CN111998063A

CN111998063A - Single-arm planetary structure and gear box

Info

Publication number: CN111998063A
Application number: CN202010928397.6A
Authority: CN
Inventors: 李效龙; 金龙; 黄元; 孙京超; 陆雅朦
Original assignee: Nanjing High Speed and Accurate Gear Group Co Ltd
Current assignee: Nanjing High Speed and Accurate Gear Group Co Ltd
Priority date: 2020-09-07
Filing date: 2020-09-07
Publication date: 2020-11-27

Abstract

The invention relates to the technical field of gear boxes and discloses a single-arm type planetary structure and a gear box. Wherein single armed formula planet structure includes: the planet carrier comprises a planet carrier body and an installation shaft arranged on the planet carrier body; the needle bearing is sleeved on the mounting shaft and is in clearance fit with the mounting shaft; the planet wheel is provided with a bearing hole, and the needle bearing is assembled in the bearing hole in a clearance way; and the gear ring is meshed with the planet gear. The diameter of the bearing hole of the single-arm planetary structure is reduced, the maximum force borne by the planetary wheel during bending of the planetary wheel is improved, although the diameter of the needle bearing is reduced compared with that of the existing cylindrical roller bearing, the bearing capacity of the needle bearing is still improved to a certain extent due to the fact that the needle bearing has the characteristic of high contact rate, the diameter of the mounting shaft is increased, the rigidity and the strength of the loaded deformation of the planetary frame are increased, and the bearing capacity of the single-arm planetary structure is improved.

Description

Single-arm planetary structure and gear box

Technical Field

The invention relates to the technical field of gear boxes, in particular to a single-arm type planetary structure and a gear box.

Background

As shown in fig. 1, the conventional single-arm planetary structure is assembled by using a nitrided ring gear 100, a planetary gear 200, a cylindrical roller bearing 300, a planetary carrier 400 and the like, the planetary gear 200 is provided with a bearing hole, and the cylindrical roller bearing 300 is installed in the bearing hole. Receive the restriction in single armed formula planet structure's space, because cylindrical roller bearing 300's radial dimension is great, lead to the diameter of dead eye great, and planet carrier 400 includes planet carrier body 4001 and installation axle 4002, because the external diameter of installation axle 4002 is less, make the root of installation axle 4002 easily produce stress concentration, cause the crooked bearing capacity of planet wheel 200 and planet carrier 400's bearing capacity relatively poor, consequently, in limited design space, traditional single armed formula planet structure bearing capacity is relatively poor, can't satisfy the design demand.

Disclosure of Invention

Based on the above, the invention aims to provide a single-arm planetary structure and a gearbox, which solve the problem that the traditional single-arm planetary structure in the prior art cannot meet the design requirement due to poor bearing capacity.

In order to achieve the purpose, the invention adopts the following technical scheme:

a single-arm planetary structure comprising: the planet carrier comprises a planet carrier body and an installation shaft arranged on the planet carrier body; the needle bearing is sleeved on the mounting shaft and is in clearance fit with the mounting shaft; the planet wheel is provided with a bearing hole, and the needle bearing is assembled in the bearing hole in a clearance mode; and the gear ring is meshed with the planet gear.

As a preferable scheme of a single-arm type planetary structure, the planet carrier and the gear ring both relate to a hardening and tempering process in the machining process.

As a preferable scheme of the single-arm type planetary structure, the planet wheel is a spiral line drum-shaped planet wheel.

As an optimal scheme of the single-arm type planetary structure, the single-arm type planetary structure further comprises a tooth type spline provided with limiting steps, the tooth type spline penetrates through the arrangement of the planet carrier body, a first elastic check ring is arranged on the tooth type spline, and the planet carrier body is clamped between the first elastic check ring and the limiting steps.

As a preferable scheme of the single-arm planetary structure, a first retainer ring and a second retainer ring are sleeved on the mounting shaft, the first retainer ring is located at one end of the planetary gear to axially limit the needle roller bearing and the planetary gear, and the second retainer ring is located at the other end of the planetary gear to axially limit the needle roller bearing and the planetary gear.

As a preferable scheme of the single-arm planetary structure, a first oil hole is formed in the first retainer ring, a second oil hole is formed in the second retainer ring, and the first oil hole and the second oil hole are arranged to face the needle roller bearing.

As a preferred scheme of single armed formula planet structure, be equipped with the second circlip on the installation axle, first retaining ring presss from both sides and locates between second circlip and the bearing.

As a preferred scheme of the single-arm type planetary structure, the single-arm type planetary structure further comprises a matching inner ring, the matching inner ring is sleeved on the mounting shaft in an interference fit mode, and the needle roller bearing is in clearance fit with the matching inner ring.

As an optimal scheme of a single-arm type planetary structure, an annular chamfer is arranged on the outer ring of the connecting position of the planet carrier body and the mounting shaft.

A gearbox comprising a single-arm planetary structure as described in any of the previous aspects.

The invention has the beneficial effects that: the diameter of the bearing hole of the single-arm type planet structure is reduced, the maximum force born by the planet wheel during bending the planet wheel is improved, although the diameter of the needle bearing is reduced compared with that of the existing cylindrical roller bearing, the bearing capacity of the needle bearing is still improved to a certain extent due to the fact that the needle bearing has the characteristic of high contact rate.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the contents of the embodiments of the present invention and the drawings without creative efforts.

FIG. 1 is a cross-sectional view of a conventional single-arm planetary arrangement of the prior art;

FIG. 2 is a cross-sectional view of a single arm planetary configuration provided in accordance with an embodiment of the present invention;

FIG. 3 is an enlarged view of a portion of FIG. 2 at A;

fig. 4 is a sectional view showing a process of machining a crowned meshing tooth of the planetary gear of the present embodiment.

In the figure:

100. nitriding the gear ring; 200. a planet wheel; 300. a cylindrical roller bearing; 400. a planet carrier; 4001. a planet carrier body; 4002. installing a shaft; 500. a split spline; 5001. a tool withdrawal groove;

1. a planet carrier; 11. a planet carrier body; 12. installing a shaft; 101. annular chamfering; 2. a needle bearing; 3. a planet wheel; 301. a first meshing tooth; 302. a second meshing tooth; 303. a crowned mesh tooth; 4. a ring gear; 5. a tooth spline; 51. a limiting step; 61. a first circlip; 62. a second circlip; 71. a first retainer ring; 72. a second retainer ring; 8. the inner ring is engaged.

Detailed Description

In order to make the technical problems solved, technical solutions adopted and technical effects achieved by the present invention clearer, the technical solutions of the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and 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.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Wherein the terms "first position" and "second position" are two different positions.

In the description of the present invention, it should be noted that unless otherwise explicitly stated or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection or a removable connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

As shown in fig. 2 and fig. 3, the present embodiment provides a single-arm planetary structure for a gearbox, including planet carrier 1, needle roller bearing 2, planet wheel 3 and ring gear 4, planet carrier 1 includes planet carrier body 11 and installation axle 12 that locates on planet carrier body 11, needle roller bearing 2 cover is located on installation axle 12 and needle roller bearing 2 and installation axle 12 clearance fit, is equipped with the bearing hole on planet wheel 3, and needle roller bearing 2 clearance fit is in the bearing hole, and ring gear 4 meshes with planet wheel 3.

The diameter of the bearing hole of the single-arm planetary structure provided by the embodiment is reduced, so that the radial outermost end of the bearing hole is increased in the radial distance from the outermost ring of the planetary wheel 3, the maximum force which the planetary wheel 3 can bear when the planetary wheel 3 is bent is increased, although the diameter of the needle bearing 2 is reduced compared with that of the existing cylindrical roller bearing 30, because the needle bearing 2 has the characteristic of high contact rate, the bearing capacity of the needle bearing 2 is still improved to a certain extent, compared with the traditional single-arm planetary structure, the diameter of the mounting shaft 12 of the embodiment is increased, the rigidity and the strength of the loaded deformation of the planetary carrier 1 are increased, the bearing capacity of the single-arm planetary structure of the embodiment is improved, and the design requirement can be met.

Specifically, the mounting shaft 12 of the present embodiment is formed as an integrally formed structure with the carrier body 11 by forging. Quenching and tempering processes are involved in the processing processes of the planet carrier 1 and the gear ring 4, so that the planet carrier 1 and the gear ring 4 have excellent comprehensive mechanical properties, namely, high strength and high toughness are properly matched, the load balancing performance of the planet carrier 1 and the gear ring 4 is improved, and the single-arm type planet structure can work smoothly for a long time.

It should be noted that, as shown in fig. 2, the mounting shaft 12 is not cut away, and the outer ring of the connection position of the planet carrier body 11 and the mounting shaft 12 of the present embodiment is provided with an annular chamfer 101, and the size of the annular chamfer 101 is increased as much as possible to reduce the stress concentration at the root of the mounting shaft 12.

In order to make the needle roller bearing 2 be better assembled on the mounting shaft 12, as shown in fig. 2 and 3, the single-arm planetary structure of the present embodiment further includes a fitting inner ring 8, the fitting inner ring 8 is interference-fitted on the mounting shaft 12, and the needle roller bearing 2 is in clearance fit with the fitting inner ring 8. Because the planet carrier 1 is of an integral structure, the planet carrier 1 cannot be subjected to carburizing and quenching heat treatment, the structure of the surface of the planet carrier 1 cannot meet the installation accuracy and the installation strength of the needle bearing 2, the inner ring 8 is matched to carry out the carburizing and quenching heat treatment, and the outer surface of the inner ring 8 is ground, so that the assembly accuracy and the installation strength are met.

In the prior art, as shown in fig. 1, a planet gear 200 is a straight-tooth type planet gear, a nitrided ring gear 100 and the planet gear 200 are in rigid engagement, the engagement contact rate in the tooth width and tooth height directions is poor, the load balancing performance between the planet gears 200 is also poor, and particularly for the structure of multiple groups of planet gears 200, the load balancing performance is worse. The planet wheels 3 of the present embodiment are helical drum planet wheels. Specifically, as shown in fig. 4, firstly, a plurality of rectangular first engaging teeth 301 are machined on the side surface of a blank for machining the planet wheel 3, then machining is performed from one end to the other end of the first engaging teeth 301 along the axial direction of the first engaging teeth 301 to form second engaging teeth 302, the tooth width of the second engaging teeth 302 is gradually reduced, and the difference between the maximum tooth width and the minimum tooth width of the second engaging teeth 302 is smaller and is about 0.04mm, namely, the first engaging teeth 301 are helically modified to form the second engaging teeth 302, then the second engaging teeth 302 are machined into a crowned engaging teeth 303, the periphery with the largest tooth width of the crowned engaging teeth 303 is located in the middle of the side surface of the second engaging teeth 302, and the planet wheel 3 of the crowned engaging teeth 303 is a helical planet wheel.

Specifically, because the quenching and tempering technology is involved in the processing of the gear ring 4, the hardness of the gear ring 4 is low, and when the gear ring 4 is meshed with the planet wheel 3, the gear ring 4 can be extruded by the first inclined end face and the second inclined end face on the planet wheel 3, the phenomenon of meshing unbalance loading caused by the stress deformation of the planet carrier 3 is avoided, the tooth direction load distribution coefficient and the end face load distribution coefficient when the planet wheel 3 is meshed with the gear ring 4 are reduced, the load balancing performance of the gear ring 4 and the planet wheel 3 is improved, the meshing contact rate in the tooth direction and the meshing contact rate in the tooth profile direction when the planet wheel 3 is meshed with the gear ring 4 are improved, the bearing capacity of the meshing of the planet wheel 3 and the gear ring 4 is improved, and the gear ring 4 can be better meshed with the planet wheel 3.

As shown in fig. 2, the single-arm planetary structure of the present embodiment further includes a tooth spline 5 having a limiting step 51, the tooth spline 5 is not cut away in the drawing, a mounting hole (not shown in the drawing) is formed in the planet carrier body 11, the tooth spline 5 penetrates through the mounting hole, a first elastic collar 61 is arranged on the tooth spline 5, and the planet carrier body 11 is clamped between the first elastic collar 61 and the limiting step 51. The tooth spline 5 of the present embodiment replaces the existing split spline 500, as shown in fig. 1, because the relief groove 5001 exists on the split spline 500, the load bearing capacity of the split spline 500 at the relief groove 5001 is the lowest, and the split spline 500 is prone to fracture at the relief groove 5001. Compared with the existing split type spline 500, the tooth type spline 5 of the embodiment cancels the tool withdrawal groove 5001, and avoids the phenomenon that the split type spline 500 is easy to break at the tool withdrawal groove 5001, so that the bearing capacity of the tooth type spline 5 of the embodiment is improved, and the bearing capacity of the single-arm type planetary structure is improved.

As shown in fig. 2, the mounting shaft 12 of the present embodiment is sleeved with a first retaining ring 71 and a second retaining ring 72, the first retaining ring 71 is located at one end of the planetary gear 3 to axially retain the needle roller bearing 2 and the planetary gear 3, and the second retaining ring 72 is located at the other end of the planetary gear 3 to axially retain the needle roller bearing 2 and the planetary gear 3. As shown in fig. 2 and 3, the mounting shaft 12 is provided with a second circlip 62 that can axially limit the first circlip 71, and the first circlip 71 is interposed between the second circlip 62 and the needle bearing 2.

In the present embodiment, the first retainer ring 71 is provided with a first oil hole (not shown), the second retainer ring 72 is provided with a second oil hole (not shown), and both the first oil hole and the second oil hole are disposed opposite to the needle roller bearing 2, so that the lubricating oil can enter the needle roller bearing 2 through the first oil hole and the second oil hole or be discharged from the needle roller bearing 2, and the lubricating oil can not only lubricate the needle roller bearing 2, but also take away heat generated by the needle roller bearing 2 during rotation to cool the needle roller bearing 2.

Specifically, when the needle roller bearing 2 works, the lubricating oil entering the needle roller bearing 2 through the first oil hole and the second oil hole can lubricate the needle roller bearing 2, oil films can be formed between a needle roller of the needle roller bearing 2 and an inner ring of the needle roller bearing 2 and between the needle roller bearing 2 and an assembly inner ring, the damage to the needle roller bearing 2 or the assembly inner ring 8 caused by self dry friction or dry friction with the assembly inner ring 8 in the working process of the needle roller bearing 2 is avoided, in addition, the temperature of the lubricating oil in the needle roller bearing 2 is increased due to the friction effect, the lubricating oil can take away heat generated by the needle roller bearing 2 in the rotating process, and the lubricating oil is prevented from blocking the rotation of the needle roller bearing 2 due to high-.

The single-arm planetary structure that this embodiment provided, in limited design space, all relate to quenching and tempering technology when processing planet carrier 1 and ring gear 4, diameter through increasing installation axle 12, reduce the diameter of dead eye, make the dead eye along radial outermost end and the outermost circle of planet wheel 3 increase at radial distance, the rigidity and the intensity of planet carrier 1 and planet wheel 3 have been improved, install bearing 2 in the dead eye, make bearing 2's bearing capacity promote, planet carrier body 11 is equipped with annular chamfer 101 as big as possible of size with the outer lane of the hookup location of installation axle 12, reduce the stress concentration of installation axle 12 root, the helix drum-shaped planet wheel of taking helical tooth, can increase the bearing capacity of planet wheel 3 with the ring gear 4 meshing, guarantee single-arm planetary structure's stability and reliability of operation.

The embodiment also provides a gearbox which comprises the single-arm type planetary structure.

The gearbox of the embodiment has the single-arm type planetary structure, so that the bearing capacity of the single-arm type planetary structure of the gearbox is improved, and the design requirement can be met.

It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A single-arm planetary structure, comprising:

the planet carrier (1) comprises a planet carrier body (11) and a mounting shaft (12) arranged on the planet carrier body (11);

the needle roller bearing (2) is sleeved on the mounting shaft (12), and the needle roller bearing (2) is in clearance fit with the mounting shaft (12);

the planet wheel (3) is provided with a bearing hole, and the needle roller bearing (2) is assembled in the bearing hole in a clearance mode;

a gear ring (4), the gear ring (4) being in mesh with the planet wheel (3).

2. The single-arm planetary structure according to claim 1, wherein the planet carrier (1) and the ring gear (4) are processed by a quenching and tempering process.

3. The single-arm planetary arrangement according to claim 1, characterized in that the planet (3) is a helical drum planet.

4. The single-arm planetary structure according to claim 1, further comprising a tooth spline (5) having a limit step (51), wherein the tooth spline (5) is disposed through the planet carrier body (11), a first elastic check ring (61) is disposed on the tooth spline (5), and the planet carrier body (11) is sandwiched between the first elastic check ring (61) and the limit step (51).

5. The single-arm planetary structure according to claim 1, wherein the mounting shaft (12) is sleeved with a first retainer ring (71) and a second retainer ring (72), the first retainer ring (71) is located at one end of the planetary wheel (3) to axially retain the needle bearing (2) and the planetary wheel (3), and the second retainer ring (72) is located at the other end of the planetary wheel (3) to axially retain the needle bearing (2) and the planetary wheel (3).

6. The single-arm planetary structure according to claim 5, wherein a first oil hole is provided in the first retainer ring (71), a second oil hole is provided in the second retainer ring (72), and the first oil hole and the second oil hole are provided to face the needle roller bearing (2).

7. The single-arm planetary structure according to claim 5, wherein a second circlip (62) is provided on the mounting shaft (12), and the first circlip (71) is interposed between the second circlip (62) and the needle roller bearing (2).

8. The single-arm planetary structure according to claim 1, further comprising a mating inner ring (8), wherein the mating inner ring (8) is arranged on the mounting shaft (12) in an interference fit manner, and the needle roller bearing (2) is in clearance fit with the mating inner ring (8).

9. The single-arm planetary structure according to claim 1, wherein an outer ring of a connection position of the planet carrier body (11) and the mounting shaft (12) is provided with an annular chamfer (101).

10. A gearbox comprising a single-arm planetary structure according to any one of claims 1 to 9.