Transmission assembly and speed reducer

Abstract

The invention discloses a transmission assembly and a speed reducer. The transmission assembly comprises a first transmission wheel and a second transmission wheel, a first tooth part is arranged on the peripheral side face of the first transmission wheel in a surrounding mode and provided with at least one first tooth, a second tooth part is arranged on the inner peripheral side face of the second transmission wheel in a surrounding mode and provided with at least one second tooth, and a notch is formed in the tooth root of each second tooth; according to the transmission assembly, the first transmission wheel and the second transmission wheel are connected in a meshed mode through the first tooth part and the second tooth part, and at least part of the tooth crest of the first tooth is located at the opening of the notch of the corresponding meshed second tooth. According to the transmission assembly, transmission is carried out in a gear tooth meshing mode, the problem of transmission wheel deformation caused by interference fit can be avoided, and when the first transmission wheel and the second transmission wheel are meshed, the tooth crest of the first tooth can abut against the notch of the second tooth, so that a certain gap is formed between the first tooth and the second tooth; the problem of tooth crest interference of the first teeth can be prevented.

Description

Technical Field

[0001] The invention relates to the field of reduction transmission, and in particular to a transmission component and a reducer. Background Art

[0002] Compared with traditional planetary reducers, RV reducers have the characteristics of high precision, high reliability and low backlash. RV reducers usually adopt a combination of parallel shaft transmission + planetary transmission + cycloid transmission. The passive gear of the parallel shaft transmission is connected to the sun gear of the planetary transmission to transmit the torque of the parallel shaft transmission to the planetary gear train. The passive gear of the parallel shaft transmission and the sun gear of the planetary transmission form a double gear. If the connection design of the double gear is not good, the transmission accuracy of the RV reducer will be deteriorated at the least. In extreme cases, it will cause the robot arm to slip or fall when it is impacted, causing an accident.

[0003] The conventional connection design method for duplex gears is cylindrical interference connection + shear screw. The cylindrical interference connection transmits torque through contact surface friction and large interference. The large interference will affect the tooth profile accuracy of the thin-walled sun gear, resulting in poor meshing accuracy of the planetary gear system. Summary of the invention

[0004] The present invention provides a transmission assembly and a reducer to solve at least one of the above-mentioned technical problems.

[0005] A transmission assembly for a reducer according to an embodiment of the present invention comprises:

[0006] A first transmission wheel, wherein a first tooth portion is disposed around an outer peripheral side surface of the first transmission wheel, and the first tooth portion has at least one first tooth, and;

[0007] A second transmission wheel, wherein a second tooth portion is disposed around an inner circumferential side surface of the second transmission wheel, the second tooth portion has at least one second tooth, and a notch is disposed at a tooth root of the second tooth;

[0008] The transmission assembly is configured such that the first transmission wheel and the second transmission wheel are meshedly connected via the first tooth portion and the second tooth portion, and at least a portion of the tooth top of the first tooth is located at an opening of a notch of a corresponding meshing second tooth.

[0009] The above-mentioned transmission assembly transmits power by means of gear tooth meshing, which can avoid the problem of deformation of the transmission wheel due to interference fit. Moreover, when the first transmission wheel and the second transmission wheel are meshed, the tooth top of the first tooth can abut against the notch of the second tooth, so that a certain gap is formed between the first tooth and the second tooth, thereby preventing the problem of interference of the tooth top of the first tooth.

[0010] In some embodiments, the first tooth portion is a spline structure, so as to avoid structural deformation between the transmission wheels and to avoid affecting the meshing accuracy between the first transmission wheel and other gear tooth structures.

[0011] In some embodiments, the first transmission wheel is configured such that the rotation center of the first transmission wheel is determined by the tooth top circle of the first tooth portion, and the first tooth portion and the second tooth portion can rotate around the rotation center. In this way, the radial positioning accuracy between the first transmission wheel and the second transmission wheel can be ensured, thereby effectively ensuring the meshing accuracy and transmission accuracy.

[0012] In some embodiments, the top surface of the first tooth fits the root surface of the second tooth, and the tooth side of the second tooth from the edge of the top surface of the second tooth to the notch forms a working section, and the second tooth abuts against the first tooth through the working section. In this way, the axial positioning of the second transmission wheel on the first transmission wheel can be facilitated.

[0013] In some embodiments, the notch is formed on the root surface of the second tooth, so that the position of the notch can be flexibly selected.

[0014] In some embodiments, the notch is formed on the second tooth near the root surface of the second tooth; the side wall of the second tooth portion forming the notch is divided into a first side wall section and a second side wall section, the first side wall section extends from the tooth side of the second tooth in a direction away from the first tooth, and the second side wall section extends from the first side wall section in a direction close to the root surface of the second tooth. In this way, the influence of the notch on the structural strength of the second tooth can be reduced while avoiding tooth top interference.

[0015] In some embodiments, the first side wall segment is a straight line segment, the extension direction of the first side wall segment corresponds to the radial direction of the notch start point relative to the rotation center, the notch start point is the connection point between the first side wall segment and the tooth side of the second tooth, and the first tooth portion and the second tooth portion can rotate around the rotation center. In this way, the notch can be easily processed.

[0016] In some embodiments, the position of the starting point of the notch on the second tooth portion can be determined by the following formula:

[0017] hk=rk-ra2,

[0018]

[0019] Among them, hk is the radial length of the working section relative to the center of the rotating circle, rk is the radius of the circle of the starting point of the notch relative to the center of the rotating circle, ra2 is the radius of the tooth top circle of the second transmission wheel, T is the load torque of the second tooth portion, Ψ is the load unevenness coefficient of the second tooth portion, Z is the number of teeth of the second tooth, L is the working length of the second tooth in the tooth width direction, and [p] is the allowable pressure of the material. In this way, it can be ensured that the second tooth meets the corresponding load condition requirements.

[0020] In some embodiments, the radial length of the working segment relative to the center of rotation ranges from 0.8Mn to 1.2Mn, where Mn is the normal modulus.

[0021] In some embodiments, the straight line trajectory of the first side wall segment can be determined by the position of the starting point of the notch and the pressure angle of the second tooth at the starting point of the notch.

[0022] In some embodiments, the second side wall segment is an arc segment, and the arc trajectory of the second side wall segment is tangent to the straight trajectory of the first side wall segment and the root circle of the second tooth portion respectively.

[0023] In some embodiments, the arc length of the second side wall segment ranges from 0.1Mn to 1Mn, where Mn is the normal modulus.

[0024] A reducer according to an embodiment of the present invention comprises:

[0025] The transmission assembly described in any one of the above embodiments.

[0026] The above-mentioned reducer transmits power by means of gear tooth meshing, which can avoid the problem of deformation of the transmission wheel due to interference fit. Moreover, when the first transmission wheel and the second transmission wheel are meshed, the tooth top of the first tooth can abut against the notch of the second tooth, so that a certain gap is formed between the first tooth and the second tooth, thereby preventing the problem of interference of the tooth top of the first tooth.

[0027] 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

[0028] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0029] Figure 1 is a schematic structural diagram of a transmission assembly according to an embodiment of the present invention;

[0030] Figure 2is a partial structural schematic diagram of a first tooth portion and a second tooth portion according to an embodiment of the present invention;

[0031] Figure 3 is a partial structural schematic diagram of a first tooth portion in an embodiment of the present invention;

[0032] Figure 4 is a partial structural schematic diagram of a second tooth portion in an embodiment of the present invention;

[0033] Figure 5 is another partial structural schematic diagram of the second tooth portion in an embodiment of the present invention;

[0034] Figure 6 yes Figure 2 A magnified view of part I;

[0035] Figure 7 It is a schematic diagram for determining the notch design range according to an embodiment of the present invention.

[0036] Description of main component numbers:

[0037] Transmission assembly 100;

[0038] A first transmission wheel 11, a first tooth portion 12, a first tooth 13, and a protrusion 14;

[0039] The second transmission wheel 21 , the second toothed portion 22 , the second teeth 23 , the notch 24 , the first side wall segment 25 , and the second side wall segment 26 . DETAILED DESCRIPTION

[0040] In the description of the present invention, some of the disclosed contents have been shown in the accompanying drawings accordingly, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The contents 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.

[0041] In the description of the present invention, many different contents or examples are disclosed to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention.

[0042] Furthermore, the present invention may repeat reference numerals and / or reference letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various situations and / or settings discussed.

[0043] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0044] In the description of the present invention, it should be understood that the terms used to indicate orientation or positional relationships (such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc.) are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and facilitating the understanding of the corresponding embodiments, 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. Therefore, the terms used to indicate orientation or positional relationships cannot be understood as limiting the present invention.

[0045] In the description of 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.

[0046] 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.

[0047] Please refer to Figure 1 and Figure 2 A transmission assembly 100 for a reducer of the present invention may include a first transmission wheel 11 and a second transmission wheel 21.

[0048] A first tooth portion 12 is disposed around the outer circumference of the first transmission wheel 11 . The first tooth portion 12 has at least one first tooth 13 .

[0049] A second toothed portion 22 is disposed around the inner circumference of the second transmission wheel 21 . The second toothed portion 22 has at least one second tooth 23 . A notch 24 is disposed at the tooth root of the second tooth 23 .

[0050] The transmission assembly 100 is configured such that the first transmission wheel 11 and the second transmission wheel 21 are meshedly connected via the first tooth portion 12 and the second tooth portion 22, and at least a portion of the tooth top of the first tooth 13 is located at the opening of the notch 24 of a corresponding meshing second tooth 23.

[0051] The transmission assembly 100 mentioned above transmits power by means of gear meshing, which can avoid the problem of deformation of the transmission wheel due to interference fit. Moreover, when the first transmission wheel 11 and the second transmission wheel 21 are meshed, the tooth top of the first tooth 13 can abut against the notch 24 of the second tooth 23, so that a certain gap is formed between the first tooth 13 and the second tooth 23, thereby preventing the problem of tooth top interference of the first tooth 13.

[0052] The first transmission wheel 11 and the second transmission wheel 21 can achieve the effect of coaxial rotation by means of gear meshing. Figure 1 In the figure, the rotation axes of the first transmission wheel 11 and the second transmission wheel 21 can both be represented by X.

[0053] The first transmission wheel 11 and the second transmission wheel 21 are basically annular structures. Figure 1 In the embodiment, the side of the first transmission wheel 11 facing the rotation axis can be the inner peripheral side of the first transmission wheel 11, and the side of the first transmission wheel 11 away from the rotation axis can be the outer peripheral side of the first transmission wheel 11; the side of the second transmission wheel 21 facing the rotation axis can be the inner peripheral side of the second transmission wheel 21, and the side of the second transmission wheel 21 away from the rotation axis can be the outer peripheral side of the first transmission wheel 11. The second transmission wheel 21 can be sleeved with the first transmission wheel 11 through the annular hole located inside, so that the outer peripheral side of the first transmission wheel 11 and the inner peripheral side of the second transmission wheel 21 can be in contact.

[0054] exist Figure 1 In the embodiment, the A1 direction may be the assembly direction of the second transmission wheel 21 relative to the first transmission wheel 11, or in other words, the second transmission wheel 21 may be assembled on the first transmission wheel 11 along the A1 direction. The first transmission wheel 11 may include a protrusion 14. The protrusion 14 may be arranged on the outer peripheral side of the first transmission wheel 11. When the second transmission wheel 21 is assembled on the first transmission wheel 11, the protrusion 14 will be located on one side of the second transmission wheel 21 along the A1 direction, so that the protrusion 14 can block the movement of the second transmission wheel 21 along the A1 direction, and can play a role in limiting the assembly of the second transmission wheel 21.

[0055] Please combine Figure 1 and Figure 2 ,exist Figure 2 In the embodiment, the first tooth portion 12 can be arranged around the rotation axis on the outer peripheral side of the first transmission wheel 11, so that the first tooth portion 12 can serve as the outer teeth of the first transmission wheel 11; the second tooth portion 22 can be arranged around the rotation axis on the inner peripheral side of the second transmission wheel 21, so that the second tooth portion 22 can serve as the inner teeth of the second transmission wheel 21. Through the meshing connection of the inner teeth and the outer teeth, the first transmission wheel 11 and the second transmission wheel 21 can achieve a transmission effect in the form of a double gear.

[0056] Further, in Figure 2 In the embodiment, the first tooth portion 12 may have a plurality of first teeth 13, and the second tooth portion 22 may have a plurality of second teeth 23. When the first tooth 13 and the second tooth 23 are meshed, the tooth top of the first tooth 13 can be close to the tooth root of the second tooth 23, and for the second tooth portion 22, a notch 24 is provided at the position of the tooth root of the second tooth 23. The notch 24 is an inwardly concave structure on the second tooth portion 22, so that a certain gap is formed between the second tooth 23 and the first tooth 13 at the position of the notch 24. In this way, in actual application, even if the tooth top of the first tooth 13 interferes with the second tooth 23, the tooth root of the second tooth 23 will not be grooved by the first tooth 13 due to the gap formed by the notch 24, thereby effectively preventing the problem of interference of the tooth top of the first tooth 13.

[0057] Please refer to Figure 1 , the first tooth portion 12 can be a spline structure.

[0058] In this way, structural deformation between the transmission wheels can be avoided, and the meshing accuracy between the first transmission wheel 11 and other gear structures can be avoided from being affected.

[0059] Specifically, in Figure 1 In the embodiment, the first transmission wheel 11 can be extended along the A1 direction and basically present a columnar structure. The first tooth portion 12 can be formed by processing the outer surface of the columnar structure of the first transmission wheel 11. The first tooth portion 12 is set as a spline structure. Compared with the case where the first transmission wheel 11 and the second transmission wheel 21 form a transmission structure by interference connection, it is not necessary to assemble by press fitting or shrink fitting, thereby avoiding the problem of extrusion of the structure during interference connection, which causes deformation between the first transmission wheel 11 and the second transmission wheel 21. The spline structure has the advantages of high processing efficiency, high precision and low cost, which is conducive to reducing the difficulty of assembly and the influence of part deformation on gear meshing.

[0060] Please refer to Figure 1 and Figure 2The first transmission wheel 11 can be configured such that the rotation center of the first transmission wheel 11 is determined by the tooth top circle of the first tooth portion 12, and the first tooth portion 12 and the second tooth portion 22 can rotate around the rotation center.

[0061] In this way, the radial positioning accuracy between the first transmission wheel 11 and the second transmission wheel 21 can be ensured, thereby effectively ensuring the meshing accuracy and the transmission accuracy.

[0062] Specifically, the first tooth portion 12 is convexly arranged on the outer peripheral side of the first transmission wheel 11. For the first transmission wheel 11, the center of the tooth top circle formed by the tooth tops of all the first teeth 13 in the first tooth portion 12 can be used as the rotation center of the first transmission wheel 11 by means of large diameter centering. Figure 1 In the figure, the center of rotation can be represented as O, and the center of rotation is located on the axis of rotation.

[0063] In some cases, the first transmission wheel 11 can mesh with other gear teeth structures. Since the first transmission wheel 11 is basically a columnar structure with a thick wall, and the interference connection method also requires that the wall surface of the first transmission wheel 11 be squeezed and deformed, it will affect the shape of the structure of the first transmission wheel 11 meshing with other gear teeth structures, thereby affecting the meshing accuracy and transmission accuracy between the first transmission wheel 11 and other gear teeth structures. By using the large diameter centering method to determine the center of rotation of the spline structure, when assembling the first transmission wheel 11 and the second transmission wheel 21, the radial positioning accuracy during assembly can be improved, thereby effectively ensuring the meshing accuracy and transmission accuracy between the first transmission wheel 11 and other gear teeth structures.

[0064] Please refer to Figure 2 The top surface of the first tooth 13 can fit the root surface of the second tooth 23. The tooth side of the second tooth 23 forms a working section from the edge of the top surface of the second tooth 23 to the notch 24. The second tooth 23 abuts against the first tooth 13 through the working section.

[0065] In this way, the axial positioning of the second transmission wheel 21 on the first transmission wheel 11 can be facilitated.

[0066] Please combine Figure 3 and Figure 4 , the tooth top surface of the first tooth 13 can be represented as S1, and the tooth root surface of the second tooth 23 can be represented as S2. The tooth top surface of the first tooth 13 can be formed by eliminating the tooth top of the first tooth 13, so that the edge of the surface of the first tooth 13 can be increased, so that the second tooth portion 22 can be more easily limited by the edge shape of the first tooth 13, thereby playing a role in axial positioning of the second transmission wheel 21, and during assembly, it is convenient to axially position the second transmission wheel 21.

[0067] Please refer to Figure 5The notch 24 may be provided on the root surface of the second tooth 23 .

[0068] In this way, the position of the notch 24 can be flexibly selected.

[0069] In addition, Figure 5 In the embodiment, the side wall of the notch 24 formed on the root surface of the second tooth 23 can be an arc-shaped structure, thereby changing the force distribution at the root of the second tooth 23 when the tooth top of the first tooth 13 abuts against the root of the second tooth 23 and maintaining sufficient structural strength.

[0070] Please refer to Figure 2 and Figure 6 The notch 24 may be provided on a portion of the second tooth 23 close to the root surface of the second tooth 23 .

[0071] The side wall of the second tooth portion 22 forming the notch 24 can be divided into a first side wall section 25 and a second side wall section 26. The first side wall section 25 can extend from the tooth side of the second tooth 23 in a direction away from the first tooth 13. The second side wall section 26 can extend from the first side wall section 25 in a direction close to the tooth root surface of the second tooth 23.

[0072] In this way, the influence of the notch 24 on the structural strength of the second tooth 23 can be reduced while avoiding interference of the tooth tops.

[0073] exist Figure 6 In the embodiment, a portion of the first side wall segment 25 may be formed by extending from the tooth side of the second tooth 23 along the A2 direction. In the notch 24, the first side wall segment 25 and the second side wall segment 26 may be smoothly connected. The second side wall segment 26 may extend from the position connected to the first side wall segment 25. The end of the second side wall segment 26 may extend substantially along the A3 direction.

[0074] When the recess 24 is located on the second tooth 23 near the root surface of the second tooth 23, the first tooth 13 can be prevented from interfering with the second tooth 23 in the circumferential direction, and the reduction of the contact area on the tooth side of the second tooth 23 for abutting the first tooth 13 can be avoided, so that the second tooth 23 can withstand a greater force from the first tooth 13, thereby reducing the impact on the structural strength of the second tooth 23.

[0075] Please refer to Figure 6 , the first side wall segment 25 can be a straight line segment. The extension direction of the first side wall segment 25 can correspond to the radial direction of the starting point of the notch 24 relative to the center of rotation. The starting point of the notch 24 can be the connection point between the first side wall segment 25 and the tooth side of the second tooth 23. The first tooth portion 12 and the second tooth portion 22 can rotate around the center of rotation.

[0076] In this way, the notch 24 can be processed conveniently.

[0077] exist Figure 6 In the embodiment, the first side wall segment 25 can be extended as a whole along the direction A2 to form a plane. The starting point of the notch 24 can be indicated as point K. The tooth side of the second tooth 23 will connect with the first side wall segment 25 at point K.

[0078] It can be understood that, compared with processing an arc surface, processing a plane surface is simpler, which helps to reduce the difficulty of processing the recess 24 and facilitates processing of the recess 24 .

[0079] In addition, it should be pointed out that the illustrations of the first tooth portion 12 and the second tooth portion 22 in the present invention are mainly based on the axial direction along the rotation axis as the viewing angle. In the actual structure, the corresponding structure has thickness in the direction of the rotation axis, so that the points described in the corresponding drawings will actually refer to the corresponding line segments, and the described line segments will actually refer to the corresponding surfaces. For the convenience of description and understanding, in the relevant drawings, the corresponding features will be described in the form of the viewing angle of the drawings, such as the line segments will be presented in the form of points, and the surface will be presented in the form of line segments. Those skilled in the art should understand that the description of a feature in the corresponding embodiment is different from the actual structure, and the reason should be caused by the above situation.

[0080] Please refer to Figure 7 , the position of the starting point of the notch 24 on the second tooth portion 22 can be determined by the following formula:

[0081] hk=rk-ra2 (1),

[0082]

[0083] Among them, hk is the radial length of the working section relative to the center of the rotation circle (unit: mm), rk is the radius of the circle of the starting point of the notch 24 relative to the center of the rotation circle (unit: mm), ra2 is the radius of the tooth top circle of the second transmission wheel 21 (unit: mm), T is the load-bearing torque of the second tooth portion 22 (unit: N*mm), Ψ is the load unevenness coefficient of the second tooth portion 22 (can be 0.7-0.8), Z is the number of teeth of the second tooth 23, L is the working length of the second tooth 23 in the tooth width direction (unit: mm), and [p] is the allowable pressure of the material (unit: MPa).

[0084] In this way, it can be ensured that the second tooth 23 meets the corresponding load condition requirements.

[0085] Specifically, in Figure 7In the figure, O is the center of rotation of the first transmission wheel 11 and the second transmission wheel 21. The distance between point K and point O can be taken as the radius of the circle R1 with point O as the center and passing through point K, or the radius rk of the circle at the starting point of the notch 24 relative to the center of rotation. ra2 is the radius of the tooth top circle R2 formed by the tooth tops of all the second teeth 23 in the second tooth portion 22. The connection point between the tooth top of the second tooth 23 and the tooth side of the second tooth 23, or the tooth top edge point of the second tooth 23 can be expressed as U. The portion between point U and point K on the tooth side of the second tooth 23 can be called the working section of the second tooth 23. The radial difference between circle R1 and circle R2 can form the radial length hk of the working section relative to the center of rotation.

[0086] Based on the above, formula (1) defines the radial length of the working section relative to the center of the rotation circle and the position of point K in mathematical terms, while formula (2) defines the radial length of the working section relative to the center of the rotation circle and the position of point K in physical terms. Moreover, formula (2) is the relationship between the radial length of the working section relative to the center of the rotation circle and the position of point K, which is obtained by taking the structural strength of the second tooth portion 22 as a prerequisite. Since the distances from the points on the tooth side of the second tooth 23 to O are all one-to-one corresponding, after determining rk, the position of point K on the second tooth portion 22 can be determined based on the distance from point K to point O.

[0087] By combining formula (1) and formula (2) to obtain the position of point K, after the notch 24 is provided, the working section of the second tooth 23 can still have sufficient structural strength to meet the corresponding load condition requirements. The load condition requirements of the second tooth 23 can be determined by the load-bearing torque of the second tooth portion 22.

[0088] The radial length of the working section relative to the center of rotation may range from 0.8Mn to 1.2Mn, where Mn is the normal modulus.

[0089] Please refer to Figure 7 The straight line trajectory of the first side wall segment 25 can be determined by the position of the starting point of the notch 24 and the pressure angle of the second tooth 23 at the starting point of the notch 24 .

[0090] exist Figure 7 In the figure, rb1 is the radius of the base circle R3 of the first tooth portion 12. Point N is located on the base circle R3. The angle between the line segment KN and the line segment NO is a right angle. The angle between the line segment KO and the line segment NO is the pressure angle of the starting point of the notch 24.

[0091] Specifically, after the position of point K is determined, the extension direction of the first side wall segment 25 can be determined in combination with the pressure angle of the second tooth 23 at the starting point of the notch 24 .

[0092] Please refer to Figure 7The second side wall segment 26 may be a circular arc segment. The circular arc trajectory of the second side wall segment 26 may be tangent to the straight line trajectory of the first side wall segment 25 and the tooth root circle of the second tooth portion 22 respectively.

[0093] Specifically, in Figure 7 In the figure, rf2 is the radius of the root circle of the second tooth 23. Figure 6 When the extension direction of the first side wall segment 25 and the circular trajectory of the root circle of the second tooth 23 are determined, an inscribed circle can be made between the first side wall segment 25 and the root circle of the second tooth 23, and the extension trajectory of the second side wall segment 26 can be determined according to the circular trajectory of the inner cavity circle.

[0094] The arc length of the second side wall segment 26 ranges from 0.1Mn to 1Mn, where Mn is the normal modulus.

[0095] Specifically, the arc length of the second side wall segment 26 is not less than 0.1Mn, which can avoid the problem of stress concentration caused by the short length of the second side wall segment 26; the arc length of the second side wall segment 26 is not greater than 1Mn, which can avoid affecting the strength of the second tooth 23.

[0096] In addition, based on the above content, by parameterizing the position of the K point and the design range of the first side wall section 25 and the second side wall section 26 forming the recess 24, adjustments can be made to match different situations.

[0097] A reducer according to an embodiment of the present invention may include the transmission assembly 100 according to any one of the above embodiments.

[0098] The reducer may be an RV reducer. The first transmission wheel 11 may be used as a sun wheel of a planetary transmission, and the second transmission wheel 21 may be used as a passive gear that performs parallel axis transmission with the first transmission wheel 11. When the reducer transmits through the transmission assembly 100, the overall transmission effect may be prevented from being affected by the tooth top interference between the first transmission wheel 11 and the second transmission wheel 21.

[0099] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments of the present invention without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A transmission assembly for a reducer, characterized in that: include: A first transmission wheel, wherein a first tooth portion is disposed around an outer peripheral side surface of the first transmission wheel, and the first tooth portion has at least one first tooth, and; A second transmission wheel, wherein a second tooth portion is disposed around an inner circumferential side surface of the second transmission wheel, the second tooth portion has at least one second tooth, and a notch is disposed at a tooth root of the second tooth; The transmission assembly is configured such that the first transmission wheel and the second transmission wheel are meshedly connected via the first tooth portion and the second tooth portion, and at least a portion of the tooth top of the first tooth is located at an opening of a notch of a corresponding meshing second tooth.

2. The transmission assembly according to claim 1, characterized in that: The first tooth portion is a spline structure.

3. The transmission assembly according to claim 2, characterized in that: The first transmission wheel is configured such that a rotation center of the first transmission wheel is determined by a tooth tip circle of the first tooth portion, and the first tooth portion and the second tooth portion are rotatable around the rotation center.

4. The transmission assembly according to claim 1, characterized in that: The tooth top surface of the first tooth fits the tooth root surface of the second tooth, and the tooth side of the second tooth from the edge of the tooth top surface of the second tooth to the notch forms a working section, and the second tooth abuts against the first tooth through the working section.

5. The transmission assembly according to claim 4, characterized in that: The notch is formed on the root surface of the second tooth.

6. The transmission assembly according to claim 4, characterized in that: The notch is formed on a portion of the second tooth close to a root surface of the second tooth; The side wall of the recess formed by the second tooth portion is divided into a first side wall segment and a second side wall segment, wherein the first side wall segment extends from the tooth side of the second tooth in a direction away from the first tooth, and the second side wall segment extends from the first side wall segment in a direction close to the tooth root surface of the second tooth.

7. The transmission assembly according to claim 6, characterized in that: The first side wall segment is a straight line segment, and the extension direction of the first side wall segment corresponds to the radial direction of the starting point of the notch relative to the center of rotation. The starting point of the notch is the connection point between the first side wall segment and the tooth side of the second tooth, and the first tooth portion and the second tooth portion can rotate around the center of rotation.

8. The transmission assembly according to claim 7, characterized in that: The position of the starting point of the notch on the second tooth portion can be determined by the following formula: hk=rk-ra2, Among them, hk is the radial length of the working section relative to the center of the rotating circle, rk is the radius of the circle of the starting point of the notch relative to the center of the rotating circle, ra2 is the radius of the tooth top circle of the second transmission wheel, T is the load-bearing torque of the second tooth portion, Ψ is the load unevenness coefficient of the second tooth portion, Z is the number of teeth of the second tooth, L is the working length of the second tooth in the tooth width direction, and [p] is the allowable pressure of the material.

9. The transmission assembly according to claim 8, characterized in that: The radial length of the working section relative to the center of the rotation circle ranges from 0.8Mn to 1.2Mn, where Mn is the normal modulus.

10. The transmission assembly according to claim 7, characterized in that: The straight line trajectory of the first side wall segment can be determined by the position of the starting point of the notch and the pressure angle of the second tooth at the starting point of the notch.

11. The transmission assembly according to claim 7, characterized in that: The second side wall segment is an arc segment, and the arc trajectory of the second side wall segment is tangent to the straight trajectory of the first side wall segment and the tooth root circle of the second tooth portion respectively.

12. The transmission assembly according to claim 11, characterized in that: The arc length of the second side wall segment ranges from 0.1Mn to 1Mn, where Mn is the normal modulus.

13. A reducer, characterized in that: include: The transmission assembly according to any one of claims 1 to 12.

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