Ultrathin string pin wheel speed reducer based on crossed roller bearing

Abstract

The invention provides an ultra-thin string pinwheel speed reducer based on a crossed roller bearing. The ultra-thin string pinwheel speed reducer comprises an input shaft, the crossed roller bearing, an output end cover and a constant-speed transmission mechanism. The constant-speed transmission mechanism comprises a supporting end cover, an output steel ball, a planetary gear, a pinwheel and a roller pin; the roller pin is mounted in a pin wheel pin tooth groove of the pin wheel in a clearance fit manner; the planetary gear is meshed with the roller pin; the input shaft is installed in a supporting end cover inner hole of the supporting end cover and a planetary gear inner hole of the planetary gear. A supporting end cover constant-speed transmission ball pit and a plurality of planetary gear ball pits are formed in the surfaces of the supporting end cover and the planetary gear; and the output steel ball is mounted between the support end cover constant-speed transmission ball pit and the planetary gear ball pit. According to the technical scheme, the axial size is small, the structure is compact, the large transmission ratio is achieved, and sine tooth profiles are adopted for the planetary gears.

Description

Technical Field

[0001] The invention relates to the technical field of gear transmission, and in particular to an ultra-thin string pinwheel reducer based on a cross roller bearing. Background Art

[0002] With the continuous development of science and technology, mechanical equipment is developing in the direction of miniaturization and precision, and so are precision reducers. At present, precision reducers are widely used in industrial robots, medical equipment, aerospace and other industries, which requires precision reducers to have the characteristics of compact structure, large transmission ratio, high precision, large load capacity, and smooth transmission. String needle reducer (CN202111096370.6) proposes a string needle reducer structure, which is fixedly connected by a pad and the inner ring of a cross roller bearing, and is driven at a constant speed by a pin and a pin sleeve. This design makes the reducer have a large axial dimension and cannot meet the current requirements of various industries for miniaturization of precision reducers. Therefore, it is necessary to study the string needle reducer with a more compact axial structure. Summary of the invention

[0003] In view of the problem that the existing string pinwheel reducer has a large axial dimension and cannot meet the miniaturization requirements of precision reducers mentioned above, an ultra-thin string pinwheel reducer based on a crossed roller bearing is provided, in which the inner ring of the crossed roller bearing, the pinwheel and the output end cover are fixedly connected by a plurality of evenly distributed flat head screws, thereby reducing the axial dimension of the reducer; the support end cover and the outer ring of the crossed roller bearing are tightly fixed together by a plurality of evenly distributed screws, and the support end cover also serves as a constant speed transmission pad, thereby further reducing the axial dimension of the reducer; the output steel ball installed in the planetary gear ball pit rotates at a constant speed in the constant speed transmission ball pit of the support end cover, thereby causing the planetary gear to swing, and the outer teeth of the planetary gear adopt a sinusoidal tooth profile, which meshes with the needle roller installed on the pinwheel, thereby driving the pinwheel to rotate, and further causing the inner ring of the crossed roller bearing and the output end cover to rotate together. The ultra-thin chordal pinwheel reducer based on crossed roller bearings proposed in the present invention has a compact structure, small overall size, especially small axial size; the planetary gear adopts a sinusoidal tooth profile and meshes with the needle roller installed on the pinwheel to achieve a one-tooth difference transmission, with a large reduction ratio. The gears run smoothly when meshing in and out, with small impact vibration, and are particularly suitable for miniaturization, large reduction ratio and high-precision occasions.

[0004] The technical means adopted by the present invention are as follows:

[0005] An ultra-thin chord pinwheel reducer based on a cross roller bearing comprises an input shaft, a cross roller bearing, an output end cover and a constant speed transmission mechanism; the constant speed transmission mechanism comprises a support end cover, an output steel ball, a planetary gear, a pinwheel and a needle roller;

[0006] The support end cover is fixedly installed on one side of the cross roller bearing, and the needle wheel and the output end cover are fixedly installed on the other side of the cross roller bearing;

[0007] The needle roller is installed in the needle tooth groove of the needle wheel through clearance fit; the planetary gear is installed at the center of the needle wheel and meshes with the needle roller in the needle tooth groove of the needle wheel;

[0008] The input shaft is installed in the inner hole of the support end cover of the support end cover and the inner hole of the planetary gear of the planetary gear; the input shaft is axially provided with a first shaft section, an eccentric shaft section and a third shaft section with gradually increasing diameters; a first deep groove ball bearing is installed between the first shaft section and the inner hole of the support end cover; a second deep groove ball bearing is installed between the eccentric shaft section and the inner hole of the planetary gear; the sleeve located between the first deep groove ball bearing and the second deep groove ball bearing is installed outside the first shaft section; the two sides of the first deep groove ball bearing are axially fixed by the support end cover shaft shoulder and the sleeve provided at one end of the inner hole of the support end cover in contact; the two sides of the second deep groove ball bearing are axially fixed by the sleeve and the third shaft section in contact;

[0009] A third deep groove ball bearing is installed in the inner hole of the output end cover, and two sides of the third deep groove ball bearing are axially fixed by the contacting third shaft section and the output end cover shoulder arranged at one end of the inner hole of the output end cover respectively;

[0010] A plurality of support end cover constant velocity transmission ball pits and a plurality of planetary gear ball pits are evenly distributed on the corresponding surfaces of the support end cover and the planetary gear, and each of the support end cover constant velocity transmission ball pits has a one-to-one corresponding planetary gear ball pit; the output steel ball is installed between the corresponding support end cover constant velocity transmission ball pit and the planetary gear ball pit.

[0011] Furthermore, the support end cover and the cross roller bearing are fixedly connected by a plurality of evenly distributed screws; the needle wheel and the output end cover are fixedly connected to the cross roller bearing by a plurality of evenly distributed flat head screws.

[0012] Furthermore, the surface of the output end cover is provided with an annular groove corresponding to the position of the planetary gear, and a plurality of supporting steel balls are installed in the annular groove. The supporting steel balls are located between the planetary gear and the output end cover to prevent the planetary gear from deflecting during transmission.

[0013] Furthermore, the axial clearance between the needle roller and the needle tooth groove of the needle wheel is within 0.015 mm.

[0014] Furthermore, a clearance fit is adopted between the output steel ball and the planetary gear ball pit, and the spherical clearance between the output steel ball and the planetary gear ball pit is within 0.01 mm; the output steel ball is tangent to the support end cover constant velocity transmission ball pit and the planetary gear ball pit; the number of the support end cover constant velocity transmission ball pit and the planetary gear ball pit is the same as the number of the output steel balls.

[0015] Furthermore, the small diameter d of the constant velocity transmission ball pit of the support end cover is: d=2ε, and the large diameter D of the constant velocity transmission ball pit of the support end cover is: D=d1+2ε, wherein: d1 is the diameter of the output steel ball; ε is the eccentricity of the eccentric shaft segment.

[0016] Furthermore, the needle wheel is fixedly connected to the inner ring of the cross roller bearing of the cross roller bearing.

[0017] Furthermore, the planetary gear outer teeth of the planetary gear are sinusoidal tooth profiles; and a plurality of the needle rollers are evenly installed in the pin tooth grooves of the pin wheel.

[0018] Furthermore, the parametric equation f(x0, y0) of the sinusoidal tooth profile curve of the planetary gear external teeth in the plane rectangular coordinate system is:

[0019]

[0020] Among them, z1 is the number of teeth of the sinusoidal tooth profile; r1 is the radius of the sinusoidal tooth profile pitch circle; is the angular position coordinate of the sinusoidal tooth profile; a is the tooth height coefficient.

[0021] Furthermore, the output end cover has output end cover through holes with the same number as the flat head screws, the pin wheel has pin wheel through holes with the same number as the flat head screws, the cross roller bearing has cross roller bearing threaded holes with the same number as the flat head screws, and the pin wheel through holes are fixedly connected to the output end cover through holes and the cross roller bearing threaded holes via the flat head screws.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] The ultra-thin chord pinwheel reducer based on the crossed roller bearing provided by the present invention has a more compact structure and smaller size by fixing the inner ring of the crossed roller bearing, the pinwheel and the output end cover with a plurality of evenly distributed flat head screws; the support end cover and the outer ring of the crossed roller bearing are tightly fixed together by a plurality of evenly distributed screws, and the support end cover also serves as a constant speed transmission pad, which further reduces the axial size of the reducer; when the reducer is subjected to output torque, it can withstand a large axial load and moment, and can maintain the stability of accuracy and a large contact stiffness, thereby ensuring the stability of the prototype during operation; the outer teeth of the planetary gear adopt a sinusoidal tooth profile, which meshes with the needle roller installed on the pinwheel to achieve a one-tooth difference transmission, so that the reducer provides a larger transmission ratio with a smaller size.

[0024] Based on the above reasons, the present invention can be widely promoted in the field of string pinwheel reducers. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0026] Figure 1 This is a schematic diagram of the structure of the ultra-thin string pinwheel reducer based on the crossed roller bearing according to the present invention.

[0027] Figure 2 This is a schematic diagram of the cross-sectional structure of the ultra-thin string pinwheel reducer based on the cross roller bearing described in the present invention.

[0028] Figure 3 It is a schematic diagram of the supporting end cover structure of the present invention.

[0029] Figure 4 This is a schematic diagram of the input shaft structure of the present invention.

[0030] Figure 5 It is a schematic diagram of the sleeve structure of the present invention.

[0031] Figure 6 This is a schematic diagram of the planetary gear structure of the present invention.

[0032] Figure 7 This is a schematic diagram of the structure of the cross roller bearing of the present invention.

[0033] Figure 8 It is a schematic diagram of the pin wheel structure of the present invention.

[0034] Fig. 9 This is a schematic diagram of the output end cover structure of the present invention.

[0035] In the figure: 1. Support end cover; 101. Inner hole of support end cover; 102. Shoulder of support end cover; 103. Constant speed transmission ball pit of support end cover; 104. Threaded hole of support end cover; 2. First deep groove ball bearing; 3. Input shaft; 301. First shaft section of input shaft; 302. Eccentric shaft section of input shaft; 303. Third shaft section of input shaft; 4. Sleeve; 5. Output steel ball; 6. Planetary gear; 601. Inner hole of planetary gear; 602. Ball pit of planetary gear; 603. External gear of planetary gear; 7. Screw; 8. Cross roller bearing; 80 1. Crossed roller bearing outer ring; 802. Crossed roller bearing inner ring; 803. Crossed roller bearing countersunk through hole; 804. Crossed roller bearing threaded hole; 9. Needle wheel; 901. Needle wheel needle tooth groove; 902. Needle wheel through hole; 10. Needle roller; 11. Support steel ball; 12. Second deep groove ball bearing; 13. Third deep groove ball bearing; 14. Flat head screw; 15. Output end cover; 1501. Inner hole of output end cover; 1502. Annular groove of output end cover; 1503. Output end cover shoulder; 1504. Output end cover through hole. DETAILED DESCRIPTION

[0036] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0037] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0039] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, the numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0040] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0041] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below their position devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0042] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0043] Example 1

[0044] like Figure 1-9 As shown, the present invention provides an ultra-thin string pinwheel reducer based on a cross roller bearing, an ultra-thin string pinwheel reducer based on a cross roller bearing, comprising an input shaft 3, a cross roller bearing 8, an output end cover 15 and a constant speed transmission mechanism; the constant speed transmission mechanism comprises a support end cover 1, an output steel ball 5, a planetary gear 6, a pinwheel 9 and a needle roller 10;

[0045] The support end cover 1, the cross roller bearing 8, the pin wheel 9 and the output end cover 15 are coaxially arranged in sequence, the support end cover 1 is fixedly installed on one side of the cross roller bearing 8, and the pin wheel 9 and the output end cover 15 are fixedly installed on the other side of the cross roller bearing 8;

[0046] The needle roller 10 is installed in the needle wheel pin tooth groove 901 of the needle wheel 9 through clearance fit; the planetary gear 6 is installed at the center of the needle wheel 9 and meshes with the needle roller 10 in the needle wheel pin tooth groove 901, and the planetary gear 6 can achieve meshing transmission with the needle roller 10 to achieve a one-tooth difference transmission;

[0047] The input shaft 3 is installed in the support end cover inner hole 101 of the support end cover 1 and the planetary gear inner hole 601 of the planetary gear 6; the input shaft 3 is axially provided with a first shaft section 301, an eccentric shaft section 302 and a third shaft section 303 with gradually increasing diameters; a first deep groove ball bearing 2 is installed between the first shaft section 301 and the support end cover inner hole 101; a second deep groove ball bearing 12 is installed between the eccentric shaft section 302 and the planetary gear inner hole 601; the sleeve 4 located between the first deep groove ball bearing 2 and the second deep groove ball bearing 12 is installed outside the first shaft section 301; the two sides of the first deep groove ball bearing 2 are axially fixed by the support end cover shaft shoulder 102 and the sleeve 4 provided at one end of the support end cover inner hole 101 in contact; the two sides of the second deep groove ball bearing 12 are axially fixed by the sleeve 4 and the third shaft section 303 in contact;

[0048] The output end cover inner hole 1501 of the output end cover 15 is installed with a third deep groove ball bearing 13, and the two sides of the third deep groove ball bearing 13 are axially fixed by the contacting third shaft section 303 and the output end cover shaft shoulder 1503 provided at one end of the output end cover inner hole 1501;

[0049] A plurality of support end cover constant speed transmission ball pits 103 and a plurality of planetary gear ball pits 602 are evenly distributed on the corresponding surfaces of the support end cover 1 and the planetary gear 6, and each of the support end cover constant speed transmission ball pits 103 has a one-to-one corresponding planetary gear ball pit 602; the output steel ball 5 is installed between the corresponding support end cover constant speed transmission ball pit 103 and the planetary gear ball pit 602.

[0050] Furthermore, the support end cover 1 and the cross roller bearing 8 are fixedly connected by a plurality of evenly distributed screws 7 ; the needle wheel 9 and the output end cover 15 are fixedly connected to the cross roller bearing 8 by a plurality of evenly distributed flat head screws 14 .

[0051] Furthermore, in order to prevent the planetary gear 6 from being close to the output end cover 15 during the transmission process of the reducer and affecting the transmission effect, an annular groove 1502 corresponding to the position of the planetary gear 6 is provided on the surface of the output end cover 15 facing the pin wheel 9, and a plurality of closely packed supporting steel balls 11 with a diameter of 1.5 mm are installed in the annular groove 1502. The supporting steel balls 11 are located between the planetary gear 6 and the output end cover 15, and are used to fix the planetary gear 6 to prevent the planetary gear 6 from being skewed during the transmission process.

[0052] Furthermore, the axial clearance between the needle roller 10 and the needle wheel needle tooth groove 901 is within 0.015 mm. In order to prevent the needle roller 10 and the needle wheel needle tooth groove 901 from being too loose and affecting the meshing performance between the needle roller 10 and the planetary gear outer tooth 603, the diameter of the needle roller 10 is designed to be 1.2 mm, the upper deviation is 0, and the lower deviation is -0.01 mm. The design diameter of the needle wheel needle tooth groove 901 is 1.2 mm, the upper deviation is +0.005, and the lower deviation is 0, ensuring that the axial clearance is within 0.015 mm.

[0053] Further, the output steel ball 5 and the planetary gear ball pit 602 are clearance-matched, and the spherical clearance between the output steel ball 5 and the planetary gear ball pit 602 is within 0.01 mm. To prevent the output steel ball 5 and the planetary gear ball pit 602 from being too loose and affecting the constant speed transmission, the diameter of the output steel ball 5 is designed to be 2 mm, the upper deviation is 0, and the lower deviation is -0.005. The design diameter of the planetary gear ball pit 602 is 2 mm, the upper deviation is +0.005, and the lower deviation is 0, ensuring that the spherical clearance is within 0.01 mm.

[0054] The output steel balls 5 are kept tangent to the support end cover constant velocity transmission ball pit 103 and the planetary gear ball pit 602 ; the number of the support end cover constant velocity transmission ball pit 103 and the planetary gear ball pit 602 is the same as the number of the output steel balls 5 .

[0055] Furthermore, the minor diameter (bottom diameter) d of the support end cover constant velocity transmission ball pit 103 is: d=2ε, and the major diameter (opening diameter) D of the support end cover constant velocity transmission ball pit 103 is: D=d1+2ε, wherein: d1 is the diameter of the output steel ball 5; ε is the eccentricity of the eccentric shaft section 302;

[0056] Since the planetary gear 6 is installed on the eccentric shaft section 302 of the input shaft 3 with an eccentricity of 0.25, the output steel ball 5 fixed in the planetary gear ball pit 602 needs to be transmitted in the support end cover constant speed transmission ball pit 103, so the support end cover constant speed transmission ball pit 103 should be designed with twice the eccentricity; therefore, the small diameter d of the support end cover constant speed transmission ball pit 103 needs to be designed to be 0.5mm, and the large diameter D needs to be designed to be 2.5mm; the 6 output steel balls 5 and the support end cover constant speed transmission ball pit 103 always keep in contact and maintain a tangent relationship during transmission.

[0057] Furthermore, the pin wheel 9 is fixedly connected to the cross roller bearing inner ring 802 of the cross roller bearing 8 .

[0058] Furthermore, the planetary gear outer teeth 603 of the planetary gear 6 are sinusoidal tooth profiles, which enable the gear to run smoothly when meshing in and out, with little impact vibration; a plurality of the needle rollers 10 are evenly installed in the pin wheel pin tooth grooves 901.

[0059] Furthermore, the parametric equation f(x0, y0) of the sinusoidal tooth profile curve of the planetary gear external tooth 603 in the plane rectangular coordinate system is:

[0060]

[0061] Among them, z1 is the number of teeth of the sinusoidal tooth profile; r1 is the radius of the sinusoidal tooth profile pitch circle; is the angular position coordinate of the sinusoidal tooth profile; a is the tooth height coefficient.

[0062] Furthermore, the output end cover 15 has output end cover through holes 1504, the number of which is the same as the flat head screws 14, the needle wheel 9 has needle wheel through holes 902, the number of which is the same as the flat head screws 14, the cross roller bearing 8 has cross roller bearing threaded holes 804, the number of which is the same as the flat head screws 14, and the needle wheel through holes 902 are fixedly connected to the output end cover through holes 1504 and the cross roller bearing threaded holes 804 via the flat head screws 14.

[0063] Furthermore, the support end cover 1 and the outer ring 801 of the cross roller bearing are tightly connected together by 8 evenly distributed M2.5 screws 7.

[0064] Further, the crossed roller bearing 8 has 8 evenly distributed cross roller bearing countersunk through holes 803 on the crossed roller bearing outer ring 801, and 8 evenly distributed cross roller bearing threaded holes 804 on the crossed roller bearing inner ring 802; the output end cover 15 has 8 evenly distributed output end cover through holes 1504; the pin wheel 9 has 8 evenly distributed pin wheel through holes 902; the crossed roller bearing inner ring 802, the pin wheel 9 and the output end cover 15 are tightly fixed together by 8 evenly distributed M2.5 flat head screws 14;

[0065] The support end cover 1 has 8 evenly distributed support end cover threaded holes 104 and 6 evenly distributed support end cover constant speed transmission ball pits 103, and the planetary gear 6 has 6 evenly distributed planetary gear ball pits 602;

[0066] The support end cover threaded hole 104 and the cross roller bearing countersunk through hole 803 are fixedly connected by the screw 7 .

[0067] Compared with other reducers, the reducer of the present invention adopts an outer ring output transmission method, the pin wheel 9 is fixedly connected with the inner ring 802 of the cross roller bearing, and the support end cover 1 also serves as a constant speed transmission pad, which greatly reduces the axial size of the reducer.

[0068] The ultra-thin string pinwheel reducer based on the cross roller bearing described in this embodiment has the following overall dimensions: outer diameter 67 mm, total length 17 mm; the planetary gear outer teeth 603 are sinusoidal tooth profiles; the theoretical parameters of the string pinwheel transmission are shown in Table 1 below:

[0069] Table 1 Structural theoretical parameters

[0070]

[0071] The working principle of the present invention is as follows: the input shaft 3 is driven to rotate, and the eccentric shaft section 302 will carry the planetary gear 6 to revolve around the axis of the input shaft 3. During the movement, it will mesh with the needle roller 10 on the pin wheel 9 with a small tooth difference. The chord outer teeth 603 of the planetary gear 6 mesh with the needle roller 10 on the pin wheel 9 with the same transmission ratio. Six ball pits 602 are evenly distributed on the planetary gear 6, and the output steel balls 5 are evenly installed in the planetary gear ball pits 602, and the output steel balls 5 are tangentially installed in the constant-speed transmission ball pits 103 of the support end cover, so that the output steel balls 5 are transmitted in the constant-speed transmission ball pits 103 of the support end cover. Due to the eccentricity of the eccentric shaft section 302, the planetary gear 6 will make a swinging motion, driving the pin wheel 9, the inner ring 802 of the cross roller bearing, and the output end cover 15 to rotate together, realizing constant-speed transmission.

[0072] Compared with the prior art, the ultra-thin chord pinwheel reducer based on crossed roller bearings proposed in the present invention tightly connects the inner ring 802 of the crossed roller bearing, the pinwheel 9 and the output end cover 15 together through a plurality of evenly distributed flat head screws 14, which greatly reduces the axial size of the reducer; the support end cover 1 and the outer ring 801 of the crossed roller bearing are tightly connected together through a plurality of evenly distributed screws 7, and the support end cover 1 also serves as a constant speed transmission pad, which further reduces the axial size of the reducer; when the reducer is subjected to output torque, it can withstand a large axial load and moment, and can maintain the stability of accuracy and a large contact stiffness, thereby ensuring the stability of the prototype during operation; the outer teeth 603 of the planetary gear mesh with the needle roller 10 installed on the pinwheel 9 to realize a one-tooth difference transmission, so that the gear runs smoothly when meshing in and out, with small impact vibration.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An ultra-thin string pinwheel reducer based on crossed roller bearings, It is characterized in that It comprises an input shaft (3), a cross roller bearing (8), an output end cover (15) and a constant speed transmission mechanism; the constant speed transmission mechanism comprises a support end cover (1), an output steel ball (5), a planetary gear (6), a pin wheel (9) and a needle roller (10); The support end cover (1) is fixedly mounted on one side of the cross roller bearing (8), and the pin wheel (9) and the output end cover (15) are fixedly mounted on the other side of the cross roller bearing (8); The needle roller (10) is installed in the needle wheel pin tooth groove (901) of the needle wheel (9) through clearance fit; the planetary gear (6) is installed at the center of the needle wheel (9) and meshes with the needle roller (10) in the needle wheel pin tooth groove (901); The input shaft (3) is installed in the inner hole (101) of the support end cover of the support end cover (1) and the inner hole (601) of the planetary gear (6); the input shaft (3) is provided with a first shaft section (301), an eccentric shaft section (302) and a third shaft section (303) with gradually increasing diameters along the axial direction; a first deep groove ball bearing (2) is installed between the first shaft section (301) and the inner hole (101) of the support end cover; a second deep groove ball bearing (2) is installed between the eccentric shaft section (302) and the inner hole (601) of the planetary gear (6). A deep groove ball bearing (12); the first shaft section (301) is provided with the sleeve (4) located between the first deep groove ball bearing (2) and the second deep groove ball bearing (12); the two sides of the first deep groove ball bearing (2) are axially fixed by the support end cover shaft shoulder (102) and the sleeve (4) provided at one end of the inner hole (101) of the support end cover in contact; the two sides of the second deep groove ball bearing (12) are axially fixed by the sleeve (4) and the third shaft section (303) in contact; The output end cover inner hole (1501) of the output end cover (15) is provided with a third deep groove ball bearing (13), and the two sides of the third deep groove ball bearing (13) are axially fixed by the contacting third shaft section (303) and an output end cover shaft shoulder (1503) provided at one end of the output end cover inner hole (1501); A plurality of support end cover constant speed transmission ball pits (103) and a plurality of planetary gear ball pits (602) are evenly distributed on the corresponding surfaces of the support end cover (1) and the planetary gear (6), and each of the support end cover constant speed transmission ball pits (103) has a one-to-one corresponding planetary gear ball pit (602); the output steel ball (5) is installed between the corresponding support end cover constant speed transmission ball pit (103) and the planetary gear ball pit (602).

2. The ultra-thin string pinwheel reducer based on a cross roller bearing according to claim 1, It is characterized in that The support end cover (1) and the cross roller bearing (8) are fixedly connected by a plurality of evenly distributed screws (7); the needle wheel (9) and the output end cover (15) are fixedly connected to the cross roller bearing (8) by a plurality of evenly distributed flat head screws (14).

3. The ultra-thin string pinwheel reducer based on a cross roller bearing according to claim 1, It is characterized in that The output end cover (15) is provided with an annular groove (1502) corresponding to the position of the planetary gear (6) on its surface, and a plurality of supporting steel balls (11) are installed in the annular groove (1502). The supporting steel balls (11) are located between the planetary gear (6) and the output end cover (15) and are used to prevent the planetary gear (6) from being deflected during the transmission process.

4. The ultra-thin string pinwheel reducer based on a cross roller bearing according to claim 1, It is characterized in that The axial clearance between the needle roller (10) and the needle wheel needle tooth groove (901) is within 0.015 mm.

5. The ultra-thin string pinwheel reducer based on a cross roller bearing according to claim 1, It is characterized in that The output steel ball (5) and the planetary gear ball pit (602) are clearance-matched, and the spherical clearance between the output steel ball (5) and the planetary gear ball pit (602) is within 0.01 mm; the output steel ball (5) is tangent to the support end cover constant velocity transmission ball pit (103) and the planetary gear ball pit (602); the number of the support end cover constant velocity transmission ball pit (103) and the planetary gear ball pit (602) is the same as the number of the output steel ball (5).

6. The ultra-thin string pinwheel reducer based on a cross roller bearing according to claim 1, It is characterized in that The minor diameter d of the constant velocity transmission ball pit (103) of the support end cover is: d=2ε, and the major diameter D of the constant velocity transmission ball pit (103) of the support end cover is: D=d 1 +2ε, where: d 1 is the diameter of the output steel ball (5); and ε is the eccentricity of the eccentric shaft section (302).

7. The ultra-thin string pinwheel reducer based on a cross roller bearing according to claim 1, It is characterized in that The needle wheel (9) is fixedly connected to the cross roller bearing inner ring (802) of the cross roller bearing (8).

8. The ultra-thin string pinwheel reducer based on a cross roller bearing according to any one of claims 1 to 7, It is characterized in that The planetary gear outer teeth (603) of the planetary gear (6) are sinusoidal tooth profiles; and a plurality of the needle rollers (10) are evenly distributed and installed in the pin wheel pin tooth grooves (901).

9. The ultra-thin string pinwheel reducer based on a cross roller bearing according to claim 8, It is characterized in that The parameter equation f(x) of the sinusoidal tooth profile curve of the planetary gear external tooth (603) in a plane rectangular coordinate system is 0 ,y 0 )for: Among them, z 1 is the number of teeth of the sinusoidal tooth profile; r 1 is the pitch circle radius of the sinusoidal tooth profile; is the angular position coordinate of the sinusoidal tooth profile; a is the tooth height coefficient.

10. The ultra-thin string pinwheel reducer based on a cross roller bearing according to claim 2, It is characterized in that The output end cover (15) has the same number of output end cover through holes (1504) as the flat head screws (14); the pin wheel (9) has the same number of pin wheel through holes (902) as the flat head screws (14); the cross roller bearing (8) has the same number of cross roller bearing threaded holes (804) as the flat head screws (14); the pin wheel through holes (902) are fixedly connected to the output end cover through holes (1504) and the cross roller bearing threaded holes (804) via the flat head screws (14).

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