CN213870936U - Balance shaft assembly - Google Patents

Abstract

The utility model provides a balance shaft assembly, include with connecting the balance shaft casing on the engine cylinder body, and rotate and locate first balance shaft and second balance shaft in the balance shaft casing, be equipped with the first transmission portion of accepting crankshaft drive on the first balance shaft, be equipped with between first balance shaft and the second balance shaft and constitute both synchronous pivoted second transmission portions, and first transmission portion and second transmission portion all are located in the balance shaft casing, and in be equipped with balanced subassembly on the axis body of first balance shaft and second balance shaft respectively, balanced subassembly has the balancing piece to and the grease proofing shroud that sets up between the balancing piece, and because of the cylindric lock of balancing piece and grease proofing shroud makes balanced subassembly is cylindric or similar. The utility model discloses a balanced axle assembly makes balanced subassembly be cylindric or similar cylindric, balanced axle oil mixing when can avoiding the operation, and can reduce the rotten probability of machine oil.

Description

Balance shaft assembly

Technical Field

The utility model relates to the technical field of engines, in particular to balance shaft assembly.

Background

In order to balance the second-order reciprocating inertia force of an in-line four-cylinder engine in the engine, a balance shaft structure is generally added to the engine with higher NVH requirement. The existing balance shaft arrangement structure generally includes a central balance shaft and a bottom balance shaft, the central balance shaft is generally a hole on the cylinder block, the balance shaft penetrates into the hole and is assembled on the cylinder block, and the bottom balance shaft is generally arranged in the oil pan through a separate box-type structure. In addition, the prior balance shaft arrangement is generally driven by a sprocket or gear structure and is rotatably arranged by using a bushing or a bushing, and for the fixed phase relation required to be arranged between the balance shaft and the crankshaft, the phase relation between the balance shaft and the crankshaft is also generally determined by a timing mark at present.

To current balance shaft arrangement structure, the central balance shaft can make the cylinder block structure complicated owing to arrange on the cylinder block, and the assembly is difficult, and bottom balance shaft arranges in the oil pan, also has balance shaft balancing piece to stir oil, makes the problem that machine oil is rotten easily. For the balance shaft structure driven by the chain wheel, the balance shaft structure is not suitable for transmission with a smaller center distance, and for the balance shaft structure driven by the gear, the gear is continuously engaged in and out in the working process, so that the gear knocking sound is easy to occur, and even the transmission failure of the balance shaft can be caused.

In addition, the existing balance shaft adopts a mode that a bearing bush or a bush is arranged in a rotating mode and is lubricated by high-pressure engine oil, so that the friction loss of an engine is increased, the oil consumption of the engine is increased, and the increasingly severe emission requirements of the engine are difficult to meet. In the method of determining the phase relationship between the balance shaft and the crankshaft through the timing mark, the phase relationship needs to be aligned during assembly, so that assembly difficulty is caused, and the misassembly risk is increased.

SUMMERY OF THE UTILITY MODEL

In view of this, the present invention is directed to a balance shaft assembly to avoid oil stirring of the balance shaft and overcome one or more defects of the conventional balance shaft arrangement structure.

In order to achieve the above purpose, the technical scheme of the utility model is realized like this:

the utility model provides a balance shaft assembly, includes with connecting the balance shaft casing on the engine cylinder body to and rotate and locate first balance shaft and second balance shaft in the balance shaft casing, be equipped with the first transmission portion of accepting crankshaft drive on the first balance shaft, first balance shaft with be equipped with between the second balance shaft and constitute both synchronous pivoted second transmission portions, just first transmission portion with second transmission portion all is located in the balance shaft casing, and in first balance shaft with be equipped with balanced subassembly on the axis body of second balance shaft respectively, balanced subassembly have the balancing piece, and with the grease proofing shroud that the lock set up between the balancing piece, and because of the balancing piece with the cylindric lock of grease proofing shroud, and make balanced subassembly is cylindric or similar cylindric.

Furthermore, the first transmission part comprises a transmission gear which is press-fitted on the first balance shaft in an interference manner, and the transmission gear is meshed with a driving gear ring arranged on the crankshaft.

Furthermore, the second transmission part comprises a driving gear and a driven gear, wherein the driving gear is in interference press fit on the first balance shaft, the driven gear is in interference press fit on the second balance shaft, and the driven gear is meshed with the driving gear.

Furthermore, the balancing block and the oil-proof cover cap are detachably fixed on the shaft body through fixing bolts.

Furthermore, the cross section of the oil-proof cover is arc-shaped, a notch is formed on the shaft body corresponding to the oil-proof cover, and an oil drainage hole is formed in the oil-proof cover.

Further, oil-proof shroud adopts PA66 or PA66+ GF30 to make, just oil-proof shroud is last to be equipped with the confession the through-hole that fixing bolt passed, and in the port department of through-hole is equipped with to press from both sides and locates fixing bolt with the gasket between the oil-proof shroud.

Further, the first balance shaft and the second balance shaft are rotatably arranged in the balance shaft shell through bearing assemblies.

Furthermore, the bearing assembly is provided with a front end bearing, a middle section bearing and a rear end bearing which are arranged along the axial direction of the shaft body at intervals, the first transmission part and the second transmission part are located between the front end bearing and the middle section bearing, and the balance assemblies are respectively arranged on two opposite sides of the middle section bearing.

Furthermore, the front end bearing is a ball bearing, the middle section bearing and the rear end bearing are needle roller bearings, snap springs for respectively limiting outer rings of the front end bearing, the middle section bearing and the rear end bearing are arranged on the balance shaft shell, and a limiting bolt for limiting an inner ring of the front end bearing is arranged at the end part of the shaft body.

Further, corresponding to the second balance shaft, insertion holes are formed in the bottom of the balance shaft shell in a penetrating mode, corresponding to the insertion holes, locking holes are formed in the second balance shaft, and the locking holes can be arranged in an aligned mode with the insertion holes along with rotation of the second balance shaft.

Compared with the prior art, the utility model discloses following advantage has:

the utility model discloses a balanced axle assembly is through setting up the grease proofing shroud with the balancing piece lock for balanced subassembly is whole to be cylindricly or similar cylindricly, so can avoid the stirring of balanced axle to machine oil when moving, thereby can reduce the rotten probability of machine oil.

In addition, two transmission portions adopt the gear drive structure, and the transmission is steady, and the transmission precision is high, and balancing piece and grease proofing shroud can be dismantled fixedly, can do benefit to the design of balanced axle assembly according to the reciprocal mass matching balancing piece of engine. The oil-proof cover is made of materials, so that the weight of the balance assembly can be reduced, and the oil-proof cover can be prevented from being crushed by the gasket.

In addition, two balance shafts all set up through the bearing, reducible rotation frictional resistance to do benefit to and reduce the engine oil consumption, and the reliability that each bearing set up can be guaranteed in jump ring and spacing bolt's setting, the setting in cartridge hole and the locking hole that corresponds can utilize frock locking round pin to carry out the locking to balance shaft when the assembly, with confirm the phase relation between balance shaft and the bent axle, it compares in current and carries out the mode confirmed through the mark in right time, can eliminate the risk of timing mistake dress.

Drawings

The accompanying drawings, which form a part hereof, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention without undue limitation. In the drawings:

fig. 1 is an overall schematic view of a balance shaft assembly according to an embodiment of the present invention;

fig. 2 is a schematic view of a first balance shaft and a second balance shaft according to an embodiment of the present invention;

fig. 3 is a schematic diagram illustrating a first balance shaft according to an embodiment of the present invention;

fig. 4 is a schematic diagram illustrating a second balance shaft according to an embodiment of the present invention;

fig. 5 is a schematic view illustrating arrangement of guide pin holes according to an embodiment of the present invention;

fig. 6 is a schematic radial dimension view of a bolt through hole and a mounting bolt according to an embodiment of the present invention;

fig. 7 is a schematic view of an arrangement of a guide pin according to an embodiment of the present invention;

fig. 8 is a schematic diagram of the engagement between the transmission gear and the driving ring gear according to the embodiment of the present invention;

fig. 9 is a partial enlarged view of a portion a in fig. 8;

fig. 10 is a schematic structural view of a locking pin according to an embodiment of the present invention;

FIG. 11 is a schematic view of a locking pin according to an embodiment of the present invention;

description of reference numerals:

1-balance shaft shell, 101-bolt through hole, 102-guide pin hole;

2-a first balance shaft, 201-a first shaft body, 202-a transmission gear, 203-a driving gear, 204-a first front end bearing, 205-a first middle section bearing, 206-a first rear end bearing, 207-a first balance block, 208-a first oil-proof cover, 209-a first balance block fixing bolt, 2010-a first oil-proof cover fixing bolt, 2011-a first gasket, 2012-a first front end clamp spring, 2013-a first middle section clamp spring, 2014-a first rear end clamp spring, 2015-a first limit bolt;

3-a second balance shaft, 301-a second shaft body, 302-a driven gear, 303-a second front end bearing, 304-a second middle section bearing, 305-a second rear end bearing, 306-a second balance block, 307-a second oil-proof cover, 308-a second balance block fixing bolt, 309-a second oil-proof cover fixing bolt, 3010-a second gasket, 3011-a second front end clamp spring, 3012-a second middle section clamp spring, 3013-a second rear end clamp spring, 3014-a second limiting bolt;

4-driving the gear ring;

5-locking pin, 501-locking end;

6, mounting a bolt;

7-engine block, 701-guide pin, 702-bolt hole.

Detailed Description

It should be noted that, in the present invention, the embodiments and features of the embodiments may be combined with each other without conflict.

In the description of the present invention, it should be noted that, if terms indicating orientation or positional relationship such as "upper", "lower", "inner", "back", etc. appear, they are based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention. Furthermore, the appearances of the terms first, second, etc. in this specification are not necessarily all referring to the same item, but are instead intended to cover the same item.

The present invention will be described in detail with reference to the accompanying drawings 1 to 11, in conjunction with an embodiment.

The present embodiment relates to a balance shaft assembly, which, as shown in fig. 1 and 2, includes a balance shaft housing 1 to be connected to an engine block 7, and a first balance shaft 2 and a second balance shaft 3 rotatably provided in the balance shaft housing 1. The first balance shaft 2 is provided with a first transmission part for receiving the driving of the crankshaft, and a second transmission part for forming the synchronous rotation of the first balance shaft 2 and the second balance shaft 3 is also provided between the two. And above-mentioned first transmission portion and second transmission portion also all are located balance shaft casing 1, simultaneously, still are provided with balanced subassembly respectively on the axis body of first balance shaft 2 and second balance shaft 3.

As a preferred implementation form, the first transmission part of the present embodiment specifically includes a transmission gear 202 press-fitted onto the first balance shaft 2 in an interference manner, and the transmission gear 202 is also specifically in meshing connection with a driving ring gear 4 provided on the crankshaft, so that the driving of the crankshaft to the entire balance shaft assembly is realized through meshing transmission between the driving ring gear 4 and the transmission gear 202.

As with the above first transmission unit, the second transmission unit of the present embodiment preferably includes a driving gear 203 press-fitted onto the first balance shaft 2 in an interference manner, and a driven gear 302 press-fitted onto the second balance shaft 3 in an interference manner. The driven gear 302 is meshed with the driving gear 203, and thus, the rotational driving force received by the first balance shaft 2 is transmitted to the second balance shaft 3.

Further, as an exemplary implementation form, the balance shaft assembly of the present embodiment may be, for example, a shaft assembly for balancing second-order reciprocating inertia force generated by an engine, and at this time, the transmission ratio between the transmission gear 202 and the driving ring gear 4 may be 1: 2, i.e. the ratio of the rotational speed between the first balance shaft 2 and the crankshaft is 2: 1. the transmission ratio between the driving gear 203 and the driven gear 302 is 1: 1, so that the rotation speed ratio between the two balance shafts is 1: 1.

in this embodiment, the balance assembly has a balance block and an oil-proof cover fastened to the balance block, and the balance block and the oil-proof cover are fastened together to form a cylindrical or similar cylindrical balance assembly. Meanwhile, as a preferred embodiment, the first balance shaft 2 and the second balance shaft 3 of the present embodiment are both rotatably disposed in the balance shaft housing 1 through a bearing assembly, and are supported by rolling of the bearing assembly, so that friction resistance when the two balance shafts rotate can be reduced, and further, an effect of reducing oil consumption of the engine is achieved.

At this time, the present embodiment will be specifically described with reference to the description of the two balance shaft structures, so as to describe the specific arrangement of the balance assembly and the bearing assembly. In which fig. 3 shows the overall construction of the first balance shaft 2, fig. 4 shows the overall construction of the second balance shaft 3, and for the convenience of description, the respective corresponding crowns are distinguished by "first" and "second" for each of the two balance shafts.

Specifically, the balance assembly on the first balance shaft 2 is fixed on the first shaft 201 on the first balance shaft 2, and the first weight 207 of the balance assembly on the first balance shaft 2 is detachably fixed on the first shaft 201 through two first weight fixing bolts 209, and the first oil-proof cover 208 fastened with the first weight 207 is detachably fixed on the first shaft 201 through a first oil-proof cover fixing bolt 2010. In this arrangement, the first bonnet mounting stud 2010 is also disposed between the two first counterweight mounting studs 209 to effect the respective mounting of each mounting stud to the first shaft 201.

In the present embodiment, the cross section of the first oil-proof cover 208 is specifically configured to be arc-shaped, and corresponding to the first oil-proof cover 208, as shown in fig. 3, a notch is also formed on the first shaft 201. The first oil cover 208 is fastened to the recess of the first shaft 201, and at this time, an oil drain hole is also formed in the first oil cover 208, so that the engine oil immersed in the first oil cover 208 can be smoothly drained. In a particular arrangement, the oil relief holes may be generally two on either side of the first bonnet mounting stud 2010, as shown in FIG. 3.

In order to reduce the overall weight of the balance assembly when the first oil cover 208 is provided, the first oil cover 208 of the present embodiment is preferably made of PA66 or PA66+ GF 30. Meanwhile, for the fixing of the first oil cover 208, it is common to provide the first oil cover 208 with a through hole for the first oil cover fixing bolt 2010 to pass through, and the first oil cover fixing bolt 2010 is screwed onto the first shaft 201 through the through hole.

In view of the fact that the first oil cover 208 is of an arcuate thin-walled structure and is made of a material having a relatively low density, in order to prevent the first oil cover 208 from collapsing during the fixing process, as a preferred embodiment, a first spacer 2011 may be disposed at a port of the through hole of the first oil cover 208 and interposed between the first oil cover fixing bolt 2010 and the first oil cover 208. The first shim 2011 is made of the same material as the first bonnet mounting stud 2010 and may be partially embedded in the through hole to provide a stable mounting on the first bonnet 208.

It should be noted that the sector opening of the first weight 207 of the present embodiment is generally not greater than 180 °, and it can be adjusted according to the actual balance shaft boundary position and the unbalance amount. Based on the sector opening of the first weight 207, the sector opening of the first oil-proof cover 208 fastened with the first weight is correspondingly set, so that the balance assembly formed by the first weight and the first oil-proof cover is cylindrical or similar to a cylinder, and the stirring of engine oil can be reduced.

In the present embodiment, as an exemplary embodiment, the bearing assembly described above has a first front end bearing 204, a first middle section bearing 205, and a first rear end bearing 206 arranged at intervals in the axial direction of the first shaft body 201. Corresponding to the three bearing structures, the first transmission part formed by the transmission gear 202 and the driving gear 203 in the second transmission part of the present embodiment are located between the first front end bearing 204 and the first middle section bearing 205, and meanwhile, the two opposite sides of the first middle section bearing 205 are also respectively provided with a balance assembly formed by a first balance block 207 and a first oil-proof cover 208.

At this time, the balance assembly, the transmission gear 202 and the driving gear 203, which are located on the same side of the first middle section bearing 205, may be sequentially fixed along the axial direction of the first shaft 201. And the transmission gear 202 and the driving gear 203 are arranged on the first shaft body 201 by adopting a conventional interference press-fitting mode.

As a preferred embodiment, the present embodiment also specifically uses a ball bearing as the first front end bearing 204, and uses a needle bearing as the first middle section bearing 205 and the first rear end bearing 206. Meanwhile, in order to facilitate the positioning of the bearing structures in the balance shaft housing 1, a snap spring for limiting the outer rings of the first front end bearing 204, the first middle section bearing 205 and the first rear end bearing 206 is also arranged on the balance shaft housing 1, and a first limiting bolt 2015 for limiting the inner ring of the first front end bearing 204 is also arranged at the end of the first shaft body 201.

In detail, the clamp springs specifically include a first front-end clamp spring 2012 for restraining the first front-end bearing 204, a first middle-section clamp spring 2013 for restraining the first middle-section bearing 205, and a first rear-end clamp spring 2014 for restraining the first rear-end bearing 206. Corresponding to each snap spring, a snap spring groove is respectively provided in the balance shaft housing 1, and each snap spring is located in the corresponding snap spring groove through a shrink snap, and the arrangement of each snap spring in the balance shaft housing 1 can be specifically seen in fig. 11, and meanwhile, the specific arrangement of each bearing and the second shaft body 301 in the first shaft body 201 and the second balance shaft 3 in the balance shaft housing 1 can also be seen in fig. 11.

In this embodiment, the specific structure of the second balance shaft 3 is substantially the same as that of the first balance shaft 2, except that only the driven gear 302 is press-fitted onto the second shaft body 301. In the second balance shaft 3, the balance assembly on the second shaft body 301 includes a second balance block 306 and a second oil cover 307, the second balance block 306 is fixed by a second balance block fixing bolt 308, the second oil cover 307 is fixed by a second oil cover fixing bolt 309, and a second spacer 3010 is also disposed at a through hole port of the second oil cover 307.

Meanwhile, the bearing assembly for rotatably disposing the second shaft body 301 includes a second front end bearing 303, a second middle section bearing 304 and a second rear end bearing 305, the second front end bearing 303 adopts a ball bearing, the second middle section bearing 304 and the second rear end bearing 305 adopt needle bearings, and a second front end clamp spring 3011, a second middle section clamp spring 3012 and a second rear end clamp spring 3013 for limiting are also disposed corresponding to each bearing structure. A second stopper bolt 3014 for stopping the inner ring of the second tip bearing 303 is also provided at the end of the second shaft 301.

In this embodiment, as shown in fig. 1 in combination with fig. 5 to 7, for the connection between the balance shaft housing 1 and the engine block 7, specifically, a plurality of bolt through holes 101 are provided on the balance shaft housing 1, and the balance shaft housing 1 is also connected to the engine block 7 through mounting bolts 6 inserted into the bolt through holes 101. At this time, the inner diameter of the bolt through hole 101 is also larger than the outer diameter of the mounting bolt 5, that is, there is a gap M radially between the two, and meanwhile, the embodiment further has a guide assembly between the balance shaft housing 1 and the engine block 7, and the guide assembly can guide the balance shaft housing 1 to translate relative to the engine block 7 along a direction orthogonal to the axial direction of the first shaft body 201 or the second shaft body 301.

Through the arrangement of the guide assembly, as shown in fig. 8 and 9, when the balance shaft assembly is assembled, the tooth surface backlash L of the gear pair formed by the transmission gear 202 and the drive gear ring 4 is further adjusted by using the translation of the balance shaft assembly in the embodiment, so that the assembled gear backlash L is in a better range, and therefore, the occurrence of tooth knocking noise can be avoided.

As an exemplary embodiment, the guide assembly specifically includes guide pin holes 102 respectively disposed at two opposite sides of the balance shaft housing 1, and a guide pin 701 disposed on the engine block 7 corresponding to each guide pin hole 102. The guide pin holes 102 are located on a connecting surface at the top of the balance shaft housing 1 for connecting with the engine block 1, the guide pins 701 are located on a mounting surface at the bottom of the engine block 7 for mounting the balance shaft housing 1, the guide pin holes 102 are also in a strip shape which is orthogonal to the axial direction of the first shaft body 201 or the second shaft body 301, and the guide pins 701 can be embedded in the corresponding guide pin holes 102 and constrained to slide along the length direction of the corresponding guide pin holes 102.

At this time, as for the above-mentioned guide pin 701 constrained to slide along the length direction of the corresponding guide pin hole 102, it may be, for example, such that the outer diameter dimension N of the guide pin 701 is slightly smaller than the width of the elongated guide pin hole 102, so that the guide pin 701 can be just inserted into the corresponding guide pin hole 102, but cannot move along the width direction of the guide pin hole 102, and can only move along the length direction of the guide pin hole 102.

In addition, based on the above-mentioned guiding pin hole 102 formed on the balancing shaft housing 1 in the concave shape and the guiding pin 701 formed on the bottom of the engine block 7 in the convex shape, as a preferred embodiment, the guiding pin hole 102 may be specifically aligned with and penetrated through a bolt through hole 101 thereof, the guiding pin 701 is also in a ring shape, and the bolt hole 702 is formed on the engine block 7 inside the guiding pin 701. At this time, the mounting bolt 6 passing through the guide pin hole 102 is screwed into the bolt hole 702 inside the guide pin 701, so that the guide pin hole 102 and one of the mounting bolts 6 are integrally arranged.

According to the guide assembly formed by the guide pin hole 102 and the matched guide pin 701, when the balance shaft assembly is assembled, the balance shaft assembly can be pre-connected to the engine block 7 by pre-tightening the mounting bolts 6. Then, after the crankshaft is locked, the balance shaft assembly can be pushed to translate by the tool under the guiding action of the guiding component by utilizing the gap M between each mounting bolt 6 and the corresponding bolt through hole, so that the transmission gear 202 is in contact with the driving gear ring 4. Then, the contact position of the transmission gear 202 and the driving gear ring 4 is taken as a reference point, the balance shaft assembly is reversely pushed to translate the set tooth surface backlash quantity L, and finally, each mounting bolt 6 is screwed.

The back clearance L is selected according to actual design requirements and through NVH test verification.

In the present embodiment, as shown in fig. 10 and 11 in combination, an insertion hole is also provided in the bottom of the balance shaft housing 1 corresponding to the second balance shaft 3, and a locking hole is also provided in the second balance shaft 3 corresponding to the insertion hole. At this time, along with the rotation of the second balance shaft 3, the locking holes may also be aligned with the insertion holes, and when the balance shaft assembly is assembled, the tool, that is, the locking pin 5, may be inserted into the insertion holes by aligning the insertion holes and the locking holes, and the locking end 501 on the locking pin 5 is inserted into the locking holes.

The locking of the second balance shaft 3 can be realized by inserting the locking end 501 of the locking pin 5 into the locking hole of the second balance shaft 3, and the locking of the first balance shaft 2 can be realized by the engagement between the driven gear 302 and the driving gear 203. At this time, the two balance shafts are locked to determine the phase relation between the balance shafts and the crankshaft, and compared with the conventional method of determining through the timing mark, the method can eliminate the risk of timing misassembly.

In addition, in the implementation, the above insertion holes may be, for example, threaded holes, and the locking pin 5 may be correspondingly provided with threaded sections, so that the locking pin 5 may be positioned in the insertion holes on the balance shaft housing 1 in a threaded manner. After the phase position between the balance shaft and the crankshaft is determined, the locking pin 5 is directly removed.

The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. A balance shaft assembly characterized by: comprises a balance shaft shell (1) connected with an engine cylinder body (7), a first balance shaft (2) and a second balance shaft (3) which are rotatably arranged in the balance shaft shell (1), a first transmission part for bearing the drive of the crankshaft is arranged on the first balance shaft (2), a second transmission part for forming the synchronous rotation of the first balance shaft (2) and the second balance shaft (3) is arranged between the first balance shaft and the second balance shaft, and the first transmission part and the second transmission part are both positioned in the balance shaft shell (1), and the shaft bodies of the first balance shaft (2) and the second balance shaft (3) are respectively provided with a balance component which is provided with a balance block, and the oil-proof cover cap is buckled with the balance blocks, and the balance assembly is cylindrical or similar to a cylinder due to the buckling of the balance blocks and the oil-proof cover cap.

2. The balance shaft assembly of claim 1, wherein: the first transmission part comprises a transmission gear (202) which is press-mounted on the first balance shaft (2) in an interference fit mode, and the transmission gear (202) is meshed and connected with a driving gear ring (4) arranged on the crankshaft.

3. The balance shaft assembly of claim 1, wherein: the second transmission part comprises a driving gear (203) which is press-mounted on the first balance shaft (2) in an interference mode and a driven gear (302) which is press-mounted on the second balance shaft (3) in an interference mode, and the driven gear (302) is meshed with the driving gear (203).

4. The balance shaft assembly of claim 1, wherein: the balancing block and the oil-proof cover cap are detachably fixed on the shaft body through fixing bolts.

5. The balance shaft assembly of claim 4, wherein: the cross section of the oil-proof cover is arc-shaped, a notch is formed on the shaft body corresponding to the oil-proof cover, and an oil drainage hole is formed in the oil-proof cover.

6. The balance shaft assembly of claim 5, wherein: grease proofing shroud adopts PA66 or PA66+ GF30 to make, just be equipped with the confession on the grease proofing shroud the through-hole that fixing bolt passed, and in the port department of through-hole is equipped with to press from both sides and locates fixing bolt with the gasket between the grease proofing shroud.

7. The balance shaft assembly of claim 1, wherein: the first balance shaft (2) and the second balance shaft (3) are rotatably arranged in the balance shaft shell (1) through bearing assemblies.

8. The balance shaft assembly of claim 7, wherein: the bearing assembly is provided with a front end bearing, a middle section bearing and a rear end bearing which are arranged along the axial direction of the shaft body at intervals, the first transmission part and the second transmission part are located between the front end bearing and the middle section bearing, and the two opposite sides of the middle section bearing are respectively provided with the balance assembly.

9. The balance shaft assembly of claim 8, wherein: the front end bearing adopts a ball bearing, the middle section bearing and the rear end bearing adopt needle roller bearings, snap springs for respectively limiting outer rings of the front end bearing, the middle section bearing and the rear end bearing are arranged on the balance shaft shell, and a limiting bolt for limiting an inner ring of the front end bearing is arranged at the end part of the shaft body.

10. The balance shaft assembly of any one of claims 1 to 9 wherein: corresponding to the second balance shaft (3), inserting holes which are arranged in a penetrating mode are formed in the bottom of the balance shaft shell (1), corresponding to the inserting holes, locking holes are formed in the second balance shaft (3), and the locking holes can be aligned with the inserting holes along with rotation of the second balance shaft (3).

Images