JP5716476B2 - Bearing structure of internal combustion engine - Google Patents

Description

  The present invention relates to a bearing structure for an internal combustion engine, and more particularly, to a bearing structure for an internal combustion engine in which a rotary shaft of the internal combustion engine is supported by a radial slide bearing via lubricating oil and the radial slide bearing is held by a bearing holding portion.

  Patent Document 1 below discloses a related art of a bearing structure in which a rotating shaft of an internal combustion engine is supported by a radial slide bearing via lubricating oil. In Patent Document 1, a first oil passage for supplying oil in an oil pan to each part of the engine by a main pump and a second oil passage for supplying oil in a heat storage tank to the periphery of the crankshaft by a sub pump are provided. When the engine is cold started, the hot oil in the heat storage tank is discharged by the sub pump toward the crankshaft area (mainly the journal), thereby promoting warm-up around the crankshaft and reducing friction. After the engine is warmed up, high temperature oil is stored in the heat storage tank by the sub pump.

JP 2009-144623 A JP-A-6-74237 JP-A-6-74230 JP 2010-127375 A

  When the rotary shaft of the internal combustion engine is supported by a radial slide bearing through the lubricating oil, the viscosity of the lubricating oil is high at low temperatures, so that the viscous friction loss when the rotating shaft rotates increases. In order to reduce the viscous friction loss, it is desirable to quickly raise the temperature of the lubricating oil to quickly lower the viscosity of the lubricating oil.

  In Patent Document 1, the viscous friction loss is reduced by discharging high-temperature lubricating oil in the heat storage tank toward the periphery of the crankshaft when the engine is cold started. However, the crankshaft portion has a very large heat capacity, and a large amount of heat is required to promote warm-up around the crankshaft. For this reason, the discharge of lubricating oil around the crankshaft has low thermal efficiency and insufficient warm-up around the crankshaft. Further, the sensible heat capacity of the lubricating oil is small, and in order to store a sufficient amount of heat to promote warm-up around the crankshaft, it is necessary to store an enormous amount of lubricating oil in the heat storage tank.

  An object of the present invention is to efficiently raise the temperature of a lubricating oil at low temperatures when the rotating shaft of an internal combustion engine is supported by a radial slide bearing via the lubricating oil.

  The internal combustion engine bearing structure according to the present invention employs the following means in order to achieve the above-described object.

  A bearing structure for an internal combustion engine according to the present invention is a bearing structure for an internal combustion engine in which a rotating shaft of the internal combustion engine is supported by a radial slide bearing via lubricating oil, and the radial sliding bearing is held by a bearing holding portion. A lubricating oil supply passage for supplying the oil to the clearance between the radial slide bearing and the rotary shaft, and a lubricating oil outlet formed in the radial slide bearing for allowing the lubricating oil to flow out from the clearance between the radial slide bearing and the rotary shaft. A heat exchange oil passage formed in the outer periphery of the radial slide bearing in the bearing holding portion and communicating with the lubricating oil outlet, and heat for exchanging the lubricating oil passing through the heat exchange oil passage with the bearing holding portion. The gist of the present invention is to have an exchange oil passage and a lubricating oil discharge passage formed in the bearing holding portion and communicating with the heat exchange oil passage.

  According to the above configuration, when the lubricating oil has a high viscosity and the temperature is low, the heat generated by the sliding friction between the rotary shaft and the radial slide bearing is used to generate heat between the heated lubricating oil passing through the heat exchange oil passage and the bearing holder. By warming up the bearing holding portion by heat exchange, it is possible to efficiently raise the temperature of the lubricating oil supplied to the gap between the rotary shaft and the radial slide bearing and to reduce the viscosity.

  In one aspect of the present invention, the lubricating oil supply path is formed in the bearing holder, and the lubricating oil discharge path is lubricated so that the lubricating oil passing through the lubricating oil discharge path exchanges heat with the lubricating oil passing through the lubricating oil supply path. It is preferable that it is arranged close to the supply path.

Furthermore, in this onset Ming, the gap between the radial sliding bearing rotation axis, both end portions with respect to the rotation axis direction is not narrower than the other portions.

Further, in this onset bright, bearing holding portion is formed by fastening the cap to the bearing holder body, the heat exchange fluid path, that is formed on the outer circumference of the radial slide bearing in the cap.

Further, in this onset bright, bearing holding portion is formed by fastening a cap to the bearing holder body, the heat exchange fluid passage is formed in the outer periphery of the radial slide bearing in the bearing holder body, the bearing holder heat insulating layer that has been formed at a position of the outer peripheral side of the heat exchanger fluid passage in the main body.

  In one aspect of the present invention, it is preferable that the lubricating oil supply path is formed in the bearing holding portion, and the lubricating oil can be supplied to the lubricating oil supply path after being preheated by the preheating device.

Further, in this onset bright, lubricating oil supply passage is formed in the bearing holding portion, the lubricating oil Ri supply available Der was cooled in the refrigerator into the lubricating oil supply passage, the cooling device, the cooling liquid of the internal combustion engine Ru der utilizes the heat exchange with the.

Further, in this onset bright, heat exchange fluid heat exchange passage can be supplied for lubricating oil and heat exchange through the heat exchange fluid path that is further formed on the outer periphery of the radial slide bearing in the bearing holder . In one aspect of the present invention , the heat exchange fluid is preferably a coolant for an internal combustion engine.

  As described above, according to the present invention, when the rotary shaft of the internal combustion engine is supported by the radial slide bearing via the lubricating oil, the temperature of the lubricating oil can be efficiently raised at a low temperature.

It is a figure showing a schematic structure of a bearing structure of an internal-combustion engine concerning an embodiment of the present invention. It is a figure showing a schematic structure of a bearing structure of an internal-combustion engine concerning an embodiment of the present invention. It is a figure showing a schematic structure of a bearing structure of an internal-combustion engine concerning an embodiment of the present invention. It is a figure showing a schematic structure of a bearing structure of an internal-combustion engine concerning an embodiment of the present invention. It is a figure which shows the other schematic structure of the bearing structure of the internal combustion engine which concerns on embodiment of this invention. It is a figure which shows the other schematic structure of the bearing structure of the internal combustion engine which concerns on embodiment of this invention. It is a figure which shows the other schematic structure of the bearing structure of the internal combustion engine which concerns on embodiment of this invention. It is a figure which shows the other schematic structure of the bearing structure of the internal combustion engine which concerns on embodiment of this invention. It is a figure which shows the other schematic structure of the bearing structure of the internal combustion engine which concerns on embodiment of this invention. It is a figure which shows the other schematic structure of the bearing structure of the internal combustion engine which concerns on embodiment of this invention. It is a figure which shows the other schematic structure of the bearing structure of the internal combustion engine which concerns on embodiment of this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as embodiments) will be described with reference to the drawings.

  1-4 is a figure which shows schematic structure of the bearing structure of the internal combustion engine which concerns on embodiment of this invention. 1 shows a cross-sectional view of the bearing structure as viewed from the direction of the rotation axis, FIGS. 2 and 4 show an internal configuration diagram as viewed from a direction perpendicular to the direction of the rotation axis of the bearing structure, and FIG. An enlarged view is shown. In the bearing structure of the internal combustion engine according to the present embodiment, the crank journal 18 of the crankshaft that is the rotation shaft of the internal combustion engine is supported by a radial slide bearing (also referred to as a journal slide bearing) 30 via a lubricating oil, and the radial slide. The bearing 30 is held by the bearing holding portion 13.

  The bearing holding part 13 includes a bearing holding part main body 20 constituted by a part of a cylinder block of the internal combustion engine and a cap 21 fastened to the bearing holding part main body 20. A metal material such as iron or aluminum is used for the bearing holding portion 13 (the bearing holding portion main body 20 and the cap 21). The volume of the bearing holder main body 20 is larger than the volume of the cap 21, and the heat capacity of the bearing holder main body 20 is larger than the heat capacity of the cap 21. A bearing mounting surface 13A, which is a substantially semi-cylindrical concave curved surface, is formed on the bearing holder main body 20, and a bearing mounting surface 13B, which is a substantially semi-cylindrical concave curved surface, is formed on the cap 21. . By fastening the cap 21 to the bearing holder main body 20 with the bolt 15 as a fastening member, a through hole through which the crank journal 18 is inserted is formed between the bearing mounting surfaces 13A and 13B, and the radial sliding bearing 30 having a half structure. Is held by the bearing holding portion 13 by being mounted on the bearing mounting surfaces 13A and 13B.

  The radial plain bearing 30 is constituted by half bearing metals 31A and 31B having a substantially semi-cylindrical shape divided into two in the circumferential direction of the rotating shaft. One half bearing metal 31A faces the bearing mounting surface 13A by being mounted on the bearing mounting surface 13A of the bearing holding body 20 and the other half bearing metal 31B is mounted on the bearing mounting surface 13B of the cap 21. Thus, the radial sliding bearing 30 is configured by facing the bearing mounting surface 13B and aligning both ends of the two half bearing metals 31A and 31B in the circumferential direction. Each half bearing metal 31A, 31B includes a backing metal and a bearing alloy layer as a lining layer formed on the inner peripheral side of the backing metal. Examples of the back metal include steel, and examples of the bearing alloy layer include a copper-lead alloy and an aluminum alloy.

  The bearing holding portion 13 and the radial sliding bearing 30 communicate with the gap between the radial sliding bearing 30 and the crank journal 18 and supply a lubricating oil supply path for supplying lubricating oil to the gap between the radial sliding bearing 30 and the crank journal 18. 41 is formed. In the example shown in FIGS. 1-4, the lubricating oil supply path 41 is each formed in the bearing holding | maintenance part main body 20, the half bearing metal 31A, and the cap 21 and the half bearing metal 31B, These two lubricating oil supply paths 41 are each formed. However, the positions in the circumferential direction of the bearing are shifted (180 ° in the examples shown in FIGS. 1 to 4). Lubricating oil discharged from the outlet 40 b of the oil pump 40 is supplied to the lubricating oil supply path 41. An oil preheating device 52 is provided on the outlet 40b side of the oil pump 40. By operating the oil preheating device 52, the lubricant discharged from the outlet 40b of the oil pump 40 is preheated (heated) by the oil preheating device 52. Then, it can be supplied to the lubricating oil supply passage 41.

  In this embodiment, as shown in FIGS. 2 and 3, the inner peripheral surface of the radial plain bearing 30 (half bearing metal 31 </ b> A, 31 </ b> B) has other end portions in the rotational axis direction (crankshaft axial direction). It protrudes more radially inward (crank journal 18 side). As a result, the gap between the inner peripheral surface of the radial plain bearing 30 and the outer peripheral surface of the crank journal 18 is narrower at both ends than the other portions in the direction of the rotation axis. The clearance between the radial plain bearing 30 and the crank journal 18 at both ends of the rotation axis direction is such that high-viscosity lubricating oil is applied in the direction of the rotation axis of the bearing holder 13 at a low temperature (for example, about 20 ° C.) immediately after the start of the internal combustion engine. The gap is set so as not to flow out from both end faces. Further, in the crankshaft (crank journal 18), the diameter of the portion located on the inner peripheral side of the radial slide bearing 30 is smaller than the diameter of the portion located on both sides in the rotation axis direction from this portion, and has a stepped shape. ing. Further, the radial sliding bearing 30 is formed with a lubricating oil outlet 43 that communicates with the gap between the radial sliding bearing 30 and the crank journal 18 and allows the lubricating oil to flow out of the gap between the radial sliding bearing 30 and the crank journal 18. Has been. In the example shown in FIGS. 1 to 4, the lubricating oil outlet 43 is formed by forming a clearance, for example, by a notch or a recess, between the mating surfaces (both end surfaces in the bearing circumferential direction) of the half bearing metals 31 </ b> A and 31 </ b> B. (However, clearance is not formed or narrowed at both ends in the rotation axis direction so that the lubricant does not leak outside), and the position in the bearing circumferential direction is shifted with respect to the lubricant supply path 41 (FIGS. 1 to 1). (90 ° in the example shown in FIG. 4) a lubricating oil outlet 43 is arranged. However, it is also possible to form the lubricating oil outlet 43 in the half bearing metal 31A or the half bearing metal 31B.

  Further, in the present embodiment, a plurality of heat exchange oil passages 42 communicating with the lubricating oil outlet 43 are formed around the outer periphery of the radial plain bearing 30 inside the bearing holding portion 13. The lubricating oil passing through the shaft exchanges heat with the bearing holder 13. Further, the bearing holding portion 13 is formed with a lubricating oil discharge path 44 communicating with each heat exchange oil path 42, and the lubricating oil passing through the lubricating oil discharge path 44 is heated with the lubricating oil passing through the lubricating oil supply path 41. The lubricating oil discharge path 44 is disposed close to the lubricating oil supply path 41 so as to be replaced. One end portions of the plurality of heat exchange oil passages 42 communicate with the lubricating oil outlet 43 in a state of being spaced apart from each other in the rotation axis direction, and the other end portion of each heat exchange oil passage 42 communicates with the lubricating oil discharge passage 44. . In the example shown in FIGS. 1 to 4, a plurality of heat exchange oil passages 42 are formed on the outer periphery of the half bearing metal 31 </ b> A inside the bearing holding body 20, and a plurality of heat exchange oil passages 42 are formed on the outer periphery of the half bearing metal 31 </ b> B inside the cap 21. The heat exchange oil passage 42 is formed. A plurality of lubricating oil discharge passages 44 are formed in the bearing holding body 20 close to the lubricating oil supply passage 41, and a plurality of lubricating oil discharge passages 44 are formed in the cap 21 close to the lubricating oil supply passage 41. ing. 1 to 4, the thickness of the radial slide bearing 30, the gap between the radial slide bearing 30 and the crank journal 18, the lubricating oil supply passage 41, the heat exchange oil passage 42, and the lubricating oil outlet 43. The size of the lubricating oil discharge passage 44 and the like are shown larger than the actual size for convenience of explanation.

  The lubricating oil supplied from the oil pump 40 to the lubricating oil supply passage 41 flows into the gap between the inner peripheral surface of the radial slide bearing 30 and the outer peripheral surface of the crank journal 18 as shown by the arrows in FIG. The radial plain bearing 30 receives the load along the radial direction of the crank journal 18 via the lubricating oil by rotatably supporting the crank journal 18 via the lubricating oil. The lubricating oil flows through the clearance between the radial slide bearing 30 and the crank journal 18 in the bearing circumferential direction (rotating direction of the crank journal 18), and flows out from the lubricating oil outlet 43. In that case, the clearance between the radial slide bearing 30 and the crank journal 18 is narrower at the both end portions than the other portions in the rotation axis direction, so that the lubricating oil flows out from both end surfaces in the rotation axis direction of the bearing holding portion 13. Is suppressed. Furthermore, by making the crankshaft (crank journal 18) have the above-mentioned stepped shape, it is possible to prevent the lubricating oil from flowing out from both end surfaces of the bearing holding portion 13 in the rotation axis direction. The lubricating oil here has the main role of operating the engine without the seizure of the rotating shaft and the bearing by forming an oil film, and reducing friction loss and wear between the rotating shaft and the bearing, It also plays a role of cooling, cleaning, rust prevention and so on.

  As shown by the arrows in FIGS. 1 and 4, the lubricating oil that has flowed out from the lubricating oil outlet 43 flows through each heat exchange oil passage 42 to exchange heat with the bearing holder 13. The lubricating oil that has flowed out of each heat exchange oil passage 42 flows through the lubricating oil discharge passage 44 and exchanges heat with the lubricating oil that flows through the lubricating oil supply passage 41. The lubricating oil that has flowed out of the bearing holder 13 from the lubricating oil discharge path 44 returns to the inlet 40a side of the oil pump 40. In FIG. 1, a specific configuration for supplying the lubricating oil from the outlet 40 b (oil preheating device 52) of the oil pump 40 to the lubricating oil supply path 41, and the lubricating oil from the lubricating oil discharge path 44 to the inlet 40 a of the oil pump 40. Although the specific configuration for returning is simplified, it can be realized by a known configuration.

  At low temperatures, such as immediately after starting the internal combustion engine, the viscosity of the lubricating oil increases. When the crank journal 18 rotates with respect to the radial slide bearing 30, the lubricating oil supplied to the gap between the radial slide bearing 30 and the crank journal 18 generates heat due to shear force (sliding friction), and the viscosity of the lubricating oil is reduced. The higher the value, the greater the amount of heat generated by the shear force. In the present embodiment, the lubricating oil generated by the sliding friction between the crank journal 18 and the radial slide bearing 30 is supplied to each heat exchange oil passage 42 via the lubricating oil outlet 43. At that time, as described above, it is possible to prevent the lubricating oil generated by the sliding friction from flowing out from both end surfaces of the bearing holding portion 13 in the rotation axis direction. The generated lubricating oil passing through each heat exchange oil passage 42 heats the bearing holder 13 by exchanging heat with the bearing holder 13 (the outer periphery of the radial slide bearing 30). Accordingly, the lubricating oil supplied to the gap between the radial slide bearing 30 and the crank journal 18 can be heated from the outer peripheral side, and the viscosity of the lubricating oil can be lowered. Viscous friction loss can be reduced. In that case, the number and length of the heat exchange oil passages 42 formed in the bearing holding portion 13 are increased to increase the contact area between the lubricating oil passing through the heat exchange oil passage 42 and the bearing holding portion 13. Thus, it is possible to increase the amount of heat supplied from the heated lubricating oil passing through the heat exchange oil passage 42 to the bearing holder 13. Further, the heated lubricating oil passing through the lubricating oil discharge path 44 heats the lubricating oil passing through the lubricating oil supply path 41 by exchanging heat with the lubricating oil passing through the lubricating oil supply path 41. Also by this, the lubricating oil supplied to the clearance between the radial slide bearing 30 and the crank journal 18 can be heated, and the viscosity of the lubricating oil can be lowered.

  As described above, in this embodiment, when the viscosity of the lubricating oil is high, such as immediately after starting the internal combustion engine, at a low temperature, the heat generated between the lubricating oil that has generated heat passing through the heat exchange oil passage 42 in the bearing holding portion 13 and the bearing holding portion 13. By using the replacement to warm up the bearing holder 13, it is possible to quickly raise the temperature of the lubricating oil supplied to the gap between the radial slide bearing 30 and the crank journal 18, thereby reducing the viscosity. In that case, the temperature rise efficiency per heat quantity can be improved by supplying heat quantity to the bearing holding part 13 whose heat capacity (volume) is smaller than that of the crankshaft. Further, by utilizing the thermal resistance constituted by the gap between the radial slide bearing 30 and the crank journal 18 and a thin oil film, heat loss to the crankshaft of the amount of heat supplied to the bearing holder 13 can be suppressed, The temperature rise of the bearing holding part 13 can be promoted. Further, the lubricating oil supplied to the gap between the radial sliding bearing 30 and the crank journal 18 is obtained by warming up the bearing holding portion 13 using the lubricating oil generated by the sliding friction between the crank journal 18 and the radial sliding bearing 30. Can be efficiently heated. In that case, it is possible to prevent the lubricant generated by the sliding friction from flowing out from both end surfaces in the rotation axis direction of the bearing holding portion 13, thereby preventing the heat generated by the sliding friction from escaping to the outside of the bearing holding portion 13. Thus, it is possible to warm up the bearing holder 13 by effectively using the heat generated by the sliding friction. Further, the lubrication supplied to the gap between the radial slide bearing 30 and the crank journal 18 can also be achieved by utilizing heat exchange between the heated lubricating oil passing through the lubricating oil discharge passage 44 and the lubricating oil passing through the lubricating oil supply passage 41. The temperature of the oil can be raised efficiently.

  Therefore, according to the present embodiment, the viscosity of the lubricating oil supplied to the gap between the radial slide bearing 30 and the crank journal 18 is efficiently raised at a low temperature when the viscosity of the lubricating oil is high, such as immediately after starting the internal combustion engine. Can be lowered. As a result, it is possible to quickly reduce viscous friction loss when the crank journal 18 rotates.

  Furthermore, in the present embodiment, the oil preheating device 52 is operated at a low temperature when the viscosity of the lubricating oil is high, such as immediately after the start of the internal combustion engine, so that the lubricating oil discharged from the outlet 40b of the oil pump 40 is discharged by the oil preheating device 52. It can also be supplied to the lubricating oil supply passage 41 after preheating. By supplying preheated lubricating oil to the gap between the radial slide bearing 30 and the crank journal 18 from the lubricating oil supply passage 41 inside the bearing holding portion 13, the bearing holding portion 13 is warmed up and the radial sliding bearing 30 and the crank journal are heated. The viscosity of the lubricating oil supplied to the gap between 18 can be reduced. Further, the heat loss of the preheated lubricating oil to the crankshaft can be suppressed.

  In the present embodiment, for example, as shown in FIGS. 5 and 6, a heat insulating layer 58 can be provided at a position on the outer peripheral side of the heat exchange oil passage 42 in the bearing holding body 20. In the example shown in FIGS. 5 and 6, the heat insulating layer 58 is further provided on both ends of the bearing holding unit body 20 in the rotation axis direction with the heat exchange oil passage 42 interposed therebetween. As a material of the heat insulation layer 58, for example, ceramics such as zirconia and alumina can be used. The bearing holder main body 20 has a larger heat capacity (volume) than the cap 21 and requires a larger amount of heat to raise the temperature. According to this configuration example, the lubricating oil that has generated heat in the heat exchange oil passage 42 at a low temperature. Since the heat insulation layer 58 can suppress the amount of heat supplied to the bearing holder main body 20 from diffusing outside, the temperature of the bearing holder main body 20 can be increased efficiently.

  Moreover, in this embodiment, as shown, for example in FIGS. 7-9, the lubricating oil supply path 41, the heat exchange oil path 42, and the lubricating oil discharge path 44 are made into the heat capacity (of the bearing holding | maintenance part main body 20 and the cap 21 ( It is also possible to form only the cap 21 having the smaller volume. 7-9, the lubricating oil supply path 41, the heat exchange oil path 42, and the lubricating oil discharge path 44 of the bearing holding body 20 are omitted as compared with the structural examples shown in FIGS. ing. According to this configuration example, the temperature rise efficiency per heat quantity can be further improved by supplying the heat quantity of the lubricating oil in the heat exchange oil passage 42 to the cap 21 having a small heat capacity at the low temperature to warm up. .

  In the present embodiment, for example, as shown in FIG. 10, an oil cooling device 62 can be provided on the outlet 40 b side of the oil pump 40. The oil cooling device 62 can cool and supply the lubricating oil discharged from the outlet 40 b of the oil pump 40 to the lubricating oil supply passage 41 by heat exchange with the cooling water of the internal combustion engine cooled by the radiator 64. is there. Alternatively, the lubricating oil can be cooled using heat exchange with the coolant in the external sub tank.

  In the configuration example shown in FIG. 10, the cooling water of the internal combustion engine is supplied from the radiator 64 to the oil cooling device 62 to operate the oil cooling device 62 when the viscosity of the lubricating oil is low, such as after the internal combustion engine is warmed up. Thus, the lubricating oil cooled by the oil cooling device 62 passes through the lubricating oil supply passage 41 inside the bearing holding portion 13 and then is supplied to the gap between the radial plain bearing 30 and the crank journal 18. Thus, the bearing holding portion 13 and the sliding portions of the crank journal 18 and the radial slide bearing 30 can be cooled. Further, the lubricating oil cooled by the oil cooling device 62 flows out from the lubricating oil outlet 43 and flows through each heat exchange oil passage 42, thereby exchanging heat with the bearing holder 13 and from the lubricating oil discharge passage 44. leak. Thereby, the bearing holding part 13 can be cooled. Therefore, the temperature of the sliding portion of the crank journal 18 and the radial slide bearing 30 and the bearing holding portion 13 can be reduced at a high temperature such as after the internal combustion engine is warmed up. Can be prevented. In particular, heat exchange with engine coolant whose temperature is controlled by the radiator cap pressure enables stable supply of lubricating oil and temperature management of the sliding portion. In addition, the same effect can be expected in the temperature management by the external sub tank.

  Further, in the present embodiment, for example, as shown in FIG. 11, it is possible to further form a heat exchange water channel 68 around the outer periphery of the radial plain bearing 30 inside the bearing holding portion 13. The cooling water of the internal combustion engine cooled by the radiator 66 can be supplied to the heat exchange channel 68 as a heat exchange fluid, and the cooling water passing through the heat exchange channel 68 exchanges heat with the lubricating oil passing through the heat exchange channel 42. As described above, the heat exchange water channel 68 is disposed close to the heat exchange oil channel 42. In the example shown in FIG. 11, a plurality of heat exchange water channels 68 are formed in the outer periphery of the half bearing metal 31 </ b> A inside the bearing holding body 20 near the heat exchange oil passage 42, and the half bearing metal inside the cap 21. A plurality of heat exchange water channels 68 are formed in proximity to the heat exchange oil channel 42 around the outer periphery of 31B.

  In the configuration example shown in FIG. 11, by cooling water flowing through the heat exchange water channel 68 at a high temperature such as after the internal combustion engine is warmed up, heat is exchanged with the lubricating oil passing through the heat exchange oil channel 42 to cool the lubricating oil. It can be carried out. Furthermore, the cooling water passing through the heat exchange water channel 68 can exchange heat with the bearing holder 13 to cool the bearing holder 13. Accordingly, the temperature of the sliding portion of the crank journal 18 and the radial slide bearing 30 and the temperature of the bearing holding portion 13 can be reduced at a high temperature such as after the internal combustion engine is warmed up. In particular, in a bearing configuration with a limited heat capacity, high heat exchange efficiency can be realized, and temperature controllability of the lubricating oil can be improved. In addition, by performing heat exchange with engine coolant whose temperature is controlled by the radiator cap pressure, stable temperature management of the sliding portion is possible.

  In the above description, the bearing structure of the crank journal 18 of the crankshaft has been described as an example of the bearing structure of the internal combustion engine according to the embodiment of the present invention. However, the bearing structure of the internal combustion engine according to the present invention is applied to the bearing structure of the rotary shaft of other internal combustion engines such as a bearing structure of the camshaft of the internal combustion engine, in addition to the bearing structure of the crank journal 18 of the crankshaft. It is possible.

  As mentioned above, although the form for implementing this invention was demonstrated, this invention is not limited to such embodiment at all, and it can implement with a various form in the range which does not deviate from the summary of this invention. Of course.

  13 Bearing holder, 13A, 13B Bearing mounting surface, 18 Crank journal, 20 Bearing holder body, 21 Cap, 30 Radial slide bearing, 31A, 31B Half bearing metal, 40 Oil pump, 41 Lubricating oil supply path, 42 Heat Exchange oil passage, 43 Lubricating oil outlet, 44 Lubricating oil discharge passage, 52 Oil preheating device, 58 Heat insulation layer, 62 Oil cooling device, 64, 66 Radiator, 68 Heat exchange water passage.

Claims (9)

A bearing structure for an internal combustion engine in which a rotating shaft of an internal combustion engine is supported by a radial slide bearing via lubricating oil, and the radial slide bearing is held by a bearing holding portion,
A lubricating oil supply path for supplying lubricating oil to the gap between the radial slide bearing and the rotary shaft;
A lubricating oil outlet formed on the radial sliding bearing, for allowing the lubricating oil to flow out from a gap between the radial sliding bearing and the rotary shaft;
A heat exchange oil passage formed on the outer periphery of the radial slide bearing in the bearing holding portion and communicating with the lubricating oil outlet, and heat exchange for exchanging the lubricating oil passing through the heat exchange oil passage with the bearing holding portion. Oil passage,
A lubricating oil discharge passage formed in the bearing holding portion and communicating with the heat exchange oil passage;
I have a,
A bearing structure for an internal combustion engine in which a gap between the radial slide bearing and the rotating shaft is narrower at the both ends than in the other portions in the rotating shaft direction . A bearing structure for an internal combustion engine in which a rotating shaft of an internal combustion engine is supported by a radial slide bearing via lubricating oil, and the radial slide bearing is held by a bearing holding portion ,
A lubricating oil supply path for supplying lubricating oil to the gap between the radial slide bearing and the rotary shaft;
A lubricating oil outlet formed on the radial sliding bearing, for allowing the lubricating oil to flow out from a gap between the radial sliding bearing and the rotary shaft;
A heat exchange oil passage formed on the outer periphery of the radial slide bearing in the bearing holding portion and communicating with the lubricating oil outlet, and heat exchange for exchanging the lubricating oil passing through the heat exchange oil passage with the bearing holding portion. Oil passage,
A lubricating oil discharge passage formed in the bearing holding portion and communicating with the heat exchange oil passage;
Have
The bearing holding part is configured by fastening a cap to the bearing holding part body,
The heat exchange oil passage is a bearing structure for an internal combustion engine, which is formed on the outer periphery of the radial slide bearing in the cap . A bearing structure for an internal combustion engine in which a rotating shaft of an internal combustion engine is supported by a radial slide bearing via lubricating oil, and the radial slide bearing is held by a bearing holding portion ,
A lubricating oil supply path for supplying lubricating oil to the gap between the radial slide bearing and the rotary shaft;
A lubricating oil outlet formed on the radial sliding bearing, for allowing the lubricating oil to flow out from a gap between the radial sliding bearing and the rotary shaft;
A heat exchange oil passage formed on the outer periphery of the radial slide bearing in the bearing holding portion and communicating with the lubricating oil outlet, and heat exchange for exchanging the lubricating oil passing through the heat exchange oil passage with the bearing holding portion. Oil passage,
A lubricating oil discharge passage formed in the bearing holding portion and communicating with the heat exchange oil passage;
Have
The bearing holding part is configured by fastening a cap to the bearing holding part body,
The heat exchange oil passage is formed on the outer periphery of the radial slide bearing in the bearing holding body,
A bearing structure for an internal combustion engine , wherein a heat insulating layer is provided at a position on the outer peripheral side of the heat exchange oil passage in the bearing holding body . A bearing structure for an internal combustion engine in which a rotating shaft of an internal combustion engine is supported by a radial slide bearing via lubricating oil, and the radial slide bearing is held by a bearing holding portion ,
A lubricating oil supply path for supplying lubricating oil to the gap between the radial slide bearing and the rotary shaft;
A lubricating oil outlet formed on the radial sliding bearing, for allowing the lubricating oil to flow out from a gap between the radial sliding bearing and the rotary shaft;
A heat exchange oil passage formed on the outer periphery of the radial slide bearing in the bearing holding portion and communicating with the lubricating oil outlet, and heat exchange for exchanging the lubricating oil passing through the heat exchange oil passage with the bearing holding portion. Oil passage,
A lubricating oil discharge passage formed in the bearing holding portion and communicating with the heat exchange oil passage;
Have
A bearing structure for an internal combustion engine, wherein a heat exchange flow path capable of supplying a heat exchange fluid for exchanging heat with lubricating oil passing through the heat exchange oil path is further formed on the outer periphery of the radial plain bearing in the bearing holding portion . A bearing structure for an internal combustion engine according to claim 4 ,
A bearing structure for an internal combustion engine, wherein the heat exchange fluid is a coolant for the internal combustion engine. A bearing structure for an internal combustion engine according to any one of claims 1 to 5,
The lubricating oil supply path is formed in the bearing holder,
A bearing structure for an internal combustion engine, in which the lubricating oil can be preheated by a preheating device and then supplied to the lubricating oil supply passage. A bearing structure for an internal combustion engine according to any one of claims 1 to 5,
The lubricating oil supply path is formed in the bearing holder,
A bearing structure for an internal combustion engine that can supply lubricating oil to a lubricating oil supply path after cooling the lubricating oil with a cooling device. A bearing structure for an internal combustion engine in which a rotating shaft of an internal combustion engine is supported by a radial slide bearing via lubricating oil, and the radial slide bearing is held by a bearing holding portion ,
A lubricating oil supply path for supplying lubricating oil to the gap between the radial slide bearing and the rotary shaft;
A lubricating oil outlet formed on the radial sliding bearing, for allowing the lubricating oil to flow out from a gap between the radial sliding bearing and the rotary shaft;
A heat exchange oil passage formed on the outer periphery of the radial slide bearing in the bearing holding portion and communicating with the lubricating oil outlet, and heat exchange for exchanging the lubricating oil passing through the heat exchange oil passage with the bearing holding portion. Oil passage,
A lubricating oil discharge passage formed in the bearing holding portion and communicating with the heat exchange oil passage;
Have
The lubricating oil supply path is formed in the bearing holder,
The lubricating oil can be supplied to the lubricating oil supply passage after being cooled by a cooling device.
The cooling device is a bearing structure for an internal combustion engine that uses heat exchange with the coolant of the internal combustion engine. A bearing structure for an internal combustion engine according to any one of claims 1 to 8,
The lubricating oil supply path is formed in the bearing holder,
A bearing structure for an internal combustion engine , wherein the lubricating oil discharge path is arranged close to the lubricating oil supply path so that the lubricating oil passing through the lubricating oil discharge path exchanges heat with the lubricating oil passing through the lubricating oil supply path .

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