Cycloidal gear, speed reducer and industrial robot

Abstract

The invention discloses a cycloidal gear, a speed reducer and an industrial robot, the speed reducer comprises a pin gear, the cycloidal gear is in meshing transmission with the pin gear, the pin gear comprises a plurality of cylindrical pin teeth, and in the contour line from the tooth root to the tooth crest of the cycloidal gear, the pin teeth are meshed with the pin teeth. The difference between the radius of a circle formed by any point on the standard cycloidal gear and the circle center of the standard cycloidal gear and the radius of a root circle of the standard cycloidal gear is defined as a reference radius, the modification amount of the reference radius in different numerical value intervals is determined by a preset modification amount parameter delta, delta = e * (d2 + (2 * Rn-2 * R1) 2) 0.5 / 1000, e is the eccentricity of the standard cycloidal gear, d is the diameter of a pin gear, and the diameter of the pin gear is smaller than that of the standard cycloidal gear. R1 is the root circle radius of the standard cycloid gear, and Rn is the addendum circle radius of the standard cycloid gear. The standard cycloid gear is shaped, so that the phenomenon that the cycloid gear is stuck or friction is aggravated when the cycloid gear is meshed with the outer pin gear can be reduced, and the load distribution of the cycloid gear is improved.

Description

[0001] This application is a divisional application with the application date of "2023.10.11", application number "202311318515.1", and application name "Cycloidal gear tooth profile modification method, cycloidal gear, reducer and industrial robot". Technical Field

[0002] The present invention relates to the technical field of speed reducers, and in particular to a cycloid gear, a speed reducer and an industrial robot. Background Art

[0003] The cycloid gear transmission in the planetary cycloid reducer mainly relies on the meshing of the cycloid gear and the pin teeth to transmit speed and torque. The rationality of the cycloid gear design directly affects the comprehensive performance of the reducer. Among them, the design of the cycloid gear tooth shape directly affects the key performance of the reducer such as load distribution, life, transmission accuracy and stability.

[0004] When the reducer is under load, the cycloid gear and the pin teeth are tightly meshed. Due to the changes in the clearances of the various components inside the reducer and the deformation of the reducer itself, the cycloid gear and the pin teeth are prone to getting stuck or the friction increases, which directly leads to the deterioration of the reducer performance. Summary of the invention

[0005] The embodiments of the present invention provide a cycloid gear, a reducer and an industrial robot to solve at least one of the above-mentioned technical problems.

[0006] A cycloid gear in an embodiment of the present invention is used for a reducer, and the reducer includes a pin-tooth gear, the cycloid gear meshes with the pin-tooth gear for transmission, and the pin-tooth gear includes a plurality of cylindrical pin teeth. In the contour line from the root of the cycloid gear to the top of the tooth, the difference between the radius of a circle formed by any point on the standard cycloid gear and the center of the standard cycloid gear and the root circle radius of the standard cycloid gear is defined as a reference radius, and the modification amount of the reference radius in different numerical ranges is determined by a preset modification amount parameter δ, δ=e×(d^2+(2×Rn-2×R1)^2)^0.5 / 1000, wherein e is the eccentricity of the standard cycloid gear, d is the diameter of the pin tooth, R1 is the root circle radius of the standard cycloid gear, and Rn is the top circle radius of the standard cycloid gear.

[0007] According to an embodiment of the present invention, a cycloidal gear has at least the following beneficial effects: by defining the difference between the radius of the circle formed by any point on the standard cycloidal gear and the center of the standard cycloidal gear and the root circle radius of the standard cycloidal gear in the contour line from the root to the top of the tooth of the cycloidal gear as the reference radius, the modification amount of the reference radius in different numerical intervals is determined by the preset modification amount parameter δ, δ = e × (d^2 + (2 × Rn-2 × R1)^2)^0.5 / 1000, wherein e is the eccentricity of the standard cycloidal gear, d is the diameter of the pin tooth, R1 is the root circle radius of the standard cycloidal gear, and Rn is the top circle radius of the standard cycloidal gear. Therefore, by modifying the standard cycloidal gear, the phenomenon of jamming or increased friction when the cycloidal gear and the external pin tooth are meshed can be reduced, and the load distribution of the cycloidal gear can be improved, which is beneficial to improving the comprehensive performance of the reducer. According to some embodiments of the present invention, the value range of the modification amount at the reference radius equal to zero is [0.8δ, 8.3δ].

[0008] According to some embodiments of the present invention, the value range of the modification amount at the tooth height of the standard cycloid gear where the reference radius is greater than zero and less than 0.3 times is [0.7δ, 4.1δ].

[0009] According to some embodiments of the present invention, the value range of the modification amount at the reference radius greater than 0.3 times the tooth height of the standard cycloid gear and less than or equal to 0.5 times the tooth height of the standard cycloid gear is [0.56δ, 1.4δ].

[0010] According to some embodiments of the present invention, the value range of the modification amount at the reference radius greater than 0.5 times the tooth height of the standard cycloid gear and less than or equal to 0.7 times the tooth height of the standard cycloid gear is [0.7δ, 1.6δ].

[0011] According to some embodiments of the present invention, the value range of the modification amount at the reference radius greater than 0.7 times the tooth height of the standard cycloid gear and less than the tooth height of the standard cycloid gear is [0.78δ, 4.3δ].

[0012] According to some embodiments of the present invention, the modification amount at the reference radius equal to the tooth height of the standard cycloid gear has a value range of [0.83δ, 8.2δ]. A reducer according to an embodiment of the present invention includes the cycloid gear according to any one of the above embodiments.

[0013] An industrial robot according to an embodiment of the present invention includes the reducer described in the above embodiment.

[0014] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0016] Figure 1 is a flow chart of a method for modifying a cycloid gear tooth profile according to an embodiment of the present invention;

[0017] Figure 2 It is a partial structural schematic diagram of a reducer according to an embodiment of the present invention;

[0018] Figure 3 is a schematic structural diagram of a cycloid gear and a pin gear according to an embodiment of the present invention;

[0019] Figure 4 is a schematic diagram of the tooth profile of a cycloid gear according to an embodiment of the present invention;

[0020] Figures 5 to 10 is a flow chart of a method for modifying a cycloid gear tooth profile according to an embodiment of the present invention;

[0021] Fig.11 is a schematic diagram of the tooth profile of a cycloid gear according to an embodiment of the present invention;

[0022] Fig.12 It is a simulated force curve diagram of the cycloid gear according to the embodiment of the present invention.

[0023] Figure Number:

[0024] Cycloid gear 10; pin gear 12; pin gear 14; crankshaft 16; through hole 18; pin gear housing 20; needle bearing 22; planetary gear 24;

[0025] Reducer 100. DETAILED DESCRIPTION

[0026] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0027] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0028] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be directly connected or indirectly connected through an intermediate medium. It can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0030] The disclosure herein provides many different embodiments or examples for realizing different structures of the present invention. In order to simplify the disclosure of the present invention, the components and settings of specific examples are described herein. Of course, they are merely examples, and the purpose is not to limit the present invention. In addition, the present invention may repeat reference numerals and / or reference letters in different examples, and such repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides various specific examples of processes and materials, but those of ordinary skill in the art may appreciate the application of other processes and / or the use of other materials.

[0031] See also Figures 1 to 4, an embodiment of the present invention provides a method for modifying the tooth profile of a cycloid gear 10, the method for modifying the tooth profile of a cycloid gear 10 comprising:

[0032] Step S101: determining at least one modification point Dx in the contour line from the tooth root to the tooth top of the standard cycloid gear;

[0033] Step S103: obtaining a reference radius Rx of the modification point Dx, where the reference radius Rx is the difference between the radius of a circle formed by any point on the standard cycloid gear and the center of the standard cycloid gear and the radius of the tooth root circle of the standard cycloid gear;

[0034] Step S105: determining the shaping amount of the shaping point Dx according to the reference radius Rx of the shaping point Dx and a preset shaping amount parameter;

[0035] Step S107 : modifying the standard cycloid gear according to the modification amount of the modification point Dx to obtain the cycloid gear 10 .

[0036] The above-mentioned method for modifying the tooth profile of the cycloid gear 10 can reduce the jamming or increased friction when the cycloid gear 10 and the outer pin teeth 14 are meshed by modifying the standard cycloid gear, and improve the load distribution of the cycloid gear 10, which is beneficial to improving the comprehensive performance of the reducer 100.

[0037] Specifically, the cycloid gear 10 can be applied to the reducer 100. Optionally, the reducer 100 can be a RV (Rotary Vector) reducer. The RV reducer is a core component of an industrial robot and has the advantages of high precision, high rigidity and long life.

[0038] like Figure 2 As shown, the motion transmission path of the RV reducer starts from the input shaft, and the motion and force are transmitted to the planetary gear 24 through the meshing of the input shaft and the planetary gear 24. The planetary gear 24 is connected to the crankshaft 16, and the crankshaft 16 and the planetary gear 24 make the same motion. The cycloid gear 10 has a through hole 18, and the cycloid gear 10 is sleeved on the flange of the crankshaft 16 through the through hole 18. The crankshaft 16 will drive the cycloid gear 10 to make an eccentric motion and mesh with the pin gear 14, and finally transmit the load and motion to the output shaft.

[0039] The pin gear 12 includes pin teeth 14 and a pin gear housing 20, wherein the pin teeth 14 are arranged on the inner circumference of the pin gear housing 20. In addition, the reducer further includes a needle bearing 22, which is arranged between the crankshaft 16 and the cycloid gear 10 to reduce friction when the two move relative to each other.

[0040] The RV reducer mainly transmits speed and torque by meshing the cycloid gear 10 with the pin teeth 14 on the pin gear 12. Whether the design of the cycloid gear 10 is reasonable directly affects the comprehensive performance of the reducer 100. The tooth shape design of the cycloid gear 10 directly affects the key performances of the reducer 100, such as load distribution, life, transmission accuracy, and stability.

[0041] The theoretical tooth shape of the cycloid gear 10 can be expressed by the cycloid curve formula according to the meshing principle of the cycloid gear 10 and the pinion gear 12. However, since the theoretical tooth shape is a cycloid tooth shape without modification and is tightly meshed with the pinion gear 14, when the reducer 100 is loaded, due to the changes in the clearances of the various components inside the reducer 100 and the deformation of the reducer 100 itself, the cycloid gear 10 and the pinion gear 14 are easily stuck or the friction is aggravated, which directly leads to the performance of the reducer 100 being deteriorated.

[0042] Therefore, the tooth profile of the cycloid gear 10 is appropriately modified so that even when the cycloid gear 10 is deformed under load, the tooth meshing can still carry the load evenly, thereby ensuring the performance such as service life and transmission accuracy.

[0043] The modification of the cycloid gear 10 is performed on the standard cycloid gear. A modification method for the tooth profile of a cycloid gear 10 provided in an embodiment of the present invention first determines an arbitrary modification point Dx on the tooth profile of the standard cycloid gear from the tooth root to the tooth top, then obtains a reference radius Rx of the modification point Dx, and determines the modification amount at the modification point according to the reference radius Rx and a preset modification amount parameter.

[0044] like Figure 4 Schematic diagram of partial tooth profiles of the cycloid gear 10 and the standard cycloid gear, from top to bottom are the tooth profile contours of the standard cycloid gear and the cycloid gear 10 respectively.

[0045] The root of the standard cycloid gear is recorded as D1, the root circle of the standard cycloid gear is recorded as C1, the top of the standard cycloid gear is recorded as Dn, the top circle of the standard cycloid gear is recorded as Cn, any point on the tooth profile of the standard cycloid gear is recorded as Dx, the circle formed by Dx and the circle of the standard cycloid gear is recorded as Cx, the tooth height of the standard cycloid gear is recorded as H, and the reference radius of the Dx point is recorded as Rx.

[0046] It should be noted that the standard cycloid gear is a cycloid gear 10 having a theoretical tooth shape. The theoretical tooth shape is a tooth shape expressed by a cycloid curve formula based on the meshing principle of the cycloid gear 10 and the pin-tooth gear 12 .

[0047] On the tooth profile from the tooth root to the tooth top of the standard cycloid gear, a modification point Dx can be arbitrarily selected, and the number of the modification points Dx can be one, two, three or any value greater than three.

[0048] The reference radius Rx is defined as the difference between the radius of the circle formed by any point on the standard cycloid gear tooth profile and the center of the standard cycloid gear and the root radius of the standard cycloid gear. The reference radius Rx of the modification point Dx is the difference between the radius of the circle formed by the modification point Dx and the center of the standard cycloid gear and the root radius of the standard cycloid gear.

[0049] Profiling is the conscious modification of the gear tooth profile shape.

[0050] The modification amount at the modification point Dx can be understood as the amount of modification of the standard cycloid gear along the normal direction of the modification point Dx on the circle formed by the modification point Dx and the center of the standard cycloid gear.

[0051] In some embodiments, the cycloid gear 10 is used in a reducer 100, which includes a pinion gear 12. The cycloid gear 10 is meshed with the pinion gear 12 for transmission. The pinion gear 12 includes a plurality of cylindrical pinions 14. The preset modification parameters are related to the eccentricity of the standard cycloid gear, the diameter of the pinions 14, the root circle radius of the standard cycloid gear, and the top circle radius of the standard cycloid gear.

[0052] In this way, preset modification parameters for different models or sizes can be determined based on standard cycloid gears and other transmission components on the reducer 100 .

[0053] Specifically, the preset modification parameter δ=e×(d^2+(2×Rn-2×R1)^2)^0.5 / 1000, wherein e is the eccentricity of the standard cycloid gear, d is the diameter of the pin tooth 14, R1 is the root circle radius of the standard cycloid gear, and Rn is the top circle radius of the standard cycloid gear.

[0054] See also Figure 5 In some embodiments, step S105 includes:

[0055] Step S1051: when the reference radius Rx is equal to zero, determine that the value range of the shaping amount of the shaping point Dx is [0.8δ, 8.3δ].

[0056] In this way, when the selected modification point Dx is on the tooth root of the standard cycloid gear, the modification amount at the modification point Dx can be determined according to the value range of the modification point Dx.

[0057] Specifically, when the reference radius Rx is equal to zero, that is, the radius of the circle formed by the modification point Dx and the circle of the standard cycloid gear is equal to the radius of the root circle of the standard cycloid gear, that is, the modification point Dx is located on the root circle of the standard cycloid gear, and at this time, the value range of the modification amount at the modification point Dx is [0.8δ, 8.3δ]. For example, the modification amount can be 0.8δ, 1.5δ, 2.5δ, 3.5δ, 4.5δ, 5.5δ, 6.5δ, 7.5δ, 8δ or 8.3δ, or any other value within the range [0.8δ, 8.3δ].

[0058] See also Figure 6 In some embodiments, step S105 includes:

[0059] Step S1052: when the reference radius Rx is greater than zero and less than or equal to 0.3 times the tooth height of the standard cycloid gear, determine that the value range of the modification amount of the modification point Dx is [0.7δ, 4.1δ].

[0060] In this way, the value range of the shaping amount at the shaping point Dx can be determined according to the reference radius Rx and the preset shaping amount parameter, thereby determining the shaping amount at the shaping point Dx.

[0061] Specifically, on a standard cycloid gear, at a position where the reference radius Rx is less than 0.3 times the tooth height of the standard cycloid gear, the value range of the modification amount is [0.7δ, 4.1δ]. For example, the value of the modification amount can be 0.7δ, 0.8δ, 0.9δ, 1.2δ, 1.5δ, 2.5δ, 3δ, 3.5δ, 3.8δ or 4.1δ, or any other value within the range [0.7δ, 4.1δ].

[0062] See also Figure 7 In some embodiments, step S105 includes:

[0063] Step S1053: when the reference radius Rx is greater than 0.3 times the tooth height of the standard cycloid gear and less than or equal to 0.5 times the tooth height of the standard cycloid gear, determine that the value range of the modification amount of the modification point Dx is [0.56δ, 1.4δ].

[0064] In this way, the value range of the shaping amount at the shaping point Dx can be determined according to the reference radius Rx and the preset shaping amount parameter, thereby determining the shaping amount at the shaping point Dx.

[0065] Specifically, on the standard cycloid gear, at a position where the reference radius Rx is greater than 0.3 times the tooth height of the standard cycloid gear and less than 0.5 times the tooth height of the standard cycloid gear, the value range of the modification amount is [0.56δ, 1.4δ]. For example, the value of the modification amount can be 0.5δ, 0.55δ, 0.6δ, 0.65δ, 0.7δ, 0.75δ, 0.85δ, 0.9δ, 1.2δ or 1.4δ, or any other value within the range [0.7δ, 4.1δ].

[0066] See also Figure 8 In some embodiments, step S105 includes:

[0067] Step S1054: when the reference radius Rx is greater than 0.5 times the tooth height of the standard cycloid gear and less than or equal to 0.7 times the tooth height of the standard cycloid gear, determine that the value range of the modification amount of the modification point Dx is [0.7δ, 1.6δ].

[0068] In this way, the value range of the shaping amount at the shaping point Dx can be determined according to the reference radius Rx and the preset shaping amount parameter, thereby determining the shaping amount at the shaping point Dx.

[0069] Specifically, on the standard cycloid gear, at a position where the reference radius Rx is greater than 0.5 times the tooth height of the standard cycloid gear and less than 0.5 times the tooth height of the standard cycloid gear, the value range of the modification amount is [0.7δ, 1.6δ]. For example, the value of the modification amount can be 0.7δ, 0.78δ, 0.8δ, 0.85δ, 0.87δ, 0.9δ, 0.95δ, 1.1δ, 1.3δ or 1.6δ, or any other value within the range [0.7δ, 1.6δ].

[0070] See also Fig. 9 In some embodiments, step S105 includes:

[0071] Step S1055: when the reference radius Rx is greater than 0.7 times the tooth height of the standard cycloid gear and less than or equal to the tooth height of the standard cycloid gear, determine that the value range of the modification amount of the modification point Dx is [0.78δ, 4.3δ].

[0072] In this way, the value range of the shaping amount at the shaping point Dx can be determined according to the reference radius Rx and the preset shaping amount parameter, thereby determining the shaping amount at the shaping point Dx.

[0073] Specifically, on the standard cycloid gear, at a position where the reference radius Rx is greater than 0.7 times the tooth height of the standard cycloid gear and less than the tooth height of the standard cycloid gear, the value range of the modification amount is [0.78δ, 4.3δ]. For example, the value of the modification amount can be 0.7δ, 0.8δ, 0.85δ, 0.95δ, 1.2δ, 1.8δ, 2.5δ, 3.2δ, 3.8δ or 4.3δ, or any other value within the range [0.78δ, 4.3δ].

[0074] See also Fig.10 In some embodiments, step S105 includes:

[0075] Step S1056: When the reference radius Rx is equal to the tooth height of the standard cycloid gear, determine that the value range of the modification amount of the modification point Dx is [0.83δ, 8.2δ].

[0076] In this way, when the selected modification point Dx is on the tooth top of the standard cycloid gear, the modification amount at the modification point Dx can be determined according to the value range of the modification point Dx.

[0077] Specifically, when the reference radius Rx is equal to the tooth height of the standard cycloid gear, that is, the radius of the circle formed by the modification point Dx and the circle of the standard cycloid gear is equal to the radius of the addendum circle of the standard cycloid gear, that is, the modification point Dx is located on the addendum circle of the standard cycloid gear, at this time, the value range of the modification amount at the modification point Dx is [0.8δ, 8.3δ]. For example, the modification amount can be 0.83δ, 1.5δ, 2.5δ, 3.5δ, 4.5δ, 5.5δ, 6.5δ, 7.5δ, 8δ or 8.2δ, or any other value within the range [0.8δ, 8.3δ].

[0078] In summary, an arbitrary point is selected on the tooth profile of the standard cycloid gear, and the modification amount of each modification point Dx selected on the tooth profile of the standard cycloid gear is determined according to the reference radius Rx of the point and the value range of the modification amount set for different reference radius Rx ranges. The standard cycloid gear is modified accordingly, and the modified cycloid gear 10 obtained can bear load evenly and ensure performance such as life and transmission accuracy.

[0079] In one embodiment, six modification points Dx are selected on the tooth profile from the root to the top of the standard cycloid gear, and are denoted as D1, D2, D3, D4, D5 and D6. The reference radii Rx corresponding to the six modification points Dx are R1, R2, R3, R4, R5 and R6 respectively.

[0080] Among them, R1=0, that is, D1 is located at the root of the standard cycloid gear tooth profile, and the value range of the modification amount at D1 is [0.8δ, 8.3δ].

[0081] 0<R2<0.3H, then the value range of the modification amount at D2 is [0.7δ, 4.1δ].

[0082] 0.3H<R3<0.5H, then the value range of the modification amount at D3 is [0.56δ, 1.4δ].

[0083] 0.5H<R4<0.7H, then the value range of the modification amount at D4 is [0.7δ, 1.6δ].

[0084] 0.7H<R5<0.9H, then the value range of the modification amount at D5 is [0.78δ, 4.3δ].

[0085] R6=H, that is, D6 is located at the top of the standard cycloid gear tooth profile, and the value range of the modification amount at D6 is [0.83δ, 8.2δ].

[0086] When choosing the specific amount of modification, we can consider the coordination with the size of other transmission parts, and ensure that the modified tooth profile is not prone to intersections, forming a continuous smooth tooth profile. It should be noted that the curvature change amplitude of continuous points on the tooth profile is small, and there is no sudden change, which proves that the gear is very smooth and the tooth surface is continuous.

[0087] like Fig.11 As shown, the tooth profile of the cycloid gear 10 with different modification amounts.

[0088] like Fig.12 As shown, the force distribution of the cycloid gear 10 after modification (the lower curve in the figure) is compared with the theoretical tooth profile force distribution before modification (the upper curve in the figure). It can be seen that the force distribution of the cycloid gear 10 after modification is significantly improved. The improvement of force distribution is beneficial to improving the comprehensive performance of the reducer 100.

[0089] In other embodiments, a modification point Dx may be selected, such as the tooth root of a standard cycloid gear, or the tooth top of a standard cycloid gear, or any position from the tooth root to the tooth top.

[0090] In other embodiments, two, three or any number of modification points Dx may be selected, which may include the tooth root position and the tooth top position, or may include only one of the tooth root and the tooth top, or may not include the tooth root and the tooth top position.

[0091] A cycloid gear 10 according to an embodiment of the present invention is formed by processing a standard cycloid gear using the tooth profile modification method of the cycloid gear 10 according to any one of the above embodiments.

[0092] In some embodiments, the value range of the modification amount at the reference radius Rx equal to zero is [0.8δ, 8.3δ].

[0093] In this way, the modification amount of the standard cycloid gear can be determined based on the reference radius Rx.

[0094] Specifically, when the reference radius Rx is equal to zero, that is, the radius of the circle formed by the modification point Dx and the circle of the standard cycloid gear is equal to the radius of the root circle of the standard cycloid gear, that is, the modification point Dx is located on the root circle of the standard cycloid gear, and at this time, the value range of the modification amount at the modification point Dx is [0.8δ, 8.3δ]. For example, the modification amount can be 0.8δ, 1.5δ, 2.5δ, 3.5δ, 4.5δ, 5.5δ, 6.5δ, 7.5δ, 8δ or 8.3δ, or any other value within the range [0.8δ, 8.3δ].

[0095] In certain embodiments, the value range of the modification amount at the reference radius Rx greater than zero and less than 0.3 times the tooth height of the standard cycloid gear is [0.7δ, 4.1δ].

[0096] In this way, the modification amount of the standard cycloid gear can be determined based on the reference radius Rx.

[0097] Specifically, on a standard cycloid gear, at a position where the reference radius Rx is less than 0.3 times the tooth height of the standard cycloid gear, the value range of the modification amount is [0.7δ, 4.1δ]. For example, the value of the modification amount can be 0.7δ, 0.8δ, 0.9δ, 1.2δ, 1.5δ, 2.5δ, 3δ, 3.5δ, 3.8δ or 4.1δ, or any other value within the range [0.7δ, 4.1δ].

[0098] In certain embodiments, the value range of the modification amount at a reference radius Rx greater than 0.3 times the tooth height of a standard cycloid gear and less than or equal to 0.5 times the tooth height of a standard cycloid gear is [0.56δ, 1.4δ].

[0099] In this way, the modification amount of the standard cycloid gear can be determined based on the reference radius Rx.

[0100] Specifically, on the standard cycloid gear, at a position where the reference radius Rx is greater than 0.3 times the tooth height of the standard cycloid gear and less than 0.5 times the tooth height of the standard cycloid gear, the value range of the modification amount is [0.56δ, 1.4δ]. For example, the value of the modification amount can be 0.5δ, 0.55δ, 0.6δ, 0.65δ, 0.7δ, 0.75δ, 0.85δ, 0.9δ, 1.2δ or 1.4δ, or any other value within the range [0.7δ, 4.1δ].

[0101] In certain embodiments, the value range of the modification amount at a reference radius Rx greater than 0.5 times the tooth height of a standard cycloid gear and less than or equal to 0.7 times the tooth height of a standard cycloid gear is [0.7δ, 1.6δ].

[0102] In this way, the modification amount of the standard cycloid gear can be determined based on the reference radius Rx.

[0103] Specifically, on the standard cycloid gear, at a position where the reference radius Rx is greater than 0.5 times the tooth height of the standard cycloid gear and less than 0.5 times the tooth height of the standard cycloid gear, the value range of the modification amount is [0.7δ, 1.6δ]. For example, the value of the modification amount can be 0.7δ, 0.78δ, 0.8δ, 0.85δ, 0.87δ, 0.9δ, 0.95δ, 1.1δ, 1.3δ or 1.6δ, or any other value within the range [0.7δ, 1.6δ].

[0104] In certain embodiments, the value range of the modification amount at a reference radius Rx greater than 0.7 times the tooth height of a standard cycloid gear and less than the tooth height of a standard cycloid gear is [0.78δ, 4.3δ].

[0105] In this way, the modification amount of the standard cycloid gear can be determined based on the reference radius Rx.

[0106] Specifically, on the standard cycloid gear, at a position where the reference radius Rx is greater than 0.7 times the tooth height of the standard cycloid gear and less than the tooth height of the standard cycloid gear, the value range of the modification amount is [0.78δ, 4.3δ]. For example, the value of the modification amount can be 0.7δ, 0.8δ, 0.85δ, 0.95δ, 1.2δ, 1.8δ, 2.5δ, 3.2δ, 3.8δ or 4.3δ, or any other value within the range [0.78δ, 4.3δ].

[0107] In certain embodiments, the value range of the modification amount at the reference radius Rx equal to the tooth height of the standard cycloid gear is [0.83δ, 8.2δ].

[0108] In this way, the modification amount of the standard cycloid gear can be determined based on the reference radius Rx.

[0109] Specifically, when the reference radius Rx is equal to the tooth height of the standard cycloid gear, that is, the radius of the circle formed by the modification point Dx and the circle of the standard cycloid gear is equal to the radius of the addendum circle of the standard cycloid gear, that is, the modification point Dx is located on the addendum circle of the standard cycloid gear, at this time, the value range of the modification amount at the modification point Dx is [0.8δ, 8.3δ]. For example, the modification amount can be 0.83δ, 1.5δ, 2.5δ, 3.5δ, 4.5δ, 5.5δ, 6.5δ, 7.5δ, 8δ or 8.2δ, or any other value within the range [0.8δ, 8.3δ].

[0110] A speed reducer 100 according to an embodiment of the present invention includes the cycloid gear 10 according to any one of the above embodiments.

[0111] An industrial robot according to an embodiment of the present invention includes the reducer 100 according to the above embodiment.

[0112] The above-mentioned cycloid gear 10, reducer 100 and industrial robot can reduce the jamming or increased friction when the cycloid gear 10 and the outer pin teeth 14 are meshed by modifying the standard cycloid gear, improve the load distribution of the cycloid gear 10, and thus be beneficial to improving the overall performance of the reducer 100.

[0113] It should be noted that the above explanation of the implementation method and beneficial effects of the cycloid gear 10 is also applicable to the reducer 100 and the industrial robot used in the implementation method of the present invention, and will not be elaborated here in order to avoid redundancy.

[0114] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0115] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A cycloid gear, the cycloid gear is used for a reducer, the reducer comprises a pin gear, the cycloid gear meshes with the pin gear for transmission, the pin gear comprises a plurality of cylindrical pin teeth, characterized in that: In the contour line from the root to the top of the cycloid gear, the difference between the radius of the circle formed by any point on the standard cycloid gear and the center of the standard cycloid gear and the root circle radius of the standard cycloid gear is defined as the reference radius. The modification amount of the reference radius in different numerical ranges is determined by a preset modification amount parameter δ, δ=e×(d^2+(2×Rn-2×R1)^2)^0.5 / 1000, wherein e is the eccentricity of the standard cycloid gear, d is the diameter of the pin tooth, R1 is the root circle radius of the standard cycloid gear, and Rn is the top circle radius of the standard cycloid gear.

2. The cycloid gear according to claim 1, characterized in that: The value range of the modification amount when the reference radius is equal to zero is [0.8δ, 8.3δ].

3. The cycloid gear according to claim 1, characterized in that: The value range of the modification amount at the tooth height of the standard cycloid gear where the reference radius is greater than zero and less than 0.3 times is [0.7δ, 4.1δ].

4. The cycloid gear according to claim 1, characterized in that: The value range of the modification amount at the reference radius which is greater than 0.3 times the tooth height of the standard cycloid gear and less than or equal to 0.5 times the tooth height of the standard cycloid gear is [0.56δ, 1.4δ].

5. The cycloid gear according to claim 1, characterized in that: The value range of the modification amount at the reference radius which is greater than 0.5 times the tooth height of the standard cycloid gear and less than or equal to 0.7 times the tooth height of the standard cycloid gear is [0.7δ, 1.6δ].

6. The cycloid gear according to claim 1, characterized in that: The value range of the modification amount at the reference radius which is greater than 0.7 times the tooth height of the standard cycloid gear and less than the tooth height of the standard cycloid gear is [0.78δ, 4.3δ].

7. The cycloid gear according to claim 1, characterized in that: The value range of the modification amount at the reference radius equal to the tooth height of the standard cycloid gear is [0.83δ, 8.2δ].

8. A reducer, characterized in that: Includes the cycloid gear as described in any one of claims 1 to 7.

9. An industrial robot, characterized in that: Including the reducer as described in claim 8.

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