JP5714371B2 - Rolling bearing for crank journal - Google Patents

Description

  The present invention relates to a rolling bearing, and more particularly to a rolling bearing for a crank journal that rotatably supports a crankshaft of an engine.

  A crankshaft of an engine mounted on a vehicle such as an automobile has a plurality of crank journals spaced apart from each other along a rotation axis, and a plurality of crankpins corresponding to each cylinder. Both ends of each crankpin are integrally connected to the crank journal by a crank arm, and a counterweight (balance weight) is integrally connected to the boss portion of each crank arm on the side opposite to the crankpin in the radial direction with respect to the rotation axis. Yes.

  Each crank journal is supported by a cylinder block so as to be rotatable around a rotation axis of the crankshaft via a crank journal rolling bearing. The rolling bearing is fixed to the cylinder block and surrounds the crank journal, a plurality of rolling elements such as rollers and balls which are accommodated in a circumferential groove provided on the inner surface of the outer ring and abut against the crank journal, and each rolling element is surrounded by the rolling ring. A retainer that is spaced apart in the direction.

  The rolling bearing is lubricated by lubricating oil supplied from the main gallery provided in the cylinder block through an internal passage. For example, as described in Patent Document 1 below, the outer ring of the rolling bearing is provided with an oil supply passage that communicates with the inner passage at the radially outer end and communicates with the circumferential groove at the radially inner end. Oil is supplied around the rolling elements in the circumferential groove from the internal passage through the oil supply passage.

JP 2010-31967 A

[Problems to be Solved by the Invention]
In the conventional crank journal rolling bearing as described in the above publication, the interior of the rolling bearing communicates with the main gallery via an oil supply passage and an internal passage. The cross-sectional areas of the oil supply passage and the internal passage are set to a size that allows free flow of the lubricant so that the oil supply passage and the internal passage do not become clogged with lubricating oil. Therefore, since the throttling effect and pressure drop in these passages are very small, the amount of lubricating oil supplied into the bearing becomes excessive and the pressure of the lubricating oil in the bearing becomes high. Therefore, there is a problem that the resistance to stirring of the lubricating oil generated in the bearing is high.

The present invention has been made in view of the above-mentioned problems in conventional rolling bearings for crank journals, and the main object of the present invention is to reduce the supply pressure of lubricating oil into the bearing, thereby It is to reduce the agitation resistance of the lubricating oil in the bearing by lowering the pressure of the lubricating oil in the bearing while ensuring good lubrication of the bearing.
[Means for Solving the Problems and Effects of the Invention]

According to the present invention, the above-mentioned main problem is that, according to the present invention, the outer ring that is fixed to the cylinder block of the engine and surrounds the crank journal, and the circumferential groove provided on the inner surface of the outer ring are partly provided. A crank journal rolling bearing having a plurality of rolling elements accommodated and abutting against the crank journal, the oil supply groove having an oil supply groove provided on an outer surface of the outer ring and extending to at least one end surface of the outer ring, The groove communicates with an internal oil supply passage provided in the cylinder block, and lubricating oil passes through the internal oil supply passage through the oil supply groove, a space between an end surface of the outer ring and a boss part of the crank arm, an inner surface of the outer ring, and the is supplied to around the rolling element via the space between the crank journal, the oil supply groove set on the outer surface of the outer ring at between the internal oil supply passage and an end face of the outer ring A circumferentially extending arc groove, a first oiling groove communicating with the internal oil supply passage and the arc groove, and a position spaced apart from the first oiling groove in the circumferential direction of the outer ring. This is achieved by a rolling bearing for a crank journal characterized by including a second oil supply groove extending from the end face and communicating with the arc groove .

According to the first aspect of the present invention, the circumferential groove that partially accommodates the rolling elements is not in direct communication with the internal oil supply passage. Lubricating oil is supplied from the internal oil supply passage to the periphery of the rolling element through an oil supply groove, a space between the end surface of the outer ring and the boss portion of the crank arm, and a space between the inner surface of the outer ring and the crank journal. Therefore, compared with the conventional crank journal rolling bearing in which the circumferential groove communicates directly with the internal oil supply passage, the supply pressure of the lubricating oil into the circumferential groove is reduced and the lubricating oil into the bearing is reduced. The supply amount and the pressure of the lubricating oil in the bearing can be lowered. Therefore, while ensuring good lubrication of the bearing, it is possible to reduce the agitation resistance of the lubricating oil in the bearing as compared with the conventional rolling bearing for crank journal.
Moreover, according to the structure of the said Claim 1, the position of the 2nd oil supply groove | channel can be set to the position of the circumferential direction different from the position of the 1st oil supply groove | channel. Therefore, the lubricating oil can flow into the circumferential groove from the space between the end face of the outer ring and the boss portion of the crank arm at a position in the circumferential direction different from the internal oil supply passage and the first oil supply groove.

  According to the present invention, in order to effectively achieve the above-mentioned main problems, in the configuration of claim 1, the inner surface of the outer ring is provided between one end surface of the outer ring and the circumferential groove. It is comprised so that the communicating groove which extends may be provided (structure of Claim 2).

  According to the configuration of the second aspect, since the communication groove extending between the one end surface of the outer ring and the circumferential groove is provided on the inner surface of the outer ring, the one end surface of the outer ring and the boss portion of the crank arm Lubricating oil can be satisfactorily supplied around the rolling element through the communication groove from the space between.

  According to the present invention, in order to effectively achieve the above-mentioned main problems, the oil supply groove and the communication groove are configured to be aligned with each other in the radial direction. (Configuration of claim 3).

  According to the third aspect of the present invention, the oil supply groove and the communication groove are aligned with each other in the radial direction. Therefore, compared with the case where these grooves are not aligned with each other in the radial direction, the lubricating oil in the oil supply groove is efficiently transferred to the communication groove through the space between one end face of the outer ring and the boss portion of the crank arm. It can be made to flow.

According to the present invention, in order to effectively achieve the above-mentioned main problems, in the structure according to any one of claims 1 to 3 , the second oil supply groove has a reciprocating motion of a piston and a crank. the outer ring due to rotation of the shaft is configured to force received radially outwardly from the crank journal is provided becomes highest region (the fourth aspect).

According to this configuration 4, in the region where the force due to the rotation of the reciprocating motion and the crankshaft of the piston outer ring is subjected to radially outwardly from the crank journal is the highest, the crank journal and rolling bearings The space between the rolling elements can be effectively lubricated. Therefore, compared with the case where the second oil supply groove is provided in another region, the rotational resistance of the crank journal when the outer ring receives the highest force radially outward from the crank journal is reduced. The rotational resistance of the crankshaft can be effectively reduced.

According to the present invention, in order to effectively achieve the above-described main problems, in the configuration according to any one of claims 1 to 4, the inner surface of the outer ring is connected to one end surface of the outer ring. A communication groove extending between the peripheral groove and the circumferential groove is provided, and the second oil supply groove and the communication groove are configured to be aligned with each other in the radial direction (configuration of claim 5 ).

According to the configuration of the fifth aspect, the communication groove extending between the one end surface of the outer ring and the circumferential groove is provided on the inner surface of the outer ring, and the second oil supply groove and the communication groove are mutually in the radial direction. Consistent. Therefore, compared with the case where the communication groove is not provided or the case where the second oil supply groove and the communication groove are not aligned with each other in the radial direction, the lubricating oil in the second oil supply groove is removed from the end face of the outer ring and the crank arm. It is possible to efficiently flow to the communication groove through the space between the boss portions.

According to the present invention, in order to effectively achieve the above main problem, in the configuration of any one of claims 1 to 5 , the inner surface of the outer ring includes the other end surface of the outer ring and the end surface. A drain oil groove extending between the circumferential groove and the circumferential groove is provided (structure of claim 6 ).

According to the sixth aspect of the present invention, the oil drain groove extending between the other end surface of the outer ring and the circumferential groove is provided on the inner surface of the outer ring. Therefore, the lubricating oil in the circumferential groove can be discharged efficiently through the oil draining groove, compared with the case where the oil draining groove is not provided on the inner surface of the outer ring. Can be circulated.

According to the present invention, in order to effectively achieve the main problem described above, in the configuration of claim 6 , the other end surface of the outer ring is communicated with the oil drain groove at one end in the radial direction. It is comprised so that the outflow groove | channel extended outward may be provided (structure of Claim 7 ).

According to the seventh aspect of the present invention, the outflow groove that communicates with the oil drain groove at one end and extends radially outward is provided on the other end face of the outer ring. Therefore, compared with the case where the outflow groove is not provided on the other end surface of the outer ring, the lubricating oil in the oil draining groove can be efficiently discharged on the other end surface side of the outer ring. The lubricating oil can be circulated in the interior even more efficiently.

  According to one preferable aspect of the present invention, in the structure according to any one of the first to third aspects, the oil supply groove is configured to extend along the axis of the crank journal (Preferable aspect 1). ).

  According to another preferred aspect of the present invention, in the structure of claim 2 or 3, the communication groove is configured to extend along the axis of the crank journal (preferred aspect 2).

  According to another preferred aspect of the present invention, in the configuration of claim 2, the oil supply groove and the communication groove are provided at different circumferential positions (preferred aspect 3).

According to another preferred embodiment of the present invention, in any one of the first to third aspects, at least one of the first and second oil supply grooves extends along the axis of the crank journal. It is comprised so that it exists (Preferable aspect 4).

According to another preferred embodiment of the present invention, in the structure according to any one of claims 1 to 4 , the second oil supply groove and the communication groove are provided at different circumferential positions. Constructed (preferred embodiment 5).

According to another preferred aspect of the present invention, in the configuration of claim 7 , the outer ring is fixed to the cylinder block by a bearing cap, and the bearing cap communicates with the outflow groove at one end and is radially outward. It is comprised so that the outflow groove | channel extended to may be provided (Preferred aspect 6).

1 is a longitudinal sectional view along a rotation axis showing a first embodiment of a rolling bearing for a crank journal according to the present invention. It is a longitudinal cross-sectional view perpendicular | vertical to the rotating shaft which shows the outer ring | wheel and roller of 1st Embodiment shown by FIG. It is a longitudinal cross-sectional view which follows the rotating shaft line which shows 2nd embodiment of the rolling bearing for crank journals by this invention. It is a longitudinal cross-sectional view perpendicular | vertical to the rotating shaft which shows the outer ring | wheel and roller of 2nd Embodiment shown by FIG. It is the schematic which shows the crankshaft for inline 4 cylinder engines. It is explanatory drawing which shows the circumferential direction position of a 2nd oil supply groove | channel and a communication groove | channel about the rolling bearing of the 1st and 5th crank journal of the crankshaft shown by FIG. It is explanatory drawing which shows the circumferential direction position of a 2nd oil supply groove | channel and a communication groove | channel about the rolling bearing of the 2nd and 4th crank journal of the crankshaft shown by FIG. It is explanatory drawing which shows the circumferential direction position of a 2nd oil supply groove | channel and a communication groove | channel about the rolling bearing of the 3rd crank journal of the crankshaft shown by FIG. It is a longitudinal cross-sectional view which follows the rotating shaft line which shows 3rd embodiment of the rolling bearing for crank journals by this invention comprised as a modification of 2nd embodiment. FIG. 10 is a longitudinal sectional view perpendicular to a rotation axis showing the outer ring and the roller of the third embodiment shown in FIG. 9. It is an expansion partial longitudinal cross-sectional view in alignment with the rotating shaft which shows the principal part of the 1st modification example about the structure of 1st embodiment. It is an expansion partial longitudinal cross-sectional view in alignment with the rotating shaft which shows the principal part of the 2nd modification about the structure of 1st embodiment. It is an expansion partial longitudinal cross-sectional view in alignment with the rotating shaft which shows the principal part of the 3rd modification about the structure of 1st embodiment. It is an expansion partial longitudinal cross-sectional view along the rotating shaft which shows the principal part of the 4th modification about the structure of 2nd and 3rd embodiment. It is an expansion partial longitudinal cross-sectional view along the rotating shaft which shows the principal part of the 5th modification about the structure of 2nd and 3rd embodiment. It is an expansion partial longitudinal cross-sectional view which follows the rotating shaft which shows the principal part of the 6th modification example about the structure of 2nd and 3rd embodiment.

The present invention will now be described in detail with reference to a few preferred embodiments with reference to the accompanying drawings.
[First embodiment]

  FIG. 1 is a longitudinal sectional view along a rotation axis showing a first embodiment of a rolling bearing for a crank journal according to the present invention, and FIG. 2 is a rotation axis showing an outer ring and a roller of the first embodiment shown in FIG. It is a vertical longitudinal sectional view.

  In these drawings, reference numeral 10 denotes the crankshaft as a whole, and reference numeral 12 denotes a cylinder block. Although not shown in FIGS. 1 and 2, the crankshaft 10 has a plurality of crank journals 16 spaced apart from each other along the rotation axis 14 and a plurality of crankpins corresponding to each cylinder. Each crank pin is spaced apart from the rotation axis 14 in a direction perpendicular thereto, and both ends of each crank pin are integrally connected to the crank journal 16 by a crank arm 18. A counterweight (balance weight) 20 is integrally connected to the boss portion 18A of each crank arm 18 on the side opposite to the crank pin in the radial direction with respect to the rotation axis 14.

  Each crank journal 16 is rotatably supported around the rotation axis 14 by the cylinder block 12 via the rolling bearing 22 according to the first embodiment of the present invention. The bearing 22 is disposed in a semi-cylindrical recess 24 provided in the cylinder block 12 and opened downward, and a semi-cylindrical recess 28 provided in the bearing cap 26 and opened upward. The bearing 22 is fixed to the cylinder block 12 by fixing a bearing cap 26 to the cylinder block 12 with a bolt (not shown) so that the axis 30 thereof is aligned with the rotation axis 14.

  Although not shown in the drawing, a thrust plate for preventing these frictional contacts may be disposed between the bearing 22 and the boss portion 18A of the crank arm 18. The thrust plate includes a pair of plate members extending in a semicircular arc shape, and the pair of plate members are connected to each other so as to surround the crank journal 16.

  The bearing 22 includes an outer ring 32 that is fixed to the cylinder block 12 and surrounds the crank journal 16, and a plurality of rollers 36 that are partially accommodated in a circumferential groove 34 provided on the inner surface 32 a of the outer ring 32 and that abut against the crank journal 16. Have. The outer ring 32 includes a semi-cylindrical upper outer ring half body 32A disposed in the recess 24 and a semi-cylindrical lower outer ring half body 32B disposed in the recess 28 and opened upward. .

  Between the crank journal 16 and the outer ring 32 is disposed a cylindrical retainer 38 having a C-shaped cross section, and the retainer 38 has a thickness smaller than the radial distance between the crank journal 16 and the outer ring 32. Have The retainer 38 has a plurality of holes that rotatably receive the roller 36, and these holes are spaced apart from each other in the circumferential direction, so that the rollers 36 can be rotated while being spaced apart from each other in the circumferential direction. Is held in.

  A main gallery 40 for supplying lubricating oil is provided in the cylinder block 12, and an internal portion for supplying lubricating oil from the main gallery 40 to the bearing 22 is provided in a portion corresponding to each crank journal 16 of the cylinder block 12. A passage 42 is provided. An oil supply groove 44 is provided on the outer surface 32b of the upper outer ring half body 32A. The oil supply groove 44 communicates with the internal passage 42 at the inner end, and extends along the axis 30 and the rotation axis 14 to one end face 32c of the outer ring. It is extended.

  A communication groove 46 extending between one end surface 32c of the outer ring and the circumferential groove 34 is provided on the inner surface 32a of the outer ring 32. The communication groove 46 also extends along the axis 30 and the rotation axis 14. Yes. The communication groove 46 is provided above the axis 30, and is therefore provided at the same circumferential position as the oil supply groove 44 when viewed about the axis 30 and the rotation axis 14. The communication groove 46 may be provided at a circumferential position different from the oil supply groove 44, and a plurality of communication grooves 46 may be provided.

  According to the first embodiment, the lubricating oil in the main gallery 40 flows into the oil supply groove 44 through the internal passage 42 as shown by the arrow A, and the oil supply groove as shown by the arrow B. 1 moves to the left as viewed in FIG. 1 and flows out from the end face 32c of the outer ring 32. The lubricating oil fills the space between the end surface 32c of the outer ring 32 and the boss portion 18A of the crank arm 18 over the entire circumference around the axis 30, and a part of it falls into an oil pan not shown in the drawing. To do. As indicated by arrow C, the other lubricating oil moves to the right in the communication groove 46 in FIG. 1 and flows into the circumferential groove 34. As a result, the lubricating oil lubricates around the roller 36 and reduces the friction between the crank journal 16 and the roller 36.

  The lubricating oil that has flowed into the circumferential groove 34 sequentially moves to the right as viewed in FIG. 1, and the space between the inner surface 32a and the crank journal 16 toward the end surface 32d opposite to the end surface 32c is viewed in FIG. It moves to the right and flows out into the space between the end face 32d and the boss portion 18A of the crank arm 18. Therefore, the lubricating oil is circulated and supplied into the bearing 22.

  Thus, according to the first embodiment, when the lubricating oil flows out from the oil supply groove 44 into the space between the end surface 32c of the outer ring 32 and the boss portion 18A of the crank arm 18, the pressure of the lubricating oil is released. The high pressure in the gallery 40 and the internal passage 42 does not act on the bearing 22. Therefore, compared with the conventional bearing, the supply pressure of the lubricating oil into the bearing 22 can be lowered to reduce the pressure of the lubricating oil in the bearing, thereby ensuring good lubrication of the bearing. As compared with the conventional bearing, the stirring resistance of the lubricating oil in the bearing can be reduced.

  In particular, according to the illustrated first embodiment, it is only necessary to provide the communication groove 46 and the oil supply groove 44 extending along the axis 30 to the end face 32c on the inner surface 32a and the outer surface 32b of the outer ring 32, respectively. Therefore, the pressure of the lubricating oil in the bearing 22 can be lowered with a simple and inexpensive structure as compared with other embodiments described later.

According to the first embodiment, the oil supply groove 44 and the communication groove 46 are aligned with each other in the radial direction. Therefore, compared with the case where these grooves are not aligned with each other in the radial direction, the lubricating oil in the oil supply groove 44 is communicated through the space between the one end face 32c of the outer ring 32 and the boss portion 18A of the crank arm 18. It is possible to efficiently flow into the groove 46.
[Second Embodiment]

  FIG. 3 is a longitudinal sectional view along a rotation axis showing a second embodiment of a rolling bearing for a crank journal according to the present invention, and FIG. 4 is a rotation axis showing an outer ring and a roller of the second embodiment shown in FIG. It is a vertical longitudinal sectional view. In FIGS. 3 and 4, the same members as those shown in FIGS. 1 and 2 are denoted by the same reference numerals as those shown in FIGS. The same applies to FIGS. 9 and 10 showing the third embodiment.

  In the second embodiment, a first oil supply groove 44A is provided at the uppermost position of the outer surface of the upper outer ring half body 32A of the outer ring 32. The first oil supply groove 44A communicates with the internal passage 42 at the inner end, and extends along the axis 30 and the rotation axis 14 to the front of the end face 32c of the outer ring. The outer end of the first oil supply groove 44A communicates with an arc groove 48 provided on the outer surface 32b of the upper outer ring half body 32A and the lower outer ring half body 32B of the outer ring 32 and extending over the entire circumference of the outer ring.

  A second oil supply groove 44B is provided at the lowest position of the outer surface 32b of the lower outer ring half body 32B of the outer ring 32. The second oil supply groove 44B communicates with the circular arc groove 48 at the inner end, and extends along the axis 30 and the rotation axis 14 to one end face 32c of the outer ring. In addition, the communication groove 46 of the second embodiment is not the same circumferential position as the first oil supply groove 44A, but the same circumferential position as the second oil supply groove 44B when viewed about the axis 30 and the rotation axis 14. That is, it is provided at the lowest position. The second oil supply groove 44B and the communication groove 46 may be provided at different circumferential positions.

  According to the second embodiment, the lubricating oil in the main gallery 40 flows into the oil supply groove 44 through the internal passage 42 as indicated by the arrow A, and the first oil as indicated by the arrow B. The oil supply groove 44A moves to the left as viewed in FIG. Lubricating oil flows into the arc groove 48 from the first oil supply groove 44A, flows downward in the arc groove 48 as indicated by the arrow D, and the second oil supply groove 44B as indicated by the arrow E. It flows out from the end surface 32c of the outer ring | wheel 32 through.

  The lubricating oil fills the space between the end surface 32c of the outer ring 32 and the boss portion 18A of the crank arm 18 over the entire circumference around the axis 30, and a part of it falls into an oil pan not shown in the drawing. To do. As indicated by the arrow F, the other lubricating oil moves to the right in the communication groove 46 in FIG. 1 and flows into the circumferential groove 34. As a result, the lubricating oil lubricates around the roller 36 and reduces the friction between the crank journal 16 and the roller 36.

  FIG. 5 is a schematic view showing a crankshaft for an in-line four-cylinder engine. As shown in FIG. 5, the crankshaft 10 has first to fifth five crank journals 16-1 to 16-5 from the front end side (left side in FIG. 5) of the engine to the rear end side. . The crank journals 16-1 to 16-5 are rotatably supported around the rotation axis 14 by the cylinder block 12 via the rolling bearings 22-1 to 22-5 of the second embodiment. A pair of crank arms 18-1 to 18-4 is provided between two adjacent crank journals 16-1 to 16-5 so as to be spaced apart from each other along the rotation axis 14. Counterweights 20-1 to 20-4 are integrally provided on one of the pair of crank arms 18-1 to 18-4, respectively.

  Crank pins 50-1 to 50-4 for the first to fourth cylinders are integrally provided between the pair of crank arms 18-1 to 18-4. The axes of the crankpins 50-1 and 50-4 of the first and fourth cylinders are spaced in the same direction perpendicular to the rotation axis 14. The axis of the crankpins 50-2 and 50-3 of the second and third cylinders has a rotational phase of 180 degrees around the rotation axis 14 with respect to the axes of the crankpins 50-1 and 50-4 of the first and fourth cylinders. Are spaced apart in the same direction perpendicular to the rotational axis 14. The counterweights 20-1 to 20-4 are located on the opposite side in the radial direction from the crank pins 50-1 to 50-4, respectively, with respect to the rotation axis 14.

  Although not shown in FIG. 5, the large ends of the connecting rods are rotatably connected to the crank pins 50-1 to 50-4, respectively, and the small ends of the connecting rods are the pistons of the first to fourth cylinders. The piston pin is rotatably connected. Therefore, the pistons of the first and fourth cylinders reciprocate synchronously with each other, and the pistons of the second and third cylinders reciprocate synchronously with each other in the opposite direction to the pistons of the first and fourth cylinders. These reciprocating motions of the piston are converted into rotation of the crankshaft 10 around the rotation axis 14 by the cooperation of the connecting rod and the crankshaft 10.

  Therefore, the inertial force accompanying the reciprocating motion of the piston is transmitted to the crankpins 50-1 to 50-4 via the connecting rod. This inertial force increases when the piston moves near the top dead center and the bottom dead center, and reaches a maximum value when the piston moves near the top dead center and the bottom dead center. Therefore, the bearings 22-1 to 22-5 are radially outward from the crank journals 16-1 to 16-5, respectively, due to the reciprocating motion of the pistons of the adjacent cylinders and the inertial force accompanying the rotation of the crankshaft 10. The load is repeatedly applied.

  The first and fifth crank journals 16-1 and 16-5 are strongly influenced by the inertial force associated with the reciprocating motion of the pistons of the first and fifth cylinders, respectively. Maximum value when moving. Therefore, as shown in FIG. 6, the communication grooves 46 of the bearings 22-1 and 22-5 are provided on the same side as the crank pins 50-1 and 50-5 with respect to the axis 30 and the rotation axis 14. That is, when the crankshaft 10 is in the position shown in FIG. 5, the communication grooves 46 of the bearings 22-1 and 22-5 are provided in the uppermost region.

  The second crank journal 16-2 is mainly influenced by the inertial force accompanying the reciprocating motion of the pistons of the first and second cylinders, and the fourth crank journal 16-4 is mainly the pistons of the fourth and fifth cylinders. It is affected by the inertial force that accompanies the reciprocating motion of. However, the inertial forces associated with the reciprocating motion of the pistons of the first and fifth cylinders are also supported by the bearings 22-1 and 22-5, respectively. Accordingly, the second and fourth crank journals 16-2 and 16-4 are strongly influenced by the inertial force accompanying the reciprocating motion of the pistons of the second and fourth cylinders, respectively.

  These inertial forces are maximized when the pistons of the second and fourth cylinders move near the bottom dead center and the pistons of the first and fifth cylinders move near the top dead center. Accordingly, the radially outward loads that the bearings 22-2 and 22-4 of the second and fourth crank journals 16-2 and 16-4 receive from the crank journals 16-2 and 16-4, respectively, It is higher than the load that 1 and 22-5 receive.

  Therefore, as shown in FIG. 7, two communication grooves 46 of the bearings 22-2 and 22-4 are provided on the same side as the crank pins 50-2 and 50-4 with respect to the axis 30 and the rotation axis 14, respectively. ing. That is, when viewing the case where the crankshaft 10 is in the position shown in FIG. 5, two communication grooves 46 of the bearings 22-1 and 22-5 are provided in the lowest region.

  Further, the third crank journal 16-3 is affected by the inertial force accompanying the reciprocating motion of all the pistons, and the peak is not as high as the influence of the inertial force received by other crank journals. Therefore, the peak in the radially outward load that the bearing 22-3 of the third crank journal 16-3 receives from the crank journal 16-3 is not as high as the peak of the load that other bearings receive.

  Therefore, as shown in FIG. 8, the communication groove 46 of the bearing 22-3 is provided on the same side as each crank pin with respect to the axis 30 and the rotation axis 14, and is provided at a position of a phase of 90 degrees with respect to them. ing. That is, looking at the case where the crankshaft 10 is at the position shown in FIG. 5, the communication groove 46 of the bearing 22-3 is provided in the uppermost and lowermost regions and the region of the rotational phase of 90 degrees with respect to them. Yes.

  Thus, according to the second embodiment, the second oil supply groove 44B and the communication groove 46 can be provided at positions different from the main gallery 40 and the internal passage 42 as positions around the axis 30 and the rotation axis 14. Therefore, the degree of freedom of setting the position where the lubricating oil flows into the bearing 22 can be increased, and a plurality of inflow positions can be set.

  In particular, according to the second embodiment, the communication groove 46 is provided in a region where the radially outward load received by the crank journal due to the reciprocating motion of the piston and the rotation of the crankshaft 10 is maximized. . Therefore, as in the first embodiment described above, compared to the case where the communication groove 46 is provided in a region other than the region where the radial outward load received by the crank journal is the maximum value, the radially outward Even in the region where the load on the bearing reaches the maximum value, the bearing can be lubricated satisfactorily.

According to the second embodiment, the second oil supply groove 44B and the communication groove 46 are aligned with each other in the radial direction. Accordingly, as compared with the case where these grooves are not aligned with each other in the radial direction, the lubricating oil in the second oil supply groove 44B is removed from the space between the one end face 32c of the outer ring 32 and the boss portion 18A of the crank arm 18. Thus, the fluid can be efficiently flowed to the communication groove 46. This effect can also be obtained in the third embodiment described later.
[Third embodiment]

  FIG. 9 is a longitudinal sectional view taken along a rotational axis showing a third embodiment of a rolling bearing for a crank journal according to the present invention configured as a modification of the second embodiment, and FIG. 10 is a third sectional view shown in FIG. It is a longitudinal cross-sectional view perpendicular | vertical to the rotating shaft which shows the outer ring | wheel and roller of embodiment.

  In the third embodiment, the inner surface 32a of the outer ring 32 is provided with an oil drain groove 52 extending between the circumferential groove 34 and the other end surface 32d of the outer ring. It extends along the axis 30 and the rotation axis 14. The circumferential position of the oil drain groove 52 around the axis 30 and the rotation axis 14 is set to a position different from the circumferential position of the communication groove 46. The end surface 32d of the outer ring 32 is provided with an outflow groove 54 that communicates with the oil draining groove 52 at the inner end and extends radially outward to the outer surface 32b. An outflow groove 56 that communicates with the outer end of the outflow groove 54 and extends radially outward to the outer surface is provided. The other points of the third embodiment are configured in the same manner as in the second embodiment described above.

  According to the third embodiment, the lubricating oil in the bearing 22 efficiently flows out through the oil draining groove 52 and efficiently flows out from the oil draining groove 52 through the outflow grooves 54 and 56. Therefore, in addition to obtaining the same operational effects as in the case of the second embodiment described above, lubricating oil is circulated and supplied into the bearing 22 more efficiently than in the case of the first and second embodiments. be able to.

In the illustrated third embodiment, the circumferential positions of the oil draining grooves 52 and the outflow grooves 54 and 56 around the axis 30 and the rotation axis 14 are different from the circumferential positions of the communication grooves 46. It may be the same as the circumferential position of the communication groove 46. Although only one oil drain groove 52 and outflow grooves 54 and 56 are provided, a plurality of sets may be provided. Furthermore, the outflow grooves 54 and 56 may be omitted, or only the outflow grooves 56 may be omitted.
[First to sixth modification examples]

  In each of the above-described embodiments, the end surface of the cylinder block 12 and the end surface of the bearing cap 26 that are aligned with the end surface 32c of the outer ring 32 are flat. The end surface of the boss portion 18A of the crank arm 18 that faces the end surface 32c of the outer ring 32 is also flat. Therefore, a modification may be made to increase the ratio of the lubricating oil flowing into the communication groove 46 out of the lubricating oil filling the space between the end face 32c of the outer ring 32 and the boss portion 18A of the crank arm 18.

  FIG. 11 thru | or FIG. 13 is an expanded partial longitudinal cross-sectional view in alignment with the rotating shaft which shows the principal part of the 1st thru | or 3rd modification about the structure of 1st embodiment. Similarly, FIGS. 14 to 16 are enlarged partial longitudinal sectional views along the rotation axis showing the main parts of the fourth to sixth modifications of the structures of the second and third embodiments.

  In the first modification, as shown in FIG. 11, an end face of the cylinder block 12 and an end face of the bearing cap 28 are provided with a bank 58 extending annularly around the axis 30 and the rotation axis 14. ing. In this case, the bank 58 is preferably provided adjacent to the oil supply groove 44.

  In the second modification, as shown in FIG. 12, the end surface of the boss portion 18 </ b> A of the crank arm 18 facing the end surface 32 c of the outer ring 32 extends annularly around the axis 30 and the rotation axis 14. A bank 60 is provided. In this case, the bank 60 is preferably provided adjacent to the oil supply groove 44 on the radially outer side with respect to the oil supply groove.

  In the third modification, as shown in FIG. 13, a thrust plate 62 is interposed in the space between the end surface 32 c of the outer ring 32 and the boss portion 18 </ b> A of the crank arm 18. On the outer periphery of one side surface of the thrust plate 62 facing the end surfaces of the cylinder block 12 and the bearing cap 26, a bank 64 is provided that extends annularly around the axis 30 and the rotation axis 14. In this case, it is preferable that the bank 64 is also provided on the radially outer side adjacent to the oil supply groove 44 with respect to the oil supply groove.

  In the fourth modified example, as shown in FIG. 14, an end face of the cylinder block 12 and an end face of the bearing cap 26 are provided with an axis 30 and a bank 66 extending annularly around the rotation axis 14. ing. In this case, the bank 66 is preferably provided adjacent to the second oil supply groove 44B.

  In the fifth modification, as shown in FIG. 15, the end face of the boss portion 18 </ b> A of the crank arm 18 facing the end face 32 c of the outer ring 32 extends annularly around the axis 30 and the rotation axis 14. A bank 68 is provided. In this case, the bank 68 is preferably provided on the outer side in the radial direction with respect to the second oil supply groove 44 adjacent to the second oil supply groove 44B.

  In the sixth modified example, as shown in FIG. 16, a thrust plate 70 is interposed in the space between the end surface 32 c of the outer ring 32 and the boss portion 18 </ b> A of the crank arm 18. On the outer periphery of one side surface of the thrust plate 70 facing the end surfaces of the cylinder block 12 and the bearing cap 26, a bank 72 extending annularly around the axis 30 and the rotation axis 14 is provided. In this case, it is preferable that the bank 72 is also provided radially outside the second oil supply groove 44 adjacent to the second oil supply groove 44B.

  According to the first to sixth modifications, the lubricating oil fills the space between the end surface 32c of the outer ring 32 and the boss portion 18A of the crank arm 18 as compared with the first to third embodiments. Among them, the ratio of the lubricating oil flowing into the communication groove 46 can be increased. Further, the ratio of the lubricating oil flowing into the communication groove 46 can be set by setting the ratio of the height of each bank to the distance between the end surface 32c of the outer ring 32 and the boss portion 18A of the crank arm 18.

  According to the first to third embodiments and the first to sixth modifications, the inner surface 32a of the outer ring 32 has a communication groove 46 extending between one end surface 32c of the outer ring and the circumferential groove 34. Is provided. Therefore, the lubricating oil in the space between the end surface 32c of the outer ring 32 and the boss portion 18A of the crank arm 18 can be efficiently guided to the circumferential groove 34 as compared with the case where the communication groove 46 is not provided. it can.

  Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to the above-described embodiments, and various other embodiments are possible within the scope of the present invention. It will be apparent to those skilled in the art.

  For example, in each of the embodiments described above, the oil supply grooves 44, 44 </ b> A, 44 </ b> B and the communication groove 46 extend along the axis 30 and the rotation axis 14. It does not have to extend along.

  In each of the above-described embodiments, the inner surface 32a of the outer ring 32 is provided with a communication groove 46 extending between the end surface 32c of the outer ring and the circumferential groove 34, but the communication groove 46 is omitted. Conversely, a plurality of communication grooves 46 may be provided in bearings other than the bearings shown in FIGS.

  Further, when the communication groove 46 is omitted, the oil supply grooves 44, 44A and the circumferential groove 34 are arranged so that the distance between the inner surface 32a and the crank journal 16 is larger than when the communication groove 46 is provided. The inner diameter 32a on the side provided with 44B may be set to a large value.

  In addition, a groove similar to the oil drain groove 52 or the outflow grooves 54 and 56 in the third embodiment described above or its modification may be provided in the bearing of the first embodiment.

  Further, in the second and third embodiments described above, the arc groove 48 extends over the entire circumference around the axis 30 and the rotation axis 14, but only one around the axis 30 and the rotation axis 14. It may extend along the arc of the part.

  In each of the above embodiments, the roller bearing is a roller bearing and the rolling element is a roller. However, the bearing structure of the present invention may be applied to a ball bearing in which the rolling element is a ball.

  In the second embodiment described above, the five bearings supporting the crankshaft for the in-line four-cylinder engine have been described. However, the engine to which the bearing of the present invention is applied is an engine other than the in-line four-cylinder engine. There may be.

  DESCRIPTION OF SYMBOLS 10 ... Crankshaft, 12 ... Cylinder block, 14 ... Axis of rotation, 16 ... Crank journal, 18 ... Crank arm, 22 ... Rolling bearing, 32 ... Outer ring, 34 ... Circumferential groove, 36 ... Roller, 40 ... Main gallery, 42 ... Internal passage, 44 ... oil supply groove, 46 ... communication groove, 48 ... arc groove, 50 ... crank pin, 52 ... oil discharge groove, 54, 56 ... outflow groove, 58, 60 ... bank, 62 ... thrust plate, 64-68 ... bank, 70 ... thrust plate, 72 ... bank

Claims (7)

A crank journal rolling bearing having an outer ring fixed to a cylinder block of an engine and surrounding a crank journal, and a plurality of rolling elements partially accommodated in a circumferential groove provided on an inner surface of the outer ring and in contact with the crank journal In
An oil supply groove provided on the outer surface of the outer ring and extending to at least one end surface of the outer ring, the oil supply groove communicates with an internal oil supply passage provided in the cylinder block, and lubricant is supplied from the internal oil supply passage. The oil supply groove, the space between the end surface of the outer ring and the boss portion of the crank arm, and the space between the inner surface of the outer ring and the crank journal are supplied around the rolling element ,
The oil supply groove is provided on the outer surface of the outer ring between the end surface of the outer ring and the internal oil supply passage, and extends in the circumferential direction. The first oil supply communicates with the internal oil supply passage and the circular groove. A groove, and a second oil groove extending from the end face of the outer ring and communicating with the arc groove at a position spaced circumferentially from the first oil groove.
A rolling bearing for a crank journal characterized by that.   The rolling bearing for a crank journal according to claim 1, wherein a communication groove extending between one end face of the outer ring and the circumferential groove is provided on an inner surface of the outer ring.   The rolling bearing for a crank journal according to claim 2, wherein the oil supply groove and the communication groove are aligned with each other in a radial direction. The second oil supply groove is provided in a region where a force that the outer ring receives radially outward from the crank journal is highest due to reciprocating movement of a piston and rotation of a crankshaft. Item 4. The crank journal rolling bearing according to any one of Items 1 to 3 . A communication groove extending between one end face of the outer ring and the circumferential groove is provided on the inner surface of the outer ring, and the second oil supply groove and the communication groove are aligned with each other in the radial direction. The rolling bearing for a crank journal according to any one of claims 1 to 4, wherein the rolling bearing is for a crank journal. The crank according to any one of claims 1 to 5 , wherein an oil drain groove extending between the other end face of the outer ring and the circumferential groove is provided on an inner surface of the outer ring. Journal rolling bearings. The rolling bearing for a crank journal according to claim 6 , wherein an outflow groove that communicates with the oil draining groove and extends radially outward is provided at one end of the other end surface of the outer ring.

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