CN111108276A

CN111108276A - Balancing device with oil pump and balancing device

Info

Publication number: CN111108276A
Application number: CN201880061261.0A
Authority: CN
Inventors: 鬼形良治
Original assignee: Hitachi Automotive Systems Ltd
Current assignee: Hitachi Astemo Ltd
Priority date: 2017-09-20
Filing date: 2018-09-03
Publication date: 2020-05-05
Also published as: JPWO2019058939A1; WO2019058939A1

Abstract

A balancing device (11) with an oil pump (1) comprises: a pump housing side wall portion (10) that closes off the recess (8a) of the pump housing (8); a non-pump casing side wall (15) facing the pump casing side wall (10); and a balance shaft (12) which is axially supported by a first bearing part (16) and a plane bearing (18) which are arranged on the wall parts (10, 15). The balance shaft (12) has an oil passage (27) formed therein and extending from the first opening (28) to the second opening (29) so as to expand in diameter in a conical shape. The first opening (28) opens into an annular groove (30) formed in the first bearing section (16). The annular groove (30) communicates with the recess (8a) via an oil groove (32) formed in the first bearing (16). The second opening (29) opens into an annular bearing groove (31) formed in the inner peripheral surface of the flat bearing (18).

Description

Balancing device with oil pump and balancing device

Technical Field

The present invention relates to a balancer device with an oil pump and a balancer device.

Background

As a balancer device with an oil pump, for example, a balancer device with an oil pump described in patent document 1 below is known.

In the balancer device with an oil pump of patent document 1, oil guided from the oil pump to the main oil passage of the internal combustion engine is supplied to each bearing portion of the balancer shaft rotatably supported by the balancer device.

Prior art documents

Patent document

Patent document 1: japanese patent laid-open publication No. 2011-64332

Disclosure of Invention

Problems to be solved by the invention

In the above-described balancing device with an oil pump, it is necessary to secure the capacity of the oil pump to the remaining supply amount to the bearing portion. Therefore, the oil pump is increased in size and the damping is increased, and as a result, the efficiency of the oil pump may be reduced.

The present invention has been made in view of the conventional circumstances, and an object thereof is to provide a balancer device with an oil pump and a balancer device that improve the efficiency of the oil pump.

Means for solving the problems

According to the present invention, the balancer shaft includes the oil passage extending in the inner axial direction of the balancer shaft, and the first opening and the second opening communicating with the oil passage. The first opening communicates with the oil groove of the side wall of the pump housing, while the second opening opens toward the second bearing.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, the efficiency of the oil pump is improved.

Drawings

Fig. 1 is a vertical cross-sectional view of a balancer device with an oil pump and the like of the first embodiment.

Fig. 2 is an enlarged sectional view of the balancing apparatus with the oil pump of the first embodiment.

FIG. 3 is an enlarged sectional view of a side wall portion of the pump housing of FIG. 2.

FIG. 4 is an enlarged sectional view of the side wall of the non-pump casing shown in FIG. 2.

Fig. 5 is a front view of the oil pump of the first embodiment in a state of being removed from a pump housing side wall portion.

Fig. 6 is a front view of the pump housing side wall portion of the first embodiment in a state of being removed from the pump housing.

Fig. 7 is an oil pressure circuit diagram of the oil pump of the first embodiment.

Fig. 8 is a sectional view of the balancing apparatus with oil pump of the second embodiment.

Fig. 9 is a sectional view of the balancing apparatus with oil pump of the third embodiment.

Fig. 10 is a sectional view of the balancing apparatus with oil pump of the fourth embodiment.

Fig. 11 is a sectional view of the balancer device with oil pump of the fifth embodiment.

Fig. 12 is a sectional view of the balancing apparatus with oil pump of the sixth embodiment.

Fig. 13 is a sectional view of the balancing apparatus with oil pump of the seventh embodiment.

Detailed Description

Hereinafter, an embodiment of the balancer device with an oil pump according to the present invention will be described with reference to the drawings.

[ first embodiment ]

(construction of Balancing device with oil Pump)

Fig. 1 is a longitudinal sectional view of a balancer device with an oil pump according to a first embodiment, and fig. 2 is an enlarged sectional view of the balancer device with an oil pump according to the first embodiment.

The oil pump 1 is driven by torque transmitted from the crankshaft 2, and supplies oil in an oil pan 3 of an unillustrated internal combustion engine, which is connected in series with 3 cylinders arranged in a posture in which the crankshaft 2 extends horizontally, to a main oil passage 4 (see fig. 7). The oil pump 1 is disposed in the oil pan 3, and is fixed to the lower surface of a cylinder 5 or a ladder (ラダーフレーム)6 of the internal combustion engine by a plurality of fixing members, for example, bolts 7, in a suspended state. The oil pump 1 is configured such that a pump element 63 is housed in a recess 8a of a pump housing 8 formed of metal, for example, aluminum alloy, and an opening surface of the recess 8a is closed by a pump housing side wall 10 of a balance housing 9 described later. The oil pump 1 is also mounted in a balancing device 11 arranged in the oil pan 3.

The balancing device 11 reduces secondary vibration of the internal combustion engine due to the reciprocating motion of the pistons of the internal combustion engine of the series 3 cylinders. The balancer device 11 includes: a balance housing 9; a balance shaft 12 rotatably supported by the balance case 9; balance

weights

13 and 23, which are rotating members provided at both ends of the balance shaft 12.

The balance case 9 has: a plate-shaped pump housing side wall portion 10 formed of a metal, for example, an aluminum alloy, and functioning as a lid member for closing the recess portion 8a of the pump housing 8; a plate-shaped non-pump casing side wall portion 15 facing the pump casing side wall portion 10.

The pump casing side wall 10 is formed with an annular first bearing portion 16 which is an inner peripheral surface of a through hole penetrating in the rotational axis direction of the balancer shaft 12 (the direction along the rotational axis M). On the other hand, an annular second bearing portion 17, which is an inner peripheral surface of a through hole penetrating in the rotation axis direction of the balance shaft 12, is formed in the non-pump casing side wall portion 15, and a metal flat bearing 18 formed in an annular shape is provided in the second bearing portion 17. The balance shaft 12 is rotatably supported by a flat bearing 18 provided in the first bearing portion 16 and the second bearing portion 17. In a state where the balance shaft 12 is rotatably supported, the balance shaft 12 protrudes outward in the rotation axis direction from the pump casing 8 and the non-pump casing side wall portion 15, respectively.

The end portion 12a of the balance shaft 12 on the pump housing 8 side is fitted into the circular recess 13a provided in the disk-shaped balance weight 13 made of metal, and the balance weight 13 is attached to the end portion 12a of the balance shaft 12 by a fixing member, for example, a bolt 19. That is, the balance weight 13 is mounted to the end portion 12a of the balance shaft 12 by the axial force of the bolt 19 by screwing the bolt 19 into the mounting hole 21 provided in the end portion 12a of the balance shaft 12 through the insertion hole 20 in the bottom wall of the circular recess 13 a.

An unillustrated tooth portion formed on the outer peripheral portion of the balance weight 13 meshes with an unillustrated tooth portion fixed to the outer peripheral portion of the crank gear 64 of the crank shaft 2. Therefore, the torque from the crankshaft 2 is transmitted to the balance shaft 12 via the crank gear 64 and the balance weight 13, and the pump element 63 of the oil pump 1 rotates integrally with the balance shaft 12 and is driven via the balance shaft 12.

On the other hand, a circular recess 23a provided in a disk-shaped balance weight 23 made of metal is fitted into an end portion 12b of the balance shaft 12 on the non-pump casing side wall portion 15 side, and the balance weight 23 is attached to the end portion 12b of the balance shaft 12 by a sealing member, for example, a bolt 24. That is, the bolt 24 is screwed into the shaft opening 26 provided in the end portion 12b of the balance shaft 12 through the insertion hole 25 in the bottom wall of the circular recess 23a, and the balance weight 23 is attached to the end portion 12b of the balance shaft 12 by the axial force of the bolt 24. In other words, the bolt 24 is inserted into the pump housing 8 side from the outer end portion 17a of the second bearing portion 17 in the direction of the rotation axis M, the shaft opening portion 26 communicating with the oil passage 27 is closed by screwing, and the balance weight 23 is attached to the end portion 12b of the balance shaft 12. As shown in fig. 1 and 2, a circular recess 23a is formed in the vicinity of the radially outer side of the balance weight 23. Therefore, the balance weight 23 is attached to the end portion 12b of the balance shaft 12 so as to be radially eccentric with respect to the rotation axis M of the balance shaft 12.

The balancer shaft 12 includes an oil passage 27 formed inside and extending in the direction of the rotation axis of the balancer shaft 12 at the

outer end surfaces

10a and 15a of the pump housing side wall portion 10 and the non-pump housing side wall portion 15. The oil passage 27 extends in the rotation axis direction so as to be expanded in a conical shape from the first bearing portion 16 toward the second bearing portion 17. That is, the oil passage 27 extends in the rotation axis direction so as to be expanded in a conical shape from a first opening 28 side, which will be described later, facing the first bearing portion 16 toward a second opening 29 side, which will be described later, facing the flat bearing 18 of the second bearing portion 17.

In the present embodiment, a part of the lower hole of the shaft opening portion 26, which is the mounting hole for forming the bolt 24, is left between the oil passage 27 and the bolt 24, but some of the lower hole may remain due to the processing of the shaft opening portion 26, and the lower hole is also included in the oil passage 27.

The pump casing side wall portion 10 has a protruding portion 34 protruding in a cylindrical shape from the end surface 10b on the counterweight 23 side toward the non-pump casing side wall portion 15 side, and a pump casing side seal portion 35 having a two-step portion is formed on the tip end surface of the protruding portion 34 in the rotation axis direction. On the other hand, a balance shaft side seal 36 having a two-step portion forming a labyrinth structure between two-step portions of the pump housing side seal 35 is formed on the outer peripheral side of the balance shaft 12.

Fig. 3 is an enlarged sectional view of the pump housing side wall 10 of fig. 2.

The oil passage 27 communicates with a first opening 28, which is a hole extending in the radial direction of the balancer shaft 12, on the pump housing side wall 10 side. As shown in fig. 3, the first opening 28 opens into an annular groove 30 formed in the first bearing portion 16 in the circumferential direction. The annular groove portion 30 communicates with an oil groove 32 formed in the first bearing portion 16, and the oil groove 32 is formed along the axial direction of the first bearing portion 16 and communicates with a pump chamber 33, described later, of the pump element 63 in the recess 8 a.

Fig. 4 is an enlarged sectional view of the non-pump casing side wall 15 of fig. 2.

The oil passage 27 communicates with a second opening 29, which is a hole extending in the radial direction of the balancer shaft 12, on the non-pump casing side wall portion 15 side. The second opening 29 is provided at a position shifted by 180 ° from the first opening 28 in the circumferential direction of the balance shaft 12. As shown in fig. 4, the second opening 29 opens to an annular bearing groove portion 31 formed in the circumferential direction on the inner circumferential surface of the flat bearing 18.

(construction of oil Pump)

Fig. 5 is a front view of the oil pump 1 of the first embodiment in a state where the oil pump 1 is removed from the pump housing side wall portion 10. Fig. 6 is a front view of the pump housing side wall portion 10 of the first embodiment in a state of being removed from the pump housing 8.

The pump housing 8 is formed in a thick plate shape, and a circular recess 8a, which is a rotor housing portion, is formed at an end portion on the pump housing side wall portion 10 (see fig. 1 and 2). An outer rotor 37 is rotatably housed in the recess 8a, and an inner rotor 38 is rotatably disposed on the inner peripheral side of the outer rotor 37. The outer rotor 37, the inner rotor 38, and the balance shaft 12 constitute a pump element 63.

The outer rotor 37 has nine inner teeth 37a formed of trochoid curves on the inner periphery. On the other hand, the inner rotor 38 has eight outer teeth 38a formed by a trochoid curve that mesh with the inner teeth 37a of the outer rotor 37 formed on the outer periphery thereof. The balance shaft 12 is inserted into and coupled to a through hole 39 provided at a central position of the inner rotor 38. The outer rotor 37 is disposed radially eccentrically with respect to the rotation axis M of the balance shaft 12, the inner teeth 37a mesh with the

outer teeth

38a, 38a of the inner rotor 38 at the most eccentric position, and the remaining portion is in sliding contact with the outer teeth 38a at a plurality of positions in the circumferential direction.

A plurality of space portions formed between contact portions of the outer rotor 37 and the inner rotor 38 serve as the pump chambers 33, and the volumes of the pump chambers 33 are continuously increased and decreased with rotation of the inner rotor 38.

As shown in fig. 6, the inner bottom surface of the pump housing side wall portion 10 constitutes the suction port 40 (left side in fig. 6) and the discharge port 41 (right side in fig. 6) on both sides of the bearing hole 65.

Each pump chamber 33 communicates with a suction port 44 provided in the pump housing side wall portion 10 via the suction port 40. The suction port 44 communicates with the oil pan 3 (not shown) via an oil filter 45 (see fig. 7).

Each pump chamber 33 communicates with a discharge port 46 provided in the pump housing side wall portion 10 via the discharge port 41. The discharge port 46 is connected to the main oil passage 4 (see fig. 7).

Further, a substantially annular shaft holding portion 47 is formed in the pump housing side wall portion 10, and a bearing hole 65 for rotatably supporting the balancer shaft 12 is provided on the inner peripheral side of the shaft holding portion 47.

An oil groove 32 extending in the axial direction of the shaft holding portion 47 and communicating with the bearing hole 65 is formed in the inner end portion of the shaft holding portion 47 of the pump housing side wall portion 10. The oil groove 32 communicates with a groove portion 48 extending in the radial direction of the shaft holding portion 47, and the groove portion 48 communicates with the discharge port 41. The oil groove 32 supplies oil for lubricating the balance shaft 12 in the bearing hole 65. The oil groove 32 helps to lubricate the first bearing portion 16 and the flat bearing 18 by guiding the oil leaking through the oil groove 32 to the second opening 29 through the annular groove portion 30, the first opening 28, and the oil passage 27.

The pump housing 8 has substantially circular projections 8b at six positions on the outer periphery thereof, and each projection 8b is formed with an insertion hole 8c into which a fixing member, not shown, such as a bolt, is inserted. On the other hand, the pump housing side wall portion 10 having an outer shape corresponding to the pump housing 8 has the same substantially circular protruding portion 10c at six positions corresponding to the protruding portions 8b on the outer periphery of the pump housing 8, and is formed with an insertion hole 10d into which a fixing member such as a bolt is inserted. The pump housing side wall portion 10 is attached to the pump housing 8 by screwing bolts into the insertion holes 8c through the insertion holes 10 d.

Fig. 7 is a hydraulic circuit diagram of the oil pump 1 of the first embodiment.

The oil pump 1 is driven by a rotational driving force input from the crankshaft 2 to the balance shaft 12 via the crank gear 64 and the balance weight 13, and sucks oil stored in the oil pan 3 from the suction passage 50 via the oil strainer 45. The oil sucked from the suction passage 50 is pressurized by the pump element 63 and flows into the oil strainer 52 through the discharge passage 51 serving as a discharge unit. In the oil filter 52, impurities such as sludge in the oil are removed. The oil from the oil strainer 52 is guided to the main oil passage 4 formed inside the internal combustion engine, and is supplied to sliding portions such as a valve gear of the internal combustion engine, and various devices. The excess oil after lubrication of the sliding portions and the like is returned to the oil pan 3.

The discharge passage 51 is connected to a pressure control valve 54 via a branch passage 53 at a position between the oil pump 1 and the oil strainer 52, and the pressure control valve 54 releases excess pressure discharged from the oil pump 1. The pressure control valve 54 includes a ball valve body 54a for opening and closing an opening end of the branch passage 53, a coil spring 54b as an urging member for urging the ball valve body 54a in a closing direction, and an annular spring seat not shown.

(description of operation of the balancer with oil Pump)

In this oil-pump-equipped balancer, the rotational driving force of the crankshaft 2 is transmitted to the balance shaft 12 via the crank gear 64 and the balance weight 13 (see fig. 1). Thereby, the oil pump 1 is driven by rotating the pump element 63 of the oil pump 1 integrally with the balance shaft 12 (see fig. 1). The oil introduced from the suction port 44 of the pump housing side wall portion 10 flows into the pump chamber 33 of the pump element 63 through the suction port 40 and is pressurized (see fig. 5 and 6). The pressurized oil is supplied to the main oil passage 4 through the discharge port 41 and the discharge port 46 (see fig. 5 and 6).

Further, a part of the oil in the pump chamber 33 leaks to the balancer device 11 side through the groove portion 48 of the pump housing side wall portion 10 and the oil groove 32 that lubricate the balancer shaft 12, and flows into the annular groove portion 30 (see fig. 1, 2, and 6). The oil in the annular groove portion 30 flows into a gap 66 (see fig. 3) between the first bearing portion 16 and the balance shaft 12. Thereby, the first bearing portion 16 is lubricated with oil. The oil in the annular groove portion 30 is guided into the oil passage 27 through the first opening portion 28, and flows toward the non-pump casing side wall portion 15 along the conical inclination of the oil passage 27. Then, the oil flows into the annular bearing groove portion 31 through the second opening portion 29. The oil in the bearing groove 31 flows into the gap 67 between the inner peripheral surface of the flat bearing 18 and the balance shaft 12. At this time, a part of the impurities in the oil flowing through the gap 67 is collected by being buried in the inner circumferential surface of the flat bearing 18, and the remaining impurities are discharged through the gap 67 together with the oil and fall into the oil pan 3.

Further, the

balance weights

13 and 23 rotate integrally with the balance shaft 12 by the torque from the crankshaft 2, thereby reducing secondary vibration of the internal combustion engine caused by the reciprocating motion of the pistons of the internal combustion engine, not shown, having 3 cylinders connected in series.

[ Effect of the first embodiment ]

In the balancer device with an oil pump of patent document 1, oil guided from the oil pump to the main oil passage of the internal combustion engine is supplied to each bearing portion of the balancer shaft rotatably supported by the balancer device. Therefore, in the balancer device with the oil pump, it is necessary to secure an oil margin of an amount to be supplied to the balancer device in addition to the oil to be supplied to the main oil passage. This increases the size of the oil pump, which increases the damping, and thus may reduce the efficiency of the oil pump.

However, in the first embodiment, the oil leaking from the oil pump 1 flows through the groove portion 48 and the oil groove 32 of the pump housing side wall portion 10 and the annular groove portion 30 of the first bearing portion 16 to the gap 66 between the inner peripheral surface of the first bearing portion 16 and the outer peripheral surface of the balancer shaft 12. The oil in the annular groove portion 30 flows through the first opening 28, the oil passage 27, and the second opening 29 into the gap 67 between the inner circumferential surface of the flat bearing 18 and the outer circumferential surface of the balance shaft 12.

As described above, in the first embodiment, the first bearing portion 16 and the flat bearing 18 are lubricated by the oil leaked from the oil pump 1 without securing the extra oil for supplying to the balancer device 11. Therefore, the increase in the size of the oil pump 1 accompanying the lubrication of the first bearing portion 16 and the flat bearing 18 is suppressed, and the increase in the damping accompanying this is suppressed. This can improve the efficiency of the oil pump 1.

In the first embodiment, the oil passage 27 has a diameter that increases conically from the first opening 28 toward the second opening 29.

Therefore, the oil easily flows from the first opening 28 to the second opening 29 along the inclination of the oil passage 27. Thus, the flat bearing 18 can be effectively lubricated.

In the first embodiment, the first bearing portion 16 has the annular groove portion 30 that communicates the oil groove 32 with the first opening 28 on the inner peripheral surface.

Therefore, in the annular groove portion 30 surrounding the balance shaft 12, the oil flowing from the oil groove 32 and accumulated in the annular groove portion 30 can be supplied from an arbitrary position in the circumferential direction with respect to the first opening portion 28 that moves in the circumferential direction of the balance shaft 12 when the balance shaft 12 rotates. Accordingly, when the balance shaft 12 rotates during operation of the oil pump 1, the oil in the annular groove portion 30 is constantly supplied to the first opening portion 28, and the supply of the oil to the second opening portion 29 through the oil passage 27 is stabilized. Thus, the flat bearing 18 can be effectively lubricated.

In the first embodiment, the pump casing side wall portion 10 includes the pump casing side seal portion 35 having the step portion, and the balance shaft 12 includes the balance shaft side seal portion 36 having the step portion forming the labyrinth structure between the step portions of the pump casing side seal portion 35.

This suppresses oil leakage from the gap 66 between the balance shaft 12 and the pump housing side wall portion 10. Therefore, more oil is accumulated in the annular groove portion 30, and the oil is easily supplied to the second opening 29 through the first opening 28 and the oil passage 27. This enables the flat bearing 18 to be effectively lubricated.

Further, in the first embodiment, the flat bearing 18 has an annular bearing groove portion 31 communicating with the second opening portion 29 on its inner peripheral surface.

Therefore, the oil accumulated in the bearing groove portion 31 flows out in a large amount through the gap 67 between the inner peripheral surface of the flat bearing 18 and the outer peripheral surface of the balance shaft 12, and therefore a large amount of impurities can be discharged to the oil pan 3 through the gap 67. Thus, the foreign substances in the balancing device 11 can be discharged without increasing the capacity of the oil pump 1.

In addition, in the first embodiment, the flat bearing 18 is mounted on the second bearing portion 17.

Therefore, when the oil flows into the gap 67 through the oil passage 27 and the second opening 29, the impurities in the oil are collected by being buried in the inner circumferential surface of the flat bearing 18. Therefore, the impurities can be efficiently recovered by the constituent elements of the balancing device 11 without using a filter, and the amount of the impurities returned to the oil pan 3 can be reduced.

In the first embodiment, the balance shaft 12 has the shaft opening 26 that communicates with the oil passage 27 and opens to the end portion 12b of the non-pump casing side wall portion 15, and the shaft opening 26 is closed by the bolt 24.

Therefore, the shaft opening 26 can be efficiently closed by the bolt 24 functioning as both the fixing member and the sealing member without using a rubber sealing member. Therefore, the number of parts of the balancing device 11 is reduced, which leads to a reduction in the cost associated with the manufacture of the balancing device 11. Further, the number of components is reduced, thereby improving the assembling property of the balancer device 11.

In addition, in the first embodiment, the bolt 24 is inserted to a position closer to the pump housing 8 side than the outer end portion 17a of the second bearing portion 17 in the direction of the rotation axis M.

Thereby, the entry position of the oil in the oil passage 27 to the second opening portion 29 is restricted to the vicinity of the second opening portion 29. Therefore, the oil from the oil passage 27 easily flows into the gap 67 between the flat bearing 18 and the balance shaft 12 through the second opening 29. This enables the flat bearing 18 to be effectively lubricated.

Further, in the first embodiment, the balance weight 23 is attached to the end portion 12b of the balance shaft 12 on the non-pump casing side wall portion 15 side with the bolt 24.

It is assumed that in the case of fixing the balance weight 23 on the balance shaft 12 by press-fitting, a special device for press-fitting is required.

However, in the first embodiment, since the mounting is performed by the bolt 24, the above-described special equipment is not required. Thus, the assembly of the balancing device 11 becomes easy.

In the first embodiment, the mounting hole 21 to which the bolt 19 is attached is formed in the end portion 12a of the balance shaft 12 on the pump casing side wall portion 10 side, and the balance weight 13 is attached to the end portion 12a of the pump casing side wall portion 10 by the bolt 19.

Therefore, as with the non-pump housing side wall portion 15 side, no special equipment is required for mounting the balance weight 13, and therefore assembly of the balancing apparatus 11 becomes easy.

[ second embodiment ]

In the second embodiment, the inner peripheral surface of the oil passage 27 has a spiral recess 55 that is spirally continuous from the first opening portion 28 to the second opening portion 29. In the present embodiment, the spiral recess 55 is indicated by dots in fig. 8, and indicates a groove that is recessed on the outer peripheral side of the balance shaft 12 with respect to the inner peripheral surface of the oil passage 27 and is continuous in the circumferential direction of the balance shaft 12.

The spiral recess 55 is configured such that, in a cross section passing through the rotation axis M of the balance shaft 12, a minor angle α of angles between the rotation axis M of the balance shaft 12 and the side wall 55a of the spiral recess 55 is an obtuse angle.

[ Effect of the second embodiment ]

In the second embodiment, the inner peripheral surface of the oil passage 27 has a spiral recess 55 that is spirally continuous from the first opening portion 28 to the second opening portion 29.

Thus, the oil efficiently flows from the first opening 28 to the second opening 29 while being guided to the spiral recess 55 on the inner peripheral portion of the balancer shaft 12 by the centrifugal force generated by the rotation of the balancer shaft 12. Therefore, the flat bearing 18 can be lubricated more efficiently than a case where only the taper having a diameter increased in a conical shape is used.

In the second embodiment, in the cross section of the spiral recess 55 passing through the rotation axis M of the balance shaft 12, the minor angle α of the angles between the rotation axis M of the balance shaft 12 and the side wall 55a of the spiral recess 55 is an obtuse angle.

Thus, as shown in fig. 8, the passage in which the spiral recess 55 inclines downward from the first opening 28 to the second opening 29 is repeated along the rotation axis direction, and therefore the oil does not flow backward toward the first opening 28, but flows easily toward the second opening 29.

[ third embodiment ]

In the third embodiment, the balancer shaft 12 has the oil passage 56 formed inside the balancer shaft 12 without forming the oil passage 27 having a diameter that increases in a conical shape, and extending in a cylindrical shape with a constant inner diameter in the axial direction between the first opening portion 28 and the second opening portion 29, and the inner peripheral surface of the oil passage 56 has the spiral recessed portion 55 that continues in a spiral shape from the first opening portion 28 to the second opening portion 29, and the spiral recessed portion 55 is configured such that the minor angle α of the angles between the rotation axis M of the balancer shaft 12 and the side wall 55a of the spiral recessed portion 55 is an obtuse angle, as with the spiral recessed portion 55 of the second embodiment.

The balance shaft 12 includes an oil reservoir 57 that communicates the oil passage 56 with the second opening 29, and the oil reservoir 57 is formed by expanding the oil passage 56 in a stepped shape. The oil passage 56 and the oil reservoir 57 are connected by an annular inclined portion 58 that gradually increases the inner diameter of the oil passage 56.

[ Effect of the third embodiment ]

In the third embodiment, the balancer shaft 12 has the oil reservoir 57 that communicates the oil passage 56 with the second opening portion 29, and the oil reservoir 57 is formed by expanding the oil passage 56 in a stepwise manner.

Thus, at the time of engine start, the oil that has been stored in the oil reservoir 57 passes through the second opening 29 and easily flows into the gap 67 between the inner peripheral surface of the flat bearing 18 and the outer peripheral surface of the balancer shaft 12. Thus, lubrication of the flat bearing 18 at the start of the internal combustion engine is improved.

In addition, in the third embodiment, the oil passage 56 and the oil reservoir 57 are connected by the inclined portion 58 in which the inner diameter of the oil passage 56 gradually increases.

This facilitates the oil flowing through the oil passage 56 to flow into the oil reservoir 57 along the inclined portion 58.

[ fourth embodiment ]

In the fourth embodiment, the oil communication hole 59 is formed in the non-pump casing side wall portion 15 so as to penetrate the non-pump casing side wall portion 15 and the flat bearing 18 from the upper surface 15b thereof and open to the bearing groove portion 31. Oil dropping from the cylinder 5 side, for example, oil scraped off by a piston ring or oil discharged from a fuel discharge portion is introduced into the oil communication hole 59. The oil introduced from the oil communication hole 59 flows through the bearing groove portion 31 to the gap 67 between the inner circumferential surface of the flat bearing 18 and the outer circumferential surface of the balance shaft 12.

[ Effect of the fourth embodiment ]

In the fourth embodiment, an oil communication hole 59 for introducing oil dripping from the cylinder 5 side is formed in the non-pump casing side wall portion 15 and communicates with the second opening portion 29.

Therefore, the inner peripheral surfaces of the first bearing portion 16 and the flat bearing 18 are lubricated by the oil leaked from the oil pump 1, and the inner peripheral surface of the flat bearing 18 is lubricated by the oil flowing through the oil communication hole 59. This further improves the lubrication of the flat bearing 18.

[ fifth embodiment ]

In the fifth embodiment, the balancer shaft 12 has the oil passage 27 and the spiral recess 55 similar to those of the second embodiment, and the oil communication hole 60 that penetrates the pump casing side wall portion 10 from the upper surface 10c thereof to open to the annular groove portion 30 is formed in the pump casing side wall portion 10, not in the non-pump casing side wall portion 15. In the oil communication hole 60, oil dropping from the cylinder 5 side is introduced, as in the fourth embodiment. The oil introduced from the oil communication hole 60 flows through the annular groove portion 30 into the gap 66 between the inner peripheral surface of the first bearing portion 16 and the outer peripheral surface of the balancer shaft 12.

[ Effect of the fifth embodiment ]

In the fifth embodiment, an oil communication hole 60 for introducing oil dripping from the cylinder 5 side is formed in the pump housing side wall portion 10 and communicates with the first opening portion 28.

Therefore, the oil flows into the bearing groove 31 through the oil communication hole 60, the annular groove 30, the first opening 28, the oil passage 27, and the second opening 29. Therefore, even if oil leaking from the oil pump 1 is not used, both the first bearing portion 16 and the flat bearing 18 can be lubricated by the oil from the oil communication hole 60. In other words, even if the balancer device does not include the oil pump 1, the first bearing portion 16 and the flat bearing 18 can be lubricated.

[ sixth embodiment ]

In the sixth embodiment, the blocking member 61 is pressed into the shaft opening 26 provided in the end portion 12b of the non-pump casing side wall portion 15 of the balancer shaft 12 without using the bolt 24 of the first embodiment.

In the sixth embodiment, the balance weight 23 of the first embodiment is not used, and the balance weight 62 is attached to the outer peripheral portion of the balance shaft 12 at a position close to the second opening portion 29 between the first opening portion 28 and the second opening portion 29.

[ Effect of the sixth embodiment ]

In the sixth embodiment, a balance weight 62 is fixed to the outer peripheral portion of the balance shaft 12 between the first opening portion 28 and the second opening portion 29.

Accordingly, the balance weight 62 can be stably supported by the pump casing side wall portion 10 and the non-pump casing side wall portion 15 in a double-supported manner.

[ seventh embodiment ]

In the seventh embodiment, the balancer shaft 12 has the cylindrical oil passage 56 having a constant inner diameter in the axial direction, and in the seventh embodiment, the balancer 11 with the oil pump 1 is attached to the internal combustion engine, not shown, in a state where the crank gear 64 side is inclined upward at an angle β with respect to the horizontal line H, in other words, the balancer 11 is attached to the internal combustion engine such that the pump housing side wall portion 10 side is disposed on the upper side in the gravitational direction than the non-pump housing side wall portion 15 side.

[ Effect of the seventh embodiment ]

In the seventh embodiment, the balancer device 11 is attached to the internal combustion engine such that the pump housing side wall portion 10 is disposed on the upper side in the direction of gravity than the non-pump housing side wall portion 15.

Therefore, since the oil passage 56 in the balance shaft 12 is also inclined downward from the first opening 28 across the second opening 29, the oil introduced into the oil passage 56 from the first opening 28 flows along the inclined oil passage 56 toward the second opening 29 due to gravity. By using the cylindrical oil passage 56 which is easier to machine than the oil passage 27 having a diameter increased in a conical shape, both the first bearing portion 16 and the flat bearing 18 can be lubricated more efficiently at a lower cost.

As the balancing device with an oil pump according to the embodiment described above, for example, the following method is considered.

As one aspect of the balancer device with an oil pump, there is provided: a pump housing that houses a pump element that performs suction and discharge of oil by rotational driving in the recess; a balance casing having a pump casing side wall portion that closes the recess of the pump casing and has an oil groove that communicates with the pump chamber of the pump element, and a non-pump casing side wall portion that faces the pump casing side wall portion; a balance shaft rotatably supported by a first bearing portion formed in the pump housing side wall portion and a second bearing portion formed in the non-pump housing side wall portion and extending through the pump housing, the balance shaft including an oil passage formed in the balance shaft and extending in a rotational axis direction of the balance shaft, a first opening communicating the oil passage with the oil groove, and a second opening communicating with the oil passage and opening to the second bearing portion, the balance shaft rotating integrally with the pump element; the rotating component is arranged on the balance shaft.

In a preferred aspect of the balancing apparatus with the oil pump, the oil passage is conically expanded from the first opening portion toward the second opening portion.

In another preferred aspect of any one of the aspects of the balancer device with oil pump, an inner peripheral surface of the oil passage has a spiral recess portion that is continuous in a spiral shape from the first opening portion to the second opening portion.

In another preferred aspect of any one of the aspects of the balancer device with the oil pump, a minor angle of an angle defined by the rotation axis of the balancer shaft and a side wall of the spiral recess in a cross section passing through the rotation axis of the balancer shaft is an obtuse angle.

In another preferred aspect, in any one of the aspects of the balancer device with oil pump, the first bearing portion has an annular groove portion on an inner peripheral surface thereof, the annular groove portion communicating the oil groove and the first opening portion.

In another preferred aspect of any one of the aspects of the balancing device with the oil pump, the pump casing side wall portion includes a pump casing side seal portion having a step portion, the balancing shaft includes a balancing shaft side seal portion having a step portion, and the step portion forms a labyrinth structure between the step portions of the pump casing side seal portion.

In another preferred aspect, in any one of the aspects of the balancer device with oil pump, a flat bearing is attached to the second bearing portion.

In another preferred aspect, in any one of the aspects of the balancer device with oil pump, the flat bearing has an annular bearing groove portion communicating with the second opening portion on an inner peripheral surface thereof.

In another preferred aspect of any one of the aspects of the balancer device with oil pump, the balancer shaft includes an oil reservoir portion that communicates the oil passage and the second opening portion, and the oil reservoir portion is formed by expanding the oil passage in a stepwise manner.

In another preferred aspect, in any one of the aspects of the balancer device with oil pump, the oil passage and the oil reservoir are connected by an inclined portion that gradually increases an inner diameter of the oil passage.

In another preferred aspect of any one of the aspects of the balancer device with oil pump, the balancer shaft has a shaft opening portion that communicates with the oil passage and is open at an end portion of the non-pump-housing-side wall portion, and the shaft opening portion is closed by a seal member.

In another preferred aspect, in any one of the aspects of the balancing device with the oil pump, the seal member is inserted to a position closer to the pump housing side than an outer end portion of the second bearing portion in the direction of the rotation axis.

In another preferred aspect, in any one of the aspects of the balancer device with oil pump, the rotating member is attached to an end portion of the balancer shaft on the side of the non-pump housing side wall by the seal member.

In another preferred aspect, in any one of the aspects of the balancer device with oil pump, the rotating member is fixed to an outer peripheral portion of the balancer shaft between the first opening portion and the second opening portion.

In another preferred aspect of any one of the aspects of the balancer device with the oil pump, a mounting hole for mounting a fixing member is formed in an end portion of the balancer shaft on the side of the pump housing side wall portion, and the rotating member is mounted to the end portion of the pump housing side wall portion by the fixing member.

As another oil pump-equipped balancing device according to the embodiment described above, for example, the following configuration can be considered.

As one aspect, a balancer device with an oil pump includes: a pump housing that houses a pump element that performs suction and discharge of oil by being rotationally driven by an input from a crankshaft in a recess; a balance casing having a pump casing side wall portion that closes the recess of the pump casing and has an oil groove that communicates with the pump chamber of the pump element, and a non-pump casing side wall portion that faces the pump casing side wall portion; a balance shaft rotatably supported by a first bearing portion formed in the pump housing side wall portion and a second bearing portion formed in the non-pump housing side wall portion and extending through the pump housing, the balance shaft including an oil passage formed in the balance shaft and extending in a rotational axis direction of the balance shaft, a first opening communicating the oil passage with the oil groove, and a second opening communicating with the oil passage and opening to the second bearing portion, the balance shaft rotating integrally with the pump element; a rotating member provided on the balance shaft; the balancer device with the oil pump is attached to the internal combustion engine such that the pump housing side wall portion is disposed on the upper side in the direction of gravity than the non-pump housing side wall portion.

As a balancing device according to the embodiment described above, for example, the following method is considered.

As one aspect, the balancing device includes: a balance case provided at a lower portion of the cylinder, having a pair of wall portions facing each other, and having an oil communication hole formed therein for introducing oil dripping from the cylinder side; a balance shaft rotatably supported by a first bearing portion formed in one wall portion and a second bearing portion formed in the other wall portion, the balance shaft having an oil passage formed inside the balance shaft and extending in a rotation axis direction of the balance shaft, a first opening portion communicating with the oil passage, and a second opening portion communicating with the oil passage and opening toward the second bearing portion; the rotating component is arranged on the balance shaft.

In a preferred aspect of the balancing apparatus, the oil communication hole is formed in the one wall portion and communicates with the first opening portion.

In another preferred aspect, in any one of the aspects of the balancer device, the oil communication hole is formed in the other wall portion and communicates with the second opening portion, and the first opening portion communicates with a pump chamber of an oil pump via an oil groove provided in the one wall portion.

Claims

1. A balancing device with an oil pump, comprising:

a pump housing that houses a pump element that performs suction and discharge of oil by rotational driving in the recess;

a balance casing having a pump casing side wall portion that closes the recess of the pump casing and has an oil groove that communicates with the pump chamber of the pump element, and a non-pump casing side wall portion that faces the pump casing side wall portion;

a balance shaft rotatably supported by a first bearing portion formed in the pump housing side wall portion and a second bearing portion formed in the non-pump housing side wall portion and extending through the pump housing, the balance shaft including an oil passage formed in the balance shaft and extending in a rotational axis direction of the balance shaft, a first opening communicating the oil passage with the oil groove, and a second opening communicating with the oil passage and opening to the second bearing portion, the balance shaft rotating integrally with the pump element;

the rotating component is arranged on the balance shaft.

2. The balancer device with oil pump as claimed in claim 1,

the oil passage has a diameter that increases in a conical shape from the first opening toward the second opening.

3. The balancer device with oil pump as claimed in claim 1,

the inner peripheral surface of the oil passage has a spiral recess portion that is spirally continuous from the first opening portion to the second opening portion.

4. The balancer device with an oil pump according to claim 3,

in a cross section passing through the rotation axis of the balance shaft, a minor angle of angles between the rotation axis of the balance shaft and the side wall of the spiral recess is an obtuse angle.

5. The balancer device with oil pump as claimed in claim 1,

the first bearing portion has an annular groove portion on an inner peripheral surface thereof, the annular groove portion communicating the oil groove and the first opening portion.

6. The balancer device with oil pump as claimed in claim 1,

the pump casing side wall portion includes a pump casing side seal portion having a step portion, the balance shaft includes a balance shaft side seal portion having a step portion, and a labyrinth structure is formed between the step portions of the pump casing side seal portion.

7. The balancer device with oil pump as claimed in claim 1,

a flat bearing is mounted on the second bearing portion.

8. The balancer device with an oil pump according to claim 7,

the flat bearing has an annular bearing groove portion on an inner peripheral surface thereof, the annular bearing groove portion communicating with the second opening portion.

9. The balancer device with oil pump as claimed in claim 1,

the balance shaft includes an oil reservoir that communicates the oil passage and the second opening, and the oil reservoir is formed by expanding the oil passage in a stepped shape.

10. The balancer device with oil pump as claimed in claim 9,

the oil passage and the oil reservoir are connected by an inclined portion that gradually increases the inner diameter of the oil passage.

11. The balancer device with oil pump as claimed in claim 1,

the balance shaft has a shaft opening portion that communicates with the oil passage and is open at an end portion of the non-pump casing side wall portion, and the shaft opening portion is closed by a seal member.

12. The balancer device with an oil pump according to claim 11,

the seal member is inserted to a position closer to the pump housing side than an outer end portion in the direction of the rotation axis of the second bearing portion.

13. The balancer device with an oil pump according to claim 12,

the rotating member is attached to an end portion of the balance shaft on the side of the non-pump housing side wall by the seal member.

14. The balancer device with oil pump as claimed in claim 1,

the rotating member is fixed to an outer peripheral portion of the balancer shaft between the first opening and the second opening.

15. The balancer device with oil pump as claimed in claim 1,

a mounting hole for mounting a fixing member is formed in an end portion of the balance shaft on the side of the pump housing side wall portion, and the rotating member is mounted to the end portion of the pump housing side wall portion by the fixing member.

16. A balancing device with an oil pump is characterized by comprising:

a pump housing that houses a pump element that performs suction and discharge of oil by being rotationally driven by an input from a crankshaft in a recess;

a rotating member provided on the balance shaft;

the balancer device with the oil pump is attached to the internal combustion engine such that the pump housing side wall portion is disposed on the upper side in the direction of gravity than the non-pump housing side wall portion.

17. A balance device is characterized by comprising:

a balance case provided at a lower portion of the cylinder, having a pair of wall portions facing each other, and having an oil communication hole formed therein for introducing oil dripping from the cylinder side;

a balance shaft rotatably supported by a first bearing portion formed in one wall portion and a second bearing portion formed in the other wall portion, the balance shaft having an oil passage formed inside the balance shaft and extending in a rotation axis direction of the balance shaft, a first opening portion communicating with the oil passage, and a second opening portion communicating with the oil passage and opening toward the second bearing portion;

the rotating component is arranged on the balance shaft.

18. The balancing apparatus according to claim 17,

the oil communication hole is formed in the one wall portion and communicates with the first opening portion.

19. The balancing apparatus according to claim 17,

the oil communication hole is formed in the other wall portion and communicates with the second opening portion, and the first opening portion communicates with a pump chamber of the oil pump via an oil groove formed in the one wall portion.