CN111765217A

CN111765217A - RV reducer for precision control

Info

Publication number: CN111765217A
Application number: CN202010750564.2A
Authority: CN
Inventors: 吴绍松; 刘谷华; 刘巍巍; 吴小杰
Original assignee: Suzhou Huazhen Industry RV Reducer Co Ltd
Current assignee: Suzhou Huazhen Industry RV Reducer Co Ltd
Priority date: 2020-07-30
Filing date: 2020-07-30
Publication date: 2020-10-13

Abstract

The invention discloses an RV reducer for precision control, which relates to the technical field of robot reducers and comprises a pin gear shell and two-stage reduction parts arranged in the pin gear shell: the first-stage component comprises an input shaft, a sun gear and a planet gear; the second stage part comprises an eccentric shaft, a cycloid wheel, a pin, a rigid disc and a bearing, and after the cycloid wheel is trimmed, the lateral clearance between the pin and the two sides of the tooth space of the cycloid wheel is 0.1 lambda₁≤Δc＜0.7λ₁，λ₁The theoretical radial thermal expansion of the cycloid wheel is the theoretical radial thermal expansion of the cycloid wheel when doing work under rated torque. The shape modification of the cycloid wheel meets the requirements of a lateral clearance delta c and the thermal expansion amount lambda of the cycloid wheel₁Is thus describedThe material has good dynamic characteristics, less heat generation and less abrasion; the conventional manufacturing precision and the cost are low; interchangeable with existing RV reducers.

Description

RV reducer for precision control

Technical Field

The invention relates to the technical field of robot reducers, in particular to an RV reducer with good dynamic characteristics for precision control.

Background

The robot is a pearl on the top of the crown in the manufacturing industry and is an important mark for measuring the level of national technological innovation and high-end manufacturing industry. The RV reducer is one of the most core components of the robot and is the only component which is not truly localized.

One is patent CN 110966357A, CN 111059225A, CN 110985611A, CN 110985610A and the like, because the lateral clearance is set based on the calculation parameter of the theoretical thermal expansion amount, the thermal expansion coefficient is α t =1.379 · 10^-5(1/. degree. C.) from research on the thermal expansion coefficient of precision parts and the precise thermal expansion coefficient of materials, page 95 (Miao En Ming, university of Hefei, 2004.09), the actual thermal expansion of the solid round bar-shaped structural bearing steel material was measured. The actual cycloid wheel structure is a porous disc-shaped structure, and is far from the solid round bar-shaped structure of a theoretical actual sample. According to the solid Physics introduction (Girtell C [ Mei ]]Beijing: scientific press, 1979) that the thermal deformation is closely related to the form factor. Meanwhile, through the actual measurement and comparative study on the thermal expansion of the cycloidal bearing steel material with the existing structure and different structures, the thermal expansion coefficient of the porous disc-shaped structure bearing steel material is proved to be greatly different from that of the solid circular rod-shaped structure bearing steel material. Therefore, the prior art is difficult to be implemented to meet the design requirement.

The other is that, CN 108869644A, CN 106641110 a and other patents do not make any quantitative setting for specifically defining the range of the side clearance of the cycloid gear, and only if the side clearance is too small, the principle description will be given that the side clearance will cause heat generation due to wear, poor dynamic performance, shortened life and the like when expanding under temperature rise, and such principle knowledge is well known to those skilled in the art.

Disclosure of Invention

The invention aims to provide a correct relational expression of a lateral clearance delta c and a thermal expansion amount after the modification of a cycloid wheel, which is used for overcoming the defects of easy heating, easy abrasion, poor precision retentivity and the like in the prior art and providing an RV reducer for precision control with good dynamic characteristics.

In order to solve the technical problems, the invention adopts a technical scheme that:

the RV reducer for precise control comprises a pin gear shell and a two-stage reduction part arranged in the pin gear shell:

the first-stage speed reduction component comprises an input shaft, a sun gear and 2 or 3 uniformly distributed planet gears;

the second-stage speed reduction component comprises an eccentric shaft, a cycloid wheel, a pin, a rigid disc and a bearing; 2 or 3 eccentric shafts are uniformly distributed around the input shaft, the extension ends of the eccentric shafts are connected with the planet wheels, first bearings for supporting the cycloid wheel are arranged on two eccentric sections of the eccentric shafts, shaft extensions on two sides of the eccentric sections are respectively supported in peripheral holes of the left rigid disk and the right rigid disk by using second bearings, and the left rigid disk and the right rigid disk are respectively supported in inner holes on two sides of the needle gear shell by using third bearings; the input shaft is respectively supported in the central holes of the left rigid disk and the right rigid disk by a fourth bearing, 2 or 3 flanges are uniformly distributed on the left rigid disk, pass through 2 or 3 through holes uniformly distributed on the cycloid wheel and are connected with the right rigid disk into a rigid body by screws and positioning pins; the cycloid wheel comprises a left cycloid wheel and a right cycloid wheel, and the shape modification is carried out by adopting equal distance-displacement, so that a lateral gap delta c and a radial gap are formed between a pin and a tooth groove of the cycloid wheel,

(1) when lambda 1 is the theoretical radial thermal expansion amount of the cycloid wheel when the speed reducer does work:

the range of the lateral clearance delta c between the needle pin and the single side of the tooth space of the cycloidal gear is as follows: Δ c is more than or equal to 0.1 λ 1 and less than 0.7 λ 1;

(2) when lambda 2 is the actual radial thermal expansion amount of the cycloid wheel when the speed reducer does work:

a lateral clearance delta c = (0.1-5) lambda 2 between the needle pin and the single side of the tooth groove of the cycloidal gear;

(3) when lambda is the actual lateral thermal expansion amount of the cycloid wheel when the speed reducer does work:

and a lateral clearance delta c = (0.1-5) lambda between the pin and one side of the tooth groove of the cycloidal gear.

In a preferred embodiment of the invention, a lateral clearance Δ c = (0.2-0.6) λ 1 between the pin and a single side of the cycloidal gear slot.

In a preferred embodiment of the invention, a lateral clearance delta c = (0.1-4) lambda 2 between the pin and a single side of the cycloidal gear tooth slot.

In a preferred embodiment of the invention, a lateral clearance delta c = (0.2-3) lambda 2 between the pin and a single side of the cycloidal gear tooth slot.

In a preferred embodiment of the invention, the lateral clearance Δ c = λ 2 between the pin and a single side of the cycloidal gear slot.

In a preferred embodiment of the present invention, the range of the lateral clearance between the pin and one side of the tooth space of the cycloidal gear is as follows: Δ c is more than or equal to 0.1 λ 2 and less than 0.7 λ 2.

In a preferred embodiment of the invention, a lateral clearance Δ c = (0.2-0.6) λ 2 between the pin and a single side of the cycloidal gear slot.

In a preferred embodiment of the invention, the lateral clearance delta c = (0.1-4) lambda between the pin and one side of the cycloidal gear tooth slot.

In a preferred embodiment of the invention, the lateral clearance Δ c = (0.2-3) λ between the pin and a single side of the cycloidal gear slot.

In a preferred embodiment of the invention, the lateral clearance Δ c = λ between the pin and a single side of the cycloidal gear slot.

In a preferred embodiment of the present invention, the range of the lateral clearance between the pin and one side of the tooth space of the cycloidal gear is as follows: delta c is more than or equal to 0.1 lambda and less than 0.7 lambda.

In a preferred embodiment of the invention, a lateral clearance Δ c = (0.2-0.6) λ is formed between the pin and a single side of the slot of the cycloidal gear.

In a preferred embodiment of the present invention, the shape of the through hole is a fan-like structure, or expansion reducing holes are formed on both sides of the through hole, and the shape of the expansion reducing holes is circular, polygonal or irregular.

In a preferred embodiment of the invention, the theoretical radial thermal expansion amount λ 1= (d0 Δ t) α t1 of the cycloid wheel, the actual radial thermal expansion amount λ 2= (d0 Δ t) α t2 of the cycloid wheel, and the actual lateral thermal expansion amount λ = (d0 Δ t) α t of the cycloid wheel, wherein α t, α t1,α t2 is the actual lateral thermal expansion coefficient, the theoretical radial thermal expansion coefficient and the actual radial thermal expansion coefficient of the cycloid wheel bearing steel respectively, delta t is the temperature rise of the cycloid wheel, d0 is the average diameter of the addendum circle and the dedendum circle of the cycloid wheel, α t1=1.38 · 10^-5(1/° c), temperature rise Δ t =45 ℃, λ 1= (d0 Δ t) α t =0.00062d 0.

The invention has the beneficial effects that:

(1) the lateral clearance delta c generated by the 'equidistant-displacement' modification is closely related to the thermal expansion amount of the cycloid wheel, so that the cycloid wheel has good dynamic characteristics and is not overheated when the cycloid wheel operates and does work under rated load;

(2) the invention adopts conventional manufacturing precision, simple process and low cost;

(3) the invention has the same external dimension as the common RV reducer and can be interchanged with the common RV reducer.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without inventive efforts, wherein:

FIG. 1 is a schematic cross-sectional view of a preferred embodiment of a precision control RV reducer according to the invention;

FIG. 2 is a schematic structural view of an embodiment of a cycloid wheel in an RV reducer for precision control according to the present invention;

FIG. 3 is a schematic structural view of another embodiment of a cycloid wheel in an RV reducer for precision control according to the invention;

in the figure: 1. the planetary gear set comprises a needle gear shell, 2. a third bearing, 3. a left cycloidal gear, 4. a needle pin, 5. a right cycloidal gear, 6. an eccentric shaft, 7. a second bearing, 8. a first bearing, 9. an input shaft, 10. a fourth bearing, 11. a flange, 12. a right rigid disk, 13. a left rigid disk, 14. a sun gear, 15. a planetary gear, 16. a through hole and 17. an expansion reducing hole.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, 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.

Referring to fig. 1-3, an embodiment of the present invention includes:

the utility model provides a RV reduction gear for precision control, its includes the pin gear shell and places the two-stage reduction part in it:

the second-stage speed reduction component comprises an eccentric shaft, a cycloid wheel, a pin, a rigid disc and a bearing; 2 or 3 eccentric shafts are uniformly distributed around the input shaft, the extension ends of the eccentric shafts are connected with the planet wheels, first bearings for supporting the cycloid wheel are arranged on two eccentric sections of the eccentric shafts, shaft extensions on two sides of the eccentric sections are respectively supported in peripheral holes of the left rigid disk and the right rigid disk by using second bearings, and the left rigid disk and the right rigid disk are respectively supported in inner holes on two sides of the needle gear shell by using third bearings; the input shaft is respectively supported in the central holes of the left rigid disk and the right rigid disk by a fourth bearing, 2 or 3 flanges are uniformly distributed on the left rigid disk, pass through 2 or 3 through holes uniformly distributed on the cycloid wheel and are connected with the right rigid disk into a rigid body by screws and positioning pins; the cycloidal gear comprises a left cycloidal gear and a right cycloidal gear, and is modified by adopting an equal distance-displacement mode, so that a lateral gap delta c and a radial gap are formed between a pin and a tooth groove of the cycloidal gear, wherein the positive equal distance-positive displacement mode is preferentially adopted during modification, and the negative equal distance-negative displacement mode can be selected for modification.

When lambda 1 is the theoretical radial thermal expansion amount of the cycloid wheel when the speed reducer does work:

the range of the lateral clearance Δ c is: Δ c is more than or equal to 0.1 λ 1 and less than 0.7 λ 1.

The shape of the through hole on the cycloid wheel can be a fan-like structure, or expansion reducing holes are formed in two sides of the through hole, and the shape of the expansion reducing holes can be circular, polygonal or special-shaped.

According to the discovery that thermal deformation and form factors are inseparable in a thermal expansion research theory, the actual measurement and comparison research on the thermal expansion coefficients of the bearing steel materials of the cycloidal gears with different structures finds that the thermal expansion coefficients of the bearing steel materials of the cycloidal gears with different structures are different, and particularly the structural change of the through holes of the cycloidal gears or the structural change around the through holes has influence on the thermal expansion of the cycloidal gears. Therefore, the cycloid wheel structure is reasonably arranged, particularly the through hole or the structure around the through hole is reasonably arranged, so that the thermal expansion of the cycloid wheel is minimum, and the precision design of the speed reducer is facilitated. Through the comparison research of the thermal expansion of a large number of cycloidal gears with different structures, on the premise of ensuring the rigidity of the cycloidal gear, the through holes of the cycloidal gear are designed into fan-like shapes from the existing circular or fan-shaped structures, namely the through holes are expanded to the two sides of the fan-shaped structures to form the fan-like shapes; or the two sides of the through hole are provided with expansion reducing holes, and the shape of the expansion reducing holes is a circular or polygonal or special-shaped structure.

Therefore, the temperature of the molten metal is controlled,

(1) when lambda 2 is the actual radial thermal expansion amount of the cycloid wheel when the speed reducer does work:

(2) when lambda is the actual lateral thermal expansion amount of the cycloid wheel when the speed reducer does work:

The actual radial thermal expansion amount of the cycloid wheel can be obtained by actually measuring the thermal expansion amount, or can be obtained by calculation after actually measuring the thermal expansion coefficient, namely lambda 2= (d0 delta t) alpha t2, or can be obtained by calculation and derivation of the actual lateral thermal expansion amount; the actual lateral thermal expansion of the cycloid gear can be obtained by actually measuring the thermal expansion, or can be obtained by calculation after actually measuring the thermal expansion coefficient, namely lambda = (d0 delta t) alpha t, or can be obtained by calculation and derivation through the actual radial thermal expansion; wherein alpha t and alpha t2 are thermal expansion coefficients of the bearing steel of the cycloidal gear, delta t is the temperature rise of the cycloidal gear, and d0 is the average diameter of the addendum circle and the dedendum circle of the cycloidal gear.

According to the quasi-resonance approximation theory of the solid physics introduction (Kittall C [ Mei ], Beijing: scientific Press, 1979), the mechanism of thermal expansion is that a solid is composed of tiny crystals, the crystals are formed by arranging atoms at certain positions in space, the atoms have potential energy and kinetic energy, when the atoms are in equilibrium, the sum of the kinetic energy and the potential energy is minimum, the kinetic energy of the atoms is increased along with the increase of temperature, so that the displacement among the atoms is increased, the potential energy is increased, the macroscopic expression is the occurrence of thermal expansion, and the thermal expansion can be regarded as that the object is subjected to uniform outward expansion force. The amount of thermal expansion is closely related to the shape of the object.

According to the research of 'research on influence of shape parameters on thermal expansion of parts' (Miaoming, Fuyitai, applied science bulletin, 2003.06), the thermal deformation is found to be inseparable with the shape factor; the calculation of the thermal expansion coefficient generally includes a simple calculation method, a statistical calculation method, a ruley hessian formula and the like, and the methods all have certain limitations, so that the calculated thermal expansion coefficient value is greatly different from an actual measured value, the currently used thermal expansion coefficient is still an actual measured value using a round rod with a certain size, and the measured value of the thermal expansion coefficient inevitably contains the influence of a shape factor.

According to the search on page 95 (Miao En Ming, Hei Fu university, 2004.09) of research on the thermal expansion coefficient of precision parts and the precise thermal expansion coefficient of materials, the thermal expansion coefficient of α t = 1.38.10 of the bearing steel^-5(1/. degree. C.), is a measured value of a solid round bar structure bearing steel material with a certain size.

According to the linear expansion coefficient and density table (table 12.2-4) of the materials commonly used in the Chinese mechanical design classics (volume 1), the linear expansion coefficient α t table (table 1-1-12) of the materials in the mechanical design manual (volume 1) and the linear expansion coefficient table (table 1-1-12) of the materials commonly used in the modern mechanical design manual (volume 1), the retrieval shows that the linear expansion coefficients of the reference chromium steel at 20-100 ℃ are α t = 1.12-10^-5Coefficient of thermal expansion of bearing steel α t =1.38 · 10 only^-581.12% of (1/. degree. C.).

According to the national standard GB/T36491-. The specific value of the temperature rise of the cycloid gear can be calculated by the temperature difference between the shell of the speed reducer and the environment and the temperature difference between the shell and the cycloid gear, and can also be directly taken as 45 ℃. When the temperature rise of the cycloid wheel is 45 ℃, the thermal expansion amount of the cycloid wheel is relatively high because the speed reducer generally works in a room temperature environment.

The actual structure of the cycloid wheel is a porous disc-shaped structure, and is far from the solid round bar-shaped structure of a theoretical actual measurement sample. The actual coefficient of thermal expansion of the bearing steel material of the cycloid wheel will be lower than the theoretical coefficient of thermal expansion of the bearing steel material.

By applying a related thermal expansion research theory and through the actual measurement research on the thermal expansion coefficients of the cycloidal bearing steel materials with the existing structures and different structures, the actual thermal expansion coefficients of the cycloidal bearing steel materials with the existing structures and different structures are also proved to be lower than the thermal expansion coefficient of the theoretical bearing steel materials.

In summary, the theoretical thermal expansion amount, the thermal expansion coefficient and the temperature rise of the cycloid wheel are all larger than the actual thermal expansion amount, the thermal expansion coefficient and the temperature rise, so as to obtain the correct lateral clearance, the actual thermal expansion amount, or the data of the thermal expansion coefficient and the temperature rise of the cycloid wheel can be measured by various existing means, and the actual thermal expansion amount is multiplied by a certain coefficient to be adjusted, so as to obtain the parameter of the actually required lateral clearance Δ c.

Although the amount of thermal expansion, the coefficient of thermal expansion, the temperature, and the multiplied coefficient may be different from the present patent, the value of the final lateral clearance Δ c is within the claims of the present patent and is included in the scope of the present patent. Similarly, the actual lateral thermal expansion amount value range is set, and if the theoretical lateral thermal expansion amount extended from the theoretical radial thermal expansion amount has no practicability, the theoretical lateral thermal expansion amount is covered by the practicability of the actual lateral thermal expansion amount, and meanwhile, the theoretical lateral thermal expansion amount can be directly derived from the theoretical radial thermal expansion amount, so that the value of the theoretical lateral thermal expansion amount is included in the patent protection range of the invention.

In part of the prior art, due to the reasons of large values of theoretical thermal expansion coefficient, temperature rise and adjustment coefficient and the like, the lateral clearance delta c is over-large, so that the precision is poor.

In part of the prior art, the lateral clearance delta c is too small, so that the cycloidal gear and the pin are in interference friction, and the problem of poor dynamic performance is inevitable. To further illustrate the problem, the national 863 program of RV reducers, which is jointly attacked by a famous expert at university of large-scale transportation and a research institute of middle-sized villa weir machine, is taken as an example, and published parameters in 2017 and 9 months are as follows: rz =77, e =1.50, Za =39, K1=0.7792, Δ Rz = -0.027, Δ Rz = -0.047, return difference 0.29'.

When the return difference = 0.29' is constant, it is calculated that:

lateral gap ac =0.003 (mm).

And the theoretical radial thermal expansion amount lambda 1= (d0 delta t) α t =0.00062d0 (mm) =0.09548 (mm) of the cycloid wheel, when the temperature rise delta t =45 ℃, in the formula, the thermal expansion coefficient α t = 1.38.10 of the bearing steel GCr15^-5(1/° C), d0 is the average diameter of the tip circle and the root circle of the cycloidal gear.

And further calculating to obtain that the actual radial thermal expansion amount lambda 2 of the cycloid wheel is smaller than the theoretical radial thermal expansion amount lambda 1, namely lambda 2 is smaller than lambda 1.

And further calculating to obtain that the actual radial thermal expansion amount lambda 2 of the cycloid wheel is smaller than the actual lateral thermal expansion amount lambda, namely lambda 2 is smaller than lambda, wherein lambda is the actual lateral thermal expansion amount of the cycloid wheel when the speed reducer works under rated torque.

And simultaneously, obtaining that the actual lateral thermal expansion amount lambda of the cycloid wheel is smaller than the theoretical radial thermal expansion amount lambda 1, namely lambda is smaller than lambda 1.

Therefore, the lateral clearance delta C is less than the set 0.1 lambda 2, less than the set 0.1 lambda 1, less than the actual radial thermal expansion lambda 2, less than the actual lateral thermal expansion lambda, less than the theoretical radial thermal expansion lambda 1, namely, delta C is less than 0.1 lambda 2 and less than 0.1 lambda 1 and less than lambda 2 and less than lambda 1.

From this, it is found that the lateral clearance Δ C of this item is smaller than the actual lateral thermal expansion amount λ, i.e., Δ C < λ, and Δ C = (0.1 to 5) λ, 0.1 λ 1 ≦ Δ C < 0.7 λ 1, and Δ C = (0.1 to 5) λ 2 are not satisfied. Therefore, the interference friction between the cycloid wheel and the pin inevitably occurs, and the problems of poor dynamic performance such as heating, abrasion, precision reduction and the like inevitably occur.

The effect of the reducer in use at different side clearances is shown in the following table,

from the above table, it can be seen that:

the first expression is as follows: when the lateral clearance delta c meets the condition that delta c is more than or equal to 0.1 lambda 1 and less than 0.7 lambda 1, the standard is reached;

performing two steps: when the lateral clearance delta c = (0.1-5) lambda 2, the standard is reached;

the third expression is that: when the lateral clearance delta c = (0.7-5) lambda 1, delta c is less than 0.1 lambda 1, and delta c is more than 5 lambda 1, the standard is not reached;

the expression is four: when the lateral clearance delta c is less than 0.1 lambda 2 and the delta c is more than 5 lambda 2, the standard is not reached;

and (5) performing the following steps: under the condition of reaching the standard, the temperature rise is lower than 45 ℃.

Therefore, to sum up, the above table can more intuitively display the technical effects achieved by the improvement point of the present application from the perspective of actual detection, that is:

(1) when the theoretical radial thermal expansion amount lambda 1 is adopted, the lateral clearance needs to meet the condition that delta c is more than or equal to 0.1 lambda 1 and less than 0.7 lambda 1, so that the heating condition caused by abrasion can be effectively reduced, and meanwhile, the precision of the speed reducer can be maintained at a higher level;

(2) when the radial thermal expansion amount lambda 2 is obtained through actual measurement, the measured radial thermal expansion amount is generally smaller than the theoretical radial thermal expansion amount, so that the requirements of reducing temperature rise, reducing abrasion, prolonging service life and maintaining high precision can be met only when the lateral clearance meets the requirement that delta c = (0.1-5) lambda 2.

(3) When the lateral thermal expansion amount lambda is obtained through actual measurement, the lateral clearance can meet the requirements of reducing temperature rise, reducing abrasion, prolonging service life and maintaining high precision only if the lateral clearance meets delta c = (0.1-5) lambda because the actual measurement lateral thermal expansion amount is generally smaller than the theoretical radial thermal expansion amount.

Similarly, through theoretical calculation and actual measurement and research of the thermal expansion coefficients of the cycloidal gears with different structures, it is deduced that the lateral clearance delta c between the pin and the single side of the tooth groove of the cycloidal gear needs to satisfy the formula that delta c is more than or equal to 0.1 lambda 1 and less than 0.7 lambda 1, and the theoretical calculation and the actual measurement results are met through actual operation tests.

Furthermore, the through hole is of a fan-like structure, or expansion reducing holes are formed in two sides of the through hole, the expansion reducing holes are of a circular or polygonal or special-shaped structure, and corresponding to various RV reducer models, the lateral clearance delta c between the pin and one side of the tooth space of the cycloidal gear is not less than (0.2-0.6) lambda 1.

Furthermore, the through hole is of a fan-like structure, or expansion reducing holes are formed in two sides of the through hole, the expansion reducing holes are of a circular or polygonal or special-shaped structure, and a lateral clearance delta c = (0.1-4) lambda 2 between the pin and one side of the tooth space of the cycloidal gear corresponding to various RV reducer models.

Furthermore, the through hole is of a fan-like structure, or expansion reducing holes are formed in two sides of the through hole, the expansion reducing holes are of a circular or polygonal or special-shaped structure, and a lateral clearance delta c = (0.2-3) lambda 2 between the pin and one side of the tooth space of the cycloidal gear corresponding to various RV reducer models.

Furthermore, the through hole is of a fan-like structure, or expansion reducing holes are formed in two sides of the through hole, the expansion reducing holes are of a circular or polygonal or special-shaped structure, and corresponding to various RV reducer models, the lateral clearance delta c = lambda 2 between the pin and one side of the tooth space of the cycloidal gear.

Furthermore, the shape of the through hole is a fan-like structure, or expansion reducing holes are formed in two sides of the through hole, the shape of the expansion reducing holes is a circular or polygonal or special-shaped structure, and the range of a lateral clearance between the pin and one side of the tooth space of the cycloidal gear is as follows corresponding to various RV reducer models: Δ c is more than or equal to 0.1 λ 2 and less than 0.7 λ 2.

Furthermore, the through hole is of a fan-like structure, or expansion reducing holes are formed in two sides of the through hole, the expansion reducing holes are of a circular or polygonal or special-shaped structure, and corresponding to various RV reducer models, the lateral clearance delta c between the pin and one side of the tooth space of the cycloidal gear is = (0.2-0.6) lambda 2.

Furthermore, the through hole is of a fan-like structure, or expansion reducing holes are formed in two sides of the through hole, the expansion reducing holes are of a circular or polygonal or special-shaped structure, and a lateral clearance delta c between the pin and one side of the tooth space of the cycloidal gear is not less than (0.1-4) lambda corresponding to various RV reducer models.

Furthermore, the through hole is of a fan-like structure, or expansion reducing holes are formed in two sides of the through hole, the expansion reducing holes are of a circular or polygonal or special-shaped structure, and a lateral clearance delta c = (0.2-3) lambda between the pin and one side of the tooth space of the cycloidal gear corresponding to various RV reducer models.

Furthermore, the through hole is of a fan-like structure, or expansion reducing holes are formed in two sides of the through hole, the expansion reducing holes are of a circular or polygonal or special-shaped structure, and corresponding to various RV reducer models, the lateral clearance delta c = lambda between the pin and one side of the tooth space of the cycloidal gear is larger than the lateral clearance delta c = lambda.

Furthermore, the shape of the through hole is a fan-like structure, or expansion reducing holes are formed in two sides of the through hole, the shape of the expansion reducing holes is a circular or polygonal or special-shaped structure, and the range of a lateral clearance between the pin and one side of the tooth space of the cycloidal gear is as follows corresponding to various RV reducer models: delta c is more than or equal to 0.1 lambda and less than 0.7 lambda.

Furthermore, the through hole is of a fan-like structure, or expansion reducing holes are formed in two sides of the through hole, the expansion reducing holes are of a circular or polygonal or special-shaped structure, and corresponding to various RV reducer models, the lateral clearance delta c between the pin and one side of the tooth space of the cycloidal gear is not less than (0.2-0.6) lambda.

Detailed description of the preferred embodiment

The utility model provides a RV reduction gear for precision control, its structure includes pin gear shell 1 and places the two-stage speed reduction part in it: the first-stage speed reduction component comprises an input shaft 9, a sun gear 14 and 3 uniformly distributed planet gears 15; the second-stage speed reducing component comprises an eccentric shaft 6, a left cycloidal gear 3, a right cycloidal gear 5, a pin 4, a left rigid disk 13, a right rigid disk 12 and bearings, wherein the eccentric shaft 6 is uniformly distributed by 3 input shafts 9, the shaft extension end of the eccentric shaft 6 is connected with a planet wheel 15, two eccentric sections of the eccentric shaft 6 are provided with first bearings 8 for supporting the cycloidal gear, the shaft extensions at two sides of the eccentric sections are respectively supported in peripheral holes of the left rigid disk 13 and the right rigid disk 12 by second bearings 7, the left rigid disk 13 and the right rigid disk 12 are respectively supported in inner holes at two sides of a pin gear shell 1 by a third bearing 2, the input shafts 9 are respectively supported in central holes of the left rigid disk 13 and the right rigid disk 12 by fourth bearings 10, 3 flanges 11 uniformly distributed on the left rigid disk 13 penetrate through corresponding 3 through holes 16 on the cycloidal gear and are connected with the right rigid disk 12 by screws and positioning pins to form a solid body, and the 3 through holes 16 are of, the cycloidal gears 3 and 5 adopt 'equidistance-displacement' modification, the modification enables a lateral clearance delta c and a radial clearance to be formed between the pin 4 and tooth sockets of the cycloidal gears 3 and 5, and the lateral clearance delta c = lambda of the single side of the pin 4 and the tooth sockets of the cycloidal gears 3 and 5 is as follows: lambda is the actual lateral thermal expansion of the cycloid gears 3 and 5 when the speed reducer does work under the rated torque.

Meanwhile, the size of the lateral clearance delta c is related to factors such as the adjacent distance machining precision of the pin, the diameter machining precision of the pin, the fit clearance of the pin and a semi-buried hole, the pitch deviation of the cycloid wheel, the deviation generated by assembly and the like, and is related to the size of the model of the RV reducer, the lateral clearance delta c is too small, interference friction is generated, and vibration is easily generated when the input rotating speed is too high.

Therefore, the lateral clearance delta c in the embodiment is equal to the actual lateral thermal expansion, namely, delta c = lambda, so that good gear meshing is realized, and interference friction is avoided; meanwhile, the requirement on the processing precision is greatly reduced, so that the investment, production and management costs of enterprises are greatly reduced.

Compared with the prior art, the RV reducer for precise control provided by the invention has the following advantages:

(1) the invention adopts the side clearance delta c generated by 'equidistant-displacement' modification to be closely related to the thermal expansion lambda of the cycloid wheel, thereby having good dynamic characteristics and not overheating when the cycloid wheel operates and does work under rated load.

(2) The invention uses conventional manufacturing precision, and has simple process and low cost.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by the present specification, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. The utility model provides a RV reduction gear for precision control, includes the pin gear shell and places the two-stage reduction part in it: the first-stage speed reduction part comprises an input shaft, a sun gear and a planet gear; the second-stage speed reducing component comprises an eccentric shaft, a cycloid wheel, a pin, a rigid disc and bearings, wherein the eccentric shaft is uniformly distributed around an input shaft, the extension end of the eccentric shaft is connected with a planet wheel, two eccentric sections of the eccentric shaft are provided with first bearings for supporting the cycloid wheel, the shaft extensions at two sides of the eccentric sections are respectively supported in peripheral holes of a left rigid disc and a right rigid disc by using second bearings, the left rigid disc and the right rigid disc are respectively supported in inner holes at two sides of a pin gear shell by using third bearings, the input shaft is respectively supported in central holes of the left rigid disc and the right rigid disc by using fourth bearings, flanges are uniformly distributed on the left rigid disc, through holes are uniformly distributed on the cycloid wheel and are connected with the right rigid disc by using screws and positioning pins to form a rigid body, the cycloid wheel comprises a left cycloid wheel and a right cycloid wheel, and the shape modification of 'equidistant-displacement' is adopted, so that a lateral clearance delta, the method is characterized in that:

the range of the lateral clearance delta c between the needle pin and the single side of the tooth space of the cycloidal gear is as follows: Δ c = (0.1 to 5) λ 2;

the range of the lateral clearance delta c between the needle pin and the single side of the tooth space of the cycloidal gear is as follows: Δ c = (0.1 to 5) λ.

2. The RV reducer for precision control according to claim 1, characterized in that: and a lateral clearance delta c = (0.2-0.6) lambda 1 between the needle pin and one side of the tooth groove of the cycloidal gear.

3. The RV reducer for precision control according to claim 1, characterized in that: and a lateral clearance delta c = (0.1-4) lambda 2 between the pin and one side of the tooth groove of the cycloidal gear.

4. The RV reducer for precision control according to claim 3, characterized in that: and a lateral clearance delta c = (0.2-3) lambda 2 between the pin and one side of the tooth groove of the cycloidal gear.

5. The RV reducer for precision control according to claim 4, characterized in that: and the lateral clearance delta c = lambda 2 between the pin and the single side of the tooth space of the cycloidal gear.

6. The RV reducer for precision control according to claim 1, characterized in that: the range of the lateral clearance between the needle pin and the single side of the tooth space of the cycloid wheel is as follows: Δ c is more than or equal to 0.1 λ 2 and less than 0.7 λ 2.

7. The RV reducer for precision control according to claim 1, characterized in that: and a lateral clearance delta c = (0.1-4) lambda between the pin and one side of the tooth groove of the cycloidal gear.

8. The RV reducer for precision control according to claim 7, characterized in that: and a lateral clearance delta c = (0.2-3) lambda between the pin and one side of the tooth groove of the cycloidal gear.

9. The RV reducer for precision control according to claim 8, characterized in that: and the lateral clearance delta c = lambda between the pin and one side of the tooth space of the cycloidal gear.

10. The RV reducer for precision control according to claim 1, characterized in that: the range of the lateral clearance between the needle pin and the single side of the tooth space of the cycloid wheel is as follows: delta c is more than or equal to 0.1 lambda and less than 0.7 lambda.

11. The RV reducer for precision control according to any one of claims 1 to 10, characterized in that: the through hole is of a fan-like structure, or expansion reducing holes are formed in the two sides of the through hole and are circular, polygonal or special-shaped.

12. The RV reducer for precise control according to any one of claims 1-10, characterized in that theoretical radial thermal expansion amount λ 1= (d0 Δ t) α t1 of the cycloid wheel, actual radial thermal expansion amount λ 2= (d0 Δ t) α t2 of the cycloid wheel, actual lateral thermal expansion amount λ = (d0 Δ t) α t of the cycloid wheel, wherein α t1 is theoretical radial thermal expansion coefficient of the cycloid bearing steel, α t2 is actual radial thermal expansion coefficient of the cycloid bearing steel, α t is actual lateral thermal expansion coefficient of the cycloid bearing steel, Δ t is temperature rise of the cycloid wheel, d0 is average diameter of the cycloid tooth crest circle and tooth root circle, α t1= (1.378-1.382) · 10^-5(1/° c), temperature rise Δ t =45 ℃, λ 1= (d0 Δ t) α t1= 0.00062d 0.