Fixed-shaft helical gear reducer and uniform load method thereof

Abstract

According to the fixed-shaft helical gear speed reducer, a planetary structure with the first-stage driving gear and the second-stage driven gear as center gears and the duplicate gear as a planet gear is formed, the planet carrier provided with the duplicate gear is fixed to the shell and does not participate in transmission, power is transmitted to the output shaft only through autorotation of the duplicate gear, the influence of the centrifugal force of the planet carrier is avoided, and the transmission efficiency is improved. The large transmission ratio application requirement in a compact space is met; helical gear meshing errors caused by gear manufacturing and assembling are compensated through radial floating of the first-stage driving gear and the second-stage driven gear, so that all duplicate gears are evenly borne, abrasion of gear faces is reduced, transmission noise is lowered, structural stability is improved, the fault rate of the speed reducer is lowered, and the service life of the speed reducer is prolonged. The invention further provides a load balancing method of the fixed-shaft helical gear reducer.

Description

TECHNICAL FIELD

[0001] The present application relates to a fixed shaft helical gear reducer and a load sharing method thereof, and belongs to the technical field of gear reducers. BACKGROUND

[0002] With the increasing power density of the motor, the large torque and high speed technology route gradually integrate, which puts forward the requirements of bearing large torque, high speed, compact structure and low noise for the reducer. The planetary reduction structure is an important development direction due to its unique power split design, high stability brought by symmetrical force and compactness brought by coaxial structure. However, the planetary structure has the following defects: 1. In the planetary structure, the sun gear is used as the input power to drive the planetary gear to rotate, and the planetary gear drives the planet carrier to rotate to form power transmission. The planet carrier has a large volume and weight, and a large centrifugal force is generated during high-speed rotation, which increases the load of the planetary gear and bearing assembled on the planet carrier, affects the reliability of transmission, limits the speed ratio improvement of the planetary structure, and is not suitable for application scenarios with limited space but requiring large transmission ratio.

[0003] 2. Due to manufacturing and assembly errors, the sizes of the meshing of the sun gear and the planetary gears have certain differences, which causes uneven load of each planetary gear during transmission, accelerates the wear of the gear surface, increases the noise, affects the transmission stability, and shortens the service life of the planetary structure.

[0004] 3. In order to adapt to the transmission of large torque and improve the carrying capacity, the helical gear is mostly used in the planetary structure, but the axial force is formed during the operation of the helical gear, which is transmitted to the assembled bearing, accelerates the wear of the bearing, and also affects the service life of the planetary structure. SUMMARY

[0005] The fixed shaft helical gear reducer provided by the present application avoids the influence of the centrifugal force of the planet carrier, meets the application requirements of large transmission ratio in a compact space, and uses the radial floating of the primary driving gear and the secondary driven gear to compensate for the helical gear meshing error caused by gear manufacturing and assembly, so that each double gear uniformly bears, reduces the wear of the gear surface, reduces the transmission noise, improves the stability of the structure, thereby reduces the failure rate of the reducer, and prolongs the service life of the reducer. The present application also provides a load sharing method of the fixed shaft helical gear reducer.

[0006] To achieve the above purpose, the technical scheme adopted by the present application is: The application relates to a fixed-shaft helical gear reducer, which comprises an input shaft, a primary reduction gear set, a secondary reduction gear set and an output shaft which are sequentially connected in transmission, and the input shaft and the output shaft are coaxially aligned, characterized in that the primary reduction gear set is composed of a primary driving gear and a primary driven gear which forms helical gear engagement with the primary driving gear, the secondary reduction gear is composed of a secondary driving gear and a secondary driven gear which forms helical gear engagement with the secondary driving gear, the primary driving gear is gap-fitted on the input shaft and forms spline connection with the input shaft, the secondary driven gear is gap-fitted on the output shaft and forms spline connection with the output shaft, the primary driven gear and the secondary driving gear are coaxially fixed to form a double gear, and the double gear is rotatably assembled on a planet carrier which is fixed with a housing of the reducer and is uniformly distributed along the circumference of the primary driving gear.

[0007] Preferably, the planet carrier seals the front end of the housing, the front end of the double gear is rotatably assembled on the planet carrier, and the rear end is rotatably assembled on the housing.

[0008] Preferably, the primary driven gear is press-fitted on the secondary driving gear, the front end of the secondary driving gear is press-fitted with a cylindrical roller bearing I, the rear end is press-fitted with a cylindrical roller bearing II, the cylindrical roller bearing I is assembled on the planet carrier, and the cylindrical roller bearing II is assembled on the housing.

[0009] Preferably, the front end of the input shaft penetrates out of the planet carrier, the rear end of the output shaft penetrates out of the rear end of the housing, a tapered roller bearing I and a tapered roller bearing II are press-fitted on the input shaft, and a tapered roller bearing III is press-fitted on the output shaft, the tapered roller bearing I is supported between the input shaft and the planet carrier, the tapered roller bearing II is supported between the input shaft and the secondary driven gear, and the tapered roller bearing III is supported between the output shaft and the housing.

[0010] Preferably, an axial positioning ring I is integrally formed on the input shaft, an axial positioning ring II is integrally formed on the output shaft, the primary driving gear is axially positioned between the tapered roller bearing I and the axial positioning ring I, the front end of the tapered roller bearing II abuts against the axial positioning ring I, the secondary driven gear is axially positioned between the tapered roller bearing II and the axial positioning ring II, and the tapered roller bearing III is axially positioned between the axial positioning ring II and the housing.

[0011] Preferably, an axial stop ring is clamped on the output shaft and extends into an annular groove formed on the secondary driven gear.

[0012] The load sharing method of the fixed-shaft helical gear reducer is characterized in that: Adjust the fit clearance between the input shaft and the primary driving gear to control the radial floating amount of the primary driving gear on the input shaft, and adjust the fit clearance between the output shaft and the secondary driven gear to control the radial floating amount of the secondary driven gear on the output shaft, and compensate for the manufacturing and assembly errors of the primary reduction gear set and the secondary reduction gear set through the radial floating of the primary driving gear and the secondary driven gear during transmission, so that each double gear is uniformly loaded.

[0013] Preferably, Adjust the helix angle of the helical gear on the primary driven gear and the helix angle of the helical gear on the secondary driving gear, so that the axial force of the primary driven gear and the axial force of the secondary driving gear form a pair of balanced forces with equal size and opposite direction during transmission, forming axial force balance on the double gear, eliminating the axial load of the cylindrical roller bearing one and the cylindrical roller bearing two, so that the cylindrical roller bearing one and the cylindrical roller bearing two only bear the radial load formed during the rotation of the double gear.

[0014] The beneficial effects of the application are: The input shaft and the output shaft of the fixed shaft helical gear reducer are coaxially aligned, power is input to the input shaft, and is sequentially output from the output shaft through the primary driving gear, the primary driven gear, the secondary driving gear and the secondary driven gear. The primary driven gear and the secondary driving gear are coaxially fixed to form a double gear, which is engaged with the outer periphery of the primary driving gear and the secondary driven gear, forming a planetary structure with the primary driving gear and the secondary driven gear as the center wheel and the double gear as the planetary gear. The planetary carrier of the double gear is fixed with the housing and does not participate in transmission, and only transmits power to the output shaft through the rotation of the double gear, avoiding the influence of centrifugal force of the planetary carrier, adapting to high-speed transmission scenarios, increasing the transmission ratio through the engagement of two center wheels and multiple double gears, reducing the number of series transmission stages, simplifying the transmission structure, and meeting the application requirements of large transmission ratio in compact space. The primary driving gear and the secondary driven gear are gap-fitted with the input shaft and the output shaft, respectively, so that the primary driving gear can radially float on the input shaft, and the secondary driven gear can radially float on the output shaft. The radial floating of the primary driving gear and the secondary driven gear compensates for the helical gear meshing error caused by gear manufacturing and assembly, so that multiple double gears are uniformly meshed with the primary driving gear and the secondary driven gear during transmission, and each double gear is uniformly loaded, reducing the wear of the gear surface, reducing the transmission noise, improving the stability of the structure, thereby reducing the failure rate of the reducer and prolonging the service life of the reducer.

[0015] By adjusting the helix angle of the helical gear on the primary driven gear and the helix angle of the helical gear on the secondary driving gear, the axial force of the primary driven gear is equal to the axial force of the secondary driving gear, a pair of balanced forces with equal size and opposite direction are formed, the axial force balance is formed on the double gear, the axial load of the cylindrical roller bearing one and the cylindrical roller bearing two at both ends of the double gear is eliminated, both cylindrical roller bearings only bear radial load, the bearing load is reduced, the wear is reduced, and the bearing life is improved. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a schematic view of the fixed shaft helical gear reducer of the application.

[0017] Figure 2 It is an assembly schematic view of the input shaft, the primary reduction gear set, the secondary reduction gear set and the output.

[0018] Figure 3 It is a partial enlarged schematic view of Figure 1 . DETAILED DESCRIPTION

[0019] The embodiments of the application will be described in detail below. Figures 1-3 The embodiments of the application will be described in detail below.

[0020] The fixed shaft helical gear reducer comprises an input shaft 1, a primary reduction gear set, a secondary reduction gear set and an output shaft 2 connected in sequence, and the input shaft 1 and the output shaft 2 are coaxially aligned, characterized in that the primary reduction gear set is composed of a primary driving gear 3 and a primary driven gear 4 in helical gear engagement with the primary driving gear 3, the secondary reduction gear is composed of a secondary driving gear 5 and a secondary driven gear 6 in helical gear engagement with the secondary driving gear 5, the primary driving gear 3 is gap-fitted on the input shaft 1 and forms a spline connection with the input shaft 1, the secondary driven gear 6 is gap-fitted on the output shaft 2 and forms a spline connection with the output shaft 2, the primary driven gear 4 and the secondary driving gear 5 are coaxially fixed to form a double gear 7, the double gear 7 is rotatably assembled on a planet carrier 9 fixed with the housing 8 of the reducer, and is uniformly distributed along the circumference of the primary driving gear 3.

[0021] The above-mentioned fixed shaft helical gear reducer, the input shaft 1 is coaxial with the output shaft 2, the power is input to the input shaft 1, and is sequentially output from the output shaft 2 through a primary driving gear 3, a primary driven gear 4, a secondary driving gear 5, and a secondary driven gear 6. The primary driven gear 4 and the secondary driving gear 5 are coaxially fixed to form a double gear 7, which is engaged with the outer periphery of the primary driving gear 3 and the secondary driven gear 6, forming a planetary structure with the primary driving gear 3 and the secondary driven gear 6 as the center gears and the double gear 7 as the planetary gear. The planetary carrier 9 assembled with the double gear 7 is fixed with the housing 8 and does not participate in transmission, and only transmits power to the output shaft 2 through the rotation of the double gear 7, avoiding the influence of the centrifugal force of the planetary carrier, and can adapt to high-speed transmission scenarios. By engaging the two center gears and multiple double gears, the transmission ratio is increased, the number of series transmission stages is reduced, the transmission structure is simplified, and the application requirements of large transmission ratio in compact space are met. The primary driving gear 3 and the secondary driven gear 6 are respectively gap-fitted with the input shaft 1 and the output shaft 2, so that the primary driving gear 3 can radially float on the input shaft 1, and the secondary driven gear 6 can radially float on the output shaft 2. The radial floating of the primary driving gear 3 and the secondary driven gear 5 compensates for the helical gear meshing error caused by gear manufacturing and assembly, so that multiple double gears 7 are uniformly meshed with the primary driving gear 3 and the secondary driven gear 6 during transmission, each double gear 7 is uniformly loaded, the wear of the gear surface is reduced, the transmission noise is reduced, the stability of the structure is improved, thereby reducing the failure rate of the reducer and prolonging the service life of the reducer.

[0022] Among them, the planetary carrier 9 seals the front end of the housing 8, and the double gear 7 is rotatably assembled on the front end of the planetary carrier 9 and rotatably assembled on the rear end of the housing 8. The planetary carrier 9 is used as the front end cover of the housing 8, the front end of the housing 8 is sealed, the planetary carrier 9 is fixed and does not rotate, and the structure of the reducer housing is simplified, the structural compactness is improved, and the space utilization rate in the housing is improved.

[0023] The first driven gear 4 is pressed on the second driving gear 5, the front end of the second driving gear 5 is pressed on the cylindrical roller bearing 10, the rear end is pressed on the cylindrical roller bearing 11, the cylindrical roller bearing 10 is assembled on the planet carrier 9, and the cylindrical roller bearing 11 is assembled on the housing 8. As shown in the drawings, the second driving gear 5 is a gear shaft integrated with the shaft, the first driven gear 4 is pressed on the shaft shoulder of the second driving gear 5, and the rotational direction of the first driven gear 4 and the second driving gear 5 is the same during transmission. Therefore, the axial force of the first driven gear 4 due to the helical gear transmission is opposite to the axial force of the second driving gear 5 due to the helical gear transmission. By adjusting the helix angle of the helical gear on the first driven gear 4 and the helix angle of the helical gear on the second driving gear 5, the axial force of the first driven gear 4 is equal to the axial force of the second driving gear 5, forming a pair of balanced forces with equal size and opposite direction, balancing the axial force on the double gear 7, eliminating the axial load of the cylindrical roller bearing 10 and the cylindrical roller bearing 11 at both ends of the double gear 7, and reducing the bearing load, wear and bearing life.

[0024] The front end of the input shaft 1 is out of the planet carrier 9, the rear end of the output shaft 2 is out of the rear end of the housing 8, the tapered roller bearing 12 and the tapered roller bearing 13 are pressed on the input shaft 1, the tapered roller bearing 14 is pressed on the output shaft 2, the tapered roller bearing 12 is supported between the input shaft 1 and the planet carrier 9, the tapered roller bearing 13 is supported between the input shaft 1 and the second driven gear 6, and the tapered roller bearing 14 is supported between the output shaft 2 and the housing 8. As shown in the drawings, the tapered roller bearing 12, the tapered roller bearing 13 and the tapered roller bearing 14 form coaxial support for the input shaft 1 and the output shaft 2, the tapered roller bearing has a centering function, and the centering function of the three tapered roller bearings can also provide a certain radial floating amount for the first driving gear 3 and the second driven gear 6, increase the radial floating amount of the first driving gear 3 and the second driven gear 6 during transmission, further improve the load balancing reliability of each double gear 7, make the transmission structure have good load balancing effect, improve the transmission stability, further reduce the noise, and prolong the service life.

[0025] Wherein, the input shaft 1 is integrally formed with an axial positioning ring 15, the output shaft 2 is integrally formed with an axial positioning ring 16, the primary driving gear 3 is axially positioned between the conical roller bearing 12 and the axial positioning ring 15, the front end of the conical roller bearing 13 abuts against the axial positioning ring 15, the secondary driven gear 6 is axially positioned between the conical roller bearing 13 and the axial positioning ring 16, and the conical roller bearing 14 is axially positioned between the axial positioning ring 16 and the housing 8.

[0026] Wherein, the output shaft 2 is clamped with an axial blocking ring 17, the axial blocking ring 17 extends into the annular groove formed in the secondary driven gear 6. The conical roller bearing 13 axially positions the input shaft 1 and the secondary driven gear 6, the secondary driven gear 6 is axially positioned with the output shaft 2 by the axial blocking ring 17, the input shaft 1 and the output shaft 2 are axially separated and not in contact, the axial load of the conical roller bearing 13 is reduced, the axial load of the conical roller bearing 12 and the conical roller bearing 13 is reduced, and the bearing life is prolonged.

[0027] The application also protects a load sharing method of the axial bevel gear reducer, which is characterized in that: The matching gap between the input shaft 1 and the primary driving gear 3 is adjusted to control the radial floating amount of the primary driving gear 3 on the input shaft 1, the matching gap between the output shaft 2 and the secondary driven gear 6 is adjusted to control the radial floating amount of the secondary driven gear 6 on the output shaft 2, the manufacturing and assembly errors of the primary reduction gear set and the secondary reduction gear set are compensated by the radial floating of the primary driving gear 3 and the secondary driven gear 6 during transmission, and each double gear 7 is uniformly loaded.

[0028] The even load method adjusts the fit clearance between the input shaft 1 and the primary driving gear 3, adjusts the fit clearance between the output shaft 2 and the secondary driven gear 6, controls the radial floating amount of the primary driving gear 3 on the input shaft 1 and the radial floating amount of the secondary driven gear 6 on the output shaft 2, compensates for the helical gear meshing error caused by gear manufacturing and assembly through the radial floating of the primary driving gear 3 and the secondary driven gear 5, makes the multiple double gears 7 evenly mesh with the primary driving gear 3 and the secondary driven gear 6 during transmission, makes each double gear 7 evenly loaded, reduces the wear of the gear surface, reduces the transmission noise, improves the stability of the structure, thereby reduces the failure rate of the speed reducer, and prolongs the service life of the speed reducer.

[0029] The helix angle of the helical gear on the primary driven gear 4 and the helix angle of the helical gear on the secondary driving gear 5 are adjusted, so that the axial force of the primary driven gear 4 and the axial force of the secondary driving gear 5 form a pair of balanced forces with equal size and opposite direction during transmission, axial force balance is formed on the double gear, and the axial load of the cylindrical roller bearing one 10 and the cylindrical roller bearing two 11 is eliminated, so that the cylindrical roller bearing one 10 and the cylindrical roller bearing two 11 only bear the radial load formed during the rotation of the double gear 7. Since the rotation direction of the primary driven gear 4 and the secondary driving gear 5 is the same during transmission, the axial force of the primary driven gear 4 due to helical gear transmission is exactly opposite to the axial force of the secondary driving gear 5 due to helical gear transmission. By adjusting the helix angle of the helical gear on the primary driven gear 4 and the helix angle of the helical gear on the secondary driving gear 5, the axial force of the primary driven gear 4 and the axial force of the secondary driving gear 5 are equal, forming a pair of balanced forces with equal size and opposite direction, axial force balance is formed on the double gear 7, and the axial load of the cylindrical roller bearing one 10 and the cylindrical roller bearing two 11 at both ends of the double gear 7 is eliminated. Both cylindrical roller bearings only bear radial load, reduce the load on the bearings, reduce wear, and improve bearing life.

[0030] The technical solutions of the embodiments of the application are described in detail above in combination with the drawings. It should be noted that the described embodiments are only a part of the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the application.

Claims

1. A fixed-axis helical gear reducer, comprising an input shaft, a first-stage reduction gear set, a second-stage reduction gear set, and an output shaft connected in sequence, wherein the input shaft and the output shaft are coaxially aligned, characterized in that: The primary reduction gear set is composed of a primary driving gear and a primary driven gear in helical gear engagement with the primary driving gear, and the secondary reduction gear set is composed of a secondary driving gear and a secondary driven gear in helical gear engagement with the secondary driving gear, the primary driving gear is gap-fitted on the input shaft and is in spline connection with the input shaft, the secondary driven gear is gap-fitted on the output shaft and is in spline connection with the output shaft, the primary driven gear and the secondary driving gear are coaxially fixed to form a double gear, the double gear is rotatably assembled on the planet carrier fixed with the housing of the reducer, and is uniformly distributed along the circumference of the primary driving gear.

2. The fixed-axle helical gear reducer of claim 1, wherein: The planet carrier seals the front end of the housing, the front end of the double gear is rotatably assembled on the planet carrier, and the rear end is rotatably assembled on the housing.

3. The fixed-axle helical gear reducer of claim 2, wherein: The primary driven gear is press-fitted on the secondary driving gear, the front end of the secondary driving gear is press-fitted with a cylindrical roller bearing 1, and the rear end is press-fitted with a cylindrical roller bearing 2, the cylindrical roller bearing 1 is assembled on the planet carrier, and the cylindrical roller bearing 2 is assembled on the housing.

4. The fixed-axle helical gear reducer of claim 1, wherein: The front end of the input shaft passes out of the planet carrier, the rear end of the output shaft passes out of the rear end of the housing, a tapered roller bearing 1 and a tapered roller bearing 2 are press-fitted on the input shaft, and a tapered roller bearing 3 is press-fitted on the output shaft, the tapered roller bearing 1 is supported between the input shaft and the planet carrier, the tapered roller bearing 2 is supported between the input shaft and the secondary driven gear, and the tapered roller bearing 3 is supported between the output shaft and the housing.

5. The fixed-axle helical gear reducer of claim 4, wherein: An axial positioning ring 1 is integrally formed on the input shaft, an axial positioning ring 2 is integrally formed on the output shaft, the primary driving gear is axially positioned between the tapered roller bearing 1 and the axial positioning ring 1, the front end of the tapered roller bearing 2 abuts against the axial positioning ring 1, the secondary driven gear is axially positioned between the tapered roller bearing 2 and the axial positioning ring 2, and the tapered roller bearing 3 is axially positioned between the axial positioning ring 2 and the housing.

6. The fixed-axle helical gear reducer of claim 4, wherein: An axial stop ring is clamped on the output shaft, and the axial stop ring extends into the annular groove formed in the secondary driven gear.

7. The method for uniform load of the fixed shaft helical gear reducer according to any one of claims 1 to 6, characterized in that: The fitting clearance between the input shaft and the primary driving gear is adjusted to control the radial floating amount of the primary driving gear on the input shaft, the fitting clearance between the output shaft and the secondary driven gear is adjusted to control the radial floating amount of the secondary driven gear on the output shaft, and the manufacturing and assembly errors of the primary reduction gear set and the secondary reduction gear set are compensated by the radial floating of the primary driving gear and the secondary driven gear during transmission, so that each double gear is uniformly loaded.

8. The method for uniform load of the fixed shaft helical gear reducer according to claim 7, characterized in that: The helix angles of the helical gears on the primary driven gear and the secondary driving gear are adjusted, so that the axial forces of the primary driven gear and the secondary driving gear during transmission form a pair of balanced forces with equal size and opposite direction, the axial force balance is formed on the double gear, the axial load of the cylindrical roller bearing 1 and the cylindrical roller bearing 2 is eliminated, and the cylindrical roller bearing 1 and the cylindrical roller bearing 2 only bear the radial load formed during the rotation of the double gear.

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