阅读说明：本技术 发动机平衡轴模块 (Engine balance shaft module ) 是由 尹子明 关学娣 于 2020-04-20 设计创作，主要内容包括：本公开提供了一种发动机平衡轴模块,属于发动机领域。发动机平衡轴模块包括壳体、安装在壳体内的驱动齿轮、主动平衡轴组件以及从动平衡轴组件,主动平衡轴组件包括主动平衡轴、主动齿轮以及主动平衡块,主动平衡轴可转动地安装在壳体中,驱动齿轮同轴固定套在主动平衡轴上,主动齿轮同轴固定套在主动平衡轴上,主动平衡块固定在主动平衡轴上,从动平衡轴组件包括从动平衡轴、从动齿轮以及从动平衡块,从动平衡轴可转动地安装在壳体中,从动齿轮同轴套设在从动平衡轴的第一端上,从动平衡块固定在从动平衡轴的第二端上；主动平衡块与从动平衡块结构相同且相对布置。本公开通过该发动机平衡轴模块可以将发动机的二阶惯性力平衡抵消。(The utility model provides an engine balance shaft module belongs to the engine field. The engine balance shaft module comprises a shell, a driving gear installed in the shell, a driving balance shaft assembly and a driven balance shaft assembly, wherein the driving balance shaft assembly comprises a driving balance shaft, a driving gear and a driving balance block; the driving balance block and the driven balance block are identical in structure and are oppositely arranged. The second-order inertia force balance of the engine can be offset through the engine balance shaft module.)

1. An engine balance shaft module, which is characterized by comprising a shell (1), a driving gear (2) installed in the shell (1), a driving balance shaft assembly (3) and a driven balance shaft assembly (4),

the driving balance shaft assembly (3) comprises a driving balance shaft (31), a driving gear (32) and a driving balance block (33), the driving balance shaft (31) is rotatably installed in the shell (1), the driving gear (2) is coaxially and fixedly sleeved on a first end of the driving balance shaft (31), the driving gear (2) is used for being meshed with a gear ring (100) on an engine crankshaft, the driving gear (32) is coaxially and fixedly sleeved on the driving balance shaft (31), the driving balance block (33) is fixed on a second end of the driving balance shaft (31), the driving gear (32) is located between the driving balance block (33) and the driving gear (2),

the driven balance shaft assembly (4) comprises a driven balance shaft (41), a driven gear (42) and a driven balance block (43), the driven balance shaft (41) is rotatably installed in the shell (1), the driven gear (42) is coaxially sleeved on a first end of the driven balance shaft (41), the driven gear (42) and the driving gear (32) are meshed together, and the driven balance block (43) is fixed on a second end of the driven balance shaft (41);

the driving balance weight (33) and the driven balance weight (43) are identical in structure and are arranged oppositely.

2. The engine balance shaft module according to claim 1, characterized in that the driving gear (2) comprises a driving main gear (21) and a driving pinion (22), the driving main gear (21) is fixedly sleeved on the first end of the driving balance shaft (31), the driving pinion (22) is coaxially located on the side of the driving main gear (21) away from the driving balance weight (33), and the tooth grooves of the driving main gear (21) are aligned with the tooth grooves of the driving pinion (22).

3. The engine balance shaft module according to claim 2, wherein the driving gear (2) further comprises a driving snap ring (24), a flange (210) is formed on one side of the driving main gear (21) close to the driving pinion (22), a driving snap groove (211) is formed on the peripheral wall of the flange (210), the driving snap ring (24) is mounted on the driving snap groove (211), and the driving snap ring (24) abuts against one side of the driving pinion (22) far away from the driving balance weight (33).

4. The engine balance shaft module according to claim 1, wherein the active balance shaft assembly (3) further comprises two active bearings (34), the two active bearings (34) are respectively interference-fitted on the active balance shaft (31), one of the active bearings (34) is located between the driving gear (32) and the active balance weight (33), and the other one of the active bearings (34) is located on a side of the active balance weight (33) away from the driving gear (32).

5. The engine balance shaft module of claim 4, wherein the active balance shaft assembly (3) further comprises an active balance shaft snap ring (35), the active balance shaft snap ring (35) being sleeved on the second end of the active balance shaft (31), and the active balance shaft snap ring (35) being mounted in the housing (1), the active balance shaft snap ring (35) abutting the active bearing (34) remote from the active gear (32).

6. The engine balance shaft module according to claim 1, wherein the driven balance shaft assembly (4) further comprises two driven bearings (44), the two driven bearings (44) are respectively interference-fitted on the driven balance shaft (41), one of the driven bearings (44) is located between the driven gear (42) and the driven balance weight (43), and the other driven bearing (44) is located on the side of the driven balance weight (43) away from the driven gear (42).

7. The engine balance shaft module of claim 6, wherein the driven balance shaft assembly (4) further comprises a driven balance shaft snap ring (45), the driven balance shaft snap ring (45) is sleeved on the second end of the driven balance shaft (41), the driven balance shaft snap ring (45) is installed in the housing (1), and the driven balance shaft snap ring (45) abuts against the driven bearing (44) far away from the driven gear (42).

8. The engine balance shaft module according to any one of claims 1 to 7, wherein the driving balance weight (33) and the driven balance weight (43) are both fan-shaped structural members, the fan-shaped center of the driving balance weight (33) is concentrically arranged with the axis of the driving balance shaft (31), and the fan-shaped center of the driven balance weight (43) is concentrically arranged with the axis of the driven balance shaft (41).

9. The engine balance shaft module according to any one of claims 1 to 7, characterized in that the housing (1) comprises an upper housing (11) and a lower housing (12) which are detachably connected together, the upper housing (11) and the lower housing (12) form a mounting cavity (10) for mounting the driving balance shaft assembly (3) and the driven balance shaft assembly (4), the driving gear (2) is partially mounted on the lower housing (12), and the driving gear (2) protrudes out of the housing (1).

10. The engine balance shaft module of claim 9, wherein two locating sleeves (13) are provided on the upper housing (11), the two locating sleeves (13) being diagonally arranged on the outer surface of the upper housing (11), the locating sleeves (13) being used for locating and mounting the housing (1) on an engine.

Technical Field

The disclosure belongs to the field of engines, and particularly relates to an engine balance shaft module.

Background

The working principle of the modern vehicle engine is to convert chemical energy of fuel into kinetic energy for output after combustion. In the process, a piston in an engine cylinder converts the reciprocating linear motion of the piston into the rotary motion of a crankshaft through a connecting rod. In the working cycle process of the engine, the movement speed of the piston is very high and uneven, so that great inertia force is generated on the piston, the piston pin and the connecting rod, and vibration is generated outwards through a main bearing seat of a crankshaft of the engine. Comparing the vibration frequency transmitted outwards by the engine with the rotating speed of the engine, and if the vibration frequency is the same as the rotating speed, calling first-order vibration; the frequency is twice of the rotating speed and is called second-order vibration; there are also third order, fourth order vibrations in turn. However, the higher the vibration frequency, the smaller the amplitude, and the less the external influence. For an inline four-cylinder engine, the vibration of more than the second order is negligible. According to the derivation and calculation of the reciprocating inertia force of the inline four-cylinder engine, the resultant force of the first-order reciprocating inertia force of the inline four-cylinder engine is zero. For the second-order vibration, the second-order reciprocating inertia force is related to equivalent inertia mass, crank radius, connecting rod length, rotation angular velocity and the like of a piston, a piston pin and a connecting rod assembly, so that the second-order reciprocating inertia force cannot be balanced in a system and has vibration output to the outside. Therefore, a reciprocating inertia force balancing mechanism is usually required to be added to counteract the second-order reciprocating inertia force of the engine, so as to reduce vibration and noise.

The reciprocating inertia force balance mechanism of the prior in-line four-cylinder engine is known as a double balance shaft mechanism, and the double balance mechanism usually adopts chain transmission and belt transmission.

However, the balance mechanism with belt drive or chain drive occupies a large space in the axial and radial directions, has large noise, needs to be modified greatly by adding an additional drive system, and the like, and cannot be used as a modular system.

Disclosure of Invention

The embodiment of the disclosure provides an engine balance shaft module which can balance second-order reciprocating inertia force generated by an engine. The technical scheme is as follows:

the disclosed embodiments provide an engine balance shaft module comprising a housing, a drive gear mounted within the housing, a driving balance shaft assembly, and a driven balance shaft assembly,

the driving balance shaft assembly comprises a driving balance shaft, a driving gear and a driving balance block, the driving balance shaft is rotatably arranged in the shell, the driving gear is coaxially and fixedly sleeved on the first end of the driving balance shaft, the driving gear is used for being meshed with a gear ring on a crankshaft of an engine, the driving gear is coaxially and fixedly sleeved on the driving balance shaft, the driving balance block is fixed on the second end of the driving balance shaft, the driving gear is positioned between the driving balance block and the driving gear,

the driven balance shaft assembly comprises a driven balance shaft, a driven gear and a driven balance block, the driven balance shaft is rotatably arranged in the shell, the driven gear is coaxially sleeved on the first end of the driven balance shaft, the driven gear and the driving gear are meshed together, and the driven balance block is fixed on the second end of the driven balance shaft;

the driving balance block and the driven balance block are identical in structure and are arranged oppositely.

In one implementation manner of the present disclosure, the driving gear includes a driving main gear and a driving pinion, the driving main gear is fixedly sleeved on the first end of the driving balance shaft, the driving pinion is coaxially located on one side of the driving main gear far away from the driving balance block, and a tooth slot of the driving main gear is aligned with a tooth slot of the driving pinion.

In another implementation manner of the present disclosure, the driving gear further includes a driving snap ring, a flange is formed on one side of the driving main gear, which is close to the driving pinion, a driving clamping groove is formed on a peripheral wall of the flange, the driving snap ring is installed on the driving clamping groove, and the driving snap ring abuts against one side of the driving pinion, which is far away from the driving balance block.

In another implementation manner of the present disclosure, the active balance shaft assembly further includes two active bearings, two of the active bearings are respectively interference-assembled on the active balance shaft, one of the active bearings is located between the active gear and the active balance weight, and the other one of the active bearings is located on one side of the active balance weight away from the active gear.

In another implementation manner of the present disclosure, the active balance shaft assembly further includes an active balance shaft snap ring, the active balance shaft snap ring is sleeved on the second end of the active balance shaft, the active balance shaft snap ring is installed in the housing, and the active balance shaft snap ring abuts against the active bearing far away from the active gear.

In another implementation manner of the present disclosure, the driven balance shaft assembly further includes two driven bearings, two of the driven bearings are respectively interference-fitted on the driven balance shaft, and one of the driven bearings is located between the driven gear and the driven balance weight, and the other one of the driven bearings is located on a side of the driven balance weight away from the driven gear.

In another implementation manner of the present disclosure, the driven balance shaft assembly further includes a driven balance shaft snap ring, the driven balance shaft snap ring is sleeved on the second end of the driven balance shaft, the driven balance shaft snap ring is installed in the housing, and the driven balance shaft snap ring abuts against the driven bearing far away from the driven gear.

In another implementation manner of the present disclosure, the driving balance weight and the driven balance weight are both fan-shaped structural members, a fan-shaped center of circle of the driving balance weight is concentrically arranged with an axis of the driving balance shaft, and a fan-shaped center of circle of the driven balance weight is concentrically arranged with an axis of the driven balance shaft.

In another implementation manner of the present disclosure, the housing includes an upper housing and a lower housing detachably connected together, the upper housing and the lower housing form a mounting cavity for mounting the driving balance shaft assembly and the driven balance shaft assembly, the driving gear is partially mounted on the lower housing, and the driving gear protrudes out of the housing.

In another implementation manner of the present disclosure, two positioning sleeves are disposed on the upper housing, the two positioning sleeves are diagonally disposed on the outer surface of the upper housing, and the positioning sleeves are used for positioning and mounting the housing on an engine.

In another implementation manner of the present disclosure, two positioning sleeves are disposed on the upper housing, the two positioning sleeves are diagonally disposed on the outer surface of the upper housing, and the positioning sleeves are used for positioning and mounting the housing in corresponding holes on the engine.

The technical scheme provided by the embodiment of the disclosure has the following beneficial effects:

when the engine balance shaft module provided by the embodiment is used for offsetting the second-order vibration generated by the engine crankshaft, the engine balance shaft module comprises the driving gear, the driving balance shaft assembly and the driven balance shaft assembly, so that meshing transmission can be carried out between the driving gear and the gear ring on the engine crankshaft, and the driving gear can rotate synchronously along with the engine crankshaft. And because the driving gear is fixedly sleeved on the first end of the driving balance shaft, the driving gear can drive the driving balance shaft to rotate, and meanwhile, the driving gear and the driving balance block rotate together. And because the driven gear and the driving gear are meshed with each other, when the driving gear rotates, the driven gear synchronously rotates in the opposite direction, and the driven balance shaft and the driven balance block synchronously rotate along with the driven gear.

That is, the driven counterbalance and the driving counterbalance rotate in opposite directions. And because the driven balance block and the driving balance block have the same structure and are oppositely arranged, the centrifugal force generated by the driven balance block and the driving balance block when rotating is the same, and the resultant force of the centrifugal force generated by the driving balance shaft and the driven balance shaft when rotating can effectively offset the second-order vibration inertia force generated by the engine by combining the mechanical principle, thereby finally realizing the effective balance of the second-order vibration inertia force of the engine by the engine balance module.

In addition, because the balanced axle module of engine that this embodiment provided all concentrates on installing in the casing for this balanced axle modular structure of engine modularization, and be as drive unit through drive gear, make spatial layout more reasonable, reduced the occupation space of balanced axle module of engine greatly, make balanced axle module of engine more integrate. The engine balance shaft module provided by the embodiment has a simple structure, is easy to install, and can be widely applied to an in-line four-cylinder engine of an automobile.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present disclosure, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

FIG. 1 is a schematic diagram of an overall assembly of an engine balance shaft module provided by an embodiment of the disclosure;

FIG. 2 is a schematic structural diagram of an engine balance shaft module provided by an embodiment of the disclosure;

FIG. 3 is a schematic diagram of a partial structure of an engine balance shaft module provided by an embodiment of the disclosure;

fig. 4 is a schematic diagram of the reciprocating inertia force balance of the engine provided by the embodiment.

The symbols in the drawings represent the following meanings:

1. a housing; 11. an upper housing; 12. a lower housing; 121. positioning pins; 122. an active card slot; 123. a driven card slot; 13. a positioning sleeve; 14. a connecting bolt; 15. fixing the bolt; 10. a mounting cavity;

2. a drive gear; 21. driving a main gear; 210. a flange; 211. a drive card slot; 22. a drive pinion; 221. a circular pin hole; 222. a strip pin hole; 223. a locking pin; 23. a drive ring; 231. a positioning member; 24. a drive collar;

3. a main drive balance shaft assembly; 31. an active balance shaft; 312. a first balanced card slot; 32. a driving gear; 33. an active balance weight; 34. a drive bearing; 35. an active balance shaft snap ring;

4. a driven balance shaft assembly; 41. a driven balance shaft; 411. a second balanced card slot; 42. a driven gear; 43. a driven balance weight; 44. a driven bearing; 45. a driven balance shaft snap ring;

100. a ring gear.

Detailed Description

To make the objects, technical solutions and advantages of the present disclosure more apparent, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

The disclosed embodiment provides an engine balance shaft module, as shown in fig. 1, the engine balance shaft module includes a housing 1, a driving gear 2 installed in the housing 1, a driving balance shaft assembly 3, and a driven balance shaft assembly 4.

Fig. 2 is a schematic structural diagram of an engine balance shaft module according to an embodiment of the present disclosure, and referring to fig. 2, a driving balance shaft assembly 3 includes a driving balance shaft 31, a driving gear 32, and a driving balance weight 33, the driving balance shaft 31 is rotatably installed in a housing 1, the driving gear 2 is coaxially and fixedly sleeved on a first end of the driving balance shaft 31, the driving gear 2 is configured to be engaged with a gear ring 100 on a crankshaft of an engine, the driving gear 32 is coaxially and fixedly sleeved on the driving balance shaft 31, the driving balance weight 33 is fixed on a second end of the driving balance shaft 31, and the driving gear 32 is located between the driving balance weight 33 and the driving gear 2.

The driven balance shaft assembly 4 comprises a driven balance shaft 41, a driven gear 42 and a driven balance weight 43, the driven balance shaft 41 is rotatably installed in the housing 1, the driven gear 42 is coaxially sleeved on a first end of the driven balance shaft 41, the driven gear 42 and the driving gear 32 are meshed with each other, and the driven balance weight 43 is fixed on a second end of the driven balance shaft 41.

The driving balance weight 33 and the driven balance weight 43 are identical in structure and are arranged oppositely.

When the engine balance shaft module provided by the embodiment is used for offsetting the second-order vibration generated by the engine crankshaft, the engine balance shaft module comprises the driving gear 2, the driving balance shaft assembly 3 and the driven balance shaft assembly 4, so that the driving gear 2 can be meshed with the gear ring 100 on the engine crankshaft for transmission, and the driving gear 2 can synchronously rotate along with the engine crankshaft. And because the driving gear 2 is fixedly sleeved on the first end of the driving balance shaft 31, the driving gear 2 can drive the driving balance shaft 31 to rotate, and meanwhile, the driving gear 32 and the driving balance weight 33 rotate together. Since the driven gear 42 and the driving gear 32 are meshed with each other, when the driving gear 32 rotates, the driven gear 42 rotates in the opposite direction synchronously, and the driven balance shaft 41 and the driven balance weight 43 rotate synchronously therewith.

That is, the driven counterbalance 43 rotates in the opposite direction from the driving counterbalance 33. And because the driven balance block 43 and the driving balance block 33 have the same structure and are arranged oppositely, the centrifugal forces generated by the driven balance block and the driving balance block when rotating are the same, and the resultant force of the centrifugal forces generated by the driving balance shaft 31 and the driven balance shaft 41 when rotating can effectively offset the second-order vibration inertia force generated by the engine by combining the mechanical principle, and finally the second-order vibration inertia force existing in the engine can be effectively balanced by the engine balance module.

In addition, because the balanced axle module of engine that this embodiment provided all concentrates on installing in casing 1 for this balanced axle modular structure of engine modularization, and be through drive gear 2 as drive unit, make spatial layout more reasonable, reduced the occupation space of balanced axle module of engine greatly, make balanced axle module of engine more integrate. The engine balance shaft module provided by the embodiment has a simple structure, is easy to install, and can be widely applied to an in-line four-cylinder engine of an automobile.

Illustratively, the drive gear 32 and the driven gear 42 are helical gears.

In the above implementation, the driving gear 32 and the driven gear 42 are helical gears, which helps to reduce noise generated when the two are engaged, and further reduces noise during operation of the balancing module.

In this embodiment, the rotational speed of the engine balance shaft module is twice that of the engine crankshaft, so the ratio of the number of teeth of the ring gear 100 on the crankshaft to the number of teeth of the drive gear 2 in the engine balance shaft module is 2: 1.

For example, the gear ring 100 is provided with helical teeth, and the driving gear 2 is provided with helical teeth corresponding to the helical teeth.

In the above implementation manner, the gear ring 100 and the drive gear 2 are respectively provided with the helical teeth, so that the transmission efficiency between the gear ring 100 and the drive gear 2 can be improved, and the gear ring 100 and the drive gear 2 can synchronously rotate without tooth disengagement.

Illustratively, the mounting cavity 10 is divided into a first half cavity and a second half cavity according to the arrangement positions of the driving balance shaft assembly 3 and the driven balance shaft assembly 4, the first half cavity is used for mounting the driving balance shaft assembly 3, and the second half cavity is used for mounting the driven balance shaft assembly 4. The first half cavity is sequentially provided with limit cavities corresponding to and matching with the driving bearing 34 (the structure will be described in detail later), the driving balance weight 33 and the driving bearing 34 (the structure will be described in detail later), and the second half cavity is sequentially provided with limit cavities corresponding to and matching with the driven bearing 44 (the structure will be described in detail later), the driven balance weight 43 and the driven bearing 44 (the structure will be described in detail later).

With continued reference to fig. 2, optionally, the housing 1 includes an upper housing 11 and a lower housing 12 detachably connected together, the upper housing 11 and the lower housing 12 form a mounting cavity 10 for mounting the driving balance shaft assembly 3 and the driven balance shaft assembly 4, the driving gear 2 is partially mounted on the lower housing 12, and the driving gear 2 protrudes out of the housing 1.

In above-mentioned implementation, set up casing 1 to last casing 11 and lower casing 12, can be through dismantling casing 11 and lower casing 12, install drive gear 2, initiative balance shaft subassembly 3 and driven balance shaft subassembly 4 in casing 12 down, then install casing 11 under on casing 12 again, and then realize the inside at casing 1 that installs that initiative balance shaft subassembly 3 and driven balance shaft subassembly 4 can concentrate, improve the overall structure integrated level of this balance shaft module.

In addition, because the driving gear 2 is partially installed on the lower shell 12, and the driving gear 2 protrudes out of the upper shell 11, the driving gear 2 can be ensured to be meshed with the gear ring 100 on the crankshaft of the engine, and can be limited in the shell 1.

Optionally, two positioning sleeves 13 are arranged on the upper shell 11, the two positioning sleeves 13 are diagonally arranged on the outer surface of the upper shell 11, and the positioning sleeves 13 are used for positioning and mounting the shell 1 on the engine.

In the implementation manner, the positioning sleeve 13 is arranged, and the positioning sleeve 13 is installed in the installation hole reserved on the engine, so that the assembly precision between the shell 1 and the engine can be ensured, and the installation precision between the shell 1 and the engine is finally improved.

Illustratively, five connecting bolts 14 are arranged at intervals around the upper shell 11, and the shell 1 is mounted on the engine through the five connecting bolts 14. Two connecting bolts 14 of the five bolts are sleeved with positioning sleeves 13.

In the above implementation, the upper housing 11 can be easily assembled with the engine by the connecting bolt 14, and the driving gear 2 in the housing 1 can be engaged with the ring gear 100.

Illustratively, a positioning groove (not shown) is formed inside the upper housing 11, two positioning pins 121 are formed inside the lower housing 12, each positioning pin 121 is arranged in one-to-one correspondence with the positioning groove, and each positioning pin 121 is inserted into the positioning groove in one-to-one correspondence.

In the above implementation, the positioning pin 121 can position the upper housing 11 and the lower housing 12, so that the upper housing and the lower housing can be assembled together with high precision, and the assembling efficiency can be improved.

In this embodiment, six fixing bolts 15 are arranged around the lower casing 12 at intervals, and the upper casing 11 and the lower casing 12 can be fixed together by the six fixing bolts 15, so that the installation cavity 10 is formed between the upper casing 11 and the lower casing 12.

Optionally, the driving gear 2 includes a driving main gear 21 and a driving sub-gear 22, the driving main gear 21 is fixedly sleeved on the first end of the driving balance shaft 31, the driving sub-gear 22 is coaxially located on a side of the driving main gear 21 away from the driving balance 33, and the tooth grooves of the driving main gear 21 are aligned with the tooth grooves of the driving sub-gear 22.

In the above implementation, by providing the driving gear 2 as the driving main gear 21 and the driving sub-gear 22, at least one of the driving main gear 21 and the driving sub-gear 22 can be meshed with the gear ring 100, thereby ensuring the balance shaft module to work normally.

Fig. 3 is a partial structural schematic diagram of an engine balance shaft module provided in an embodiment of the present disclosure, and in conjunction with fig. 3, in this embodiment, the driving gear 2 further includes a transmission ring 23, the transmission ring 23 is located between the driving main gear 21 and the driving sub-gear 22, and the driving sub-gear 22 is fixed together with the driving main gear 21 through the transmission ring 23.

In the implementation manner, the transmission ring 23 can simply mount the driving pinion 22 and the driving main gear 21 together, so as to ensure that the driving pinion 22 and the driving main gear 21 can rotate synchronously, and at the same time, the driving pinion 22 and the driving main gear 21 rotate relatively at a small angle, when the gear ring 100 accelerates or decelerates, at least one of the driving main gear 21 and the driving pinion 22 can always keep meshed transmission with the gear ring 100, so that the backlash between the gear ring 100 and the driving gear 2 can be automatically adjusted, impact noise generated in the transmission process between the driving gear 2 and the gear ring 100 is reduced, and the noise reduction effect of the engine balance shaft module is improved.

Alternatively, the transmission ring 23 is connected to the driving main gear 21 through two positioning members 231, the driving pinion 22 is provided with a circular pin hole 221 and a long pin hole 222 corresponding to the two positioning members 231, and the long pin hole 222 extends along the circumferential direction of the driving pinion 22, one positioning member 231 is inserted into the circular pin hole 221, the other positioning member 231 is inserted into the long pin hole 222, and the driving pinion 22 and the driving main gear 21 are assembled together.

In the above implementation, the driving main gear 21 and the driving sub-gear 22 can be easily mounted together by the positioning member 231. Further, since the long pin holes 222 are provided in the driving pinion 22, the driving pinion 22 can rotate in a small range with respect to the driving main gear 21 around the circular pin holes 221 inserted in the circular pin holes 221 by using the space provided by the long pin holes 222. Therefore, when the driving gear 2 is meshed with the gear ring 100, the relative position between the driving main gear 21 and the driving pinion 22 can be adjusted in a self-adaptive manner, and finally the rotating speed impact on a balance shaft when the rotating speed of the crankshaft of the engine is changed is reduced, so that the transmission noise between the driving gear 2 and the gear ring 100 is reduced.

Illustratively, a locking pin 223 is also provided on the drive pinion 22. The locking pin 223 may penetrate the lower case, and sequentially penetrate the driving sub gear 22 and the driving main gear 21.

In the above implementation, when the locking pin 223 is inserted on the driving main gear 21 and the driving sub-gear 22, the driving main gear 21 and the driving sub-gear 22 may be kept relatively stationary, and the tooth grooves of the two may be aligned. Also, since the lock pin 223 also passes through the lower case 12, the lock pin 223 can keep the drive main gear 21 and the drive sub-gear 22 together stationary with respect to the lower case 12. That is to say, the locking pin 223 can limit the positions of the driving balance shaft 31 and the driven balance shaft 41, so that when the balance shaft module is installed, the driving balance shaft 31 and the driven balance shaft 41 are ensured to be fixed, the installation accuracy of the driving balance shaft 31 and the driven balance shaft 41 is improved, the positions of the driving balance weight 33 and the driven balance weight 43 relative to the crankshaft of the engine are ensured to be preset proper positions, and finally, the centrifugal resultant force generated by the driving balance shaft 31 and the driven balance shaft 41 in the balance shaft module can completely balance the second-order inertia force generated by the engine when in use.

Optionally, the driving gear 2 further includes a driving snap ring 24, a flange 210 is formed on one side of the driving main gear 21 close to the driving pinion 22, a driving snap groove 211 is formed on a peripheral wall of the flange 210, the driving snap ring 24 is mounted on the driving snap groove 211, and the driving snap ring 24 abuts on one side of the driving pinion 22 away from the driving balance 33.

In the above implementation, the driving snap ring 24 is firmly fixed in the driving snap ring 211 by providing the driving snap ring 211 on the driving main gear 21, and the driving snap ring 24 is disposed to limit the side of the driving pinion 22 away from the driving balance 33, so as to prevent the driving pinion 22 from being axially displaced away from the driving balance 33.

Illustratively, the active balance shaft assembly 3 further includes two active bearings 34, the two active bearings 34 are respectively interference-fitted on the active balance shaft 31, and the active bearings 34 are both rotatably mounted in the housing 1, wherein one of the active bearings 34 is located between the active gear 32 and the active balance 33, and the other one of the active bearings 34 is located on a side of the active balance 33 away from the active gear 32.

In the above implementation, the active bearing 34 is provided to rotatably limit two ends of the active balance shaft 31 in the housing 1, so as to prevent the active balance shaft 31 from shifting relative to the housing 1 when rotating.

Optionally, the active balance shaft assembly 3 further includes an active balance shaft snap ring 35, the active balance shaft snap ring 35 is sleeved on the second end of the active balance shaft 31, the active balance shaft snap ring 35 is installed in the housing 1, and the active balance shaft snap ring 35 abuts against the active bearing 34 located on one side of the active balance weight 33 away from the active gear 32.

In the above implementation manner, the driving bearing 34 located at the second end of the driving balance shaft 31 may be limited by providing the driving balance shaft snap ring 35, so as to prevent the driving bearing 34 from moving axially away from the driving balance weight 33.

Illustratively, the active balance shaft snap ring 35 is mounted within a corresponding active snap groove 122 of the lower housing 12. This effectively secures the active balance shaft snap ring 35 to prevent axial displacement of the active bearing 34.

Optionally, the driven balance shaft assembly 4 further includes two driven bearings 44, the two driven bearings 44 are respectively interference-fitted on the driven balance shaft 41, and the driven bearings 44 are both rotatably mounted in the housing 1, wherein one driven bearing 44 is located between the driven gear 42 and the driven balance weight 43, and the other driven bearing 44 is located on the side of the driven balance weight 43 away from the driven gear 42.

In the above implementation, the driven bearing 44 is provided to rotatably limit both ends of the driven balance shaft 41 in the housing 1, so as to prevent the driven balance shaft 41 from shifting relative to the housing 1 during rotation.

Optionally, the driven balance shaft assembly 4 further includes a driven balance shaft snap ring 45, the driven balance shaft snap ring 45 is sleeved on the second end of the driven balance shaft 41, the driven balance shaft snap ring 45 is installed in the housing 1, and the driven balance shaft snap ring 45 abuts against a driven bearing 44 located on one side of the driven balance weight 43 away from the driven gear 42.

In the above implementation, the driven bearing 44 at the second end of the driven balance shaft 41 can be limited by providing the driven balance shaft snap ring 45, so as to prevent the driven bearing 44 from axially displacing away from the driven balance weight 43.

Illustratively, the driven balance shaft snap ring 45 is mounted within a corresponding driven snap groove 123 of the lower housing 12. This effectively fixes the driven balance shaft snap ring 45 to prevent the axial displacement of the driven bearing 44.

Illustratively, the driving balance weight 33 and the driven balance weight 43 are both fan-shaped structural members, a fan-shaped center of the driving balance weight 33 is concentrically arranged with the axis of the driving balance shaft 31, and a fan-shaped center of the driven balance weight 43 is concentrically arranged with the axis of the driven balance shaft 41.

In the above implementation, the driving balance weight 33 is configured as a fan-shaped structural member, so that the driving balance weight 33 can generate a centrifugal force when rotating along with the driving balance shaft 31, and similarly, the driven balance weight 43 is configured as a fan-shaped structural member, so that the driven balance weight 43 can generate a centrifugal force when rotating along with the driven balance shaft 41, and further, the resultant force of the centrifugal forces generated by the two components can counteract the second-order vibration generated by the engine.

In this embodiment, specifically, when the balance shaft module is designed according to the present disclosure, a second-order reciprocating inertial force within a working rotational speed range of an engine is calculated according to structures of a piston and a connecting rod assembly in the engine, and then a centrifugal force of a balance weight is designed to balance the second-order reciprocating inertial force.

Fig. 4 is a schematic diagram of balancing reciprocating inertia force of the engine provided by the present embodiment, and with reference to fig. 4, assuming that at a certain time, the second-order reciprocating inertia force of the piston and the connecting rod assembly in the engine is vertically upward along the cylinder direction of the engine, to fully balance the inertia force, the centrifugal force provided by the balance shaft module of the engine needs to satisfy three conditions: 1. the magnitude of the resultant force is equal to the inertia force, and the directions are opposite; 2. the frequencies are the same; 3. the first two conditions need to be satisfied at any time during the rotation of the crankshaft.

In order to satisfy the above conditions, the engine balance shaft module provided in the present embodiment uses the gear ring 100 on the crankshaft for driving, and uses dual balance shafts, and the rotation directions are opposite. Thus passing through the crank ring gear 100 and the balance ring gear100 gear ratio and the opposite rotation directions omega 2 and omega 3 of the two balance shafts, and then the horizontal resultant force F of the two balance shafts can be realized through the installation phase relation of the initial balance shaft and the crankshaft_B1hAnd F_B2hThe sizes are equal, the directions are opposite, and the external force is 0, namely no external force is transmitted in the horizontal direction; vertical direction F_B1v+F_B2vThe magnitude of the second-order reciprocating inertia force F2 is equal to that of F2, and the directions of the second-order reciprocating inertia force F2 are opposite.

As shown in FIG. 4, the front and rear parts of the balance shaft are rotating bodies, and the middle balance weight is in a fan-shaped structure. According to the principles of physics, centrifugal force is related to rotational speed, mass of center of mass and distance of center of mass to axis of rotation. Because this scheme adopts the double balance axle, consequently every balancing piece only need share half piston assembly's reciprocal inertial force, can reduce the weight and the size of single balancing piece.

In this embodiment, in order to satisfy that the balance shaft module satisfies the above 3 conditions, during assembly, the driving balance shaft 31 and the driving bearing 34 are in interference fit, the driving balance shaft 31 and the driving gear 32 are in interference press-fitting, the driven balance shaft 41 and the driven bearing 44 are in interference fit, and the driven balance shaft 41 and the driven gear 42 are also in interference press-fitting. When the driving balance shaft 31 and the driven balance shaft 41 are assembled to the lower housing 12, the end away from the ring gear 100 is fixed by a tool, and the driving gear 32 and the driven gear 42 are engaged with each other while the positions of the respective parts are kept in conformity with the initial angle requirements. Then, the driving balance shaft snap ring 35 is disposed in the driving snap groove 122 of the lower housing 12 near the second end of the driving balance shaft 31 to prevent the driving bearing 34 from moving axially, the driving balance shaft snap ring 35 is disposed at a position near the second end of the driven balance shaft 41, and the driven balance shaft snap ring 45 is disposed in the driven snap groove 123 of the lower housing 12, so as to prevent the driven bearing 44 from moving axially. Then, the locking pin 223 is inserted into a corresponding hole of the driving main gear 21 through a front end hole of the lower housing 12, so that the two driving balance shafts 31 and the driven balance shafts 41 are fixed and cannot rotate. Finally, the upper case 11 is assembled with the lower case 12 by two positioning pins 121, and fastened by 6 connecting bolts 14. And the engine balance shaft module is assembled.

The operation of the engine balance shaft module provided by the embodiment is briefly described as follows:

in the rotation process of the crankshaft of the in-line four-cylinder engine, second-order reciprocating inertia force generated by the piston, the piston pin and the connecting rod assembly cannot be balanced in the system, and vibration output is carried out outwards through the main bearing seat of the crankshaft. In order to eliminate the influence of the second-order reciprocating inertia force of the four-cylinder engine on the external vibration, the balance shaft system of the engine balance shaft module can be added.

Firstly, a gear ring 100 is mounted on a crank throw of a crankshaft of an engine, the rotation center of the gear ring 100 is the same as the main journal of the crankshaft, inclined teeth are processed on the gear ring 100, and the gear ring 100 is meshed with a driving gear 2 of an engine balance shaft module.

Because the second-order reciprocating inertia force is balanced, the rotating speed of the engine balance shaft module is required to be twice that of the crankshaft, and therefore the ratio of the number of teeth of the gear ring 100 on the crankshaft to the number of teeth of the driving gear 2 in the engine balance shaft module is 2: 1.

Then, the positioning sleeve 13 ensures that the engine balance shaft module and the gear ring 100 on the crankshaft are meshed without deviation, and the positioning sleeve 13 in the shell 1 is correspondingly matched with a corresponding hole on an engine body and is installed together.

Meanwhile, in order to ensure that the engine balance shaft module meets the 3 rd condition, the position of the crankshaft needs to be fixed during assembly, and the positions of the corresponding driving balance weight 33 and the corresponding driven balance weight 43 are determined according to stress analysis so as to meet the 1 st condition. In this state, the connecting bolt 14 in the housing 1 is tightened to fix the housing 1 to the engine body, and then the locking pin 223 at the front of the balance shaft housing is pulled out to complete the installation of the balance shaft module of the engine.

The above description is intended to be exemplary only and not to limit the present disclosure, and any modification, equivalent replacement, or improvement made without departing from the spirit and scope of the present disclosure is to be considered as the same as the present disclosure.