A planetary reducer and a method for assembling the same

Abstract

The present invention discloses a planetary reducer and an assembly method of its gear ring, which are used for assembling the gear ring and a housing into one body, wherein an opening is provided at the end of the housing, and the inner diameter of the opening matches the outer diameter of the inner gear ring; a plurality of first-order splines and a plurality of second-order splines are protruded on the outer peripheral wall of the inner gear ring, and the first-order splines and the second-order splines are arranged along the axial direction of the inner gear ring, and the outer diameter of the second-order splines is greater than the outer diameter of the first-order splines; a first-order chip groove matching the first-order splines and a second-order chip groove matching the first-order splines are provided on the outer peripheral wall of the inner gear ring; when the gear ring and the housing are assembled, the first-order splines and the second-order splines cut the inner wall of the housing opening, thereby embedding the first-order splines and the second-order splines into the housing, and then assembling the housing and the inner gear ring into one body.

Description

Technical Field

[0001] The invention relates to the field of reducers, and in particular to an assembly method of a planetary reducer and a gear ring thereof. Background Art

[0002] The main components of the planetary gear reducer for concrete mixer trucks are sun gear, planet gear, inner gear ring, planet carrier, output flange, front housing, and housing. A multi-stage NGW planetary structure is adopted. In order to achieve even load distribution of the planetary gear, a gear floating mechanism is adopted, that is, the sun gear or planet carrier floats. The gear ring is processed as a separate component and connected to the housing by a flat key or pin fixation; or the gear ring and the housing are processed as a whole. The former connection method as a separate component not only increases the outer dimensions of the reducer, but also requires an additional design structure to prevent the pin from falling off, making the design complex and the installation and operation inconvenient; the latter is processed as a whole, the gear ring and the housing are made of the same material, the housing is made of ductile iron castings, the strength of the gear ring is reduced, and the difficulty of the inner gear ring processing and heat treatment process is increased. The first-level sun gear and the second-level sun gear are processed through an overall hardening process to improve the wear resistance of the relative sliding of the two sun gears. In long-term work, the reliability of the reducer is easily reduced due to the large speed difference between the first and second-level sun gears.

[0003] The patent document with publication number CN102853055A discloses a planetary gear reducer gear ring and its assembly method. First, the ports of the small inner gear ring and the large inner gear ring are chamfered, and the chamfering degree is 15±1°; then the chamfered small inner gear ring and the large inner gear ring are placed in liquid nitrogen at -180 to 200°C and frozen for 1 to 2 hours; finally, the frozen small inner gear ring and the large inner gear ring are respectively embedded in the reducer case cover and the reducer case. In the prior art, the gear ring and the case are installed by the thermal expansion and contraction characteristics of the gear ring material. However, this installation method has high processing requirements for the gear ring and the case, and the installation process is time-consuming and costly. In addition, the relative position between the case and the gear ring is difficult to adjust, and the gear ring is also difficult to remove from the case.

[0004] The patent document with publication number CN202612574U discloses a connection structure between a housing and an inner gear ring for a reducer, which discloses a processing and assembly method of the connection structure between the housing and the inner gear ring. Specifically, the housing and the inner gear ring are first processed separately. Before assembly, the first mating surface of the housing is a cylindrical surface. After the fine teeth of the inner gear ring are pressed into the housing by a press, a side clearance-free tooth side connection is formed between the fine teeth and the housing. At the same time, the second mating surface forms a transition fit of the cylindrical surface with the outer surface of the inner gear ring, and the elastic retaining ring is assembled in the closed annular groove formed by the snap ring groove I and the snap ring groove II. The prior art ensures the stability of the connection between the inner gear ring and the housing by means of tooth connection, but this method requires the processing of fine external teeth on the inner gear ring, and the addition of fine tooth grooves matching the external teeth on the inner wall of the housing. However, the processing of the external teeth on the inner gear ring and the tooth grooves on the inner wall of the housing has greatly increased the production cost and production time of the reducer, and additional means for limiting the axial movement of the inner gear ring are required. Summary of the invention

[0005] In order to solve the problem that the installation process of the inner ring gear and the housing in the prior art takes too long, the purpose of the present invention is to provide an assembly method of a planetary reducer and its ring gear, which can quickly install the ring gear on the housing and keep the inner ring gear and the housing in a tight fit without adding any mechanism.

[0006] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a method for assembling a gear ring, which is used to assemble the gear ring and a housing into one body, wherein an opening is provided at the end of the housing, and the inner diameter of the opening matches the outer diameter of the inner gear ring; a first-order spline and a second-order spline are protruded on the outer peripheral wall of the inner gear ring, and the first-order spline and the second-order spline are arranged along the axial direction of the inner gear ring, and a cutting edge is provided on the first-order spline and the second-order spline, and there are multiple first-order splines, and the multiple first-order splines are evenly arranged on the inner gear ring; there are multiple second-order splines, and the multiple second-order splines are evenly arranged on the inner gear ring; The first-order splines are evenly arranged on the inner gear ring; the plurality of first-order splines correspond one-to-one with the plurality of second-order splines; the outer diameter of the first-order spline is larger than the inner diameter of the shell opening, and the outer diameter of the second-order spline is larger than the outer diameter of the first-order spline; the outer peripheral wall of the inner gear ring is provided with a plurality of first-order chip grooves and a plurality of second-order chip grooves, the plurality of first-order chip grooves correspond one-to-one with the plurality of first-order splines, and the plurality of second-order chip grooves correspond one-to-one with the plurality of second-order splines; the first-order spline is located between the first-order chip groove and the second-order chip groove, and the second-order chip groove is located between the first-order spline and the second-order spline;

[0007] The assembly process of the internal gear ring is as follows:

[0008] Install the shell vertically on the workbench with the opening of the shell facing upwards;

[0009] Stand the inner gear ring upright so that the axis of the inner gear ring is vertical and the cutting edges of the first-order spline and the second-order spline are facing the housing;

[0010] Use a press to press down the inner gear ring until it moves to the specified position of the housing; during the downward movement of the inner gear ring: the end of the inner gear ring is first inserted into the opening of the housing, and then the first-order spline is connected to the housing, the first-order spline cuts the housing through the cutting edge, and leaves a groove on the inner wall of the housing; as the inner gear ring continues to move downward, the second-order spline is connected to the housing, the second-order spline cuts the housing through the cutting edge, and increases the depth of the groove.

[0011] Preferably, the end face with a cutting edge on the first-order spline is connected to the inner wall of the first-order chip groove; when the first-order spline cuts the shell, the first-order chip groove first enters the opening of the shell, and then the first-order spline is against the inner wall of the shell, and the chips cut by the first-order spline on the shell enter the first-order chip groove along the end face of the first-order spline; the end face with a cutting edge on the second-order spline is connected to the inner wall of the second-order chip groove; when the second-order spline cuts the shell, the second-order chip groove first enters the opening of the shell, and then the second-order spline is against the inner wall of the shell, and the chips dropped from the shell enter the second-order chip groove along the end face of the second-order spline.

[0012] Preferably, the cutting edge of the first-order spline and the cutting edge of the second-order spline are both raised with sharp corners.

[0013] Preferably, the interference amount of the first-order spline pressed into the housing is smaller than the interference amount of the second-order spline pressed into the housing.

[0014] Preferably, the inner wall of the opening on the shell includes an embedded inner wall and a positioning end face, and the spline on the outside of the inner gear ring is connected to the embedded inner wall and leaves a groove on the embedded inner wall; after the end of the inner gear ring is abutted against the positioning end face of the opening of the shell, the assembly of the inner gear ring and the shell is completed.

[0015] A planetary reducer is assembled using the above-mentioned method for assembling a gear ring. The planetary reducer includes the above-mentioned housing and an inner gear ring, wherein the housing includes a right housing and a left housing, and both the right housing and the left housing are provided with openings; the inner gear ring includes a primary inner gear ring and a secondary inner gear ring; the primary inner gear ring is installed in the right housing using the above-mentioned method, and the secondary inner gear ring is installed in the left housing using the above-mentioned method.

[0016] Preferably, it also includes a primary sun gear, a secondary sun gear, a primary planetary gear, a secondary planetary gear, a primary planetary carrier and a secondary planetary carrier; the primary sun gear is rotatably mounted on the right housing, the primary inner gear ring is sleeved on the primary sun gear, the primary planetary gear is meshed with the primary sun gear for transmission, the primary planetary gear is meshed with the primary inner gear ring, and the primary planetary gear is rotatably mounted on the primary planetary carrier; the primary planetary carrier is transmission-connected with the secondary sun gear, the secondary planetary gear is meshed with the secondary sun gear for transmission, the secondary planetary gear is meshed with the secondary inner gear ring, and the secondary planetary gear is rotatably mounted on the secondary planetary carrier.

[0017] Preferably, the secondary sun gear is fixedly connected to the primary planet carrier via a spline.

[0018] Preferably, the primary sun gear and the secondary sun gear are rotatably connected via a bearing.

[0019] Preferably, the secondary planet carrier is sleeved on the spline hub, the drum teeth on the spline hub are meshed with the internal teeth of the secondary planet carrier for transmission, the spline hub is sleeved on the output flange, and the spline hub sleeve and the output flange are fixedly connected by splines.

[0020] The beneficial effects of the technical solution of the present invention are as follows: the housing and the inner gear ring are fixed by means of segmented interference fit, so that the installation of the housing and the inner gear ring can be completed quickly, and the inner gear ring can be ensured to be tightly clamped in the housing; wherein, the splines on the outer circumferential surface of the inner gear ring are only used as press-fit interference cutting edges and embedded fixation, so that the entire small-module multi-tooth non-standard spline does not require meshing, the processing accuracy can be greatly reduced, and the processing process is simple; the above process avoids the complex connection structure required to fix the inner gear ring, thereby making the whole machine more streamlined and compact. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is the structural schematic diagram of the planetary reducer;

[0022] Figure 2 Schematic diagram of the connection structure between the primary sun gear and the secondary sun gear;

[0023] Figure 3 It is a schematic diagram of the connection structure between the inner gear ring and the housing;

[0024] Figure 4 It is a schematic diagram of the structure of the secondary internal gear ring.

[0025] Figure numerals: 1. primary sun gear; 2. primary planetary gear; 3. primary inner ring gear; 4. primary planet carrier; 5. secondary sun gear; 6. secondary planetary gear; 7. secondary inner ring gear; 8. secondary planet carrier; 9. spline hub; 10. output flange; 11. right housing; 12. left housing; 13. hydraulic motor; 14. rolling bearing; 15. bearing seat; 16. needle roller bearing; 17. primary planetary gear shaft; 18. secondary planetary gear shaft; 19. friction plate; 20. first-order spline; 21. first-order chip groove; 22. second-order spline; 23. second-order chip groove; 24. positioning end face. Implementation

[0026] 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 intended to be used to explain the present invention, and should not be construed 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", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations 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 referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0028] 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, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more, unless otherwise clearly specified.

[0029] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] 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. Example

[0031] like Figure 3 and Figure 4 The inner gear ring and housing shown are assembled into one piece, wherein an end of the housing is provided with an opening, and the inner diameter of the opening matches the outer diameter of the inner gear ring;

[0032] The outer peripheral wall of the inner gear ring is protruded with a first-order spline 20 and a second-order spline 22, which are arranged along the axial direction of the inner gear ring, and are both provided with cutting edges.

[0033] There are multiple first-order splines 20, and the multiple first-order splines 20 are evenly arranged on the inner gear ring; there are multiple second-order splines 22, and the multiple second-order splines 22 are evenly arranged on the inner gear ring; the multiple first-order splines 20 correspond to the multiple second-order splines 22 one by one;

[0034] The outer diameter of the first-order spline 20 is larger than the inner diameter of the housing opening, and the outer diameter of the second-order spline 22 is larger than the outer diameter of the first-order spline 20;

[0035] A plurality of first-order chip grooves 21 and a plurality of second-order chip grooves 23 are provided on the outer peripheral wall of the inner gear ring. The plurality of first-order chip grooves 21 correspond to the plurality of first-order splines 20 one by one, and the plurality of second-order chip grooves 23 correspond to the plurality of second-order splines 22 one by one. The first-order splines 20 are located between the first-order chip grooves 21 and the second-order chip grooves 23, and the second-order chip grooves 23 are located between the first-order splines 20 and the second-order splines 22.

[0036] The assembly method of the gear ring is as follows:

[0037] Install the shell vertically on the workbench with the opening of the shell facing upwards;

[0038] Stand the inner gear ring upright so that the axis of the inner gear ring is vertical, and the cutting edges of the first-order spline 20 and the second-order spline 22 are both facing the housing;

[0039] Use a press to press down the inner gear ring until it moves to the specified position of the shell; during the downward movement of the inner gear ring: the end of the inner gear ring is first inserted into the opening of the shell, and the outer circumferential surface of the inner gear ring matches the inner wall of the shell, so that the inner gear ring enters the opening of the shell smoothly; then the first-order spline 20 is connected to the shell, and the first-order spline 20 cuts the shell through the cutting edge and leaves a groove on the inner wall of the shell; as the inner gear ring continues to move downward, the second-order spline 22 is connected to the shell, and the second-order spline 22 cuts the shell through the cutting edge and increases the depth of the groove.

[0040] With such an arrangement, the housing and the inner gear ring are fixed by means of segmented interference fit, so that the housing and the inner gear ring can be installed quickly and the inner gear ring can be ensured to be tightly clamped in the housing; wherein, the splines on the outer circumferential surface of the inner gear ring are only used as press-fit interference cutting edges and embedded fixation, so that the entire small-module multi-tooth non-standard spline does not require meshing, the processing accuracy can be greatly reduced, and the processing process is simplified; the above process avoids the complex connection structure required to fix the inner gear ring, thereby making the whole machine more streamlined and compact.

[0041] In order to facilitate the processing of the gear ring, in this embodiment, the outer peripheral wall of the inner gear ring is provided with a plurality of first-order chip grooves 21 integrally arranged in an annular shape, and the outer peripheral wall of the inner gear ring is provided with a plurality of second-order chip grooves 22 integrally arranged in an annular shape.

[0042] In order to avoid iron chips being stuck between the inner gear ring and the inner wall of the opening, in this embodiment, the end face with a cutting edge on the first-order spline 20 is adjacent to the inner wall of the first-order chip groove 21; when the first-order spline 20 cuts the shell, the first-order chip groove 21 first enters the opening of the shell, and then the first-order spline 20 is against the inner wall of the shell, and the chips cut off the shell by the first-order spline 20 enter the first-order chip groove 21 along the end face of the first-order spline 20; the end face with a cutting edge on the second-order spline 22 is adjacent to the inner wall of the second-order chip groove 23; when the second-order spline 22 cuts the shell, the second-order chip groove 23 first enters the opening of the shell, and then the second-order spline 22 is against the inner wall of the shell, and the chips dropped from the shell enter the second-order chip groove 23 along the end face of the second-order spline 22. With such arrangement, the chip groove has entered the shell before the spline cuts the shell, so that the chips cut off the shell can only enter the chip groove, thereby avoiding chips being stuck between the shell and the inner gear ring, affecting the assembly position of the inner gear ring, and reducing the difficulty of assembling the inner gear ring.

[0043] In order to facilitate the spline cutting of the housing, in this embodiment, Figure 4 As shown, the cutting edge of the first-order spline 20 and the cutting edge of the second-order spline 22 are both raised with a sharp angle α. Such an arrangement can reduce the difficulty of assembly and improve assembly efficiency.

[0044] In this embodiment, the interference amount of the first-order spline 20 pressed into the housing is less than the interference amount of the second-order spline 22 pressed into the housing. In this way, the segmented height mode makes the connection limit area between the left and right sides of the inner gear ring and the housing different, increasing the connection strength between the inner gear ring and the housing.

[0045] In this embodiment, the inner wall of the opening on the shell includes an embedded inner wall and a positioning end face, and the spline on the outer side of the inner gear ring is connected to the embedded inner wall and leaves a groove on the embedded inner wall; after the end of the inner gear ring abuts against the positioning end face of the shell, the assembly of the inner gear ring and the shell is completed.

[0046] like Figures 1 to 4 The reducer shown includes the above-mentioned shell and inner gear ring, wherein the shell includes a right shell 11 and a left shell 12, both the right shell 11 and the left shell 12 are provided with openings, the opening of the right shell 11 and the opening of the left shell 12 are chamfered, the left shell 12 and the right shell 11 are fixedly connected by bolts, and the opening of the left shell 12 and the opening of the right shell 11 are assembled into a cavity; the inner gear ring includes a primary inner gear ring 3 and a secondary inner gear ring 7; the primary inner gear ring 3 is installed in the right shell 11 by the above-mentioned method, and the secondary inner gear ring 7 is installed in the left shell 12 by the above-mentioned method.

[0047] In this embodiment, the reducer also includes a primary sun gear 1, a secondary sun gear 5, a primary planetary gear 2, a secondary planetary gear 6, a primary planetary carrier 4 and a secondary planetary carrier 8; the primary sun gear 1 is rotatably installed on the right housing, the primary sun gear 1 passes through the primary inner gear ring 3, the primary planetary gear 2 is meshed with the primary sun gear 1 for transmission, the primary planetary gear 2 is meshed with the primary inner gear ring 3, and the primary planetary gear 2 is rotatably installed on the primary planetary carrier 4; the primary planetary carrier 4 is connected to the secondary sun gear 5 for transmission, the secondary planetary gear 6 is meshed with the secondary sun gear 5 for transmission, the secondary planetary gear 6 is meshed with the secondary inner gear ring 7, and the secondary planetary gear 6 is rotatably installed on the secondary planetary carrier 8.

[0048] In order to make the reducer have a good load balancing effect, in this embodiment, the end of the secondary sun gear 5 is inserted into the middle hole of the primary planet carrier 4, and the secondary sun gear 5 is connected to the primary planet carrier 4 through a spline, so that the primary planet carrier 4 and the secondary sun gear 5 float as a whole.

[0049] In order to improve the reliability of the reducer, in this embodiment, Figure 1 and 2 As shown, the primary sun gear 1 and the secondary sun gear 5 are coaxially arranged, the primary planet carrier 4 is provided with a notch, a bearing seat 15 is installed in the notch, the bearing seat 15 is tightly matched with the notch, the bearing 14 is installed on the bearing seat 15, and the primary sun gear 1 is rotatably connected with the bearing seat 15 through the bearing 14; the end of the secondary sun gear 5 is inserted into the middle hole of the primary planet carrier 4, one end of the secondary sun gear 5 is splined with the primary planet carrier 4, and the other end of the secondary sun gear 5 is protruded with a stopper, the stopper is clearance-matched with the secondary planet carrier 8, and the axial floating clearance between the stopper and the secondary planet carrier 8 is 0.5~1mm. In this way, during the long-term operation of the reducer, due to the large speed difference between the primary sun gear and the secondary sun gear, a rolling bearing device is added between the primary sun gear and the secondary sun gear to convert the sliding friction between the two sun gears into rolling friction, thereby improving the reliability of the reducer. Furthermore, a avoidance groove for avoiding the bearing seat is provided at the end of the secondary sun gear.

[0050] In order to make the reducer have a larger speed ratio, in this embodiment, the first-stage planetary gear set is an NW planetary structure, and the second-stage planetary gear set is an NGW planetary structure; specifically, in the first-stage planetary gear set, there are multiple first-stage planetary gears 2, and multiple first-stage double-linked planetary gears 2 are evenly arranged around the first-stage sun gear 1; in the second-stage planetary gear, the second-stage planetary gear 6 is a universal NGW planetary structure. In this way, in the reducer, the high-speed end adopts the NW planetary structure, and the low-speed end adopts the NGW planetary structure, making the structure of the reducer more compact; and the above structure can make the output flange allow the maximum swing angle of each direction to be ±6°, while the output flange in reducers with other structures allows the maximum swing angle of each direction to be ±4°.

[0051] In order to improve the floating sensitivity of the output flange, in this embodiment, the secondary planet carrier 8 is sleeved on the spline hub 9, the drum teeth on the spline hub 9 are meshed with the internal teeth of the secondary planet carrier 8, the spline hub 9 is sleeved on the output flange 10, and the spline hub 9 sleeve and the output flange 10 are fixedly connected by splines. In this way, the secondary planet carrier 8 is connected to the spline hub 9 by the drum teeth, the floating sensitivity is high, and an inclination angle of 0.5° to 1° is allowed, which can improve the floating load balancing effect.

[0052] In order to facilitate power input, the input shaft and the first-stage sun gear are integrally formed, and the two ends of the first-stage sun gear are the input end and the output end respectively. The output end extends into the shell, and the outer peripheral surface of the output end is provided with external teeth. The external teeth of the input end are meshed with the first-stage planetary gear for transmission; a spline hole is opened on the input end, and the spline hole is connected to the hydraulic motor transmission with the interface standard being the SAE spline shaft. The spline hole is plugged into the spline shaft, the hydraulic motor is installed on the shell, and the output flange is connected to the mixing drum of the mixer truck.

[0053] In order to improve the load-bearing capacity of the reducer, in this embodiment, a primary planetary gear shaft 17 is fixed on the primary planetary carrier 4, and the primary planetary gear 2 is rotatably mounted on the primary planetary gear shaft 17 through a needle bearing 16; a secondary planetary gear shaft 18 is fixed on the secondary planetary carrier 8, and the secondary planetary gear 6 is rotatably mounted on the secondary planetary gear shaft 18 through a needle bearing 16; in the primary planetary gear set and the secondary planetary gear set, there are multiple groups of needle bearings 16, and a friction plate 19 is provided between two adjacent groups of needle bearings 16. Further preferably, the needle bearing includes a plurality of needle rollers, which are arranged around the planetary gear shaft, and the needle rollers are located between the planetary gear shaft and the planetary gear, and the outer peripheral surface of the planetary gear shaft and the inner hole of the planetary gear are both carburized, quenched and ground, and the outer peripheral surface of the planetary gear shaft is used as the inner ring of the needle bearing, and the inner hole of the planetary gear is used as the outer ring of the needle bearing.

[0054] In this embodiment, the secondary inner gear ring is pressed into the left housing as an example. The secondary inner gear ring 7 is pressed into the left housing 12. The opening of the left housing 12 and the left end of the secondary inner gear ring have a matching tolerance of φH7 / h6. After the opening of the left housing 12 and the secondary inner gear ring are positioned and matched, the first-order spline 20 of the secondary inner gear ring 7 begins to be pressed into the housing, and the iron filings cut off are pushed into the first-order chip groove 21 for storage; then the pressing continues, and the second-order spline 22 of the secondary inner gear ring 7 is also pressed into the housing, and the iron filings cut off are also pushed into the second-order chip groove 23 for storage. When the secondary inner gear ring abuts against the positioning end face 24 on the left side of the opening in the left housing, the secondary inner gear ring 7 is fixed on the housing. According to the diameter of the inner hole of the housing, the first-order press-in interference is usually 0.5mm in diameter, and the second-order press-in interference is usually 0.5-1mm larger than the first-order press-in interference.

[0055] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example 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.

[0056] 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 on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention.

Claims

1. A method for assembling a gear ring, for assembling the gear ring and a housing into one body, characterized in that: An opening is provided at the end of the shell, and the inner diameter of the opening matches the outer diameter of the inner gear ring; A first-order spline (20) and a second-order spline (22) are protruded on the outer peripheral wall of the inner gear ring. The first-order spline (20) and the second-order spline (22) are arranged along the axial direction of the inner gear ring. The first-order spline (20) and the second-order spline (22) are both provided with cutting edges. There are a plurality of first-order splines (20), and the plurality of first-order splines (20) are evenly arranged on the inner gear ring; there are a plurality of second-order splines (22), and the plurality of second-order splines (22) are evenly arranged on the inner gear ring; the plurality of first-order splines (20) correspond one to one with the plurality of second-order splines (22); The outer diameter of the first-order spline (20) is larger than the inner diameter of the housing opening, and the outer diameter of the second-order spline (22) is larger than the outer diameter of the first-order spline (20); A plurality of first-order chip grooves (21) and a plurality of second-order chip grooves (23) are provided on the outer peripheral wall of the inner gear ring. The plurality of first-order chip grooves (21) correspond one-to-one to the plurality of first-order splines (20), and the plurality of second-order chip grooves (23) correspond one-to-one to the plurality of second-order splines (22); the first-order splines (20) are located between the first-order chip grooves (21) and the second-order chip grooves (23), and the second-order chip grooves (23) are located between the first-order splines (20) and the second-order splines (22); The assembly process of the internal gear ring is as follows: Install the shell vertically on the workbench with the opening of the shell facing upwards; The inner gear ring is erected so that the axis of the inner gear ring is vertical, and the cutting edges of the first-order spline (20) and the second-order spline (22) are both facing the housing; The inner gear ring is pressed down by a press until the gear ring moves to a designated position of the housing; during the downward movement of the inner gear ring: the end of the inner gear ring is first inserted into the opening of the housing, and then the first-order spline (20) is connected to the housing, and the first-order spline (20) cuts the housing through the cutting edge and leaves a groove on the inner wall of the housing; as the inner gear ring continues to move downward, the second-order spline (22) is connected to the housing, and the second-order spline (22) cuts the housing through the cutting edge and increases the depth of the groove.

2. The method for assembling a gear ring according to claim 1, characterized in that: The end face with the cutting edge on the first-order spline (20) is adjacent to the inner wall of the first-order chip groove (21); when the first-order spline (20) cuts the shell, the first-order chip groove (21) first enters the opening of the shell, and then the first-order spline (20) abuts against the inner wall of the shell, and the chips cut off the shell by the first-order spline (20) enter the first-order chip groove (21) along the end face of the first-order spline (20); The end face with the cutting edge on the second-order spline (22) is adjacent to the inner wall of the second-order chip groove (23); when the second-order spline (22) cuts the shell, the second-order chip groove (23) first enters the opening of the shell, and then the second-order spline (22) abuts against the inner wall of the shell, and the debris dropped from the shell enters the second-order chip groove (23) along the end face of the second-order spline (22).

3. The method for assembling a gear ring according to claim 1, characterized in that: The cutting edge of the first-order spline (20) and the cutting edge of the second-order spline (22) are both raised with sharp corners.

4. The method for assembling a gear ring according to claim 1, characterized in that: The interference amount of the first-order spline (20) pressed into the housing is smaller than the interference amount of the second-order spline (22) pressed into the housing.

5. The method for assembling a gear ring according to claim 1, characterized in that: The inner wall of the opening on the shell includes an embedded inner wall and a positioning end face (24); the first-order spline (20) and the second-order spline (22) on the inner gear ring are connected to the embedded inner wall and leave a groove on the embedded inner wall; after the end of the inner gear ring abuts against the positioning end face (24) of the opening, the assembly of the inner gear ring and the shell is completed.

6. A planetary reducer, characterized in that: The assembly is performed by applying the method for assembling a gear ring according to any one of claims 1 to 5, wherein the housing comprises a right housing (11) and a left housing (12), and both the right housing (11) and the left housing (12) are provided with openings; the inner gear ring comprises a primary inner gear ring (3) and a secondary inner gear ring (7); The primary internal gear ring (3) is installed in the right housing (11) by the above method, and the secondary internal gear ring (7) is installed in the left housing (12) by the above method.

7. A planetary reducer according to claim 6, characterized in that: It also includes a first-stage sun gear (1), a second-stage sun gear (5), a first-stage planetary gear (2), a second-stage planetary gear (6), a first-stage planetary carrier (4) and a second-stage planetary carrier (8); The first-stage sun gear (1) is rotatably mounted on the right housing, the first-stage inner gear ring is sleeved on the first-stage sun gear (1), the first-stage planetary gear (2) meshes with the first-stage sun gear (1) for transmission, the first-stage planetary gear (2) meshes with the first-stage inner gear ring (3), and the first-stage planetary gear (2) is rotatably mounted on the first-stage planet carrier (4); the first-stage planet carrier (4) is transmission-connected with the second-stage sun gear (5), the second-stage planetary gear (6) meshes with the second-stage sun gear (5) for transmission, the second-stage planetary gear (6) meshes with the second-stage inner gear ring (7), and the second-stage planetary gear (6) is rotatably mounted on the second-stage planet carrier (8).

8. A planetary reducer according to claim 7, characterized in that: The secondary sun gear (5) is fixedly connected to the primary planet carrier (4) via a spline.

9. A planetary reducer according to claim 7, characterized in that: The first-stage sun gear (1) and the second-stage sun gear (5) are rotatably connected via a bearing.

10. A planetary reducer according to claim 8, characterized in that: The secondary planet carrier (8) is sleeved on the spline hub (9), the drum-shaped teeth on the spline hub (9) mesh with the internal teeth of the secondary planet carrier (8) for transmission, the spline hub (9) is sleeved on the output flange, and the spline hub (9) sleeve and the output flange (10) are fixedly connected via splines.

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