Planetary gear reduction gearbox and machining process thereof

Abstract

The planetary gear reduction gearbox comprises a shell and an end cover fixed to the end of the shell, the shell comprises a gear ring, and a step groove is formed in the end, close to the end cover, of the gear ring; the end cover is fixed to the position of the step groove of the gear ring through a die casting technology, inner teeth extending towards the two sides are arranged on the inner wall of the gear ring, a gasket is assembled in the gear ring in an interference mode, and the gasket is connected with the end face of the inner teeth. The gear ring is simple in structure, the gasket is assembled in the gear ring in an interference mode, and in the pressure casting process of the end cover, when one end of the positioning column abuts against the end face of the gasket, the shaft hole can be effectively blocked. According to the mode of combining the positioning column and the gasket, molten aluminum for die-casting the end cover is effectively prevented from flowing into the shell through the shaft hole, so that a good sealing effect is ensured, and the risk of molten aluminum leakage is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of planetary gear reduction boxes, in particular to a planetary gear reduction box and a processing technology thereof. Background Art

[0002] In the design of planetary reduction motors, a planetary gear reducer is usually integrated to achieve the functions of speed reduction and torque increase. It is widely used in situations that require precise speed control and high torque output. Specifically, the planetary gear reducer is usually composed of two main parts: the housing and the end cover. There are many ways to fix the housing and the end cover. The two most common ways are to fix with bolts or to directly die-cast the end cover on the end of the housing. Take the die-casting method as an example, such as Figure 1-4 As shown, the structure of the planetary gear reducer includes a housing 1A and an end cover 2A. In order to prevent the aluminum liquid used for die casting from entering the housing 1A, the conventional technology adopts a method of inserting a matching outer tooth column in the housing 1A to block the flow of aluminum liquid. However, since the outer tooth column is replaceable and is frequently used, a gap is easily generated between the outer tooth column and the housing 1A. Once such a gap is formed, the unsolidified aluminum liquid will pass through these gaps and enter the housing 1A, causing potential problems. In addition, in order to facilitate demolding during the manufacturing process, a plurality of top holes are designed on the end cover 2A. These top holes are connected to the inside of the end cover 2A after die casting is completed, which helps to form a more uniform pressure distribution inside the end cover, especially during cooling and shrinkage during the die casting process, ensuring that even after the end cover 2A is fixedly connected to the end of the housing 1A, the entire assembly can still maintain its structural stability and rigidity. However, in actual applications, the presence of the top holes may cause the oil to leak to the other side of the end cover through the gap between the gears and the top holes on the end cover. For this reason, a planetary gear reducer and a processing technology thereof are proposed. Summary of the invention

[0003] The object of the present invention is to provide a planetary gear reducer and a processing technology thereof to solve the problems raised in the above background technology.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a planetary gear reduction box, comprising a housing and an end cover fixed to the end of the housing, the housing comprising a gear ring, and a step groove is formed at the end of the gear ring adjacent to the end cover; the end cover is fixed to the step groove position of the gear ring by a die-casting process, the inner wall of the gear ring is provided with internal teeth extending to both sides, and a gasket is interference fitted inside the gear ring, and the gasket is connected to the end face of the internal tooth.

[0005] As a further solution of the present invention: the end cover comprises an end cover body, and an ear hole and a stopper are formed on the end surface of the end cover body away from the gear ring.

[0006] As a further solution of the present invention: a sealing cavity is formed in the end cover body, and a top hole which is not connected to the sealing cavity is formed on the end surface of the end cover body away from the gear ring.

[0007] As a further solution of the present invention: a plurality of positioning holes are provided on the step groove.

[0008] As a further solution of the present invention: a positioning pin corresponding to the positioning hole on the step groove is provided in the sealing cavity.

[0009] As a further solution of the present invention: at least one water-stopping ring groove is provided on the outer peripheral surface of the step groove.

[0010] As a further solution of the present invention: a water stop ring strip corresponding to the water stop ring groove on the step groove is provided in the sealing cavity.

[0011] A processing technology for a planetary gear reducer includes the following steps:

[0012] S1: The cut blank is clamped on the CNC equipment for rough turning, and the gasket is pressed into the shell after rough turning;

[0013] S2: The shell in S1 is loaded into the mold, and the die-casting machine drives the mold from an open state to a closed state. The aluminum liquid enters the mold from the outside to cool and solidify, and then the die-casting is ejected and cooled;

[0014] S3: Finishing the die-casting parts completed in S2.

[0015] As a further solution of the present invention: the step 2 includes the following specific steps:

[0016] S21, assemble the housing into the fixed mold, and ensure that the gasket pressed into the housing is installed in place;

[0017] S22, after the die-casting machine drives the movable mold to close the fixed mold, the aluminum liquid in the holding furnace is transferred to the cavity of the movable mold to cool and solidify to form an end cover;

[0018] S23, taking out the end cover and the shell that have been connected together after cooling from the mold cavity, and placing them on a workbench for further cooling.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention uses a gasket to be fitted inside the gear ring through interference fit. During the die-casting process of the end cover, when one end of the positioning column abuts against the end face of the gasket, the shaft hole can be effectively blocked. This combination of the positioning column and the gasket effectively prevents the aluminum liquid used for the die-cast end cover from flowing into the shell through the shaft hole, thereby ensuring a good sealing effect and avoiding the risk of aluminum liquid leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of a planetary gear reducer in the prior art of the present invention;

[0022] Figure 2 It is a cross-sectional schematic diagram of the connection between 1A and 2A of the planetary gear reducer in the prior art of the present invention;

[0023] Figure 3 1A is a schematic diagram of a planetary gear reducer in the prior art of the present invention;

[0024] Figure 4 2A is a first cross-sectional schematic diagram of a planetary gear reducer in the prior art of the present invention;

[0025] Figure 5 2A is a second cross-sectional schematic diagram of a planetary gear reducer in the prior art of the present invention;

[0026] Figure 6 It is a schematic diagram of the overall structure of the planetary gear reducer of the present invention;

[0027] Figure 7 It is a schematic diagram of the disassembly of the housing and the end cover of the present invention;

[0028] Figure 8 It is a cross-sectional schematic diagram of the planetary gear reduction box of the present invention;

[0029] Fig. 9 It is a schematic diagram of the combination of the housing and the gasket of the present invention;

[0030] Fig.10 It is a schematic diagram of the housing of the present invention;

[0031] Fig.11 is a schematic cross-sectional view of the end cover of the present invention;

[0032] Fig.12 It is a side view schematic diagram of the end cover body of the present invention;

[0033] Fig.13 It is a schematic diagram of the connection between the positioning column and the gasket of the present invention;

[0034] In the figure: 1. Shell; 11. Gear ring; 12. Internal teeth; 13. Step groove; 14. Water stop ring groove; 15. Positioning hole; 2. End cover; 21. End cover body; 22. Ear hole; 23. Sealing cavity; 24. Water stop ring strip; 25. Positioning pin; 26. Stopper; 3. Gasket. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] See also Figure 6-13 In an embodiment of the present invention, a planetary gear reduction box includes a housing 1 and an end cover 2 fixed to the end of the housing 1, the end cover 2 is integrally die-cast, the housing 1 includes a gear ring 11, and a step groove 13 is formed at the end of the gear ring 11 adjacent to the end cover 2; the end cover 2 is fixed to the step groove 13 of the gear ring 11 by a die-casting process, the inner wall of the gear ring 11 is provided with internal teeth 12 extending to both sides, wherein the end surface of the internal teeth 12 adjacent to the gear ring 11 is provided with a gasket 3, the end surface of the gasket 3 away from the internal teeth 12 is connected to the end surface of the end cover 2, the end cover 2 is coaxially arranged with the gasket 3, the gasket 3 is pressed into the housing 1 by an interference fit, and one end of the gasket 3 is connected to the housing 1 The end of the inner teeth 12 in the die-casting mold is in close contact, and during the die-casting process, when the other end of the gasket 3 is against the positioning column, the shaft hole can be effectively blocked. This combination of the positioning column and the gasket 3 prevents the aluminum liquid used for the die-casting end cover 2 from flowing into the housing 1 through the shaft hole. Specifically, the positioning column is integrally arranged with the movable mold. When both the fixed mold and the movable mold are in a closed state, the end of the positioning column just presses against the end face of the gasket 3. The design feature of the positioning column is that the outer diameter of its end face is greater than the inner diameter of the shaft hole in the middle of the gasket 3, which means that when the end of the positioning column contacts the gasket 3, the shaft hole can be effectively blocked to prevent the aluminum liquid used for the die-casting end cover 2 from flowing into the housing 1 through the hole. In contrast, the method adopted by the conventional technology is to insert a matching outer tooth column into the inner teeth 12 to block the flow of aluminum liquid. However, since the outer tooth column is replaceable and is frequently used, it is easy to generate a gap between the outer tooth column and the inner teeth 12. Once such a gap is formed, the unsolidified aluminum liquid will pass through these gaps and enter the inner teeth 12, causing potential problems.

[0037] See also Figure 7-8 In one embodiment, in this embodiment, preferably, the end cover 2 includes an end cover body 21, and the end surface of the end cover body 21 away from the gear ring 11 is provided with an ear hole 22 and a stopper 26. In this embodiment, preferably, there are two ear holes 22, which are symmetrically arranged on the end cover body 1, and a sealing cavity 23 is formed in the end cover body 21. The end surface of the end cover body 21 away from the gear ring 11 is also provided with a top hole that is not connected to the sealing cavity 23, and the stopper 26 is also not connected to the sealing cavity 23. This design ensures the stability of the planetary gear reducer during operation and avoids serious oil leakage, which would cause significant economic losses.

[0038] See also Figure 9-11 In one embodiment, in this embodiment, preferably, a plurality of positioning holes 15 are provided on the step groove 13, and a positioning pin 25 corresponding to the positioning holes 15 on the step groove 13 is provided in the sealing cavity 23. The number of the positioning pins 25 is the same as the number of the positioning holes 15, and the number of the positioning holes 15 is not limited. In this embodiment, preferably, the number of the positioning holes 15 is eight, and the eight positioning holes 15 are evenly spaced on the step groove 13, so that the shell 1 and the end cover 2 can withstand a greater relative force, and the positioning pin 25 is manufactured by a die-casting process, and can ensure good sealing performance when matched with the positioning hole 15, effectively preventing the occurrence of liquid leakage. Even if part of the liquid inside the shell 1 leaks accidentally, the liquid can only flow into the space between the water stop ring groove 14 and the water stop ring strip 24 through the gap between the positioning pin 25 and the positioning hole 15. Due to the design of the water stop ring groove 14 and the water stop ring strip 24, even if a trace of leakage occurs, it can be effectively collected and isolated, thereby avoiding the risk of liquid leakage and showing an excellent anti-leakage effect.

[0039] See also Figure 9-11 In one embodiment, in this embodiment, preferably, at least one water-stop ring groove 14 is opened on the step groove 13, and a water-stop ring strip 24 corresponding to the water-stop ring groove 14 on the step groove 13 is provided in the sealing cavity 23. The number of water-stop ring grooves 14 is not limited and can be designed according to actual conditions. In this embodiment, preferably, the number of water-stop ring grooves 14 is two, and the number of water-stop ring strips 24 is the same as the number of water-stop ring grooves 14, and the two are adapted to each other. When the gear box is in use, even if some liquid leaks out through the gap between the end cover 2 and the shell 1, since the side of the end cover 2 away from the shell 1 is in a sealed state, the liquid can only leak out along the step groove 13. At this time, the water-stop ring groove 14 and the water-stop ring strip 24 can further prevent the liquid from leaking from here, greatly improving the anti-leakage effect of the connection between the end cover 2 and the shell 1.

[0040] See also Figure 6 and Fig.13 In one embodiment, in this embodiment, preferably, the inner wall of the gear ring 11 is provided with internal teeth 12 extending to both sides, wherein the end surface of the internal teeth 12 adjacent to the gear ring 11 is provided with a gasket 3, and the end surface of the gasket 3 away from the internal teeth 12 is connected to the end surface of the end cover body 21, the end cover body 21 and the gasket 3 are coaxially arranged, and the gasket 3 is pressed into the housing 1 by interference fit. A processing technology for a planetary gear reducer: comprising the following steps:

[0041] S1: The cut blank is clamped on the CNC equipment for rough turning, and the gasket is pressed into the shell after rough turning;

[0042] Specifically, a 45# steel pipe is cut with a circular saw to obtain the blank material before shell processing, and the blank material is normalized to a hardness of HB170-217; the blank material is subsequently fixed on a CNC lathe, and the end face of the blank is used for external circumferential positioning processing to produce a step groove 13 and a water stop ring groove 14, and then a special drilling machine is used to position and process the positioning hole 15 with the end face of the gear ring 11; a CNC gear drawing machine is used to process the inner teeth 12 in the gear ring 11; the inner teeth 12 are subjected to heat treatment by a CNC high-frequency machine, and then the tooth surface hardness and the hardened layer are detected, and finally the gasket 3 is pressed into the interior of the shell 1.

[0043] S2: The shell in S1 is loaded into the mold, and the die-casting machine drives the mold from an open state to a closed state. The aluminum liquid enters the mold from the outside to cool and solidify, and then the die-casting is ejected and cooled;

[0044] S21, assemble the housing into the fixed mold, and ensure that the gasket pressed into the housing is installed in place;

[0045] S22, after the die-casting machine drives the movable mold to close the fixed mold, the aluminum liquid in the holding furnace is transferred to the movable mold cavity for cooling and solidification;

[0046] S23, ejecting the cooled die casting from the dynamic mold cavity and placing it on a workbench for cooling.

[0047] Specifically, before loading the shell into the mold, first use compressed air to blow away the debris in the mold cavity (blowing pressure ≥4 (bar), blowing time 4-15S), and then spray the prepared paint water onto the surface of the mold cavity (spraying time 4-15S, blowing pressure ≥4 (bar), paint brand and ratio: Elite 1:100, focus on spraying on the specified parts, fine mist, smooth, no dripping, spray evenly), then use compressed air to blow dry the excess paint (blowing pressure ≥4 (bar), blowing time 4-10S), then install the shell into the fixed mold, and make sure the gasket pressed into the shell is installed in place, and then the die-casting machine drives the mold from the open state to the closed state (the pressure of the mold hydraulic oil circuit is 13±1Mpa), scoop the aluminum liquid from the insulation furnace ((the scooping material must not be mixed with cold or sticky materials, the thickness of the material handle is controlled at 25-35mm, and the temperature is controlled at 650-680℃), eject the die-casting from the mold cavity and put it on the workbench to cool.

[0048] The die casting process parameters are set as follows:

[0049]

[0050] Although this specification is described according to implementation modes, not every implementation mode includes only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

[0051] Therefore, the above description is only a preferred embodiment of the present application and is not intended to limit the scope of implementation of the present application; that is, all equivalent changes made according to the scope of the claims of the present application are within the protection scope of the claims of the present application.

Claims

1. A planetary gear reduction box, comprising a housing (1) and an end cover (2) fixed to an end of the housing (1), characterized in that: The housing (1) comprises a gear ring (11), and a step groove (13) is formed at the end of the gear ring (11) adjacent to the end cover (2); the end cover (2) is fixed to the step groove (13) of the gear ring (11) by a die-casting process, and the inner wall of the gear ring (11) is provided with internal teeth (12) extending to both sides, and a gasket (3) is interference-fitted inside the gear ring (11), and the gasket (3) is connected to the end surface of the internal teeth (12).

2. The planetary gear reducer according to claim 1, characterized in that: The end cover (2) comprises an end cover body (21), and an ear hole (22) and a stopper (26) are provided on the end surface of the end cover body (21) away from the gear ring (11).

3. The planetary gear reducer according to claim 2, characterized in that: A sealing cavity (23) is formed in the end cover body (21), and a top hole which is not connected to the sealing cavity (23) is also formed on the end surface of the end cover body (21) away from the gear ring (11).

4. The planetary gear reducer according to claim 3, characterized in that: The step groove (13) is provided with a plurality of positioning holes (15).

5. The planetary gear reducer according to claim 4, characterized in that: A positioning pin (25) corresponding to the positioning hole (15) on the step groove (13) is provided in the sealing cavity (23).

6. The planetary gear reducer according to claim 3, characterized in that: At least one water-stopping annular groove (14) is formed on the outer peripheral surface of the step groove (13).

7. The planetary gear reducer according to claim 6, characterized in that: A water stop ring strip (24) corresponding to the water stop ring groove (14) on the step groove (13) is provided in the sealing cavity (23).

8. A processing technology for the planetary gear reducer according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1: The cut blank is clamped on a CNC device for rough turning, and a gasket (3) is pressed into the housing (1) after rough turning; S2: The housing (1) in S1 is loaded into the mold, and the die-casting machine drives the mold to change from an open state to a closed state. The aluminum liquid enters the mold from the outside to cool and solidify, and then the die-casting is ejected and cooled; S3: Finishing the die-casting parts completed in S2.

9. The planetary gearbox processing technology according to claim 8, characterized in that: The step 2 includes the following specific steps: S21, assembling the housing (1) into the fixed mold, and ensuring that the gasket (3) pressed into the housing (1) is installed in place; S22, after the die-casting machine drives the movable mold to close the fixed mold, the aluminum liquid in the holding furnace is transferred to the cavity of the movable mold to cool and solidify to form an end cover (2); S23, taking out the end cover (2) and the shell (1) that have been connected together after cooling from the mold cavity, and placing them on a workbench for further cooling.

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