JP2012225495A - Bearing lubrication structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently supply lubrication oil, even when a clearance between a flange of a crankshaft and thrust metal becomes narrow due to the application of a thrust load on the crankshaft.SOLUTION: When a trust load Ft is applied from an output shaft 2a of a crankshaft 5 in a distal end direction due to thermal expansion of hydraulic oil circulating in a torque converter 3 caused by frictional heat, a clearance between a large-diameter part 5a keeping oil-tightness by an oil seal 8 and a thrust metal part 12b of a sliding bearing 11 supporting a crank journal 5b becomes narrow, and a clearance between a thrust metal part 12c at an opposite side and a crank arm 5c facing the same becomes wide. Since a labyrinth clearance 13 is formed between the thrust metal part 12c and the crank arm 5c, the lubrication oil hardly flows out due to viscous resistance, and lubrication oil is relatively supplied between the large-diameter part 5a and the thrust metal part 12b to avoid insufficient lubrication.

Description

  The present invention relates to a bearing lubrication structure in which thrust bearing portions are formed on both axial sides of a sliding bearing.

  Conventionally, this type of plain bearing is, for example, disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2001-165166), in which a thrust metal and a radial metal are fixed by welding or the like, or a thrust metal is attached from a radial metal. Known are those formed and integrated by pressing such as drawing or bending.

  The thrust bearing portion formed on the slide bearing is in sliding contact with the flange portion formed on the rotating shaft to restrict the axial movement of the rotating shaft, and rotates on the thrust bearing portion. When the shaft flange portion is strongly pressed, the gap between the sliding surface between the thrust bearing portion of the bearing and the flange portion of the rotary shaft becomes narrow, and it becomes difficult to sufficiently supply the lubricating oil.

  As a countermeasure, it is conceivable to reduce the friction by reducing the outer diameter of one of the flange part formed on the rotating shaft and the thrust bearing part of the bearing and reducing the sliding area. Since the pressure receiving area of the bearing portion decreases, an excessive thrust load may be applied, which is not feasible.

  On the other hand, for example, in Patent Document 2 (Japanese Utility Model Publication No. 59-146511), an oil supply hole is drilled in a thrust bearing portion, and a cylinder block that holds the bearing is drilled to supply lubricating oil to a radial metal. A second oil passage is bored along the axial direction of the rotation shaft with respect to the first oil passage to be fed, and the feed drilled in the first oil passage and the thrust bearing portion through the second oil passage. A technique for communicating with a hole is disclosed.

  According to the technique disclosed in Patent Document 2, without reducing the pressure receiving area with respect to the thrust bearing portion, from the oil hole drilled in the cylinder block with respect to the sliding surface of the thrust bearing portion, Sufficient lubricating oil can be supplied through another oil hole and a supply hole formed in the thrust bearing portion.

JP 2001-165166 A Japanese Utility Model Publication No.59-146511

  However, according to the technique disclosed in Patent Document 2 described above, it is necessary to drill the second oil passage in the cylinder block in addition to the normal first oil passage, and accordingly, the processing man-hour is increased and the manufacturing is increased. There is a problem that costs increase. Moreover, since post-processing is required for the cylinder block, there is a problem of lack of versatility.

  In view of the above circumstances, the present invention does not require any special processing for a member such as a cylinder block to which a rotary shaft is attached, and can sufficiently supply lubricating oil to the thrust bearing portion of the bearing. An object of the present invention is to provide a bearing lubrication structure that can obtain high versatility at low cost.

  The present invention includes a rotary shaft having an output shaft at one end, a slide bearing that rotatably supports a journal of the rotary shaft, and first and second thrust bearings formed on both sides in the axial direction of the slide bearing. In a bearing lubrication structure in which a gap between the rotating shaft and the sliding bearing is lubricated by lubricating oil, with respect to the first thrust bearing portion on the side facing the direction of the thrust load applied to the rotating shaft And lubricating oil supply means for supplying the lubricating oil.

  According to the present invention, since the lubricating oil supply means for supplying the lubricating oil to the first thrust bearing portion facing the direction of the thrust load applied to the rotating shaft is provided, the rotating shaft such as the cylinder block is provided. There is no need to perform any special processing on the member to be attached, the lubricating oil can be sufficiently supplied to the first thrust bearing portion, and high versatility can be obtained at low cost.

Schematic configuration diagram of a power train according to the first embodiment Same as above, II section enlarged view of FIG. 2 is an enlarged view of the main part of FIG. IV-IV sectional view of Fig. 2 The perspective view of the half-sliding bearing by 2nd Embodiment Enlarged view of the main part equivalent to FIG.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[First Embodiment]
1 to 4 show a first embodiment of the present invention. Reference numeral 1 in FIG. 1 denotes a power train mounted on the vehicle. The engine 2 is a driving source, the torque converter 3 is connected to the output side of the engine 2, and the output side of the torque converter 3 is connected to the power train. The automatic transmission 4 is provided.

  The torque converter 3 includes a pump impeller 3b fixed to the converter case 3a, a turbine runner 3c facing the pump impeller 3b, and a stator 3d. A converter case 3 a is connected to the output shaft 2 a of the engine 2, while a turbine runner 3 c is connected to the transmission input shaft 4 a of the automatic transmission 4.

  When the pump impeller 3b rotates in response to the output from the output shaft 2a of the engine 2, the stored hydraulic fluid (ATF) circulates, and the power is amplified and transmitted to the turbine runner 3c via this hydraulic fluid, This power is transmitted to the transmission input shaft 4a of the automatic transmission 4.

  FIG. 1 shows a continuously variable transmission as an example of the automatic transmission 4. In this automatic transmission 4, a primary pulley 4b is mounted on a transmission input shaft 4a, a secondary pulley 4d is mounted on a transmission output shaft 4c, and a belt-type or chain-type transmission such as a belt or chain is transmitted to both pulleys 4b and 4d. The means 4e is wound, and a desired gear ratio is set by relatively changing the groove width (pulley width) of both pulleys 4b and 4d by hydraulic control or the like.

  The output shaft 2a is integrally formed at the rear end of the crankshaft 5 as a rotating shaft and protrudes rearward from the rear end of the engine 2. The crankshaft 5 is formed with a large-diameter portion 5a as a flange portion on the inner shaft side of the output shaft 2a, and a distal end side from the large-diameter portion 5a is disposed in a crank chamber 6 provided in a cylinder block of the engine 2. Has been. The crankshaft 5 has crank journals 5b and crankpins (not shown) alternately formed on the inner shaft side of the large-diameter portion 5a via crank arms 5c as flange portions so that the front portion of the engine 2 Extended in the direction. The crankshaft 5 disposed on the front side of the engine 2 and its peripheral structure are the same as those in the prior art, and a description thereof is omitted here.

  As shown in FIG. 2, the large-diameter portion 5 a is rotatably inserted into an oil seal retainer 7 fixed to the rear end outer wall of the engine 2 through an oil seal 8 while maintaining oil tightness. . A crank journal 5b adjacent to the large-diameter portion 5a is bolted to the bearing housing 6b formed in the crank chamber 6 and formed at the lower end of the partition wall 6a separating each cylinder. The bearing cap 9 is formed to be slidably supported via a sliding bearing 11 in an annular bearing hole 10.

  As shown in FIG. 4, the bearing hole 10 is formed by butting bearing surfaces 10 a and 10 b having semicircular cross sections formed in the bearing housing 6 b and the bearing cap 9. On the other hand, the sliding bearing 11 is formed in an annular shape by abutting two half-sliding bearings 12 of the same shape mounted on the bearing surfaces 10a and 10b.

  This half-slide bearing 12 is formed by lining a back metal such as a steel plate with an alloy such as a copper alloy or an aluminum alloy, and includes a radial metal portion 12a attached to the bearing surfaces 10a and 10b and both axial sides thereof. And a thrust metal portion 12b serving as a first thrust bearing portion and a thrust metal portion 12c serving as a second thrust bearing portion. The thrust metal portions 12b and 12c are attached to the step portions 10c and 10d formed on both sides of the bearing housing 6b and the bearing surfaces 10a and 10b of the bearing cap 9, respectively. In FIG. 4, the thrust metal portion 12b is shown in a partially broken state.

  An oil groove 12d is formed along the circumferential direction at the center in the width direction of the inner peripheral surface of the radial metal portion 12a that is in sliding contact with the crank journal 5b, and an oil hole 12e is formed in the middle thereof. The partition wall 6a is formed with a lubricating oil passage 6c that communicates with the oil hole 12e and supplies lubricating oil to the oil groove 12d through the oil hole 12e.

  As shown in FIG. 2, the radial metal portion 12a of each half sliding bearing 12 is attached to the bearing surfaces 10a and 10b, and the thrust metal portions 12b and 12c formed by bending on both sides thereof are attached to the step portions 10c and 10d. In this state, one thrust metal portion 12b is provided on the front end surface of the large diameter portion 5a, and the other thrust metal portion 12b is provided on the crank arm 5c. One thrust metal portion 12b is bent and formed into a normal flange shape. Further, a stepped portion 12f having a stepped shape from the inner periphery to the outer periphery is formed in a semi-concave conical shape on the surface of the other thrust metal portion 12b provided on the crank arm 5c side. Further, a reverse stepped portion 5d corresponding to the stepped portion 12f is formed in a convex conical shape on the surface of the crank arm 5c facing the stepped portion 12f.

  As shown in FIG. 3, a labyrinth gap 13 as a lubricating oil supply means is formed between the stepped portion 12f formed in the thrust metal portion 12c and the reverse stepped portion 5d formed in the crank arm 5c. Is done. The labyrinth gap 13 makes it difficult for the lubricating oil supplied between the sliding bearing 11 and the crank journal 5b to leak from the labyrinth gap 13 into the crank chamber 6. As a result, it is possible to ensure the amount of lubricating oil flowing out from between the thrust metal portion 12b on the rear end side and the front end face of the large diameter portion 5a.

  Next, the operation of the present embodiment having such a configuration will be described. When the engine 2 is operated, the crankshaft 5 rotates, and the output is transmitted from the output shaft 2a to the pump impeller 3b via the converter case 3a of the torque converter 3, and the pump impeller 3b rotates. The pump impeller 3b rotates to cause a flow in the hydraulic oil, and the turbine runner 3c rotates due to the inertial force of the hydraulic oil flow. At this time, the stator 3d rectifies the hydraulic oil and reduces it to the pump impeller 3b, thereby generating a torque amplifying action. Then, a predetermined torque-amplified output is input to the transmission input shaft 4a of the automatic transmission 4, and the driving force shifted by the automatic transmission 4 is transmitted from the transmission output shaft 4c to the driving wheels. The vehicle travels.

  On the other hand, between the crank journal 5b of the crankshaft 5 and the sliding bearing 11 that supports the crank journal 5b, the lubricating oil is supplied from the lubricating oil passage 6c formed in the partition wall 6a. The lubricating oil supplied from the lubricating oil passage 6c passes through the oil hole 12e of each half sliding bearing 12 constituting the sliding bearing 11, and is discharged into the oil groove 12d formed on the inner periphery of the radial metal portion 12a. From this oil groove 12d, it flows between the radial metal part 12a and the crank journal 5b, and lubricates between them. The lubricating oil lubricated between the radial metal portion 12a and the crank journal 5b is between one thrust metal portion 12b formed on both sides of the radial metal portion 12a and the front end face of the large diameter portion 5a, and The space between the other thrust metal portion 12c and the crank arm 5c is lubricated and scattered in the crank chamber 6.

  By the way, in a so-called stall state (the engine 2 rotates and the gear of the automatic transmission 4 is engaged but the vehicle is stopped), the pump impeller 3b rotates at the same speed as the crankshaft 5. Become. On the other hand, since the vehicle is stopped, the transmission input shaft 4a does not rotate, and the turbine runner 3c does not rotate. Here, the hydraulic oil flows out from the pump impeller 3b by centrifugal force along the rotation direction. However, since the rotation of the turbine runner 3c is stopped, frictional heat is generated between the hydraulic oil and many turbine blades formed in the turbine runner 3c, and the hydraulic oil itself is thermally expanded by this frictional heat. In addition, the components of the torque converter 3 are also thermally expanded. As a result, as shown in FIGS. 2 and 3, a thrust load Ft is generated on the output shaft 2a via the converter case 3a to press the crankshaft 5 in the distal direction.

  As shown in FIGS. 2 and 3, when a thrust load Ft is generated that presses the crankshaft 5 in the tip direction, the crankshaft 5 slides in the tip direction, so that the large-diameter portion 5 a and the slide bearing 11 are connected. The gap between the half-slide bearing 12 and the thrust metal portion 12b on the rear end side of each half-sliding bearing 12 is narrowed, and the gap between the thrust metal portion 12c on the tip side and the crank arm 5c is relatively wide.

  In conventional half-slide bearings, the thrust metal parts formed on both sides of the radial metal part have the same shape, so the gap between the thrust metal part on the rear end side and the front end face of the large diameter part is narrowed. When the clearance between the thrust metal portion on the front end side and the crank arm becomes wide, a large amount of lubricating oil tends to flow into the crank chamber 6 from the clearance between the thrust metal portion on the front end side and the crank arm due to the differential pressure. Therefore, the lubrication between the thrust metal portion on the rear end side and the front end surface of the large diameter portion tends to be insufficient.

  On the other hand, in the present embodiment, a concave conical stepped portion 12f is formed on the thrust metal portion 12c on the rear end side, and a convex conical stepped portion 5d is formed on the crank arm 5c opposite to the stepped portion 12d. Since the labyrinth gap 13 is formed between the two, even if the labyrinth gap 13 is somewhat widened, the lubricating oil staying in the labyrinth gap 13 becomes difficult to flow out to the crank chamber 6 side due to viscous resistance. Therefore, most of the lubricating oil flowing from the oil groove 12d flows into the crank chamber 6 from between the thrust metal portion 12b on the rear end side and the front end surface of the large diameter portion 5a due to the differential pressure. Sufficient lubricating oil is supplied between 12b and the front end face of the large-diameter portion 5a, and insufficient lubrication can be effectively avoided.

  Thus, according to the present embodiment, the stepped portions 5d and 12f are formed in the crank arm 5c of the crankshaft 5 and the thrust metal portion 12b of the half sliding bearing 12 opposite to the crank arm 5c, Since the labyrinth gap 13 is formed, no special processing is required for the member that mounts the crankshaft 5 such as a cylinder block, so that not only can the manufacturing cost be reduced, but also high versatility. Sex can be obtained.

[Second Embodiment]
5 and 6 show a second embodiment of the present invention. In the first embodiment described above, the labyrinth gap 13 is formed between the thrust metal portion 12c on the front end side and the crank arm 5c to suppress the outflow of the lubricating oil, but in this embodiment, the radial metal The oil groove 12d of the portion 12a is formed by branching an induction oil groove 12g as a lubricating oil supply means. In addition, about the component similar to 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  As shown in FIG. 5, symmetrical thrust metal portions 12b are formed on both sides of the radial metal portion 12a of the two half-slide bearings 12 'having the same shape constituting the slide bearing 11'. A plurality of induction oil grooves 12g are formed at predetermined intervals along the circumferential direction on the inner periphery of the radial metal portion 12a. Each induction oil groove 12g extends obliquely from the oil groove 12d toward the thrust metal portion 12b along the rotation direction of the crankshaft 5 (the direction indicated by the white arrow), and an end portion of the guide oil groove 12g is the thrust metal portion 12b. It is penetrated at the upper end.

  In such a configuration, when the crankshaft 5 rotates, a part of the lubricating oil that has flowed into the oil groove 12d extends along the guide oil groove 12g with the thrust metal portion 12b and the large diameter as indicated by arrows in FIG. It is supplied between the front end surface of the part 5a. At this time, the guide oil groove 12g extends from the oil groove 12g toward the thrust metal portion 12b along the rotation direction of the crankshaft 5, so that the lubricating oil flowing into the guide oil groove 12g It is guided to the thrust metal portion 12b side along the induction oil groove 12g by viscous friction accompanying rotation.

  As a result, as in the first embodiment described above, a thrust load Ft is applied to the crankshaft 5 from the rear end side toward the front end side, and the front end surface of the large diameter portion 5a and the thrust of each half-slide bearing 12 ′. Even when the gap between the metal portion 12b is narrowed, the lubricating oil can be sufficiently supplied, and insufficient lubrication can be effectively avoided.

  Furthermore, in the present embodiment, the structure is simply a structure in which the induction oil groove 12g is added to the radial metal portion 12a of the half sliding bearing 12 ′, and no special processing is required for the crankshaft 5. Compared to the first embodiment, not only can the product cost be reduced, but also higher versatility can be obtained.

  The present invention is not limited to the above-described embodiments. For example, the transmission may be a manual transmission. When the manual transmission is engaged with the friction clutch, a thrust load is generated against the crankshaft 5 in the axial tip direction due to the pressing force from the friction clutch. Therefore, the manual transmission is the same as in the first and second embodiments described above during traveling. This phenomenon is likely to occur. Further, the rotating shaft of the present invention is not limited to the crankshaft 5 but may be a camshaft or the like.

2 ... Engine,
2a ... output shaft,
3 ... Torque converter,
5 ... Crankshaft,
5b ... Crank journal,
5c ... crank arm,
5d, 12f ... reverse stepped portion,
11, 11 '... slide bearing,
12, 12 '... half sliding bearing,
12a ... Radial metal part,
12b, 12c ... Thrust metal part,
12d ... oil groove,
12 g ... guide oil groove 13 ... labyrinth gap,
Ft ... Thrust load

Claims (5)

A rotating shaft having an output shaft at one end;
A sliding bearing that rotatably supports the journal of the rotating shaft;
First and second thrust bearing portions formed on both sides in the axial direction of the sliding bearing,
In a bearing lubrication structure that lubricates between the rotating shaft and the sliding bearing with lubricating oil,
A bearing lubrication structure comprising: a lubricant supply means for supplying a lubricant to the first thrust bearing portion on the side opposite to the thrust load application direction received by the rotating shaft.   The bearing lubrication structure according to claim 1, wherein the lubrication supply means is a labyrinth gap formed on the second thrust bearing portion side provided in the same direction as the thrust load application direction of the sliding bearing. The labyrinth gap is formed by a stepped portion formed in the second thrust bearing portion and a flange portion of the rotating shaft provided opposite to the second thrust bearing portion. 2. The bearing lubrication structure according to 2. The lubricating oil supply means is a guide oil groove branched from an oil groove formed along an inner circumferential direction on an inner circumferential surface with which the journal of the sliding bearing is in sliding contact.
The bearing lubrication structure according to claim 1, wherein the guide oil groove is penetrated through the first thrust bearing portion. The bearing lubrication structure according to claim 4, wherein the guide oil groove extends obliquely from the oil groove toward the second thrust bearing portion along the rotation direction of the rotary shaft.

Images