CN110939718A

CN110939718A - A gear-driven integrally assembled dual-shaft balance shaft mechanism

Info

Publication number: CN110939718A
Application number: CN201911314696.4A
Authority: CN
Inventors: 倪松伟; 李鹏; 王宏
Original assignee: FAW Jiefang Automotive Co Ltd
Current assignee: FAW Jiefang Automotive Co Ltd
Priority date: 2019-12-19
Filing date: 2019-12-19
Publication date: 2020-03-31

Abstract

The invention discloses a gear-driven integrally assembled dual-shaft balance shaft mechanism, comprising an upper casing, a lower casing, a driving gear and a balance shaft assembly, a driven gear and a balance shaft assembly, a side cover and an intermediate gear assembly. The gear meshes with the intermediate gear and the driven gear at the same time, and the power transmission is from the intermediate gear to the driving gear to the driven gear. The intermediate gear is installed on the side cover, which can simply and conveniently adjust the meshing backlash of the intermediate gear and the crankshaft gear. The gear chamber formed by the side cover, the upper casing and the lower casing can cover the gears and reduce the noise of gear operation. The lubrication of the balance shaft, driven balance shaft and intermediate gear shaft bearing system improves the reliability and durability of the balance shaft mechanism.

Description

Gear-driven integrally-assembled double-shaft balance shaft mechanism

Technical Field

The invention belongs to the technical field of engine vibration noise, and particularly relates to a gear-driven integrally-assembled double-shaft balance shaft mechanism.

Background

Reciprocating internal combustion engines produce cyclically varying rotational and reciprocating inertial forces during operation due to the cyclical nature of their operation and movement. If these forces cannot be cancelled out in the engine, the force transmitted to the support will also change constantly, causing the machine to vibrate on the support, resulting in poor balancing of the engine. The condition not only impairs the smoothness and comfort of the whole vehicle, but also accelerates the fatigue of a driver and influences the driving safety. In addition, the vibration can also increase the noise of the whole machine, influence the durability and fatigue performance of the fastener and the supporting piece, and greatly reduce the service life of the whole vehicle and the engine. For a four-cylinder diesel engine, due to the characteristics of the whole structure, the second-order reciprocating inertia force is the main reason of poor balance of the whole engine. In view of the above technical defects, the existing effective measure is to install a double-shaft balance shaft mechanism inside the engine body to counteract or eliminate the influence of second-order reciprocating inertia force.

The invention discloses a balance shaft device of an automobile engine, which is closest to the prior art (CN 208703017U) and has the advantages of low noise, light weight, low cost and good vibration reduction effect. The engine crankshaft gear transmission device comprises a seat body and at least two balance shafts, wherein balancing weights are arranged on the balance shafts, one balance shaft is used as a driven balance shaft, the other balance shafts are used as transmission balance shafts, an input gear and an output gear are sleeved on each transmission balance shaft, a driven gear is sleeved on each driven balance shaft, the driven gear is meshed with the output gear in a matching mode, the transmission balance shafts are in one-to-one meshing transmission through the input gear and the output gear, the transmission balance shafts are in meshing transmission with an engine crankshaft gear through the input gear, and gear teeth of the driven gear and the input gear are resin gears formed by injection molding; the transmission balance shaft and the driven balance shaft are supported and installed on the seat body through self-lubricating bearings.

The balance shaft mechanism has the obvious disadvantages that: 1. the intermediate gear and the active balance shaft gear are assembled on the active balance shaft at the same time, so that the meshing backlash of the crankshaft gear and the intermediate gear cannot be conveniently adjusted, and inconvenience is brought to the assembly of the balance shaft mechanism. 2. The balance shaft mechanism is not provided with a special bearing lubricating oil passage, so that the reliability and the service life of a bearing of the balance shaft are greatly reduced. Even if the self-lubricating bearing has no input of lubricating oil, the bearing burning risk of the balance shaft mechanism is greatly improved. 3. The balance shaft mechanism is not provided with a special engine oil leakage channel, so that a large amount of lubricating oil flowing down through an engine cylinder barrel is accumulated in a lower shell of the balance shaft after long-term operation or the lubricating oil permeates into the shell of the balance shaft due to overhigh lubricating oil level of an engine oil pan, and if the lubricating oil is not discharged out of the shell of the balance shaft, the operation of the balance shaft is retarded, so that the effective power of an engine is reduced and lost.

Disclosure of Invention

In order to solve the problems, the invention provides the gear-driven integrally-assembled double-shaft balance shaft mechanism which is good in vibration reduction effect, low in cost and convenient to install. In order to achieve the purpose, the invention provides the following technical scheme: the utility model provides a balanced axle mechanism of whole assembled biax of gear drive, includes casing, lower casing, driving gear and balanced axle subassembly, driven gear and balanced axle subassembly, side shroud and intermediate gear subassembly, driving gear and balanced axle subassembly and driven gear and balanced axle subassembly pass through slide bearing and install between casing and lower casing, are used for supporting and guarantee balanced axle free rotation.

The upper shell and the lower shell are respectively provided with a semicircular bearing seat hole for mounting the bearing, and a bearing bush is arranged in the bearing seat hole; the upper shell and the lower shell are connected through bolts, and form a closed space, so that the leakage of noise generated by the operation of the balance shaft is effectively reduced; the side shroud passes through bolted connection with last casing front end and casing front end down, and the gear room that the side shroud constitutes together with last casing, casing down plays and covers the gear, reduces the effect of gear running noise.

The driving gear is meshed with the intermediate gear and the driven gear simultaneously, the tooth width of the driving gear is larger than the sum of the tooth width of the intermediate gear and the tooth width of the driven gear, the intermediate gear is meshed with the engine crankshaft gear, and a power source is provided by the engine crankshaft gear.

The driving gear and balance shaft assembly comprises a driving gear and a driving balance shaft, the driving balance shaft comprises a front shaft, a balance block and a rear shaft, the driving gear and balance shaft assembly is integrally cast, and the front end of the driving balance shaft is sleeved in the driving gear in an interference manner; the driven gear and balance shaft assembly comprises a driven gear and a driven balance shaft, the driven balance shaft and the driving balance shaft comprise a front shaft, a balance block and a rear shaft which are integrally cast, and the front end of the driven balance shaft is sleeved into the driven gear in an interference manner; the side cover and the intermediate gear assembly comprise a side cover, an intermediate gear shaft and an intermediate gear bush, wherein the intermediate gear bush is in interference fit with an inner hole of the intermediate gear, the intermediate gear bush is in clearance fit with the intermediate gear shaft, and the intermediate gear shaft is connected with the side cover through bolts.

Furthermore, the driving balance shaft and the driven balance shaft are both arranged between the upper shell and the lower shell through the support of a common aluminum-based sliding bearing, and the intermediate gear bush is a common thin-wall sliding bearing.

Furthermore, the front ends of the upper shell and the lower shell of the side cover are respectively provided with a positioning pin hole and connected through a positioning pin, and the positioning pin holes are used for locking the intermediate gear when the meshing backlash of the intermediate gear and the engine crankshaft gear is adjusted.

Furthermore, a timing hole is formed in the side cover, and the timing hole is located between the diameter of the tooth root circle and the diameter of the tooth top circle of the intermediate gear. The timing hole is used for adjusting balance blocks of the driving balance shaft and the driven balance shaft to a correct angle when the balance shaft mechanism is assembled, so that the maximization of the balance rate is realized.

Furthermore, two timing marks are processed at the rear end of the lower shell, the positions of the two timing marks are respectively vertically below the bearing seat holes of the driving balance shaft and the driven balance shaft, and timing mark holes are processed at the vertically downward positions of the end surfaces of the rear shafts of the driving balance shaft and the driven balance shaft. When the balance shaft mechanism is installed, the driving balance shaft and the driven balance shaft are adjusted to enable the timing marks of the driving balance shaft and the driven balance shaft to be aligned with the timing marks at the rear end of the lower shell.

Furthermore, two sides of a bearing seat hole at the front end of the lower shell are respectively provided with a semicircular thrust groove, a thrust shoulder is respectively arranged on the front shaft of the driving balance shaft and the front shaft of the driven balance shaft, and the thrust grooves are used for being matched with the thrust shoulders to achieve the purposes of stabilizing the axial position of the balance shaft and preventing the axial movement of the balance shaft from being overlarge.

Further, the balancing piece is eccentric structure, in order to reach the biggest inertia with minimum weight, the balancing piece is half fan-shaped structure, and its main mass concentrates on the latter half to the distribution angle theta's of balancing piece scope is: 150-175 degree

Furthermore, a main lubricating oil inlet and a lubricating oil channel leading to a bearing seat of the driving balance shaft and a bearing seat of the driven balance shaft are arranged in the upper shell and used for enhancing lubrication of a bearing system of the driving balance shaft and the driven balance shaft, and the main lubricating oil inlet is connected with an engine oil outlet of the cylinder block through a positioning sleeve.

Furthermore, a lubricating oil outlet is formed in the front end of the upper shell, a lubricating oil channel is formed in the side cover, lubricating oil enters the lubricating oil channel of the side cover through the oil outlet and is communicated with the intermediate gear shaft of the side cover, so that the lubrication of the intermediate gear shaft is enhanced, and the operation reliability of the intermediate gear shaft is ensured.

Furthermore, the upper shell is provided with two oil discharge grooves on the contact surface with the lower shell so as to ensure that lubricating oil accumulated in the lower shell can be thrown out in time, and preferably, the oil discharge grooves are rectangular.

The invention has the following beneficial effects: the intermediate gear is arranged on the side cover, so that the meshing backlash of the intermediate gear and the crankshaft gear can be simply and conveniently adjusted, the mounting efficiency of the balance shaft mechanism is greatly improved, and the time cost is saved. Set up casing and lower casing, go up the casing and constitute airtight space with lower casing, effectively reduced the outer hourglass of balance shaft operation noise that produces. Set up the side shroud, the gear room that the side shroud and last casing, lower casing are constituteed together plays and covers the gear, reduces the effect of gear running noise. And lubricating oil holes are processed in the upper shell and the side cover, and lubricating oil is adopted to enhance the lubrication of the sliding bearing, so that the reliability and the durability of the balance shaft mechanism are greatly improved. The oil drainage grooves formed in the two ends of the upper shell can timely drain lubricating oil accumulated in the lower shell, so that the effective power consumption and loss of the balance shaft mechanism to the engine are greatly reduced, and the dynamic property of the engine is improved. The invention is an integral assembly type, has simple installation and convenient assembly, has no influence on the processing and manufacturing of the cylinder body, belongs to modular design and installation, can be selectively assembled in a high-configuration version engine, and can be cancelled in a low-configuration version, so that the configuration of the whole engine is more flexible, and the adaptability of the engine is improved.

Drawings

FIG. 1 is a schematic view of the mounting position of the balance shaft mechanism in the engine

FIG. 2 is a schematic view of the bottom mounting of the balance shaft mechanism of the present invention

FIG. 3 is a schematic view of the overall structure of the balance shaft mechanism and the driving gear of the present invention

FIG. 4 is a schematic view of the balance shaft mechanism of the present invention

FIG. 5 is a schematic view of the side cover and the middle gear assembly of the balance shaft mechanism of the present invention

FIG. 6 is a schematic view of the side cover and the middle gear assembly of the balance shaft mechanism of the present invention

FIG. 7 is a top view of the side cover and the intermediate gear assembly of the balance shaft mechanism of the present invention

FIG. 8 is a front view of the upper housing structure of the balance shaft mechanism of the present invention

FIG. 9 is a top view of the upper housing structure of the balance shaft mechanism of the present invention

FIG. 10 is a structural view of the upper housing of the balance shaft mechanism and a schematic view of a lubricant passage in the housing according to the present invention

FIG. 11 is a top view of the lower housing of the balance shaft mechanism of the present invention

FIG. 12 is a right side view of the lower housing of the balance shaft mechanism of the present invention

FIG. 13 is a partial schematic view of a thrust structure I of the lower housing bearing block of the balance shaft mechanism of the present invention

FIG. 14 is a left side view of the lower housing of the balance shaft mechanism of the present invention

FIG. 15 is a right side view of the driven gear and balance shaft assembly of the balance shaft mechanism of the present invention

FIG. 16 is a front view of the driven gear and balance shaft assembly of the balance shaft mechanism of the present invention

FIG. 17 is a top view of the driven gear and balance shaft assembly of the balance shaft mechanism of the present invention

FIG. 18 is a right side view of the balance shaft mechanism drive gear and balance shaft assembly of the present invention

FIG. 19 is a front view of the balance shaft mechanism driving gear and balance shaft assembly of the present invention

FIG. 20 is a top view of the balance shaft mechanism driving gear and balance shaft assembly of the present invention

FIG. 21 is a view of the balance shaft mechanism of the present invention showing the driving and driven balance shafts A-A

Wherein: 1-driving gear, 2-side cover cap and middle gear assembly, 3-upper shell, 4-lower shell, 5-driving gear and balance shaft assembly, 6-driven gear and balance shaft assembly, 7-middle gear, 8-middle gear bush, 9-side cover cap, 10-middle gear shaft, 11-bolt, 12-positioning pin hole, 13-lubricating oil channel, 14-timing hole, 15-bolt tightening hole, 16-lubricating oil outlet, 17-threaded hole, 18-upper shell bearing seat hole, 19-oil unloading groove, 20-lubricating oil channel connected with main oil inlet, 21-lubricating oil main oil inlet, 22-bolt lubricating oil channel cross hole, 23-bolt tightening hole, 24-bolt hole, 25-lower shell bearing seat hole, 25-upper shell, 4-lower shell, 5-driving gear and balance shaft assembly, 6-driven gear and balance shaft assembly, 7-middle gear, 8-middle, 26-bolt tightening hole, 27-positioning pin hole, 28-positioning pin hole, 29-threaded hole, 30-thrust groove, 31-timing mark, 32-driven gear, 33-driven balance shaft, 34-timing mark hole, 35-front shaft, 36-rear shaft, 37-front thrust shoulder, 38-rear thrust shoulder, 39-balance block and 40-driving gear.

Detailed Description

The invention is described in detail below with reference to the accompanying drawings 1 to 21 and specific embodiments. The described embodiments are only some embodiments of the invention, not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1 to 4, a gear-driven integrally assembled balance shaft mechanism, which is installed at a lower end of an engine block by bolting and is driven by a driving gear 1 on a crankshaft, includes: the side cover and middle gear assembly 2, the upper shell 3, the lower shell 4, the driving gear and balance shaft assembly 5 and the driven gear and balance shaft assembly 6; the driving gear 1 is meshed with an intermediate gear 7 in the side cover and the intermediate gear assembly 2, and the driving gear 1 drives the intermediate gear to rotate through the rotation of the crankshaft of the engine.

As shown in fig. 5 to 7, the side cover and middle gear assembly 2 includes a middle gear 7, a middle gear bushing 8, a side cover 9, a middle gear shaft 10, a bolt 11, and a positioning pin hole 12, wherein the middle gear bushing 8 is a common thin-wall sliding bearing, and is in interference fit with an inner hole of the middle gear 7; after assembly, the intermediate gear 7 and the intermediate gear bush 8 are sleeved on the intermediate gear shaft 10 together, the intermediate gear bush 8 and the intermediate gear shaft 10 are in clearance fit, and the clearance is generally 0.8-1% of the diameter of the intermediate gear bush; the middle gear shaft 10 is screwed to a middle gear shaft mounting hole arranged on the side cover 9 through a bolt 11; the side cover 9 mainly functions to support the intermediate gear, and the side cover 9, the upper shell 3 and the lower shell 4 together form a gear chamber to cover the gear and reduce the running noise of the gear; in order to ensure that the bearing system formed by the intermediate gear bush 8 and the intermediate gear shaft 10 can operate well, a lubricating oil duct 13 is arranged on the side cover 9, and the diameter of the lubricating oil duct 13 is phi 3-phi 5.

Furthermore, 4 bolt tightening holes 15,1 timing hole 14 and 1 positioning pin hole are additionally arranged on the side cover cap 9, and the positioning pin is installed in the positioning pin hole 12 to play a role in accurate positioning during assembly. The timing hole 14 is positioned on the side cover 9, the timing hole 14 is positioned between the diameter of the dedendum circle and the diameter of the addendum circle of the intermediate gear 7, and the timing hole 14 has the function that when the balance shaft mechanism is assembled, the balance weights of the driving balance shaft and the driven balance shaft need to be adjusted to correct angles so as to maximize the balance rate; since the balance weight is designed to be eccentric and can automatically rotate to the gravity direction, a pin needs to be inserted into the timing hole 14 during assembly so as to fix the angular position of the intermediate gear and realize the timing function of the balance shaft mechanism.

The side cover and the intermediate gear assembly 2 are connected with the upper shell and the lower shell through bolts, wherein three bolt tightening holes 15 are matched with the threaded holes of the lower shell 3, and one bolt tightening hole 15 is matched with the threaded hole of the upper shell 4.

As shown in fig. 8 to 10, the upper case 3 is provided with two bolt lubrication passage cross holes 22 and four bolt tightening holes 23, and is connected and tightened with the lower case 4 by 6 bolts; a middle connecting lubricating oil channel is processed between the bolt lubricating oil channel cross holes 22 and is used for realizing the circulation of the bearing seat holes at the front end and the rear end of the shell; the front end of the upper shell is provided with a threaded hole 17, and the threaded hole 17 and the bolt tightening hole 15 on the side cover are screwed together through a bolt.

Furthermore, two oil discharge grooves 19 are formed in the contact surface of the upper shell 3 and the lower shell 4, the length of each oil discharge groove is 10-15, the height of each oil discharge groove is 5-10, and in the operation process of the balance shaft mechanism, lubricating oil accumulated in the lower shell 4 is thrown out of the balance shaft mechanism through the two oil discharge grooves 19 through the rotation of the driving balance shaft and the driven balance shaft; two sides of the oil drainage groove 19 are respectively provided with 3 bolt holes 24, and the 6 bolt holes are used for screwing the assembled balance shaft mechanism to the lower end surface of the cylinder body through 6 bolts; the upper shell 3 is an upper support shell of a driving balance shaft and a driven balance shaft, besides the support function, the upper shell 3 is provided with a main lubricating oil inlet 21, a lubricating oil channel 20 connected with the main oil inlet and a lubricating oil outlet 16 at the front end of the upper shell for enhancing the lubricating function on an upper bearing bush of a bearing system of the driving balance shaft and the driven balance shaft, and the main lubricating oil inlet 21 is connected with an engine oil outlet of a cylinder block through a positioning sleeve; in addition, the upper shell 3 and the lower shell 4 form a closed space, and the leakage of noise generated by the operation of the balance shaft is effectively reduced.

Furthermore, the upper shell 3 is provided with 4 bearing seat holes 18 at the front end and the rear end of the shell, the shape of each bearing seat hole is semicircular, a lubricating oil channel is arranged at the middle position of each bearing seat hole, each oil channel is a semicircular groove, the diameter of each oil channel is phi 3-5, and each oil channel is a flowing channel of lubricating oil and is used for providing the lubricating oil for the balance shaft bearing system.

As shown in fig. 11 to 14, the lower housing 4 has the same function as the upper housing 3, and is a lower support housing for the driving balance shaft and the driven balance shaft, wherein 4 bearing seat holes 25 are provided in the lower housing 4, and the size and specification of the bearing seat holes 25 are the same as those in the upper housing 3; in addition, 2 positioning pin holes 27 are arranged in the lower shell 4 and matched with positioning pin holes arranged in the upper shell 3, and the positioning pin holes are connected through positioning pins to play a positioning role in assembling the upper shell 3 and the lower shell 4; the lower shell 4 is also provided with 6 bolt screwing holes 26 which are matched with the bolt holes 24 in the upper shell 3 and used for screwing the upper shell and the lower shell through bolts; after the upper shell and the lower shell are assembled and screwed, the bearing seat hole 25 and the bearing seat hole 18 form a complete bearing seat hole, and a bearing bush is arranged in the bearing seat hole and used for ensuring the free rotation of the driving balance shaft and the driven balance shaft; in the lower shell 4, 4 semi-circular groove-shaped lubricating oil passages are respectively arranged in the bearing seat holes 25, and the diameter of each lubricating oil passage is the same as that of the upper shell 3.

Furthermore, two sides of a bearing seat hole at the front end of the lower shell 4 are respectively processed with a semicircular thrust groove 30 which is used for matching with a thrust shoulder of a driving balance shaft and a driven balance shaft to achieve the purposes of stabilizing the axial position of the balance shaft and preventing the axial displacement of the balance shaft from being overlarge, the width of the thrust groove 30 is △ 1, generally △ 1 is 0.5-1, correspondingly, the width of the two bearing seat holes is H1, H1 is larger than the width H2 of the bearing seat hole at one side of a side cover of the upper shell 3, H1-H2 is 0.5-1, the front end of the lower shell 4 is processed with three threaded holes 29 and a positioning pin hole 28 at the side surface which is attached with a cover, the three threaded holes 29 and the bolt tightening hole 15 on the side cover are screwed together through bolts, and the positioning pin hole 28 is connected with the positioning pin hole 12 on the side cover through a positioning pin.

Furthermore, the lower shell 4 is respectively provided with a timing mark 31 on the rear end face and the lower face of the balance shaft seat hole, the timing mark 31 is positioned right below the seat hole, when the balance shaft mechanism is installed, the timing needs to be performed through the timing hole 14 on the side cover 9, and at this time, the timing marks on the driving balance shaft and the driven balance shaft need to be adjusted to be overlapped with the timing mark 31 of the lower shell 4.

As shown in fig. 15 to 21, the driving gear and balance shaft assembly 5 and the driven gear and balance shaft assembly 6 have the same structure and size, except that the driving gear needs to be engaged with the intermediate gear and the driven gear on the side cover at the same time; therefore, the tooth width H3 of the driving gear 40 in the driving and balance shaft assembly 5 is larger than the tooth width H0 of the intermediate gear 7, larger than the tooth width H2 of the driven gear 32, and H3 > H0+ H2; the two balance shafts rotate at the same speed which is 2 times the speed of the crankshaft of the engine, so the number of teeth of the driving gear and the driven gear is the same as A1, and A1 is equal to half of the number of teeth A0 of the driving gear 1, namely A1 is 1/2A 0.

The driven gear and balance shaft assembly 6 mainly comprises a driven gear 32 and a driven balance shaft 33, the driven gear 32 and the driven balance shaft 33 are assembled together through interference fit, the driven balance shaft 33 is integrally cast, the driven gear and balance shaft assembly 6 mainly comprises a front shaft 35, a rear shaft 36 and a balance block 39, a front thrust shoulder 37 and a rear thrust shoulder 38 are arranged on the front shaft 35, the diameters of the front shaft 35 and the rear shaft 36 are B, the bearings in bearing seat holes in the front shaft 35, the rear shaft 36, the upper housing 3 and the lower housing 4 are in radial clearance fit, the clearance is generally (0.8-1)%, the diameter B is 10-30, the front thrust shoulder 37, the rear thrust shoulder 38, the thrust groove 30 in the upper housing 3 and the lower housing 4 are in axial clearance fit, the clearance is △%, the diameter of the middle thrust shoulder 38, the thrust groove is 10-30, the clearance is △%, the diameter of the middle thrust groove of the rear shaft 35, the driven gear and the balance shaft 35 is in a fan-shaped balance shaft 35-7-8H → 7 vertical balance shaft 35, the maximum eccentric weight of the driven balance shaft 35 is 175-7, the eccentric weight of the vertical balance shaft is marked by a vertical balance shaft → 7, the balance shaft 35, the eccentric weight of the balance shaft 35, the balance shaft is marked by a vertical balance shaft with a half-8-7, the index of a vertical balance shaft → 7-150, the eccentric weight of the balance shaft 35, the balance shaft is marked by a vertical balance shaft → 7, the central balance shaft is marked by a vertical balance shaft → 7, the central.

The lubricating oil channel of the invention is divided into two different circulation paths, one is used for lubricating a bearing system of a balance shaft, and the other is used for lubricating a bush of an intermediate gear; the flow path of the oil passage of the lubricating balance shaft bearing system is as follows: a main oil inlet 21 of lubricating oil → a lubricating oil channel 20 → a lubricating oil channel of a bearing seat hole → a cross hole 22 of bolt lubricating oil → a lubricating oil channel of a bearing seat hole; bolt lubricating oil cross hole 22 → middle connection lubricating oil channel → bolt lubricating oil cross hole 22 → bearing housing hole lubricating oil channel; the lubricating oil flow path for lubricating the idler gear bush 8 is: the upper shell lubricating oil main oil inlet 21 → the upper shell front end lubricating oil outlet 16 → the side cover lubricating oil channel 13 → the intermediate gear shaft 10.

Claims

1. The utility model provides a balanced axle mechanism of whole assembled biax of gear drive, includes casing, lower casing, driving gear and balanced axle subassembly, driven gear and balanced axle subassembly the driving gear and balanced axle subassembly and driven gear and balanced axle subassembly pass through slide bearing and install at last casing under and between the casing, it is equipped with respectively with the lower casing and is used for the installation to go up the casing semicircular bearing housing hole of bearing, has packed into the axle bush, its characterized in that in the bearing housing hole: the side cover is connected with the front end of the upper shell and the front end of the lower shell through bolts, the side cover, the upper shell and the lower shell form a gear chamber, the driving gear is meshed with the middle gear and the driven gear simultaneously, and the tooth width of the driving gear is larger than the sum of the tooth width of the middle gear and the tooth width of the driven gear.

2. The gear-driven integrally assembled biaxial balance shaft mechanism according to claim 1, characterized in that: the driving gear and balance shaft assembly comprises a driving gear and a driving balance shaft, the driving balance shaft comprises a front shaft, a balance block and a rear shaft, the driving gear and balance shaft assembly is integrally cast, and the front end of the driving balance shaft is sleeved in the driving gear in an interference manner; the driven gear and balance shaft assembly comprises a driven gear and a driven balance shaft, the driven balance shaft and the driving balance shaft comprise a front shaft, a balance block and a rear shaft which are integrally cast, and the front end of the driven balance shaft is sleeved into the driven gear in an interference manner; the side cover and the intermediate gear assembly comprise a side cover, an intermediate gear shaft and an intermediate gear bush, wherein the intermediate gear bush is in interference fit with an inner hole of the intermediate gear, the intermediate gear bush is in clearance fit with the intermediate gear shaft, and the intermediate gear shaft is connected with the side cover through bolts.

3. The gear-driven integrally assembled biaxial balance shaft mechanism according to claim 2, characterized in that: the driving balance shaft and the driven balance shaft are both arranged between the upper shell and the lower shell through the support of a common aluminum-based sliding bearing, and the intermediate gear bush is a common thin-wall sliding bearing.

4. The gear-driven integrally assembled biaxial balance shaft mechanism according to claim 2, characterized in that: and the side cover and the front end of the lower shell are respectively provided with a positioning pin hole, and the positioning pin holes are connected through positioning pins.

5. The gear-driven integrally assembled biaxial balance shaft mechanism according to claim 4, characterized in that: the side cover is provided with a timing hole, and the timing hole is positioned between the diameter of the tooth root circle and the diameter of the tooth top circle of the intermediate gear.

6. The gear-driven integrally assembled biaxial balance shaft mechanism according to claim 5, characterized in that: two timing marks are processed at the rear end of the lower shell, the positions of the two timing marks are respectively positioned under the bearing seat holes of the driving balance shaft and the driven balance shaft, and the timing mark holes are processed at the vertical downward positions of the end surfaces of the rear shafts of the driving balance shaft and the driven balance shaft.

7. The gear-driven integrally assembled biaxial balance shaft mechanism according to claim 6, characterized in that: two sides of a bearing seat hole at the front end of the lower shell are respectively machined with a semicircular thrust groove, the front shafts of the driving balance shaft and the driven balance shaft are respectively machined with a thrust shoulder, and the thrust grooves are used for being matched with the thrust shoulders.

8. The gear-driven integrally assembled biaxial balance shaft mechanism according to claim 7, characterized in that: the balance weight is of an eccentric structure.

9. The gear-driven integrally assembled biaxial balance shaft mechanism according to any one of claims 1 to 8, characterized in that: the lubricating oil inlet is arranged in the upper shell, the lubricating oil channel is communicated with the bearing seats of the driving balance shaft and the driven balance shaft and is used for enhancing lubrication of a bearing system of the driving balance shaft and the driven balance shaft, the lubricating oil outlet is arranged at the front end of the upper shell, the lubricating oil channel is processed in the side cover, the lubricating oil enters the lubricating oil channel of the side cover through the oil outlet and is communicated with the intermediate gear shaft of the side cover, and lubrication of the intermediate gear shaft is enhanced.

10. The gear-driven integrally assembled biaxial balance shaft mechanism according to claim 9, characterized in that: the upper shell is provided with two oil unloading grooves on the contact surface with the lower shell.