CN212360709U

CN212360709U - Worm wheel for worm gear speed reducer of steering system and speed reducer

Info

Publication number: CN212360709U
Application number: CN202021240311.2U
Authority: CN
Inventors: 史俊华
Original assignee: Hubei Henglong Kaiwanbi Electric Steering System Co ltd
Current assignee: Hubei Henglong Kaiwanbi Electric Steering System Co ltd
Priority date: 2020-06-30
Filing date: 2020-06-30
Publication date: 2021-01-15
Anticipated expiration: 2030-06-30

Abstract

The utility model belongs to the technical field of the auto steering, concretely relates to a worm wheel and decelerator for a steering system worm gear decelerator. A worm wheel for a worm gear speed reducer of a steering system comprises a gear ring, a hub, an end cover and a screw, wherein the gear ring is provided with a circle of first through holes; one side of the hub is provided with a round nut matched with the first through hole; the end cover is provided with a second through hole corresponding to the first through hole; the gear ring and the end cover clamp the hub in the middle, and the round nut is sleeved with the elastic ring and inserted into the corresponding first through hole; and the screw penetrates through the second through hole and is screwed in the round nut to fixedly connect the gear ring, the hub and the end cover. The utility model is used for solve among the prior art because of the worm gear meshing tooth wearing and tearing produce the noise problem that the clearance leads to.

Description

Worm wheel for worm gear speed reducer of steering system and speed reducer

Technical Field

The utility model belongs to the technical field of the auto steering, concretely relates to a worm wheel and decelerator for a steering system worm gear decelerator.

Background

During normal driving, the automobile turns left and right, and straight driving is the three most common basic motion actions of the automobile. In order to ensure the stable running of the automobile, a set of mechanism is arranged between the steering wheels of the automobile to complete the running track of the automobile, and the mechanism for flexibly changing the running direction of the automobile is called as the steering system of the automobile, is connected to the steering wheel of the automobile cab in a rigid or flexible mode and is directly controlled by a driver. In China, the circulating ball type hydraulic power-assisted steering gear is widely adopted by commercial vehicles, bus cars, large pickup trucks and engineering vehicles. The light passenger car, small pickup, commercial car, car and mini car mostly adopt the gear rack power steering gear. The rack and pinion power steering gear is classified in more detail according to the power type, such as HPS with pure hydraulic power, E-HPS with electric control element for hydraulic power, C-EPS with pure electric column power, SP-EPS/DP-EPS with pure electric gear power, R-EPS with pure electric rack power, mechanical steering gear MS without power by pure hand, and the like. The steering gear systems are all prototypes by using gear and rack mechanical transmission, and different power-assisted steering systems are added on the basis.

Pure electric power assisted steering system (EPS) relies on the car to provide the electric energy, and drive electric motor provides source power, through a set of decelerator, turns into the torque output of high moment of torsion, low rotational speed with electric motor high rotational speed, low torque characteristic, provides the required driving force that turns to for the wheel to make the driver obtain lightly, comfortable driving impression. A reduction gear applied to a pure electric power-assisted steering system generally adopts a worm and gear reduction gear in a pure electric tubular column type power-assisted C-EPS and a pure electric gear type power-assisted SP-EPS/DP-EPS type. In the worm gear and worm speed reducer, during the conventional design, the worm is a driving wheel and is connected with a motor, so that the worm has the characteristics of high rotating speed, low torque and small and exquisite parts, in order to better enable the worm part to obtain wear resistance and sufficient strength, the worm is made of steel, and the local strength of the meshing tooth profile of the worm part is improved through heat treatment. The worm wheel is used as a driven wheel and connected with a steering gear for rotating wheels, and has the characteristics of low rotating speed, high torque and large parts; meanwhile, in order to obtain lower friction resistance and noise reduction performance during transmission, a worm gear material meshing tooth-shaped area is usually made of nylon, and a core area is designed to be a composite structure of steel. The liquid nylon melted at high temperature and the core steel are welded by using a die and then cooled and formed, and the composite material is an individual part.

With the development of automobiles and the improvement of the quality of life of people, medium and large-sized SUVs and new energy automobiles occupy the mainstream of the passenger vehicle market; and the weight of the automobile itself increases. The power output requirements of the associated electric power steering system are correspondingly increased. The worm and gear speed reducer is an indispensable component in an electric power steering system, and the meshing tooth surface of the worm and gear speed reducer is continuously abraded in the energy conversion process, so that the gap of a tooth meshing area is continuously increased. When the meshing clearance of the worm gear and the worm is increased to a certain degree, when the automobile runs on a bumpy road surface, the jolt road surface impacts wheels and is often accompanied by the tooth-shaped collision of the worm gear and the worm of the worm gear speed reducer, the continuous 'Gedendendendendendendeng …' noise is accompanied, the extremely negative driving feeling is brought to the driving, and the great influence is generated on the comfort of the driver. Often complained by customers, with a great direct economic impact on the enterprise and a negative impact on brands. Through the actual effect of loading, the production of this type of noise of electronic steering column produces the meshing clearance and leads to after wearing and tearing by worm gear profile of tooth department. The conventional process and mechanism are difficult to eliminate or delay the abrasion of the worm gear of the speed reducer to achieve the design purpose.

The fixed-size gear ring and the fixed-tooth worm of the conventional worm gear are matched, so that the fit relation among the three parts can not generate clearance fit or overlarge interference fit in order to obtain better worm gear tooth-shaped meshing state and comfort during assembly. The interference fit of the worm and the gear can improve the noise comfort after the interference, but the center distance of the worm and the gear is interference, and the tooth-shaped meshing area is very tight, so that the meshing fluctuation is large during transmission, the resistance is large, and the mechanical efficiency is reduced. After the product is loaded into a vehicle, driving feelings of poor alignment, heavy hand feeling and the like can occur, and the product is not accepted by customers or consumers.

Due to the processing complexity of the worm gear tooth form, the worm tooth form and the main body shell, the control of the consistency of products through the processing process is difficult to realize at all; at present, the common adoption of the conventional worm and gear speed reducer is to carry out the process guarantee of grouping and matching by fully checking the tooth parts of the main body shell, the worm gear and the worm in coordination with related parameters; the control level of the size checking precision reaches 0.001mm level; the consistency control of the production process is very difficult to ensure.

Mutual abrasion of the meshing teeth of the worm and the worm gear in the working process is inevitable and irreversible. The method is obtained from a large number of experiments, and on the basis of conventional design, the tooth-shaped meshing lubricating performance of the worm and gear is improved, the material and the machining precision of parts are changed, only abrasion can be delayed, and the expected target cannot be achieved.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a worm wheel and decelerator for a steering system worm gear decelerator for solve among the prior art because of the worm wheel and worm meshing tooth portion wearing and tearing produce the noise problem that the clearance leads to.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

a worm gear for a steering system worm gear reduction, characterized by: comprising a gear ring 1, a hub 2 and screws 4, wherein,

a circle of first through holes 12 are formed in the gear ring 1;

a round nut 22 matched with the first through hole 12 is arranged on one side of the hub 2;

the round nut 22 is sleeved with an elastic ring 5 and inserted into the corresponding first through hole 12; the screw 4 is screwed in the round nut 22 to fixedly connect the gear ring 1 and the hub 2.

Further, the worm wheel also comprises an end cover 3, wherein a second through hole 31 corresponding to the first through hole 12 is arranged on the end cover 3; the end cover 3 and the gear ring 1 clamp the hub 2 in the middle, and the screw 4 penetrates through the second through hole 31 and is screwed in the round nut 22 to fixedly connect the gear ring 1, the hub 2 and the end cover 3.

Furthermore, an annular rib 11 is arranged at the axial middle part of the inner side of the gear ring 1, and a circle of first through holes 12 are positioned on the annular rib 11; the hub 2 and the end cover 3 are positioned on the inner side of the gear ring 1 and clamp the annular rib 11, and a certain gap is formed between the hub 2 and the end cover 3 and the inner side of the gear ring 1.

Further, the gear ring 1 and the annular rib 11 are of a nylon material integrally formed structure.

Furthermore, a rotation axis 21 is arranged at the center of the hub 2, a hole is arranged at the center of the end cover 3, and the rotation axis 21 is inserted into the hole.

Further, the hub 2, the rotation shaft center 21 and the round nut 22 are integrally formed.

Further, the material of the elastic ring 5 is polyurethane.

Further, ring gear 1 is the nylon material, wheel hub 2 and end cover 3 are metal material or engineering plastics.

The utility model provides a steering system worm gear decelerator which characterized in that: the worm wheel for the steering system worm gear speed reducer is included.

Further, the worm and gear speed reducer further comprises a worm 6, the worm 6 is in interference fit with the worm wheel, and one side, facing the worm 6, of the elastic ring 5 is in a compressed state.

The utility model discloses a principle and beneficial effect:

(1) the utility model has the characteristics that a worm wheel subassembly structure with aligning characteristic is provided, is to design into many parts equipment worm wheel assembly parts with free worm wheel. The new worm gear assembly part nylon gear ring and the steel core (hub) exist independently. The gear ring and the steel core are flexibly connected by adopting polyurethane or other rubber parts with high strength and high elasticity, and the elastic ring is arranged between the gear ring and the steel core. The utility model discloses a worm wheel remains and to bear under the prerequisite of sufficient torsional strength, possesses certain radial relative elastic displacement's characteristic between nylon outer lane and steel core, has realized radial elasticity between the central steel core of worm wheel and the ring gear, just is equivalent to the worm wheel of a variable centre-to-centre spacing. When the center distance between the worm wheel and the worm of the speed reducer is matched, the worm wheel can pre-compress the outer diameter of the gear ring, the gear ring is not concentric with the steel core at the moment, and the elastic ring connecting the gear ring and the steel core is always in a compression state. When the profile of tooth meshing region produced wearing and tearing because of long-time work, the worm wheel ring gear was close to the worm because of the effect of elastic ring elasticity promotion ring gear, and the clearance of elimination production because of wearing and tearing makes the profile of tooth meshing region be in perfect meshing state all the time to the clearance that the compensation eliminated wearing and tearing produced, the noise abatement promotes driving impression and travelling comfort, reduces market quality claim risk, extension a steering system life's purpose.

(2) The utility model discloses the compound worm wheel of integral type conventional relatively, whole processing simplicity that has more. Firstly, the introduction of a new structure cancels the selection and matching work of three parts of a conventional speed reducer shell main body, a worm wheel and a worm, and saves a large amount of manpower, material resources, financial resources and energy investment. And secondly, the processing of the tooth profile of the worm wheel is one of the processes with extremely high rejection rate, the worm wheel gear ring with the structure can be independently processed in the tooth profile as an independent part, and the processing and rejection cost is reduced by at least one half compared with that of the conventional worm wheel. And thirdly, for the electric steering assembly products which are assembled or sold, the utilization rate of the worm gear is improved, the worn-out products on the gear part of the sold worm gear can scrap the worm gear ring, and the hub is kept for continuous use. Fourthly, the product standardization is greatly promoted, the models of general professional steering gears are multiple, and for products with different vehicle types and different design requirements, a new design scheme corresponding to the design can be generated in many times, wherein a worm wheel is one of main parts; the utility model discloses a structure, the ring gear can many sets of different modulus of ring gear, not worm gear ring gear of equidimension correspond different products alone design, and wheel hub can relatively fixed, the diversification of the reduction product that can very big degree.

Drawings

Fig. 1 is a schematic perspective view of a self-aligning worm wheel suitable for a worm gear reduction device of a steering system in an embodiment.

Fig. 2 is an exploded schematic view of a self-aligning worm wheel suitable for a steering system worm gear reduction device in an embodiment.

Fig. 3 is a schematic sectional view of a self-aligning worm wheel suitable for a worm gear reduction device of a steering system in an embodiment.

Fig. 4 is an internal schematic view of a worm reduction gear of the steering system in the embodiment.

In the figure: the gear ring 1, the annular rib 11 and the first through hole 12; the hub 2, a rotary shaft center 21 and a round nut 22; end cap 3, second through hole 31; screw 4, elastic ring 5.

Detailed Description

For better understanding of the present invention, the technical solution of the present invention will be further described below with reference to the following embodiments and accompanying drawings.

As shown in fig. 1 and 2, the worm wheel for the worm gear speed reducer of the steering system comprises a gear ring 1, a hub 2, an end cover 3 and a screw 4.

As shown in fig. 2 and 3, an annular rib 11 is arranged at the axial middle part of the inner side of the gear ring 1, a circle of first through holes 12 are arranged on the annular rib 11, and the circle of first through holes 12 is arranged in a circle and is concentric with the gear ring 1; the gear ring 1 and the annular rib 11 are of an integrally formed structure.

The center of the hub 2 is provided with a rotary shaft center 21 for connecting with a worm wheel core shaft, one side of the hub 2 is provided with a round nut 22 matched with the first through hole 12, and the hub 2, the rotary shaft center 21 and the round nut 22 are of an integrated structure.

The end cover 3 is provided with a second through hole 31 corresponding to the first through hole 12, the center of the end cover 3 is provided with a hole, and the rotary shaft center 21 is inserted into the hole.

The hub 2 and the end cover 3 are positioned on the inner side of the gear ring 1 and clamp the annular rib 11, and a certain gap is formed between the hub 2 and the end cover 3 and the inner side of the gear ring 1. The round nut 22 is sleeved with an elastic ring 5 and inserted into the corresponding first through hole 12; the screw 4 penetrates through the second through hole 31 and is screwed in the round nut 22 to fixedly connect the gear ring 1, the hub 2 and the end cover 3.

Materials of the above main parts:

the materials of the hub 2 and the end cover 3 are preferably metal, and can also be high-strength engineering plastics, and on the premise of ensuring the strength, the materials with light weight, general temperature resistance and low cost, which are not easy to change heat, are selected as far as possible for application.

The gear ring is made of conventional nylon or reinforced nylon; the gear has the characteristics of satisfying the torque transmission strength, the wear resistance, the noise reduction performance and the self-lubricating performance of the gear.

The elastic ring is made of polyurethane, other rubber types can be selected, and the elastic ring is required to have the characteristics of high elasticity, high wear resistance, difficult aging, high oil resistance and the like.

Referring to fig. 4, the steering system worm and gear speed reducer comprises the worm wheel and the worm 6 used for the steering system worm and gear speed reducer, wherein the worm 6 is in interference fit with the worm wheel, and one side of the elastic ring 5 facing the worm 6 is in a compressed state.

As shown in fig. 4, the value a is the theoretical center distance of the worm gear in the casing of the main body of the reduction gear, and is also the theoretical center distance of the tooth-shaped design meshing of the worm gear; under normal conditions, due to the influence of a plurality of factors, the matching among the main body shell, the worm wheel and the worm is very difficult. But the worm wheel of the utility model can completely reduce the control difficulty from 0.001mm level to 0.1mm level.

The B value is the clearance between wheel hub 2 and end cover 3 and the ring gear 1 inboard, promptly the utility model discloses the aligning application scope of worm wheel can be according to the wear data after conventional decelerator market is sold, or the durable experiment of rack wearing and tearing designs for the basis. The conventional worm and gear is verified by the market or the experimental bench, and the abrasion loss is reflected by the center distance and is changed by 0.15 mm; the B value can be designed based on this value, taking into account process control capability or other factors, and is typically slightly greater than the amount of wear.

The utility model discloses a principle and effect:

the assembled worm wheel flexibly connects the gear ring 1 and the hub 2 through the elastic ring 5, so that the hub 2 and the gear ring 1 of the worm wheel have certain radial elastic displacement characteristics, and the worm wheel has an aligning function.

When the center distance between the worm wheel and the worm of the speed reducer is matched, the worm wheel can pre-compress the outer diameter of the gear ring 1, the gear ring 1 is not concentric with the hub 2 at the moment, and the elastic ring 5 connected with the gear ring 1 and the hub 2 is always in a compressed state. When the profile of tooth meshing region produced wearing and tearing because of long-time work, ring gear 1 was close to worm 6 because of the effect of 5 elasticity on the elastic ring, eliminated because of the clearance that the wearing and tearing produced, made profile of tooth meshing region be in perfect meshing state all the time to the clearance that the wearing and tearing produced is eliminated in the compensation, and the noise abatement promotes and drives impression and travelling comfort, reduces market quality claim risk, extension steering system life's purpose.

When the worm gear ring 1 is subjected to working force, the force component from the side direction can be received; in order to ensure the working stability of the gear ring 1, parts of the end cover 3 are introduced to limit the gear ring 1, the hub 2 and the end cover 3 are screwed and fixed by the screw 4, and the assembled gear ring 1 can only be displaced between the hub 2 and the end cover 3, so that the aim of aligning is fulfilled.

The above description is only an example of the present invention, and certainly, the scope of the present invention should not be limited thereto, and therefore, the present invention is not limited to the above description.

Claims

1. A worm gear for a steering system worm gear reduction, characterized by: comprises a gear ring (1), a hub (2) and a screw (4), wherein,

a circle of first through holes (12) are formed in the gear ring (1);

a round nut (22) matched with the first through hole (12) is arranged on one side of the hub (2);

the round nut (22) is sleeved with an elastic ring (5) and inserted into the corresponding first through hole (12); and the screw (4) is screwed in the round nut (22) to fixedly connect the gear ring (1) and the hub (2).

2. The worm gear for a steering system worm gear reduction as set forth in claim 1, wherein: the worm wheel also comprises an end cover (3), wherein a second through hole (31) corresponding to the first through hole (12) is formed in the end cover (3); the end cover (3) and the gear ring (1) clamp the hub (2) in the middle, the screw (4) penetrates through the second through hole (31) and is screwed in the round nut (22), and the gear ring (1), the hub (2) and the end cover (3) are fixedly connected.

3. The worm gear for a steering system worm gear reduction as set forth in claim 2, wherein: an annular rib (11) is arranged in the axial middle of the inner side of the gear ring (1), and a circle of first through holes (12) are formed in the annular rib (11); the hub (2) and the end cover (3) are located on the inner side of the gear ring (1) and clamp the annular rib (11), and a certain gap is reserved between the hub (2) and the end cover (3) and the inner side of the gear ring (1).

4. The worm gear for a steering system worm gear reduction as set forth in claim 3, wherein: the gear ring (1) and the annular rib (11) are of a nylon material integrally formed structure.

5. The worm gear for a steering system worm gear reduction as set forth in claim 2, wherein: the center of the hub (2) is provided with a rotary shaft center (21), the center of the end cover (3) is provided with a hole, and the rotary shaft center (21) is inserted into the hole.

6. The worm gear for a steering system worm gear reduction as set forth in claim 5, wherein: the hub (2), the rotary shaft center (21) and the round nut (22) are of an integrally formed structure.

7. The worm gear for a steering system worm gear reduction as set forth in claim 1, wherein: the elastic ring (5) is made of polyurethane.

8. The worm gear for a steering system worm gear reduction as set forth in claim 2, wherein: the gear ring (1) is made of nylon, and the hub (2) and the end cover (3) are made of metal or engineering plastics.

9. The utility model provides a steering system worm gear decelerator which characterized in that: a worm gear comprising the worm gear reduction for a steering system of any of claims 1-8.

10. The steering system worm gear reduction unit of claim 9, wherein: the worm and gear speed reducer further comprises a worm (6), wherein the worm (6) is in interference fit with the worm wheel, and one side, facing the worm (6), of the elastic ring (5) is in a compression state.