JPWO2016075918A1 - Mechanical device having a plurality of rotating shafts - Google Patents

Abstract

The size of a mechanical device having a plurality of rotating shafts is reduced, the number of processing and assembly processes is reduced, and the required amount of lubricating oil is reduced. In the mechanical device (10) having a plurality of rotating shafts (12F, 12R, 13), two of the plurality of rotating shafts (12R, 13) are arranged close to each other on the same axis and arranged on the same axis. The ends (12Ra, 13c) of the two rotating shafts adjacent to each other are pivotally supported by a single bearing (22), and the respective ends (12Ra, 13c) of the two rotating shafts (12R, 13) are supported. An oil passage (29) communicating with the gap (g) formed between the two is provided. [Selection] Figure 2

Description

  The present invention relates to a mechanical device having a plurality of rotating shafts, such as a balancer device that cancels secondary vibrations of an internal combustion engine.

  In reciprocating engines (hereinafter simply referred to as engines) mounted in automobiles, etc., two balancer shafts each having a balancer weight (counter weight) are arranged to cancel the secondary vibration generated by the piston, thereby transmitting power. A balancer device is installed to drive one balancer shaft by rotation of the crankshaft transmitted through the mechanism and to drive the other balancer shaft connected to each other by gears at the same speed in the opposite direction. May be.

  As such a balancer device, a first sprocket attached to a crankshaft and a second sprocket around which a first chain is wound are fixed to a first shaft, and a third gear fixed to the first shaft is used as a first balancer shaft. The fourth gear fixed to the first balancer shaft, the fifth gear fixed to the first balancer shaft and the sixth gear fixed to the second balancer shaft, and the same number of teeth of the first and second sprockets. The shaft is rotated at the same speed as the crankshaft, the number of teeth of the third gear is set to twice the number of teeth of the fourth gear, and the first balancer shaft is rotated at twice the number of rotations of the crankshaft. In addition, by setting the number of teeth of the sixth gear and the sixth gear to be the same, the first and second balancer shafts are rotated in the opposite direction at the same number of rotations, and are more effective than the first and second balancer shafts. Jin vertical configuration in (reciprocating direction of the piston) is provided with first axis downwards (position away from the crankshaft) is known (see Patent Document 1).

Japanese Patent No. 3707140

  However, in a mechanical device having a plurality of rotating shafts, if the shafts are distributed and arranged as in the configuration of Patent Document 1, a bearing must be provided for each shaft, which increases the size and processing of the device. And assembly man-hours increase. In addition, when lubricating oil is supplied to the bearings, the larger the number of bearings, the more complicated the structure of the oil passage that supplies lubricating oil to the bearings. Man-hours increase. Furthermore, if the number of bearings is large, the required amount of lubricating oil increases accordingly.

  In view of such a background, it is an object of the present invention to reduce the size of a device in a mechanical device having a plurality of rotating shafts, reduce the number of processing and assembly steps, and reduce the amount of necessary lubricating oil.

  In order to solve such a problem, the present invention provides a mechanical device (10) having a plurality of rotating shafts (12, 13, 51), and two of the plurality of rotating shafts (12R · 13). , 12F · 51) are arranged close to each other on the same axis, and ends of the two rotation shafts arranged on the same axis are supported by a single bearing (22, 24), An oil passage (29) communicating with a gap (g) formed between the end portions of the two rotary shafts is provided.

  According to this configuration, since the bearings of the two rotating shafts are made common and only one oil passage is required to supply the lubricating oil to the common bearing, the apparatus can be downsized and the number of processing and assembly processes can be reduced. can do. In addition, oil can be supplied from the gap between the two rotating shafts to the bearing gap between the bearing and the two rotating shafts, and the required amount of lubricating oil can be reduced.

  In the above invention, an annular groove (29b) constituting the oil passage is formed on the inner surface of the bearing, and the groove has a width larger than the gap and spans the gap. It is good to be arranged.

  According to this configuration, the two rotating shafts can be prevented from hitting the bearing. Further, oil easily enters the bearing gap between the bearing and the two rotating shafts.

  In the above invention, the mechanical device is provided in the internal combustion engine (1) and rotates the pair of balancer shafts (12F, 12R) in opposite directions at a rotational speed twice that of the crankshaft (2). The device (10) is a second comprising an input shaft (13) coupled to the crankshaft via a winding-type first transmission mechanism (16) and a pair of gears (13e, 12Fe) meshing with each other. A third transmission mechanism (18) comprising a first balancer shaft (12F) connected to the input shaft via a transmission mechanism (17) and a pair of gears (12Fd, 12Fd) having the same number of teeth meshing with each other. A second balancer shaft (12R) connected to the first balancer shaft via the input shaft and the second balancer chassis. Doo and are disposed proximate to coaxially, it is possible to end on the side close to each other of the two shafts is configured to be pivotally supported by the single bearing (22).

  According to this configuration, in a balancer device for an internal combustion engine having an input shaft in addition to a pair of balancer shafts, the size of the device can be reduced, the number of processing and assembly processes can be reduced, and the required amount of lubricating oil can be reduced. it can.

  In the above invention, the mechanical device is provided in the internal combustion engine (1) and rotates the pair of balancer shafts (12F, 12R) in opposite directions at a rotational speed twice that of the crankshaft (2). The device (10) is a first comprising a pair of gears (13e, 51a) meshing with an input shaft (13) connected to the crankshaft via a winding-type first transmission mechanism (16). The intermediate shaft (51) connected to the input shaft via a gear mechanism (17A) and the second shaft mechanism (17B) comprising a pair of gears (51b, 12Re) meshing with each other are connected to the intermediate shaft. A third transmission mechanism (12Rd, 12Fd) having a pair of gears (12Rd, 12Fd) having the same number of teeth meshing with each other. 8) through a first balancer shaft (12F) connected to the second balancer shaft, the input shaft and the second balancer shaft being arranged coaxially close to each other, The end portion on the adjacent side is pivotally supported by the single bearing (22), the intermediate shaft and the first balancer shaft are arranged close to each other on the same axis, and the ends of the shafts on the side close to each other The portion may be supported by the single bearing (24).

  According to this configuration, in a balancer device for an internal combustion engine having an input shaft and an intermediate shaft in addition to a pair of balancer shafts, the size of the device is reduced and the number of processing and assembly steps is reduced, and the required amount of lubricating oil is reduced. can do.

  Thus, according to the present invention, in a mechanical device having a plurality of rotating shafts, the size of the device can be reduced, the number of processing and assembly steps can be reduced, and the required amount of lubricating oil can be reduced.

Sectional drawing which shows the engine lower part which concerns on embodiment along a balancer shaft Sectional view along the line II-II in FIG. Bottom view of the upper housing shown in FIG. Sectional view showing the IV part in Fig. 2 in an enlarged manner Explanatory drawing which shows the power transmission path | route of the balancer apparatus shown in FIG. VI-VI cross section in Fig. 2 VII-VII sectional view in FIG. (A) Rear view, (B) Top view, (C) Front view of cover member Exploded perspective view of cover member (A) before deformation, (B) sectional view equivalent to FIG. 5 showing the cover member after deformation Schematic diagram of a balancer device according to a modified embodiment

  Hereinafter, an embodiment in which a balancer device 10 according to the present invention is applied to an in-line four-cylinder automobile engine (hereinafter simply referred to as an engine 1) will be described in detail with reference to the drawings.

  As shown in FIG. 1, the engine 1 is an in-line four-cylinder engine in which a crankshaft 2 extends in a horizontal direction, and is mounted on an automobile in a posture in which a cylinder axis is inclined rearward. The vertical direction is determined when the engine 1 is mounted on an automobile. However, in the description related to FIG. 1, in order to facilitate explanation and understanding, a cylinder axis direction extending substantially vertically and a crankshaft orthogonal thereto The directions are assumed to be up and down and left and right, and the directions are indicated by arrows in FIG. The left and right directions are based on the traveling direction of the automobile on which the engine 1 is mounted, and are opposite to the left and right in the drawing.

  The engine 1 forms a cylinder and has an upper block 3 having a skirt portion at the lower portion, and a lower block 5 coupled to the lower portion of the upper block 3 and defining a crank chamber 4 in cooperation with the skirt portion of the upper block 3. The oil pan 6 (upper oil pan 6A, lower oil pan 6B) that is coupled to the lower part of the lower block 5 and defines an oil reservoir below the crank chamber 4 is coupled to the lower part of the lower block 5, The balancer apparatus 10 etc. which are arrange | positioned inside are provided. Hereinafter, the upper block 3 and the lower block 5 are collectively referred to as a cylinder block 7.

  The crankshaft 2 has four crankpins 2a (hereinafter referred to as the right side (the left side in the drawing) sequentially connected from a piston pin (not shown) of a piston (not shown) slidably provided in the cylinder. A crank pin 2a), five journals 2b (hereinafter referred to as first to fifth journals 2b in order from the right side) provided between the crank pin 2a, and a crank connecting the journal 2b and the crank pin 2a. The arm 2c and the crank arm 2c are provided with a counterweight 2d integrally formed on the side opposite to the crankpin 2a. The first and fourth crankpins 2a are disposed at the same phase position, and the second and third crankpins 2a are disposed at the same phase position that is 180 degrees out of phase with the first and fourth crankpins 2a. .

  The bearing wall for supporting the first and fifth journals 2b of the crankshaft 2 is constituted by the right wall and the left wall of the cylinder block 7, and the bearing walls for supporting the second to fourth journals 2b are provided in the crank chamber 4. It is comprised by the provided partition.

  The right end of the crankshaft 2 extends further to the right from the first journal 2 b and protrudes from the right wall of the cylinder block 7. The protruding portion includes a relatively small-diameter small sprocket 2e for driving a camshaft (not shown) and a relatively large-diameter large sprocket 2f (drive sprocket) for driving the balancer device 10 on the first journal 2b side. It is fixed in this order. A chain case 9 is provided outside the large sprocket 2f so as to penetrate the crankshaft 2. A crank pulley 2g for driving an auxiliary machine of the engine 1 is fixed to the right end of the crankshaft 2 positioned outside the chain case 9.

  The oil pan 6 has a shallow bottom portion 6C having a shallow bottom portion on the left side and a deep bottom portion 6D having a deep bottom portion in order to pass an exhaust pipe (not shown) from the front to the rear through the lower side of the engine 1. It is said that. The bottom surface of the shallow bottom portion 6C is formed in the upper oil pan 6A, and the bottom surface of the deep bottom portion 6D is formed in the lower oil pan 6B. The upper oil pan 6A and the lower oil pan 6B are cast together as separate members and fastened to each other with bolts. In the present embodiment, the upper oil pan 6 </ b> A is configured to also serve as a part of the balancer device 10 (an upper housing 14 </ b> A described later).

  The balancer device 10 is a device that reduces secondary vibration of the engine 1 caused by the reciprocating motion of the piston, and is disposed in the deep bottom portion 6D of the oil pan 6. As shown in FIG. 2, in this embodiment, the balancer device 10 is integrally provided with an oil pump 11 for pumping oil to each part of the engine 1 and each sliding part of the balancer device 10. The balancer device 10 includes a pair of front and rear balancer shafts 12 (front balancer shaft 12F and rear balancer shaft 12R) disposed in parallel with the crankshaft 2, and an input shaft 13 disposed coaxially with the rear balancer shaft 12R. The balancer housing 14 supports and accommodates the two balancer shafts 12F and 12R and the input shaft 13. Both balancer shafts 12F and 12R are disposed at the same height in the cylinder axial direction.

  The balancer housing 14 is coupled to an upper housing 14A and a lower housing 14B which are divided into two vertically along a plane passing through the axial centers of the balancer shafts 12F and 12R, and a right end surface of the lower housing 14B and the upper housing 14A. The right housing 14 </ b> C constituting the pump body 11 a of the pump 11. A pump cover 11b is coupled to the right end surface of the pump body 11a of the right housing 14C. The balancer device 10 is fastened to the lower surface of the lower block 5 (below the crankshaft 2) by a through bolt inserted from below into a bolt insertion hole provided at an appropriate position of the balancer housing 14.

  The upper housing 14A is integrally formed with the upper oil pan 6A (see FIG. 3). By connecting the lower housing 14B to the lower surface of the upper housing 14A, a balancer chamber 14D for accommodating both balancer shafts 12F and 12R is formed between the upper housing 14A and the lower housing 14B (that is, in the oil pan 6). The The upper wall 19 of the upper housing 14A that defines the upper edge of the balancer chamber 14D is disposed at substantially the same height as the bottom wall of the shallow bottom portion 6C of the oil pan 6. On the other hand, the lower wall 20 of the lower housing 14B that defines the lower edge of the balancer chamber 14D is above the bottom wall of the deep bottom portion 6D of the oil pan 6 and from the joint surface between the upper oil pan 6A and the lower oil pan 6B. Is also placed at a high position. As described above, the upper housing 14A is cast as the upper oil pan 6A, and the lower housing 14B is cast as a single dedicated member.

  The input shaft 13 is provided so as to protrude rightward from the balancer housing 14, and a driven sprocket 13a is fixed at a position corresponding to the large sprocket 2f in the crankshaft direction of the protruding portion. The input shaft 13 has a first journal 13b on the left side of the driven sprocket 13a and a second journal 13c on the left end of the shaft extending leftward from the first journal 13b.

  The first journal 13b of the input shaft 13 is supported by a first journal bearing 21 formed so as to penetrate the right housing 14C, and the second journal 13c of the input shaft 13 is formed in the upper housing 14A and the lower housing 14B. Further, it is supported by a second journal bearing 22 constituted by a half bearing. The right housing 14C is assembled to the upper housing 14A and the lower housing 14B so that the first journal bearing 21 and the second journal bearing 22 are arranged coaxially.

  A roller chain 15 is wound around the large sprocket 2 f of the crankshaft 2 and the driven sprocket 13 a of the input shaft 13. That is, the large sprocket 2f, the roller chain 15, and the driven sprocket 13a constitute a winding-type first transmission mechanism 16 that transmits the rotational force of the crankshaft 2 to the input shaft 13. The input shaft 13 rotates in the same direction as the crankshaft 2.

  On the left side of the first journal 13b of the input shaft 13, a bowl-shaped thrust plate 13d (color) is integrally formed. The inner surfaces of the driven sprocket 13a and the thrust plate 13d sandwiching the first journal bearing 21 are thrust surfaces. That is, the bearing wall constituting the first journal bearing 21 also serves as a thrust bearing that supports the axial load of the input shaft 13. A relatively large first helical gear 13e is fixed between the thrust plate 13d of the input shaft 13 and the second journal 13c.

  2 and 3, in addition to the second journal bearing 22, the upper housing 14A and the lower housing 14B are divided into halves formed in the upper housing 14A and the lower housing 14B in the same manner as the second journal bearing 22. A third journal bearing 23, a fourth journal bearing 24, and a fifth journal bearing 25 constituted by bearings are formed. The third journal bearing 23 is disposed coaxially with the second journal bearing 22 and spaced leftward from the second journal bearing 22 and below the third journal 2 b of the crankshaft 2. The fourth journal bearing 24 and the fifth journal bearing 25 are coaxially arranged in front of these at the same position in the left-right direction as the second journal bearing 22 and the third journal bearing 23, respectively. The bearing walls forming the second journal bearing 22 and the fourth journal bearing 24 and the bearing walls forming the third journal bearing 23 and the fifth journal bearing 25 are each configured as an integral wall continuous in the front-rear direction. The The second to fifth journal bearings 22 to 25 have substantially the same width dimension. The bearing walls of the second to fifth journal bearings 22 to 25 are connected to each other by the upper wall 19 in the upper housing 14A, and are connected to each other by the lower wall 20 in the lower housing 14B.

  The upper housing 14A and the lower housing 14B include three bolt holes 14a formed in the bearing walls forming the second and fourth journal bearings 22 and 24, and bearing walls forming the third and fifth journal bearings 23 and 25. The bolts are fastened to each other by six bolts B1 (see FIG. 6) inserted into the three bolt holes 14a. The bolt holes 14a are arranged between the two journal bearings and outside the two journal bearings in each bearing wall. The bolt hole 14a of the lower housing 14B is configured as a bolt insertion hole penetrating the lower housing 14B, and the bolt hole 14a of the upper housing 14A is configured as a bottomed female screw hole to which the bolt B1 is screwed, and the bolt B1 Is inserted into the bolt hole 14a from below.

  As shown in FIG. 2, the balancer shafts 12R and 12F are respectively connected to the first journal 12Ra and 12Fa supported by the corresponding second journal bearing 22 or fourth journal bearing 24, and the third journal bearing 23 or fifth journal. 2nd journals 12Rb and 12Fb supported by journal bearings 25 are provided. Further, the balancer shafts 12R and 12F are provided on the left and right sides of the second journals 12Rb and 12Fb, respectively, and a pair of left and right balancer weights 12Rc having substantially the same shape in which the center of gravity is biased radially outward from the rotation center. 12Fc, and right balancer weights 12Rc, 12Fc and first helical gears 12Rd, 12Fd fixed between the first journals 12Ra, 12Fa. A bearing metal 28 is installed on the third journal bearing 23 and the fifth journal bearing 25 that pivotally support the second journals 12Rb and 12Fb between the left and right balancer weights 12Rc and 12Fc.

  The second journal bearing 22 pivotally supports both the second journal 13c of the input shaft 13 and the first journal 12Ra of the rear balancer shaft 12R. The second journal 13c of the input shaft 13 and the first journal 12Ra of the rear balancer shaft 12R have the same diameter and the same length, and face each other with a slight gap at an intermediate position in the length direction of the second journal bearing 22. Are arranged to be. Accordingly, the first journal 12Ra of the rear balancer shaft 12R is about half the length of the second journal 12Rb of the rear balancer shaft 12R and the first journal 12Fa of the front balancer shaft 12F.

  In both the balancer shafts 12R and 12F, the opposing portions of the pair of left and right balancer weights 12Rc and 12Fc have a bowl-like shape whose diameter is larger than that of the second journals 12Rb and 12Fb (see FIG. 1). The opposed inner surfaces of the bowl-shaped portions are thrust surfaces that transmit a thrust force to the third journal bearing 23 or the fifth journal bearing 25. That is, the bearing walls forming the third and fifth journal bearings 23 and 25 also serve as thrust bearings that support the axial loads of the balancer shafts 12R and 12F.

  In the rear balancer shaft 12R, the first journal 12Ra constitutes the right end. On the other hand, the front balancer shaft 12F extends further to the right from the first journal 12Fa, and a second helical gear 12Fe that meshes with the first helical gear 13e of the input shaft 13 is fixed to the extended portion. That is, the first transmission gear 17 that transmits the rotational force of the input shaft 13 to the front balancer shaft 12F is configured by the first helical gear 13e and the second helical gear 12Fe. As a result, the front balancer shaft 12F rotates in the direction opposite to the input shaft 13. Note that the directions of twisting of the second helical gear 12Fe and the first helical gear 12Fd of the front balancer shaft 12F are the same, thereby reducing the axial load of the front balancer shaft 12F.

  The first helical gear 12Fd of the front balancer shaft 12F and the first helical gear 12Rd of the rear balancer shaft 12R are engaged with each other, and the rotational force of the front balancer shaft 12F is applied to the rear balancer shaft 12R by these first helical gears 12Fd, 12Rd. A third transmission mechanism 18 for transmission is configured. The first helical gears 12Fd and 12Rd constituting the third transmission mechanism 18 have the same diameter and the same number of teeth (speed-up gear ratio = 1), and both balancer shafts 12F and 12R are the same in opposite directions. It rotates at the rotation speed.

  On the other hand, the speed increasing ratio of the first transmission mechanism 16 and the second transmission mechanism 17 is set so that the balancer shafts 12F and 12R have a rotational speed twice that of the crankshaft 2. Specifically, in the present embodiment, the chain transmission speed ratio of the first transmission mechanism 16 is set to 4/3, the speed increase gear ratio of the second transmission mechanism 17 is set to 3/2, and the first transmission mechanism The speed increasing ratio of the mechanism obtained by multiplying 16 and the second transmission mechanism 17 is 2.

  Accordingly, the diameter and the number of teeth (the number of teeth) of the driven sprocket 13a are set to 3/4 times the diameter and the number of the large sprocket 2f, and the rotational speed of the input shaft 13 is twice that of the crankshaft 2. It is larger than the ratio (1/2 times). On the other hand, the diameter and the number of teeth of the first helical gear 13e of the input shaft 13 are 3/2 times the diameter and the number of teeth of the second helical gear 12Fe of the front balancer shaft 12F, and the rotational speed of the input shaft 13 is the crankshaft. It is smaller than the ratio (twice) when it becomes the same as the rotational speed of 2.

  The right end of the front balancer shaft 12F extends further to the right from the second helical gear 12Fe and is connected to a pump shaft 11c that drives the oil pump 11 via a joint. The oil pump 11 includes a pump body 11a defining a cylindrical pump chamber by a right housing 14C and a pump cover 11b, an outer rotor 11d and an inner rotor 11e built in the pump chamber, and a pump shaft 11c fixed to the inner rotor 11e. It is a trochoid type which has a publicly known composition provided with. The pump shaft 11c is pivotally supported by a sixth journal bearing 26 formed through the wall of the right housing 14C. The joint is composed of a key groove 11f formed on the left end surface of the pump shaft 11c, and a key 12Ff which is formed to protrude from the right end surface of the front balancer shaft 12F and fits in the key groove 11f. The front balancer shaft 12F can be easily assembled by being fitted into the key groove 11f.

  The oil pump 11 sucks engine oil from an intake port of an oil strainer (not shown) formed on the bottom wall of the balancer housing 14 and supplies the engine oil to each part of the engine 1 and each sliding part of the balancer device 10 through a discharge passage. Pump. Specifically, in the balancer device 10, engine oil is supplied to the first to fifth journal bearings 21 to 25. In the first, third, and fifth journal bearings 21, 23, and 25, the flowing engine oil is supplied to thrust bearings formed on both side surfaces thereof. In the second journal bearing 22, an oil passage is communicated with a gap formed between the input shaft 13 and the rear balancer shaft 12R.

  Hereinafter, the configuration of the oil passage in the balancer device 10 will be described. As shown in FIG. 1, an oil passage 7 a that supplies oil from the main gallery to the balancer device 10 is provided on the bearing wall that supports the third journal 2 b of the crankshaft 2. The oil supplied from the oil passage 7a is introduced into the balancer device 10 from the upper surface of the upper housing 14A, and supplied to the joint surface with the lower housing 14B through an oil passage (not shown) extending vertically.

  As shown in FIG. 2, an oil passage groove 29 is formed on the upper surface of the lower housing 14B. In the oil passage groove 29, the left rear end portion of the lower housing 14B (the rear end portions of the bearing walls forming the third and fifth journal bearings 23 and 25) serves as the oil inlet 29a. The oil passage groove 29 extends forward from the oil inlet 29 a on the upper surface of the bearing wall, extends along the periphery of the bolt hole 14 a (around the bolt), and reaches the rear end of the third journal bearing 23. A bearing metal 28 is installed in the third journal bearing 23, and a part of the oil is supplied to the bearing gap of the third journal bearing 23 through a through hole formed in the bearing metal 28.

  In the third journal bearing 23, the oil passage groove 29 is formed in an annular shape on the back side of the bearing metal 28 (on the upper housing 14A and the lower housing 14B), and again from the front end of the third journal bearing 23 to the lower housing. The upper surface of 14B extends forward and reaches the rear end of the fifth journal bearing 25 before extending along the periphery of the bolt hole 14a. Also in the fifth journal bearing 25, an oil passage groove 29 is formed on the back side of the bearing metal 28, and a part of the oil passes through a through hole formed in the bearing metal 28 and the bearing clearance of the fifth journal bearing 25. The remaining oil is supplied to the front of the fifth journal bearing 25 through the annular oil passage groove 29.

  In the third journal bearing 23 and the fifth journal bearing 25, after the oil supplied to the bearing gap (inside the bearing metal 28) and lubricated leaks left and right from the bearing gap, The thrust bearings 12Rc and 12Fc are used for lubricating the thrust bearings.

  The oil channel groove 29 extends from the front end of the fifth journal bearing 25 to the front surface of the lower housing 14B again and extends along the periphery of the bolt hole 14a, and then bends, and the upper surface of the front wall of the lower housing 14B is bent to the right. Extend to. The oil passage groove 29 is curved again at the front end portion of the bearing wall forming the second and fourth journal bearings 22, 24 and extends rearward, and extends along the periphery of the bolt hole 14 a to extend the front end of the fourth journal bearing 24. To.

  No bearing metal 28 is installed in the fourth journal bearing 24, and oil passage grooves 29 are formed in an annular shape on the surfaces of the upper housing 14A and the lower housing 14B that form the bearing surface. Oil is directly supplied from the groove 29 to the bearing gap. The oil passage groove 29 extends from the rear end of the fourth journal bearing 24 to the rear of the upper surface of the lower housing 14B again, extends along the periphery of the bolt hole 14a, and reaches the front end of the second journal bearing 22.

  Also in the second journal bearing 22, the bearing metal 28 is not installed, and oil passage grooves 29 are formed in an annular shape on the surfaces of the upper housing 14A and the lower housing 14B forming the bearing surface. Oil is directly supplied from the groove 29 to the bearing gap.

  The oil passage groove 29 formed as described above includes a bearing wall that forms the third and fifth journal bearings 23 and 25, a bearing wall that forms the second and fourth journal bearings 22 and 24, and both bearing walls. In the front wall to connect, it forms in the center of the width direction of a wall. Accordingly, the second journal bearing 22 has an oil passage groove 29 formed in an annular shape in the center in the wall width direction.

  As described above, the second journal 13c and the first journal 12Ra provided at the ends of the input shaft 13 and the rear balancer shaft 12R that are close to each other have the same length, and are formed between the two. An oil passage groove 29 is formed at a position overlapping the gap g (FIG. 4). That is, the oil passage groove 29 is connected to the gap g between the input shaft 13 and the rear balancer shaft 12R (the oil passage communicates).

  As shown in FIG. 4, the width of the annular portion 29b of the oil passage groove 29 is larger than the gap g, and the end surfaces of the input shaft 13 and the rear balancer shaft 12R on the side close to each other are annular portions 29b. Is arranged at a position facing the oil passage groove 29. In other words, the annular portion 29b of the oil passage groove 29 is disposed so as to straddle the gap g. Further, the end surfaces (corner portions) of the input shaft 13 and the rear balancer shaft 12R on the sides close to each other are chamfered, and the radial bearing surfaces (cylindrical outer peripheral surfaces) of the second journal 13c and the first journal 12Ra. The end edge is disposed on the inner side overlapping the annular portion 29 b of the oil passage groove 29.

  As shown in FIG. 2, the engine oil used for lubrication at each sliding portion of the balancer device 10 is accumulated in the lower housing 14B, and the first helical gear 13e of the input shaft 13 and the second helical gear 12Fe of the front balancer shaft 12F. And the first helical gears 12Rd and 12Fd of the balancer shafts 12F and 12R and the balancer weights 12Rc and 12Fc are scattered and scattered. Therefore, as shown in FIG. 3, oil discharge is performed at positions corresponding to these portions (13e, 12Fe, 12Rd, 12Fd, 12Fc) of the upper wall 19 so that the engine oil does not accumulate excessively in the balancer chamber 14D. A plurality of openings 19a are formed. The engine oil in the balancer chamber 14D is scooped up by the balancer shafts 12F and 12R and the input shaft 13 and scattered radially, and is discharged to the outside (in the oil pan 6) through these openings 19a.

  In the balancer device 10 configured as described above, power is transmitted as shown by an arrow in FIG. That is, the rotational force of the crankshaft 2 is transmitted to the input shaft 13 via the large sprocket 2 f (FIG. 1), the roller chain 15 (FIG. 1) and the driven sprocket 13 a of the first transmission mechanism 16, and the second transmission mechanism 17. Is transmitted to the front balancer shaft 12F via the first helical gear 13e and the second helical gear 12Fe. As described above, the front balancer shaft 12F rotates in the opposite direction to the crankshaft 2 at a rotational speed twice that of the crankshaft 2. The rotational force of the front balancer shaft 12F is transmitted to the pump shaft 11c via a joint, and is also transmitted to the rear balancer shaft 12R via both first helical gears 12Fd and 12Rd constituting the third transmission mechanism 18. The pair of front and rear balancer shafts 12F and 12R rotate at the same rotational speed in opposite directions. As a result, an inertial force in the cylinder axis direction that cancels the secondary vibration of the engine 1 is generated.

  As described above, in the balancer device 10, the input shaft 13 and the rear balancer shaft 12R shown in FIG. 2 are arranged close to each other on the same axis, and the second journal 13c and the second journal 13c formed at the end portions on the sides close to each other. The first journal 12Ra is pivotally supported by a single second journal bearing 22, and an oil passage groove 29 communicates with a gap g formed between the second journal 13c and the first journal 12Ra.

  In this way, the second journal bearing 22 that pivotally supports the second journal 13c and the first journal 12Ra is made common, thereby reducing the processing man-hours of the bearing. In addition, in journal bearings composed of two half bearing halves, the bearing halves must be fastened at at least two locations on both sides of the shaft. Fastening means are required in at least four places. On the other hand, in the present embodiment, since only one second journal bearing 22 is required, the fastening means can be reduced and the number of assembly steps can be reduced. Furthermore, since the bearing width dimension (dimension in the shaft length direction) can be shortened compared to the case where a bearing is provided for each journal, the balancer device 10 can be reduced in size.

  As shown in FIG. 4, in the balancer device 10 of the present embodiment, the second journal bearing 22, the second journal 13c, and the first journal 12Ra are formed from the gap g formed between the input shaft 13 and the rear balancer shaft 12R. Oil is supplied to the bearing gap between the two. Therefore, only one oil passage groove 29 is required, and the structure of the oil passage can be simplified, whereby the balancer device 10 can be downsized and the number of processing steps can be reduced.

  In addition, since the second journal bearing 22 that pivotally supports the second journal 13c and the first journal 12Ra is used in common, the required amount of lubricating oil is reduced. That is, when a bearing is provided for each journal, the oil supplied to the bearing gap from the center in the width direction of the bearing leaks from the four openings (openings at both ends of each bearing gap). In this embodiment, it leaks only from two openings. Therefore, the required amount of lubricating oil is reduced.

  In relation to this, the pressure of the oil film in the bearing gap becomes lower as it is closer to the opening and becomes the atmospheric pressure at the opening. However, in this embodiment, the pressure of the oil film is large only at one opening in the axial direction in one journal. Since the pressure becomes atmospheric pressure and the hydraulic pressure in the gap g acts on the opening on the other side (the gap g side), the load capacity for supporting the radial load is improved. Therefore, the bearing width of each journal can be made narrower than in the case where a bearing is provided for each journal. This also allows the balancer device 10 to be downsized.

  Further, since the hydraulic pressure acts on the end surfaces of the input shaft 13 and the rear balancer shaft 12R that are close to each other, the axial movement of the input shaft 13 and the rear balancer shaft 12R can be suppressed. That is, in the balancer device 10 of the present embodiment, since the helical gears are used for the second transmission mechanism 17 and the third transmission mechanism 18, the thrust forces in the directions opposite to each other when the engine speed increases and decreases, Acting in opposite directions to the input shaft 13 and the rear balancer shaft 12R, both shafts move in the axial direction when the engine speed increases and decreases. On the other hand, in the present embodiment, the thrust force in the direction of separating the input shaft 13 and the rear balancer shaft 12R always acts, so that axial movement during engine speed switching is suppressed.

  In the present embodiment, an annular portion 29b constituting the oil passage groove 29 is formed on the inner surface of the second journal bearing 22, and the oil passage groove 29 is larger than the gap g between the second journal 13c and the first journal 12Ra. It has a width and is arranged so as to straddle the gap g. Therefore, the input shaft 13 and the rear balancer shaft 12R are prevented from coming into contact with the second journal bearing 22. Further, oil easily enters the bearing gaps between the second journal 13c and the first journal 12Ra and the second journal bearing 22. The annular portion 29b has a second journal bearing 22 in order to prevent the lubricating oil from leaking through the mating surface of the lower housing 14B and the upper housing 14A to the rear bolt hole 14a where the oil passage groove 29 is not formed. It may be C-shaped without an oil groove formed on the rear side.

  As shown in FIGS. 1 and 6, an oil level sensor 30 that detects the level of engine oil stored in the oil pan 6 is provided in the deep bottom portion 6 </ b> D of the oil pan 6. The oil level sensor 30 is a plate-shaped sensor 31 that extends in a column shape from the bottom wall of the oil pan 6 (lower oil pan 6B) in a vertical direction and supports the sensing unit 31, and is attached to the lower oil pan 6B. And a support portion 32.

  The lower oil pan 6B is mounted on the automobile in a posture in which the engine axis is inclined backward, so that the lower oil pan 6B is formed shallower toward the rear side, and the bottom wall forms a substantially horizontal bottom surface at the rear, An inclined bottom surface is formed in which the bottom wall increases toward the front. An opening 6a for inserting the sensing part 31 of the oil level sensor 30 is formed in the rear part of the bottom wall of the lower oil pan 6B, and around the opening 6a to protect the support part 32 attached to the bottom wall. Is a recess 6b that is recessed upward and accommodates the support portion 32. Also, the lower wall 20 of the lower housing 14B is formed with an opening 20a for inserting the sensing unit 31 at a position corresponding to the vertically upward direction with respect to the opening 6a of the lower oil pan 6B.

  In the oil level sensor 30, the sensing part 31 is inserted into the opening 6a of the lower oil pan 6B from the lower surface side, and the support part 32 is attached to the bottom wall of the recess 6b via a seal member (not shown). By being fastened by not shown), the sensing unit 31 is fixed to the lower oil pan 6B in a state where the sensing unit 31 is arranged at the approximate center of the deep bottom portion 6D in the front-rear direction (FIG. 6) and the left-right direction (FIG. 1). As shown in FIGS. 1, 2, and 6 (refer to the cover member 40 in FIG. 2), the sensing unit 31 is located between the balancer shafts 12F and 12R in the front-rear direction and in the left-right direction. Is located between the first helical gears 12Fd, 12Rd of the balancer shafts 12F, 12R and the right balancer weights 12Rc, 12Fc.

  As shown in FIG. 6, the sensing unit 31 of the oil level sensor 30 includes a hollow sensor housing 33 and a plate-shaped sensing element 34 disposed inside the sensor housing 33. A horizontally long slit-like oil hole 33a communicating with the lower part (oil reservoir) of the oil pan 6 is formed at the lower end of the hollow sensor housing 33, and a vent hole communicating with the balancer chamber 14D is formed at the upper end of the side wall of the sensor housing 33. 33b is formed. Normally, the lower end oil hole 33a is immersed in the engine oil in the oil pan 6, and the upper end vent hole 33b is not immersed in the engine oil. Therefore, the oil level in the sensor housing 33 rises and falls slowly compared to the oil level in the oil pan 6 so as to match the oil level in the oil pan 6 regardless of the level in the balancer device 10. The oil level sensor 30 detects the oil level in the oil pan 6 by measuring the time during which the sensing element 34 is cooled after the sensing element 34 is energized to generate heat. For example, when the oil level is high, the amount of heat released from the sensing element 34 to the engine oil is large, and the temperature drop of the sensing element 34 is accelerated. Conversely, when the oil level is low, the amount of heat released from the sensing element 34 to the engine oil is small, and the temperature drop of the sensing element 34 is delayed.

  As shown in FIGS. 2 and 6, a reverse cup-shaped cover member 40 is attached to the lower wall 20 of the lower housing 14 </ b> B so as to protect the sensing unit 31 disposed in the balancer device 10. As shown in FIGS. 8 and 9, the cover member 40 includes a cylindrical portion 41 having a substantially quadrangular pyramid shape that becomes thinner toward the upper side, and three attachment pieces 42 that extend radially outward from the lower end of the cylindrical portion 41. And. The cylindrical portion 41 includes a square cylindrical peripheral side wall 43 and an upper wall 44 that closes the upper end of the peripheral side wall 43. In the upper part of the cover member 40 (on the left side of the upper wall 44 in this embodiment), the pressure in the cylinder part 41 is the same as the pressure in the balancer chamber 14D even when the opening edge at the lower end of the cylinder part 41 is immersed in oil. An opening 40a for ventilation is formed.

  As shown in FIG. 6, the cover member 40 has a cylindrical portion 41 inserted into the opening 20a of the lower wall 20 from below, and the mounting piece 42 is fastened around the opening 6a of the lower wall 20 with a bolt B2. The side wall 43 is opposed to the balancer shafts 12F and 12R with a space therebetween, and the upper wall 44 of the cover member 40 is opposed to the upper wall 19 of the upper housing 14A with a space therebetween. Fixed to. That is, the upper end of the cover member 40 is disposed in the balancer chamber 14D, and the upper wall 19 of the upper housing 14A covers the cover member 40 from above without contact. Further, the upper wall 44 of the cover member 40 is opposed to the upper end of the sensing unit 31 inserted from below, and the peripheral side wall 43 of the cover member 40 is between the side surface of the sensing unit 31. Opposite with a gap. That is, the cylinder part 41 of the cover member 40 covers the sensing part 31 from above in a non-contact state and covers a portion of the sensing part 31 arranged in the balancer chamber 14D from the side in a non-contact state.

  As shown in FIGS. 6 and 3, the upper wall 19 of the upper housing 14 </ b> A is recessed upward along the contour of the cover member 40 in order to form the above-described gap with the upper wall 44 of the cover member 40. A recess 19b is formed. An air vent opening 19c is formed at the left end of the recess 19b. Furthermore, a stopper 50 (50A, 50B, 50C, 50D) facing the peripheral side wall 43 (side surface) of the cover member 40 is provided on the upper wall 19 of the upper housing 14A around the recess 19b. In the present embodiment, the stopper 50 has three columnar projections 50A, 50B, 50C that protrude downward from the upper wall 19 in the front-rear and left directions with respect to the cover member 40, and the right side with respect to the cover member 40. The upper wall 19 itself is formed as one right side wall 50D that is curved so as to be recessed upward, and is integrally formed with the upper wall 19. At least one of the three protrusions 50A, 50B, 50C is provided as an extrusion pin seat for taking out the upper oil pan 6A from the mold when casting the upper oil pan 6A (upper housing 14A). Also used as an extrusion pin seat and a stopper 50. The right side wall 50 </ b> D is a part of the peripheral wall that forms the recess 19 b of the upper wall 19.

  As shown in FIG. 6, the front protrusion 50 </ b> A is opposed to the front side surface of the cover member 40 with an interval smaller than the interval between the peripheral side wall 43 of the cover member 40 and the front balancer shaft 12 </ b> F. The rear protrusion 50B is opposed to the rear side surface of the cover member 40 with an interval smaller than the interval between the peripheral side wall 43 of the cover member 40 and the rear balancer shaft 12R. As shown in FIG. 7, the left protrusion 50 </ b> C faces the left side surface of the cover member 40 with a smaller distance than the distance between the peripheral side wall 43 of the cover member 40 and the right balancer weights 12 </ b> Rc and 12 </ b> Fc. The right side wall 50D is opposed to the right side surface of the cover member 40 with an interval smaller than the interval between the peripheral side wall 43 of the cover member 40 and the first helical gears 12Rd, 12Fd.

  As shown in FIGS. 8 and 9, the cover member 40 is formed as thin as possible within a range in which rigidity can be ensured because the gap between the sensing unit 31 and the balancer shafts 12F, 12R is small. In the present embodiment, the cover member 40 is a pressed product of a plate made of an aluminum alloy. The cylinder portion 41 of the cover member 40 has an elongated (deep) quadrangular pyramid shape, and it is difficult to press and mold one plate, so that it is a half cylinder extending along the longitudinal direction of the sensing portion 31. The two cover halves 45 and 46 are formed in combination. These cover halves 45 and 46 are pressed together as separate members, and are formed into a cylindrical shape by combining them so that one edge overlaps the outside of the other edge. The two cover halves 45 and 46 are joined to each other by joining the edges that overlap each other in a cylindrical shape by spot welding. In the present embodiment, the edge portions of the two cover halves 45 and 46 are joined to each other by spot welding at three points P shown in FIG. When the cover member 40 is formed in this way, the overlapped portion is not completely blocked, and oil can enter the cover member 40 from the gap between the overlapped portions, which can affect the accuracy of the oil level sensor 30. This is dealt with by the configuration described later. On the other hand, by forming the cover member 40 in this manner, the processing cost of the cover member 40 can be suppressed, and the cover member 40 can be manufactured thin and lightweight.

  As described above, since the two cover halves 45 and 46 are not welded over the entire length of the edge portion, there is a gap in the unwelded portion, and oil can enter the cylinder portion 41 from this gap. As shown in FIG. 2, the cover member 40 is arranged in a direction in which the two cover halves 45 and 46 are aligned in the axial direction of the balancer shaft 12. Therefore, the overlapping portion of the two cover halves 45 and 46 is disposed at a position away from the first helical gears 12Rd and 12Fd and the balancer weights 12Rc and 12Fc of the balancer shafts 12F and 12R, and the overlapping surfaces are scattered by engine oil. It arrange | positions in the direction orthogonal to a direction (shaft radial direction).

  Further, the cover member 40 is arranged such that the cover half 45 on the first helical gears 12Rd, 12Fd side of the two cover halves 45, 46 overlaps the outside of the cover half 46 on the balancer weights 12Rc, 12Fc side. Therefore, the gap between the overlapping portions of the two cover halves 45 and 46 is directed to the balancer weights 12Rc and 12Fc instead of the first helical gears 12Rd and 12Fd.

  Next, the operation of the embodiment of the present invention having the above configuration will be described.

  If the engine level in the oil pan 6 undulates due to shaking, acceleration / deceleration, turning, etc. of the vehicle body, the detection accuracy of the oil level sensor 30 is reduced. On the other hand, in this embodiment, as shown in FIG. 6, the sensor housing 33 is disposed between the balancer shafts 12F and 12R, and is formed at the lower end of the sensor housing 33 to receive the oil pressure corresponding to the oil level. Since the hole 33a is disposed below the balancer device 10, a change in oil pressure, that is, a change in oil level is reduced and reduced, and the detection accuracy of the oil level sensor 30 is improved.

  A cover member 40 is provided that covers the sensing unit 31 from above and covers at least a portion of the sensing unit 31 disposed in the balancer chamber 14D from the side, and has an opening 40a formed in the upper portion. Therefore, the oil level sensor 30 is prevented from contacting the balancer shaft 12 when the oil level sensor 30 is assembled, and the oil level sensor 30 is reliably prevented from contacting the balancer shaft 12 during operation.

  Further, in order to suppress an increase in weight, the cover member 40 is configured by combining two half-cylindrical cover halves 45 and 46 extending along the longitudinal direction of the sensing unit 31 as shown in FIG. The cover member 40 is thin. However, as shown in FIG. 10A, the upper housing 14A faces the side surface of the cover member 40 at a distance smaller than the distance between the pair of balancer shafts 12F and 12R of the cover member 40. Since the stopper 50 (50A, 50B) provided on the wall 19 is provided, as shown in FIG. 10B, when the cover member 40 is deformed or displaced to the balancer shaft 12 side due to external force due to operational vibration or error, the balancer The stopper 50 is contacted before contacting the shaft 12. This reliably prevents the cover member 40 from contacting the balancer shaft 12.

  As shown in FIG. 6, in the present embodiment, the upper end of the cover member 40 is disposed in the balancer chamber 14D. Therefore, it is not necessary to form a through hole through which the cover member 40 is inserted into the upper wall 19 of the upper housing 14A, and the upper wall 19 of the upper housing 14A can cover the cover member 40 from above. As a result, the oil splashed from the crankshaft 2 or the like is prevented from entering the balancer chamber 14D from above and affecting the accuracy of the oil level sensor 30. Further, since the stopper 50 is integrally formed with the upper wall 19 so as to protrude downward from the upper wall 19 of the upper housing 14A, it is not necessary to use another member for providing the stopper 50, and the number of parts and the number of assembly steps are reduced. Reduced.

  Further, since the stopper 50 includes at least one pair of the front protrusion 50A and the rear protrusion 50B formed on the upper wall 19 so as to overlap the side surface of the cover member 40 in the axial direction of the balancer shaft 12, the stopper 50 Can be made the minimum size necessary for its function, and an increase in weight due to the installation of the stopper 50 is suppressed.

  Moreover, in the said embodiment, as shown in FIG.2 and FIG.7, as the cylinder part 41 of the cover member 40 extends along the longitudinal direction of the sensing part 31, two semi-cylindrical cover halves 45 and 46 are one side. Are combined so that the edge of each other overlaps the outside of the other edge. Thereby, the cover member 40 can be thinned, and an increase in weight due to the installation of the cover member 40 is suppressed. Further, the cover member 40 is arranged in a direction in which the two cover halves 45 and 46 are arranged in the axial direction of the balancer shaft 12. As a result, the overlapping portion is located away from the first helical gears 12Rd, 12Fd and the balancer weights 12Rc, 12Fc of the balancer shafts 12F, 12R that scatter oil, and the overlapping surface intersects the oil scattering direction. Since it arrange | positions so that it may face, the permeation of the oil from an overlap part is suppressed.

  Further, the first helical gears 12Rd and 12Fd have a larger diameter than the balancer weights 12Rc and 12Fc, and it is inevitable that more oil accumulated in the balancer device 10 is scraped off by the first helical gears 12Rd and 12Fd. On the other hand, in the present embodiment, the cover member 40 is disposed between the first helical gears 12Rd, 12Fd and the balancer weights 12Rc, 12Fc, but the cover half 45 on the side close to the first helical gears 12Rd, 12Fd is the balancer. Since the oil is scraped off from the first helical gears 12Rd and 12Fd, the oil is prevented from entering the cover member 40 from the overlapped portion because it is arranged so as to overlap the outside of the cover half 46 on the side close to the weights 12Rc and 12Fc.

<< Modified Embodiment >>
Next, a balancer device 10 according to a modified embodiment will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the element which has the form or function in common with the said embodiment, and the overlapping description is abbreviate | omitted. The front-rear and left-right directions are in accordance with the above embodiment (see FIG. 2).

  In the above embodiment, in the transmission of power from the crankshaft 2 to the pair of balancer shafts 12F and 12R, the gear-type second transmission mechanism 17 comprising a pair of gears meshing with the winding-type first transmission mechanism 16 and However, in the balancer device 10 of the present modified embodiment, the second transmission mechanism 17 includes two speed increasing mechanisms (two pairs of gears), and the three speeds are increased. Is done.

  This will be specifically described below. The balancer device 10 includes an intermediate shaft 51 arranged in parallel with the input shaft 13 in addition to the pair of front and rear balancer shafts 12F and 12R and the input shaft 13. In the present modified embodiment, the intermediate shaft 51 is disposed coaxially with the front balancer shaft 12F. A first helical gear 51a that meshes with the first helical gear 13e of the input shaft 13 is fixed to the intermediate shaft 51, and a second helical gear 51b is fixed at a position spaced leftward from the first helical gear 51a.

  The configuration of the pair of balancer shafts 12F and 12R is also different from the above embodiment. Specifically, in the front balancer shaft 12F, the first journal 12Fa forms the right end, and the second helical gear 12Fe is not provided. In the rear balancer shaft 12R, a second helical gear that meshes with the second helical gear 51b at a position between the first journal 12Ra and the first helical gear 12Rd and corresponding to the second helical gear 51b of the intermediate shaft 51 in the left-right direction. 12Re is fixed.

  The intermediate shaft 51 includes a first journal 51c at the left end, a second journal 51d between the first helical gear 51a and the second helical gear 51b, and a slight gap g (see FIG. 5) between the right end surface of the front balancer shaft 12F. 4) to be opposed to each other. The first journal 51c of the intermediate shaft 51 and the first journal 12Fa of the front balancer shaft 12F are both supported by the fourth journal bearing 24. On the other hand, the second journal 13c of the input shaft 13 and the first journal 12Ra of the rear balancer shaft 12R are both pivotally supported by the second journal bearing 22 as in the above embodiment.

  When the pump shaft 11c is connected to the intermediate shaft 51 through a joint as in the above embodiment, the sixth journal bearing 26 that supports the pump shaft 11c and the second journal 51d of the intermediate shaft 51 are connected. Both of the seventh journal bearings 27 that support the shaft are required. On the other hand, when the pump shaft 11c and the intermediate shaft 51 are integrated, one of the sixth journal bearing 26 and the seventh journal bearing 27 can be omitted.

  The first gear mechanism 17A is constituted by the first helical gear 13e of the input shaft 13 and the first helical gear 51a of the intermediate shaft 51, and the second gear mechanism is constituted by the second helical gear 51b of the intermediate shaft 51 and the second helical gear 12Re of the rear balancer shaft 12R. 17B is configured. The second transmission mechanism 17 is configured by the intermediate shaft 51, the first gear mechanism 17A, and the second gear mechanism 17B.

  In the balancer device 10 configured as described above, power is transmitted as indicated by black arrows in the drawing. That is, the rotational force of the crankshaft 2 transmitted to the input shaft 13 via the first transmission mechanism 16 including the driven sprocket 13a is transmitted to the intermediate shaft 51 via the first gear mechanism 17A of the second transmission mechanism 17. The The rotational force of the intermediate shaft 51 is transmitted to the pump shaft 11c and is also transmitted to the rear balancer shaft 12R via the second gear mechanism 17B of the second transmission mechanism 17 so that the rear balancer shaft 12R is twice that of the crankshaft 2. In the same direction as the crankshaft 2. The rotational force of the rear balancer shaft 12R is transmitted to the front balancer shaft 12F via the third transmission mechanism 18, and the front balancer shaft 12F is rotated at the same rotational speed in a direction opposite to the rear balancer shaft 12R.

  The chain transmission ratio of the first transmission mechanism 16 is greater than 1 so that the rotational speed of the input shaft 13 is faster than the rotational speed of the crankshaft 2 and slower than the rotational speed of the rear balancer shaft 12R. It is set to be smaller than 2. The speed increasing gear ratio of the first gear mechanism 17A of the second transmission mechanism 17 is such that the rotational speed of the intermediate shaft 51 is faster than the rotational speed of the input shaft 13 and slower than the rotational speed of the rear balancer shaft 12R. It is set larger than 1 and smaller than 2. For example, when the chain speed increasing ratio of the first transmission mechanism 16 is set to 4/3, the speed increasing gear ratio of the first gear mechanism 17A is 4/3, and the speed increasing gear ratio of the second gear mechanism 17B is 9 /. By setting it to 8, the rotational speed of the balancer shafts 12F and 12R becomes twice the rotational speed of the crankshaft 2.

  Although detailed illustration is omitted, the oil passage groove 29 is formed as shown by a white arrow in FIG. 11 in the same manner as in the above embodiment. Specifically, the oil passage groove 29 extends forward from the oil inlet 29a on the upper surface of the lower housing 14B (FIG. 2), and extends in an annular shape in the third journal bearing 23 and the fifth journal bearing 25, and then the lower housing. It extends to the right through the upper surface of the front wall of 14B. At a position corresponding to the fourth journal bearing 24, the oil passage groove 29 branches into a first branch groove 29A extending rearward and a second branch groove 29B further extending rightward. The first branch groove 29 </ b> A reaches the fourth journal bearing 24, and the second branch groove 29 </ b> B extends in an annular shape in the seventh journal bearing 27 to reach the second journal bearing 22. In the second journal bearing 22 and the fourth journal bearing 24, the oil passage groove 29 is connected to the gap g (FIG. 4) between the shafts as in the above embodiment.

  When the seventh journal bearing 27 is omitted, the second branch groove 29B reaching the second journal bearing 22 branches from the oil inlet 29a as indicated by the white arrow indicated by an imaginary line, and the lower housing 14B It may be formed to extend to the right through the upper surface of the rear wall.

  In any case, in the second journal bearing 22 and the fourth journal bearing 24, the oil passage groove 29 forms an annular portion 29b (FIG. 4), and the width of the annular portion 29b is the clearance between the shafts. The annular portion 29b of the oil passage groove 29 may be disposed so as to straddle the gap g.

  Although the description of the specific embodiment is finished as described above, the present invention is not limited to the above embodiment and can be widely modified. For example, in the above-described embodiment, the balancer device 10 for an in-vehicle internal combustion engine has been described as an example. However, the balancer device 10 can be widely applied to railway vehicles, ships, airplanes, and the like, and is applied to mechanical devices other than the balancer device 10. You can also. Moreover, in the said embodiment, although the helical gear is used for the gear of the 2nd transmission mechanism 17 or the 3rd transmission mechanism 18, you may use a spur gear, a helical gear, etc. Moreover, in the said embodiment, although the roller chain 15 is used for the winding-type 1st transmission mechanism 16, you may use the chain of other structures, such as a silent chain. Moreover, in the said embodiment, although the stopper 50 contains protrusion 50A, 50B, 60C, the form which the surrounding wall which comprises the recessed part 19b of the upper wall 19 surrounds the upper end part of the cover member 40 may be sufficient. Further, in the above embodiment, the upper end of the cover member 40 is disposed in the balancer chamber 14D. However, an opening is formed in the upper wall 19 of the upper housing 14A, and the cover member 40 protrudes further upward from this opening. May be disposed above the balancer chamber 14D. In this case, the edge of the upper wall 19 that defines the opening may constitute the stopper 50. That is, the size of the opening may be set so that the distance between the edge portion defining the opening of the upper wall 19 and the cover member 40 is smaller than the distance between the cover member 40 and the balancer shafts 12F and 12R. In addition, the specific configuration, arrangement, quantity, angle, material, manufacturing method, and the like of each member and part can be changed as appropriate without departing from the spirit of the present invention. On the other hand, all the elements of the balancer device 10 shown in the above embodiment are not necessarily essential, and can be selected as appropriate.

1 Engine 2 Crankshaft 10 Balancer device (mechanical device)
12F Front balancer shaft (Rotating shaft)
12Fd first helical gear (element of third transmission mechanism 18)
12Fe second helical gear (element of second transmission mechanism 17)
12R Rear balancer shaft (rotating shaft)
12Rd first helical gear (element of third transmission mechanism 18)
12Re Second helical gear (element of second gear mechanism 17B)
13 Input shaft (Rotating shaft)
13e 1st helical gear (element of 2nd transmission mechanism 17)
16 1st transmission mechanism 17 2nd transmission mechanism 17A 1st gear mechanism 17B 2nd gear mechanism 18 3rd transmission mechanism 22 2nd journal bearing 24 4th journal bearing 29 Oil passage groove 29b Annular part 51 Intermediate shaft (rotating shaft)
51a First helical gear (element of first gear mechanism 17A)
51b Second helical gear (element of second gear mechanism 17B)
g Clearance

Claims (4)

A mechanical device having a plurality of rotating shafts,
Two of the plurality of rotating shafts are arranged close to each other on the same axis, and ends of the two rotating shafts arranged on the same axis are supported by a single bearing. A mechanical device having a plurality of rotating shafts, wherein an oil passage communicating with a gap formed between the end portions of each of the two rotating shafts formed in one bearing is provided.   An annular groove constituting the oil passage is formed on an inner surface of the bearing, and the groove has a width larger than the gap and is disposed so as to straddle the gap. Item 2. The machine device according to Item 1. The mechanical device is a balancer device that is provided in an internal combustion engine and rotates a pair of balancer shafts in opposite directions at a rotational speed twice that of a crankshaft.
An input shaft connected to the crankshaft via a winding-type first transmission mechanism;
A first balancer shaft coupled to the input shaft via a second transmission mechanism comprising a pair of gears meshing with each other;
A second balancer shaft connected to the first balancer shaft via a third transmission mechanism comprising a pair of gears having the same number of teeth meshing with each other;
The input shaft and the second balancer shaft are arranged close to each other on the same axis, and ends of the shafts on the sides close to each other are pivotally supported by the single bearing. The mechanical device according to claim 1 or 2. The mechanical device is a balancer device that is provided in an internal combustion engine and rotates a pair of balancer shafts in opposite directions at a rotational speed twice that of a crankshaft.
An input shaft connected to the crankshaft via a winding-type first transmission mechanism;
An intermediate shaft coupled to the input shaft via a first gear mechanism comprising a pair of gears meshing with each other;
A second balancer shaft connected to the intermediate shaft via a second gear mechanism comprising a pair of gears meshing with each other;
A first balancer shaft connected to the second balancer shaft via a third transmission mechanism comprising a pair of gears having the same number of teeth meshing with each other;
The input shaft and the second balancer shaft are arranged close to each other on the same axis, and the ends of the shafts on the sides close to each other are pivotally supported by the single bearing,
The intermediate shaft and the first balancer shaft are arranged close to each other on the same axis, and end portions of the shafts on the side close to each other are pivotally supported by the single bearing. The mechanical device according to claim 1 or 2.

Images