JP2014092206A - Balancer device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a balancer device which contributes to reduction of discharge quantity of an oil pump thereby reducing friction of an internal combustion engine, eliminates the need of a lubrication oil passage from an oil pump to the balancer device, and reduces the manufacturing costs.SOLUTION: A balancer device includes: a bearing part 5 formed by a slide bearing which rotatably supports first and second balance shafts 3, 4; and first and second gears 7, 8 which are meshed with each other so that the first balance shaft 3 and the second balance shaft 4 are rotated in directions opposite to each other by rotation power generated by the internal combustion engine. A balancer housing 2 includes: a gear storage part 25 which stores first and second gears 7, 8; and a lubrication oil supply passage 27 for the slide bearing. The gear storage part 25 has a pressure chamber 50 defined by teeth surfaces of the first gear 7 and the second gear 8, a bottom surface 25a of the gear storage part 25, and a side surface. A communication hole 51 which allows the lubrication oil supply passage 27 to communicate with the pressure chamber 50 is formed at the pressure chamber 50.

Description

  The present invention relates to a balancer device that suppresses vibrations of an internal combustion engine.

  Conventionally, as this type of balancer device, there is known a device in which a pair of balancer shafts having a weight portion are supported by a balancer housing via a rolling bearing such as a needle bearing while being disposed in an oil pan (for example, , See Patent Document 1).

  The front end of the balancer housing is provided with a gear mechanism that drives both balancer shafts, a pump housing that houses the oil pump, and a front gear housing chamber that opens upward to ensure clearance between the crankshaft and the connecting rod. It has been. The front gear housing chamber is formed to surround the gear mechanism by the balancer housing and the pump housing. In such a balancer device, oil dripping from the internal combustion engine may enter the balancer housing.

  Further, in this balancer device, the front needle bearing faces the front gear housing chamber. Therefore, when the gear mechanism rotates in the front gear housing chamber, oil is sprayed and supplied to the front needle bearing, and the needle bearing is lubricated.

JP 2010-230129 A

  However, the above-described balancer device is advantageous in that it does not need to provide a lubrication path since all the bearings are rolling bearings. It will increase in size.

  In particular, recent internal combustion engines have various physiques, and there are some internal combustion engines in which a sufficient space for arranging the balancer device is not secured. In such an internal combustion engine, it is conceivable to use a rolling bearing and a sliding bearing in combination as a balancer shaft bearing in consideration of the arrangement space of the balancer device.

  In this case, it is necessary to secure a lubrication path for the sliding bearing and supply oil from the oil pump to the lubrication path, so that the discharge amount of the oil pump cannot be reduced by that amount. Therefore, the load of the oil pump is not reduced, and as a result, there is a problem that the friction of the internal combustion engine cannot be reduced sufficiently.

  The present invention has been made to solve the above-described problems, and can contribute to reducing the discharge amount of the oil pump, thereby reducing the friction of the internal combustion engine and lubricating the oil pump to the balancer device. It aims at providing the balancer apparatus which can hold down manufacturing cost by making an oil path unnecessary.

  To achieve the above object, the balancer device according to the present invention is (1) a balancer housing, a pair of balance shafts accommodated in the balance housing, and the pair of balance shafts rotatable relative to the balancer housing. A plurality of bearing portions to be supported, and a pair of gears that are respectively attached to one ends of the pair of balance shafts and mesh with each other so that the pair of balance shafts rotate in opposite directions by the rotational power generated in the internal combustion engine; And at least one of the bearing portions is a sliding bearing, and the balancer housing includes a gear housing portion that houses the pair of gears, and a lubricating oil supply passage for supplying lubricating oil to the sliding bearing. And the gear housing portion is defined by a tooth surface of the pair of gears and a bottom surface and a side surface of the gear housing portion. Having pressure chambers, said pressure chamber has a configuration in which communication holes for communicating the pressure chamber and the lubricating oil supply passage is formed.

  With this configuration, the balancer device according to the present invention communicates the lubricating oil supply passage for the slide bearing and the pressure chamber to the pressure chamber defined by the tooth surfaces of the pair of gears and the bottom surface and side surfaces of the gear housing portion. Therefore, the lubricating oil accumulated in the pressure chamber by the rotation of the pair of gears can be supplied to the lubricating oil supply passage through the communicating hole. That is, as the pair of gears rotate, the lubricating oil is supplied to the lubricating oil supply passage by utilizing the pressure in the pressure chamber that is increased by the action of the lubricating oil sent toward the gear meshing portion along the tooth surface. Can do. Thereby, for example, the sliding bearing can be self-lubricated by the rotation of the gear of the balancer device without using an oil pump.

  As a result, the balancer device according to the present invention can contribute to a reduction in the discharge amount of the oil pump, thereby reducing the friction of the internal combustion engine. Further, the manufacturing cost can be reduced by eliminating the need for a lubricating oil path from the oil pump to the balancer device.

  The balancer device according to the present invention is the balancer device according to the above (1), wherein (2) the bearing portion includes a sliding bearing and a rolling bearing for each of the balance shafts.

  With this configuration, the balancer device according to the present invention includes a sliding bearing and a rolling bearing for each balance shaft. Therefore, the balancer device is balanced by the amount of the rolling bearing compared to a configuration in which all the bearings are configured with sliding bearings. Shaft friction can be reduced.

  The balancer device according to the present invention is the balancer device according to the above (2), wherein (3) the bearing portion has a configuration in which a relatively heavy load bearing is used as a rolling bearing in each of the balance shafts.

  With this configuration, the balancer device according to the present invention can effectively cope with the load applied to the balance shaft because the bearings with relatively high loads are the rolling bearings in each of the balance shafts. For this reason, the friction of a balance shaft can be reduced more effectively. Here, the high load includes a load due to a periodically applied load.

  The balancer device according to the present invention is the balancer device according to (3), wherein (4) the bearing portion has a configuration in which the bearing adjacent to the gear is the sliding bearing in the axial direction of the balance shaft. .

  With this configuration, in the balancer device according to the present invention, the bearing adjacent to the gear in the axial direction of the balance shaft is a sliding bearing, so that the lubricating oil supply passage for the sliding bearing can be shortened. Thereby, the processing of the lubricating oil supply passage is facilitated and the manufacturing cost can be suppressed.

  The balancer device according to the present invention is the balancer device according to the above (1) to (4), wherein (5) the balancer housing is constituted by a divided housing in which an upper housing and a lower housing are connected via bolts, Bolt through holes through which the bolts pass constitute at least a part of the lubricating oil supply passage.

  With this configuration, in the balancer device according to the present invention, the bolt through hole for passing the bolt for connecting the upper housing and the lower housing constitutes at least a part of the lubricating oil supply passage, so that the lubricating oil supply passage is formed. Therefore, the manufacturing process can be reduced, and the manufacturing cost can be suppressed. Moreover, it can contribute to size reduction of the balancer housing.

  According to the present invention, the friction of the internal combustion engine can be reduced by contributing to the reduction in the discharge amount of the oil pump, and the manufacturing cost can be suppressed by eliminating the need for the lubricating oil path from the oil pump to the balancer device. It is possible to provide a balancer device that can

It is a perspective view which shows the internal structure of the balancer apparatus which concerns on embodiment of this invention. It is a top view of the balancer device concerning an embodiment of the invention. It is BB sectional drawing in FIG. (A) is AA sectional drawing in FIG. 2, (b) is CC sectional drawing in FIG. It is EE sectional drawing in FIG. It is a perspective view which shows the internal structure of the conventional balancer apparatus.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows a schematic configuration of a balancer device according to the present embodiment. FIG. 2 is a plan view of the balancer device 1 according to the present embodiment, which makes it possible to recognize at a glance which cross section each figure has when referring to FIGS. 3 to 5.

  The balancer device 1 according to the present embodiment is a device for canceling the inertial force of the piston acting in the moving direction of the piston when an internal combustion engine mounted on a vehicle or the like is operated.

  The balancer device 1 is fixed to the lower end of a cylinder block (not shown) so as to be positioned in an oil pan in an internal combustion engine (not shown).

  In addition, an oil pump (not shown) is attached to the cylinder block of the internal combustion engine and is driven by the internal combustion engine and pumps oil as lubricating oil in the oil pan to each lubricating portion of the internal combustion engine. The oil pump has a pump shaft, and the pump shaft is connected to a crankshaft of the internal combustion engine via a chain or a belt. Therefore, the pump shaft rotates in accordance with the rotation of the crankshaft. As a result, the oil pump is driven.

  As shown in FIG. 1, the balancer device 1 includes a balancer housing 2, a pair of balance shafts 3, 4, a plurality of bearing portions 5, 6 (see FIG. 3), and a pair of gears 7, 8. It is configured.

  The balancer housing 2 includes an upper housing 21 and a lower housing 22, and is configured as a divided housing in which the upper housing 21 and the lower housing 22 are coupled to each other.

  The upper housing 21 and the lower housing 22 are made of, for example, aluminum alloy or cast iron, and are fastened to each other via a plurality of bolts 23 and 24 (see FIG. 4B) so that the split surfaces 21a and 22a are in close contact with each other. Has been.

  The balancer housing 2 is fixed to the cylinder block or the crankcase with a plurality of bolts (not shown).

  The balance shaft 3 (hereinafter referred to as the first balance shaft 3) and the balance shaft 4 (hereinafter referred to as the second balance shaft) rotate within the balancer housing 2, specifically between the upper housing 21 and the lower housing 22. It is freely housed.

  The first balance shaft 3 and the second balance shaft 4 include balance weights 30 and 40, respectively. The balance weights 30 and 40 are formed in a semicircular shape so that the center of gravity is decentered with respect to the axes of the first balance shaft 3 and the second balance shaft 4.

  Therefore, the balancer device 1 rotates the first balance shaft 3 and the second balance shaft 4 whose center of gravity is eccentric with respect to the center of rotation, thereby causing vertical vibrations caused by the secondary inertial force of the internal combustion engine. It suppresses the muffled sound.

  In the present embodiment, the balance weights 30 and 40 are formed integrally with the first balance shaft 3 and the second balance shaft 4, respectively. However, the present invention is not limited to this. The first balance shaft 3 and the second balance shaft 4 are configured separately, and the separate balance weights 30 and 40 are connected to the first balance shaft 3 and the second balance shaft 4 via fastening members such as bolts. It may be configured to be fastened to be integrally rotatable.

  Further, a gear 7 (hereinafter referred to as a first gear) and a gear 8 (hereinafter referred to as a second gear) are provided at one end (the front side in FIG. 1) of the first balance shaft 3 and the second balance shaft 4. ) Are attached.

  The first gear 7 and the second gear 8 mesh with each other so that the first balance shaft 3 and the second balance shaft 4 rotate in opposite directions by the rotational power generated in the internal combustion engine. ing.

  Specifically, the first gear 7 and the second gear 8 are configured to mesh with each other and have the same number of teeth. Thereby, the 1st balance shaft 3 and the 2nd balance shaft 4 rotate at the same speed in the mutually opposite direction.

  A driven gear 32 is attached to one end of the first balance shaft 3 adjacent to the first gear 7. This driven gear 32 meshes with a drive gear fixed to the pump shaft of the oil pump described above. Therefore, the first gear 7 rotates in conjunction with the rotation of the pump shaft. As a result, the first gear 7 rotates, and the second gear 8 meshed with the first gear 7 rotates at the same speed as the first gear 7. The rotation directions of the first gear 7 and the second gear 8 at this time are the directions of the arrows shown in FIG.

  Moreover, the 1st balance shaft 3 and the 2nd balance shaft 4 are rotatably supported with respect to the balancer housing 2 via the some bearing parts 5 and 6 (refer FIG. 3).

  Here, with reference to FIG. 3, the detail of the some bearing parts 5 and 6 is demonstrated. In the balancer device 1 according to the present embodiment, the bearing portions 5 and 6 applied to the first balance shaft 3 and the second balance shaft 4 have a common configuration. Therefore, in the following, the bearing portions 5 and 6 applied to the second balance shaft 4 will be described as an example.

  As shown in FIG. 3, the plurality of bearing portions 5 and 6 are arranged at a predetermined distance from each other with respect to the axial direction of the second balance shaft 4. Specifically, the bearing portion 5 supports the second balance shaft 4 between the balance weight 40 attached to the second gear 8 side and the second gear 8. In other words, the bearing portion 5 is disposed adjacent to the second gear 8 in the axial direction of the second balance shaft 4. On the other hand, the bearing portion 6 supports the second balance shaft 4 between the two balance weights 40.

  Of these bearing portions 5 and 6, the bearing portion 5 is constituted by a sliding bearing made of an aluminum balancer housing 2. On the other hand, the bearing part 6 is comprised by the rolling bearing which consists of a rolling element, a holder | retainer, etc. In the present embodiment, a needle bearing in which a needle-like thin roller 6a is incorporated in a rolling element is used as a rolling bearing. Thereby, compared with the rolling bearing (For example, ball bearing etc.) of another form, cross-sectional height is low and load capacity can be enlarged. Therefore, the balancer housing 2 can be reduced in size and space can be reduced. Note that the rolling bearing is not limited to a needle bearing, and a ball bearing or a roller bearing may be used.

  Thus, in the balancer device 1 according to the present embodiment, a sliding bearing and a rolling bearing are used as the bearing portions 5 and 6 for each of the first balance shaft 3 and the second balance shaft 4. For this reason, the balancer device 1 reduces the friction of the first balance shaft 3 and the second balance shaft 4 by the amount provided with the rolling bearing as compared with the case where all of the bearing portions 5 and 6 are constituted by the sliding bearing. can do.

  Further, the bearing portion 6 according to the present embodiment is subjected to a load caused by the rotation of the balance weights 30 and 40 rather than the bearing portion 5. Therefore, in the balancer device 1 according to the present embodiment, the relatively high load bearing portion 6 is constituted by a rolling bearing in each of the first balance shaft 3 and the second balance shaft 4. The high load referred to here includes a load caused by a periodically applied load.

  For this reason, the balancer device 1 can effectively cope with loads applied to the first balance shaft 3 and the second balance shaft 4. As a result, the friction of the first balance shaft 3 and the second balance shaft 4 can be more effectively reduced.

  By the way, both the bearing parts 5 and 6 need lubrication from a viewpoint of the performance maintenance. The bearing portion 6 formed of a rolling bearing can be lubricated only by the splashed oil in the internal combustion engine, that is, in the crankcase, for example. On the other hand, the bearing portion 5 constituted by a sliding bearing cannot be suitably lubricated by the splashed oil in the crankcase.

  Therefore, conventionally, such a sliding bearing is lubricated by supplying lubricating oil from an oil pump as shown in FIG. The balancer device 100 shown in FIG. 6 is a balancer device having a conventional structure, and shows an example in which all of the bearings of the balance shaft are configured by sliding bearings. In the balancer device 100, for example, it is necessary to form the lubricant supply groove 107 in the balancer housing 102 for supplying the lubricant to the sliding bearing 106 from an oil pump (not shown). The lubricating oil supply groove 107 is formed in both the upper housing 121 and the lower housing 122, and constitutes a lubricating oil supply passage when these two housings are integrated.

  However, in the conventional balancer device 100, since it is necessary to supply lubricating oil from the oil pump to all the sliding bearings including the sliding bearing 106, the discharge amount of the oil pump cannot be reduced by that much. It was.

  Therefore, in the balancer device 1 according to the present embodiment, it is not necessary to supply the lubricating oil from the oil pump, and the first gear 7 and the second gear 8 are provided with the oil pump function, so that the sliding bearing can be made self-supporting. The configuration allows lubrication. The specific configuration and the like will be described below with reference to FIGS.

  As shown in FIG. 4A, the balancer housing 2 includes a gear housing portion 25 that houses the first gear 7 and the second gear 8. The gear housing portion 25 is formed so as to surround the first gear 7 and the second gear 8, and an opening portion 26 in which a part of the balancer housing 2 is notched is formed in the upper portion.

  The opening 26 is provided to avoid interference between a counterweight attached to the crankshaft of the internal combustion engine and the balancer housing 2. Further, a part of the lubricating oil in the internal combustion engine drops into the gear housing 25 through the opening 26, for example.

  The gear housing portion 25 contains an amount of lubricating oil whose liquid level is at least higher than a communication hole 51 described later. As will be described later, the lubricating oil in the gear housing 25 is used to lubricate the sliding bearing by the oil pump function of the first gear 7 and the second gear 8. Note that the lubricating oil in the gear housing 25 decreases every time the sliding bearing is lubricated, but as described above, dripping of the lubricating oil in the internal combustion engine through the opening 26 or the oil during running of the vehicle. It is replenished as needed due to changes in the oil level of the pan, oil level rise when the engine is stopped, and the like.

  As shown in FIG. 4B, the balancer housing 2 includes a lubricating oil supply passage 27 for supplying lubricating oil to the bearing portion 5 formed of a sliding bearing. The lubricating oil supply passage 27 communicates a lubricating portion 28 formed in a predetermined angular range around each outer periphery of the first balance shaft 3 and the second balance shaft 4 with a pressure chamber 50 described later. is there. In the present embodiment, a groove for a lubrication passage is formed in one or both of the upper housing 21 and the lower housing 22 (in this embodiment, the lower housing 22), and the upper housing 21 and the lower housing 22 are integrated. When this occurs, at least a part of the lubricating oil supply passage 27 is formed by the groove.

  The lubricating oil supply passage 27 substitutes a bolt through hole 22c formed in the lower housing 22 as a part thereof for passing a bolt 24 for connecting the upper housing 21 and the lower housing 22. That is, the bolt through hole 22 c constitutes a part of the lubricating oil supply passage 27. In the present embodiment, since the diameter of the bolt through hole 22c is larger than the diameter of the shaft portion of the bolt 24, a gap between the shaft portion of the bolt 24 and the bolt through hole 22c is part of the lubricating oil supply passage 27. It is used as. Accordingly, the lubricating oil supply passage 27 is configured such that a portion connected to the lubricating portion 28 in the balancer housing 2 communicates with the bolt through hole 22c. As a result, the bolt through hole 22c and the lubricating portion 28 are in communication with each other.

  Further, as shown in FIGS. 4A and 5, the gear housing portion 25 has a pressure chamber 50 below the meshing portion between the first gear 7 and the second gear 8. The pressure chamber 50 is defined by the tooth surfaces of the first gear 7 and the second gear 8, and the bottom surface 25 a and the side surfaces 25 b and 25 c of the gear housing portion 25.

  The pressure chamber 50 is formed with a communication hole 51 that allows the lubricant supply passage 27 and the pressure chamber 50 to communicate with each other. Specifically, the communication hole 51 is formed in the lower housing 22 so as to communicate the bolt through hole 22 c and the pressure chamber 50 in the lubricating oil supply passage 27. One end of the communication hole 51 opens into the pressure chamber 50. On the other hand, the other end of the communication hole 51 is open to the bolt through hole 22c.

  Further, in the present embodiment, the communication hole 51 is inclined so as to be directed downward from the pressure chamber 50 toward the bolt through hole 22c due to processing restrictions. However, the communication hole 51 may be processed at any angle as long as the pressure chamber 50 and the bolt through hole 22c communicate with each other as long as there is no processing restriction. For example, the communication hole 51 is processed in the horizontal direction. Also good.

  Here, the pressure chamber 50 is desirably a sealed space with respect to the outside of the pressure chamber so that the first gear 7 and the second gear 8 can suitably exhibit the oil pump function. Therefore, in the present embodiment, the first balance shaft 3 and the second balance shaft 3 are arranged with respect to the center of the inner peripheral surface of the gear housing portion 25 having a slightly larger diameter than the first gear 7 and the second gear 8. The rotation center of the balance shaft 4 is offset downward. As a result, the clearance between the tooth surfaces of the first gear 7 and the second gear 8 that feed the lubricating oil into the pressure chamber 50 and the bottom surface 25a of the gear housing 25 is set to a value that can secure the pressure in the pressure chamber 50. The

  Further, as shown in FIG. 5, the clearance between the axial side surfaces of the first gear 7 and the second gear 8 and the side surfaces 25 b and 25 c of the gear housing portion 25 is set to a value that can secure the pressure in the pressure chamber 50. Is set. In particular, from the viewpoint of securing the pressure in the pressure chamber 50, if the clearance between the lower housing 22 in which the pressure chamber 50 is formed and the first gear 7 and the second gear 8 is set as described above, other clearances, For example, the clearance between the upper housing 21 and the first gear 7 and the second gear 8 may be a conventional value.

  Next, the operation of the balancer device 1 according to the present embodiment will be described.

  In FIG. 4 (a), it is assumed that the gear housing 25 contains lubricating oil to such an extent that the pressure chamber 50 is filled with lubricating oil, for example, the liquid level is the gear meshing portion.

  In this state, when the first gear 7 and the second gear 8 rotate in the direction of the arrow in FIG. 4A, the tooth gaps of the first gear 7 and the second gear 8 and the balancer housing 2 (in particular, Lubricating oil entering between the inner peripheral surface including the bottom surface 25a of the lower housing 22) moves into the pressure chamber 50 as the two gears rotate.

  Next, the lubricating oil that has moved along with the rotation of the first gear 7 and the second gear 8 is moved between the first gear 7 and the second gear 8 at the gear meshing portion located above the pressure chamber 50. When they are engaged, they are pushed into the pressure chamber 50. As a result, the pressure of the lubricating oil in the pressure chamber 50 increases.

  As the pressure rises, the lubricating oil in the pressure chamber 50 is pumped from the pressure chamber 50 to the lubricating oil supply passage 27 (see FIG. 5) including the bolt through hole 22c through the communication hole 51. Accordingly, the first gear 7 and the second gear 8 function as an oil pump.

  As shown in FIG. 4B, the lubricating oil fed to the lubricating oil supply passage 27 is supplied to the lubricating portions 28 of the first balance shaft 3 and the second balance shaft 4. Thereby, the bearing part 5 comprised with the sliding bearing is lubricated.

  As described above, the balancer device 1 according to the present embodiment includes the lubricating oil supply passage 27 for the slide bearing and the pressure chamber 50 in the pressure chamber 50 below the meshing portion of the first gear 7 and the second gear 8. Since the communication hole 51 is formed so that the first and second gears 7 and 8 rotate, the lubricating oil in the pressure chamber 50 is supplied to the lubricating oil supply passage 27 through the communicating hole 51. be able to. That is, as the first gear 7 and the second gear 8 are rotated, lubrication is performed using the pressure in the pressure chamber 50 which is increased by the action of the lubricating oil sent toward the gear meshing portion along the tooth surface. Lubricating oil can be supplied to the oil supply passage 27.

  Thus, for example, the bearing portion 5 formed of a sliding bearing can be self-lubricated by the rotation of the first gear 7 and the second gear 8 without using an oil pump. As a result, the balancer device 1 according to the present embodiment can contribute to a reduction in the discharge amount of the oil pump, thereby reducing the friction of the internal combustion engine. Further, the manufacturing cost can be reduced by eliminating the need for a lubricating oil path from the oil pump to the balancer device 1.

  Further, the balancer device 1 according to the present embodiment slides the bearing portion 5 adjacent to the first gear 7 and the second gear 8 in the axial direction of the first balance shaft 3 and the second balance shaft 4. Therefore, the lubricating oil supply passage 27 for the sliding bearing can be shortened. Thereby, the processing of the lubricating oil supply passage 27 is facilitated, and the manufacturing cost can be suppressed.

  In the balancer device 1 according to the present embodiment, the bolt through hole 22c through which the bolt 24 for connecting the upper housing 21 and the lower housing 22 passes forms at least a part of the lubricating oil supply passage 27. The processing steps for forming the oil supply passage 27 can be reduced, and the manufacturing cost can be suppressed. In addition, the balancer housing 2 can be reduced in size.

  In the present embodiment, for the convenience of the arrangement space of the balancer device 1 in the internal combustion engine, a plain bearing is not used as the bearing portion 5 but the aluminum balancer housing 2 is used as a slide bearing. Alternatively, a sliding bearing using play metal may be used.

  As described above, the balancer device according to the present invention can reduce the friction of the internal combustion engine by contributing to the reduction in the discharge amount of the oil pump, and eliminates the need for a lubricating oil path from the oil pump to the balancer device. Therefore, the manufacturing cost can be reduced, and the balancer device is effective for suppressing the vibration of the internal combustion engine.

DESCRIPTION OF SYMBOLS 1 ... Balancer apparatus, 2 ... Balancer housing, 3 ... 1st balance shaft (balance shaft), 4 ... 2nd balance shaft (balance shaft), 5, 6 ... Bearing part, 7 ... 1st gear (gear) 8 ... second gear (gear), 21 ... upper housing, 22 ... lower housing, 22c ... bolt through hole, 23,24 ... bolt, 25 ... gear housing, 25a ... bottom surface, 25b, 25c ... side, 27 ... Lubricating oil supply passage, 28 ... Lubrication part, 50 ... Pressure chamber, 51 ... Communication hole

Claims (5)

A balancer housing;
A pair of balance shafts housed in the balance housing;
A plurality of bearing portions that rotatably support the pair of balance shafts with respect to the balancer housing;
A pair of gears that are respectively attached to one ends of the pair of balance shafts and mesh with each other so that the pair of balance shafts rotate in opposite directions by the rotational power generated by the internal combustion engine,
At least one of the bearing parts is constituted by a sliding bearing;
The balancer housing has a gear accommodating portion that accommodates the pair of gears, and a lubricating oil supply passage for supplying lubricating oil to the sliding bearing,
The gear housing portion has a pressure chamber defined by a tooth surface of the pair of gears and a bottom surface and a side surface of the gear housing portion,
The pressure chamber is formed with a communication hole that communicates the lubricating oil supply passage with the pressure chamber.   The balancer device according to claim 1, wherein the bearing portion includes a sliding bearing and a rolling bearing for each of the balance shafts.   The balancer device according to claim 2, wherein the bearing portion is a rolling bearing that is a bearing with a relatively high load in each of the balance shafts.   The balancer device according to claim 3, wherein in the bearing portion, a bearing adjacent to the gear in the axial direction of the balance shaft is the sliding bearing. The balancer housing is composed of a divided housing in which an upper housing and a lower housing are connected via bolts,
The balancer device according to any one of claims 1 to 4, wherein a bolt through-hole through which the bolt is passed constitutes at least a part of the lubricating oil supply passage.

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