of the bearing.

  As described above, the seal member 10 has the outer diameter portion 11 press-fitted into the seal fitting groove 8, the radial seal lip 13 facing outward on the inner peripheral side, and the axial seal lip 14 facing inward on the inner diameter portion. . The seal member 10 is attached to the outer ring 2 by press-fitting the outer diameter portion 11 into the seal fitting groove 8.

  As shown in FIGS. 3 and 4, the radial seal lip 13 of the seal member 10 is in elastic contact with a sliding surface 31 formed of a small-diameter cylindrical surface formed outward in the axial direction of the seal groove 9, while the axial The tip of the seal lip 14 is in elastic contact with the sliding surface 32 on the inner surface of the seal groove 9. A radial allowance is formed between the radial seal lip 13 and the sliding surface 31, and an axial allowance is formed on the axial seal lip 14 and the sliding surface 32 on the inner surface of the seal groove 9 in the axial direction. Due to these tightening allowances, a rubber-like elastic deformation is generated to seal the bearing space.

  The contact surface of the radial seal lip 13 with respect to the sliding surface 31 is provided with minute protrusions 15 throughout, and the contact surface of the inner surface of the seal groove 9 of the axial seal lip 14 with respect to the sliding surface 32 is also provided. Small protrusions 17 are provided throughout.

  As shown in FIGS. 4 to 8, the radial seal lip 13 has a protrusion 15 having a protrusion height in a direction perpendicular to the sliding surface 31, that is, a normal direction perpendicular to a tangent line contacting the sliding surface 31. . Since the sliding surface 31 has a cylindrical surface shape with the bearing central axis as the center, the direction orthogonal to this is equivalent to the radial direction. The protrusion 15 is formed over the entire range from the tip of the radial seal lip 13 so as to face the sliding surface 31 in the radial direction. An oil passage 16 is formed on both sides of the projection 15 that contacts the sliding surface 31 as a boundary.

  As shown in FIGS. 4 and 6 to 8, the axial seal lip 14 is perpendicular to the sliding surface 32 on the inner surface of the seal groove 9, that is, in the normal direction perpendicular to the tangent line in contact with the sliding surface 32. A protrusion 17 having a protruding height is provided. Since the sliding surface 32 has a mortar shape centered on the bearing central axis, the direction orthogonal thereto is a direction inclined by a predetermined angle from the axial direction. The protrusion 17 is formed over the entire range from the tip of the axial seal lip 14 to the sliding surface 32 in the axial direction. An oil passage 18 is formed on both sides of the projection 17 that contacts the sliding surface 32 as a boundary.

  By the oil passage 16 and the oil passage 18, the inside of the bearing and the outside of the bearing are communicated.

  The protrusions 15 of the radial seal lip 13 are arranged at uniform intervals over the entire circumference in the circumferential direction. For this reason, the oil passage 16 also occurs at uniform intervals over the entire circumference. The protrusions 15 are distributed over the entire circumference, and the radial seal lip 13 is in sliding contact with the sliding surface 31 at the protrusion 15. Further, the projections 17 of the axial seal lip 14 are arranged at uniform intervals over the entire circumference in the circumferential direction. For this reason, the oil passage 18 also occurs at uniform intervals over the entire circumference. The protrusions 17 are distributed over the entire circumference, and the axial seal lip 14 is in sliding contact with the sliding surface 32 at the protrusion 17.

  The oil passage 16 has a groove shape substantially along the sliding surface 31 and communicates the seal groove 9 inside the bearing with the external space, and the oil passage 18 communicates between the seal groove 9 and the inside of the bearing. In the case of an oil bath or splashing, as shown by the broken arrow A in FIG. 4, the lubricating oil passes from the outside to the inside of the bearing through the oil passages 16 and 18, and is sent to the outer ring 2 side by centrifugal force. .

  FIG. 5 is an enlarged cross-sectional view of the vicinity of the radial seal lip 13 of the seal member 10. This cross section shows a gap in the direction perpendicular to the sliding surface between the radial seal lip 13 and the sliding surface 31.

  As shown in FIG. 5, the protrusion 15 is substantially deformed by the tightening force generated by the elastic deformation of the radial seal lip 13 based on the tightening margin between the radial seal lip 13 and the sliding surface 31 or the oil pressure of the lubricating oil. Does not occur.

  The radial seal lip 13 has a tip that defines the inner diameter of the radial seal lip 13 in a natural state. The protrusion 15 extends to the tip of the radial seal lip 13 and is formed over the entire range having a radial interference with the sliding surface 31.

  The protrusions 15 are arranged at regular intervals d in the circumferential direction. Considering the appearance of the radial seal lip 13 as viewed from the axial direction, a plurality of protrusions 15 appear radially arranged at a constant pitch angle θ corresponding to the distance d. The center of radiation is on the central axis of the seal member 10 (not shown).

  Since each projection 15 is present near the tip of the radial seal lip 13, the radial seal lip 13 is in sliding contact with the sliding surface 31 at each projection 15, and an oil passage 16 is formed between each projection 15.

  The protrusion 15 has an R shape that gradually approaches the sliding surface from both ends in the circumferential direction w toward the center in the circumferential direction. The R shape is given over the entire length of the protrusion 15 in the radial direction. For this reason, the region where the protrusion 15 and the sliding surface 31 are in contact exists in the center of the protrusion 15 in the circumferential direction.

  When the sliding surface 31 rotates in the direction of arrow A relative to the radial seal lip 13, the lubricating oil in the oil passage 16 is drawn into the wedge-shaped gap between the protrusion 15 and the sliding surface 31. The wedge angle in the aforementioned wedge-shaped gap gradually decreases from the wide oil passage 16 where the drawn-in lubricating oil is present toward the narrow side, so that the protrusion 15 and the sliding surface 31 are in linear contact with each other. The closer to the region, the stronger the wedge effect occurs. Accordingly, the oil pressure of the oil film in the linear region can be increased more effectively, the protrusion 15 can be completely separated from the sliding surface 31, and the oil film in the linear region can be generated thickly. It is easy to make the lubrication state between the moving surface 31 and the fluid lubrication state.

  Here, if there is an oil film that completely separates the protrusion 15 and the sliding surface 31, a fluid lubrication state in which the sliding surface 31 slides in a state where it does not directly contact the protrusion 15 is achieved. By maintaining such an oil film between each protrusion 15 and the sliding surface 31, the fluid seal between the radial seal lip 13 and the sliding surface 31 can be achieved.

  As shown in FIGS. 7 and 8, similar to the radial seal lip 13, the protrusion 17 is formed over the entire range from the tip of the axial seal lip 14 to the sliding surface 32 in the axial direction. An oil passage 18 is formed on both sides of the projection 17 that contacts the sliding surface 32 as a boundary. Similar to the projections 15 of the radial seal lip 13, the projections 17 are formed in a radial pattern in which a plurality of projections 17 are arranged in the circumferential direction at a constant pitch angle corresponding to the intervals. ing. The center of radiation is on the central axis of the seal member 10 (not shown).

  Since each projection 17 is present near the tip of the axial seal lip 14, each projection 17 is in sliding contact with the sliding surface 32, and an oil passage 18 is formed between each projection 17, 17. Similarly to the protrusion 15 of the radial seal lip 13, the protrusion 17 has an R shape that gradually approaches the sliding surface from both ends in the circumferential direction toward the center in the circumferential direction. What is necessary is just to form over.

  As described above, by providing the protrusion 17 at the tip of the axial seal lip 14, the fluid lubrication state between the sliding surface 32 of the seal groove 9 of the axial seal lip 14 can be made in the same manner as the radial seal lip 13. it can.

  As described above, in the case of oil bath or splashing, as indicated by the broken line arrow A in FIG. 4, the lubricating oil is drawn into the bearing through the oil passages 16 and 18 from the outside of the bearing, and the radial seal. Both the lip 13 and the axial seal lip 14 can be in a fluid lubrication state to reduce the seal torque.

  The rolling bearing 1 with seal in this embodiment is assumed to be used for a vehicle transmission. Oil supply to a rolling bearing with a seal present in a transmission of a vehicle is performed by a method such as splashing, an oil bath, or nozzle injection. For this reason, lubricating oil exists around the seal lip of the seal member fixed to the rolling bearing with seal. The lubricating oil to be supplied is commonly used in other lubricating parts such as gears existing in the transmission. The lubricating oil is circulated by an oil pump, and is filtered by an oil filter provided in the circulation path.

  As described in Patent Document 1, when lubricating oil filtered by an oil filter is supplied to a bearing with a seal that is used to support a rotating part of a drive system such as a transmission of a vehicle or a differential gear, the particle size As long as the seal member 10 prevents large foreign objects exceeding 50 μm from entering the inside of the bearing, there is a problem with the bearing life even if foreign materials having a particle size of 50 μm or less contained in the lubricating oil enter the bearing. Will not wake up. According to the applicant's research, if the height of the protrusions 15 and 17 is set to 0.07 mm or less, a narrow gap (including an oil passage) that cannot easily allow a foreign object having a particle diameter of 50 μm to pass through is sealed and sealed. It was found that it can occur between the sliding surfaces. Therefore, the size of the oil passage 16 formed in the radial seal lip 13 and the oil passage 18 formed in the axial seal lip 14 in this embodiment is preferably 70 μm or less.

  In this embodiment, the height h of the protrusions 15 and 17 is set to 0.07 mm or less, and specifically set to 0.05 mm. This height h is a value at the highest position in the range where it can contact the sliding surface 31 or 32 by design. This position is also where the tightening margin set between each of the protrusions 15 and 17 and the sliding surface is maximized. Since the deformation amount of the protrusion during the operation of the bearing is negligible, the gap (including the oil passage) in the direction perpendicular to the sliding surface between the seal lip 13 (14) and the sliding surface 31 (32) is slid. It becomes a height corresponding to the height h of the protrusions 15 and 17 in the narrowest direction in the direction orthogonal to the surface, and does not substantially exceed 0.05 mm. For this reason, even if a foreign substance having a particle size exceeding 50 μm is included in the external lubricating oil, it is considered that the foreign substance hardly passes through the oil passages 16 and 18.

  In addition, what is necessary is just to set the protrusion height of the processus | protrusions 15 and 17 to 0.3 mm or less if the wear powder | flour which causes the early breakage of the rolling bearing 1 with a seal | sticker is assumed as a foreign material exceeding a particle size of 0.3 mm. Further, in order to improve the oil permeability of the oil passages 16 and 18, the protrusion height of the protrusions 15 and 17 may be 0.05 mm or more. The protrusion heights of the protrusions 15 and 17 may be appropriately selected from the viewpoint of preventing oil passage through the oil passages 16 and 18 and preventing passage of foreign matter.

  As described above, the lubricating oil is drawn into the bearing through the oil passages 16 and 18 from the outside by an oil bath or splashing, as indicated by a broken arrow A in FIG. Due to the inflow of this lubricating oil, the fluid is lubricated between the seal lips 13 and 14 and the sliding surfaces 31 and 32, and a low torque can be achieved. However, if the lubricating oil enters more than necessary inside the bearing, the stirring resistance increases. The lubricating oil once entering the bearing is sent to the outer ring 2 side by centrifugal force and stays on the outer ring 2 side.

  Therefore, in this embodiment, an oil relief groove 12 that communicates the inside of the bearing and the outside of the bearing is formed on the outer peripheral surface side of the outer diameter portion 11 of the seal member 10. As shown in FIGS. 6 and 7, a plurality of oil relief grooves 12 are provided in the outer diameter portion 11 at equal intervals over the entire circumference. The oil relief grooves 12 may be provided at unequal intervals. The oil escape groove 12 is formed so that the inner peripheral side of the seal member 10 is deeper and shallower toward the outer peripheral side. In this embodiment, the lubricating oil sent to the outer ring side by centrifugal force is discharged from the oil relief groove 12 to the outside of the bearing as shown by an arrow B in FIG. In this way, by providing a plurality of oil relief grooves 12 on the outer diameter portion 11 side, the lubricating oil that has flowed more than necessary is discharged, and the lubricating oil is prevented from staying on the outer ring side, and the stirring resistance increases. To suppress.

  As shown in FIGS. 2 and 6, the oil release groove 12 is provided obliquely with respect to the axial direction so that the lubricating oil sent to the outer ring 2 side by centrifugal force can be easily released. The oil relief groove 12 is formed in an arc shape.

  The width of the oil relief groove 12 is formed so as to be wider on the bearing inner side and narrower toward the bearing outer side. By changing the width of the oil escape groove 12 in this manner, the lubricating oil can be easily discharged to the outside of the bearing, and foreign matter can be prevented from flowing into the bearing.

  As shown in FIG. 4, when the outer diameter portion 11 of the seal member 10 is fitted and attached to the seal fitting hole 8, the oil relief groove located between the outer ring 2 of the bearing and the seal member 10. It is preferable that the radial distance g of 12 is 0.05 mm or more and 0.3 mm or less. The oil relief groove 12 is mainly used to discharge the lubricating oil. However, when the lubricating oil reaches the oil relief groove 12 from the outside of the bearing when the rotating shaft is not rotating, the oil relief groove 12 is used. The lubricating oil flows from 12 into the bearing. When shifting from non-rotation to rotation, lubricating oil for initial lubrication is required, so that the lubricating oil enters from the oil relief groove 12 during non-rotating can improve the shortage of lubricating oil during initial operation. it can. However, it is not preferable for foreign matter to enter with the lubricating oil. Therefore, in order to prevent foreign matter from entering from the oil escape groove 12, the oil escape groove 12 facing the outer ring 2 side is considered to be oil-permeable and mixed with foreign matter in the same manner as the projections 15 and 17 of the seal lips 13 and 14 described above. The outer diameter portion 11 is formed in a shape with a shallower depth and a narrower width from the inner peripheral side toward the outer peripheral side so as to be 0.05 mm or more and 0.3 mm or less.

  In the above-described embodiment, the radial seal lip 13 of the seal member 10 is in elastic contact with the sliding surface 31 formed of a small-diameter cylindrical surface formed outward in the axial direction of the seal groove 9, while the axial seal lip 14. The tip of is in elastic contact with the sliding surface 32 on the inner surface of the seal groove 9. In the seal member 10 shown in another embodiment shown in FIG. 9, the seal lip 19 provided on the inner ring 3 side is a non-contact type seal member that does not contact the outer diameter surface of the inner ring 3. An oil passage is formed between the seal lip 19 and the outer diameter surface of the inner ring 3, and the lubricating oil flows into the bearing as indicated by arrow A, and the lubricating oil sent to the outer ring side by centrifugal force is arrow B As shown in FIG. 4, the oil is discharged from the oil relief groove 12 to the outside of the bearing. In this way, the lubricating oil that has flowed more than necessary is discharged, the lubricant is prevented from staying on the outer ring side, and the stirring resistance is prevented from increasing.

  In the embodiment described above, the seal member 10 is formed of the cored bar 10b and the rubber portion 10a covering the cored bar 10b. However, the seal member 10 may be a metal seal plate formed of a metal plate. What is necessary is just to comprise so that a cut groove may be formed in the outer diameter part fitted to the bearing fitting part of this metal seal board, and lubricating oil may be discharged | emitted.

  In the above-described embodiment, the oil release groove 12 is provided in the outer diameter portion 11 of the pair of seal members 10, but it may be provided only in one of the seal members 10.

  The present invention is not limited to the above-described embodiments, and can of course be implemented in various forms without departing from the gist of the present invention. The scope of the present invention is claimed. The equivalent meanings recited in the claims, and all modifications within the scope.

1: Rolling bearing with seal 2: Outer ring 3: Inner ring 4: Race groove 5: Race groove 6: Ball 7: Cage 8: Seal fitting groove 9: Seal groove 10: Seal member 10a: Rubber part 10b: Core 11: outer diameter portion 12: oil relief groove 13: radial seal lip 14: axial seal lip 15: projection 16: oil passage 17: projection 18: oil passage 19: seal lip 31: sliding surface 32: sliding surface

Claims (6)

A seal member having an outer ring, an inner ring, an outer diameter part fitted in a pair of seal fitting grooves provided at both ends of an inner diameter surface of the outer ring, and an inner diameter part including a seal lip facing the inner ring; With
Between the seal lip and the inner ring, an oil passage that communicates the bearing interior and the bearing exterior is formed,
An oil relief groove that communicates the inside of the bearing and the outside of the bearing is formed on the outer diameter side of at least one of the seal members.   The rolling bearing with seal according to claim 1, wherein the oil relief grooves are arranged at equal intervals over the entire circumference in the circumferential direction of the outer diameter portion.   The rolling bearing with seal according to claim 2, wherein the oil relief groove is provided obliquely with respect to the axial direction.   The rolling bearing with seal according to claim 3, wherein the oil relief groove is provided in an arc shape when viewed from the axial direction. The seal lip is in sliding contact with the sliding surface of the inner ring;
The sliding part of the seal lip is provided with a plurality of protrusions,
The rolling bearing with seal according to any one of claims 1 to 4, wherein the oil passage is formed between the plurality of protrusions.   The rolling bearing with seal according to any one of claims 1 to 5, wherein the outer diameter portion is formed of a rubber material.

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