Lubricating oil passage structure for planetary gear device

Abstract

The application relates to a lubricating oil path structure of a planetary gear transmission device, and relates to a lubricating oil path structure. In order to solve the problems that the lubricating oil utilization efficiency of an existing NGW type planetary gear transmission device is not high, the lubricating oil along-path resistance loss is large, and the lubricating oil supply capacity of an external oil station is high, the application has a compact structure, lubricates each component in turn by adopting a branch lubricating oil supply mode according to the actual lubricating demand of each rotating component, that is, lubricating oil flows through an oil supply hole, an oil supply annular groove and a first lubricating oil inlet hole, enters a first annular groove, the lubricating oil in the first annular groove enters an oil supply pipe and a sun gear oil injection pipe through a first lubricating oil outlet hole, thereby realizing high-efficiency lubrication of gear meshing surfaces, sliding bearings and shaft necks, replacing a commonly used planetary carrier lubricating oil passage design, compensating for the along-path loss through cooperation of each lubricating oil inlet hole, lubricating oil outlet hole and annular groove, and reducing the lubricating oil supply capacity of the external oil station. The application belongs to the technical field of lubricating oil paths of speed reducers.

Description

Technical Field

[0001] This invention relates to a lubrication circuit structure, specifically a lubrication circuit structure for a planetary gear transmission device, belonging to the technical field of reducer lubrication circuits. Background Technology

[0002] The NGW type (internal meshing-common gear-external meshing) planetary gear transmission works by using multiple planetary gears to revolve around a sun gear in a periodic motion, thereby reducing the input speed and amplifying the input torque. Due to its excellent operating characteristics, planetary gearboxes play a crucial role in many high-end mechanical fields. For example, in the electric vehicle industry, its efficient transmission performance and lightweight design can significantly improve vehicle range and performance; in robotics and industrial automation, its smooth transmission, high load-bearing capacity, and compact size can improve production line efficiency and automation. Given the rotational and revolving characteristics of the planetary gear transmission components, its compact internal structure leads to a complex oil supply system design. Efficiently and rationally supplying oil to each rotating component is a challenge in lubrication system design.

[0003] Currently, existing NGW-type planetary gear transmission devices typically employ a multi-pipeline parallel method to simultaneously supply oil to all rotating components. Specifically, the planet carrier, planet gears, and sun gear share a single oil circuit, while the input and output shaft bearings use a separate circuit. While this method ensures adequate lubrication for all rotating components, it requires drilling long, narrow oil holes in the planet carrier, increasing its overall structure and weight. Furthermore, the oil often flows back under gravity after passing through only one component, resulting in low oil utilization efficiency. Additionally, to avoid interference with rotating components, compromises are usually made in the pipeline design, leading to a complex lubrication structure, high friction loss, and high requirements for the external lubrication station's oil supply capacity.

[0004] In summary, how to propose a lubrication circuit structure to address the aforementioned technical problems has become a pressing issue for those skilled in the art. Summary of the Invention

[0005] To address the shortcomings of the prior art, this invention provides a lubrication circuit structure for a planetary gear transmission device.

[0006] The technical solution of this invention is: a lubrication circuit structure for a planetary gear transmission device, comprising a transmission unit; the transmission unit includes a hollow input shaft, an internal gear ring, a sun gear, a first planetary carrier, a second planetary carrier, a plurality of planetary gears, and a plurality of planetary gear mounting shafts. The hollow input shaft is fixedly connected to the first planetary carrier, and the hollow input shaft is rotatably connected to an input shaft bearing housing via a sliding bearing. Oil supply holes are provided on the sliding bearing and the input shaft bearing housing, and an oil supply annular groove is provided on the inner circumferential surface of the input shaft bearing housing.

[0007] The internal gear ring and the planet gears are both arranged between the first planet carrier and the second planet carrier, and the internal gear ring and the sun gear mesh with the planet gears.

[0008] The planetary gears are rotatably connected to the planetary gear mounting shafts, and the two ends of the planetary gear mounting shafts are respectively inserted into the first planetary carrier and the second planetary carrier.

[0009] Furthermore, it also includes a connecting sleeve, an oil supply pipe, and a sun gear injection pipe.

[0010] The connecting sleeve is coaxially installed in the inner hole of the hollow input shaft. A first annular groove is opened on the outer circumference of the connecting sleeve. A first lubricating oil inlet and a first lubricating oil outlet are opened on the hollow input shaft. The first lubricating oil outlet is connected to the first lubricating oil inlet through the first annular groove. The first lubricating oil inlet is connected to the oil supply hole.

[0011] The planetary gear mounting shaft includes an end cap, and a blind hole is opened on the end face of the planetary gear mounting shaft. The end cap is threadedly connected to the blind hole.

[0012] The end cap has a second oil inlet hole, the outer circumferential surface of the planetary gear mounting shaft has a second oil outlet hole and a second annular groove, and the inner circumferential surface of the planetary gear has a third oil outlet hole and a third annular groove. The third oil outlet hole is connected to the second oil inlet hole through the second oil outlet hole.

[0013] The two ends of the oil supply pipe are connected to the first lubricating oil outlet and the second lubricating oil inlet, respectively.

[0014] The two ends of the sun gear oil injection pipe are respectively inserted into the hollow input shaft and the second planetary carrier. A fourth lubricating oil outlet is opened on the outer circumference of the sun gear oil injection pipe, and the fourth lubricating oil outlet is connected to the first lubricating oil outlet.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] 1. This invention has a compact structure. Based on the actual lubrication needs of each rotating component, it adopts a branched lubricating oil supply method to lubricate each component sequentially. That is, the lubricating oil flows through the oil supply hole, the oil supply annular groove and the first lubricating oil inlet 1-1 and then enters the first annular groove. The lubricating oil in the first annular groove enters the oil supply pipe 5 and the sun gear oil injection pipe 10 through the first lubricating oil outlet 1-2, thereby achieving efficient lubrication of each gear meshing surface, sliding bearing and journal. It replaces the commonly used planetary carrier lubricating oil channel design. The cooperation of each lubricating oil inlet, lubricating oil outlet and annular groove compensates for the friction loss, reduces the lubricating oil supply capacity of the external oil station, and reduces the processing difficulty of the parts.

[0017] 2. This invention achieves efficient and reasonable lubrication of the planetary gear transmission device in a compact structure, which can make efficient use of the effective space in the housing, simplify the structure while ensuring the strength of the components, improve the utilization efficiency of lubricating oil, and further enhance the advantages of the planetary gear transmission device in terms of lightweight and compact size. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of the present invention;

[0019] Figure 2 This is a schematic diagram of the structure of the input shaft 1, the connecting sleeve 2, the sliding bearing 3, and the bearing seat 4 of the present invention;

[0020] Figure 3 This is a schematic diagram of the structure of the input shaft 1 and the connecting sleeve 2 of the present invention;

[0021] Figure 4 This is a schematic diagram of the structure of the oil supply pipe 5 of the present invention;

[0022] Figure 5 This is a schematic diagram of the structure of the planetary gear mounting shaft 6, internal gear ring 7, planetary gear 8, first planetary carrier 11-1 and second planetary carrier 11-2 of the present invention.

[0023] Figure 6 This is a schematic diagram of the arrangement of the input shaft 1, the sun gear 9, the sun gear fuel injection pipe 10, and the second planetary carrier 11-2 of the present invention.

[0024] In the diagram: 1. Input shaft; 1-1. First oil inlet; 1-2. First oil outlet; 2. Connecting sleeve; 3. Sliding bearing; 4. Bearing housing; 5. Oil supply pipe; 5-1. Straight pipe connector; 6. Planetary gear mounting shaft; 6-1. End cap; 6-2. Second oil inlet; 6-3. Second oil outlet; 7. Internal gear ring; 8. Planetary gear; 8-1. Third oil outlet; 9. Sun gear; 10. Sun gear oil injection pipe; 10-1. Fourth oil outlet; 11-1. First planetary carrier; 11-2. Second planetary carrier. Detailed Implementation

[0025] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments.

[0026] Specific implementation method one: Combining Figures 1 to 6 This embodiment describes a lubrication circuit structure for a planetary gear transmission device, which includes a transmission unit. The transmission unit includes a hollow input shaft 1, an internal gear ring 7, a sun gear 9, a first planetary carrier 11-1, a second planetary carrier 11-2, a plurality of planetary gears 8, and a plurality of planetary gear mounting shafts 6.

[0027] The hollow input shaft 1 is fixedly connected to the first planetary carrier 11-1. The hollow input shaft 1 is rotatably connected to the input shaft bearing seat 4 through the sliding bearing 3. The sliding bearing 3 and the input shaft bearing seat 4 are provided with oil supply holes, and the inner circumferential surface of the input shaft bearing seat 4 is provided with an oil supply annular groove to realize the supply of lubricating oil from the stationary sliding bearing to the rotating input shaft. During the operation of the sliding bearing, the oil film dynamic pressure increases the oil supply pressure in the oil supply annular groove, thereby improving the reliability of the lubricating oil system.

[0028] The internal gear ring 7 and the planet gear 8 are both arranged between the first planet carrier 11-1 and the second planet carrier 11-2, and the internal gear ring 7 and the sun gear 9 are both meshed with the planet gear 8.

[0029] Planetary gear 8 is rotatably connected to planetary gear mounting shaft 6, and both ends of planetary gear mounting shaft 6 are respectively inserted into the first planetary carrier 11-1 and the second planetary carrier 11-2.

[0030] Furthermore, it also includes a connecting sleeve cup 2, an oil supply pipe 5, and a sun gear injection pipe 10.

[0031] The connecting sleeve 2 is coaxially installed in the inner hole of the hollow input shaft 1. A first annular groove is opened on the outer circumferential surface of the connecting sleeve 2. A first lubricating oil inlet hole 1-1 and a first lubricating oil outlet hole 1-2 are opened on the hollow input shaft 1. The first lubricating oil outlet hole 1-2 is connected to the first lubricating oil inlet hole 1-1 through the first annular groove. The first lubricating oil inlet hole 1-1 is connected to the oil supply hole.

[0032] Furthermore, the inner hole of the hollow input shaft 1 is a stepped hole. One end of the connecting sleeve 2 abuts against the end face of the hollow input shaft 1, and the other end of the connecting sleeve 2 abuts against the bottom step of the stepped hole. An O-ring nitrile rubber seal is installed between the mating surfaces of the connecting sleeve 2 and the hollow input shaft 1. With this configuration, the first lubricating oil inlet 1-1, the first lubricating oil outlet 1-2, and the first annular groove form a connected sealed inner cavity, preventing lubricating oil leakage. At the same time, the lubricating oil in the first annular groove is subjected to centrifugal force during the rotation of the hollow input shaft 1, which can fully offset the friction loss of the lubricating oil and improve the oil supply efficiency.

[0033] The planetary gear mounting shaft 6 includes an end cover 6-1. A blind hole is opened on the end face of the planetary gear mounting shaft 6, and the end cover 6-1 is threadedly connected to the blind hole.

[0034] The end cap 6-1 has a second oil inlet hole 6-2, the outer circumferential surface of the planetary gear mounting shaft 6 has a second oil outlet hole 6-3 and a second annular groove, the inner circumferential surface of the planetary gear 8 has a third oil outlet hole 8-1 and a third annular groove, and the third oil outlet hole 8-1 is connected to the second oil inlet hole 6-2 through the second oil outlet hole 6-3.

[0035] The two ends of the oil supply pipe 5 are connected to the first lubricating oil outlet 1-2 and the second lubricating oil inlet 6-2, respectively. The lubricating oil flowing out of the oil supply pipe 5 flows through the second lubricating oil inlet 6-2, the second lubricating oil outlet 6-3, the second annular groove, the third annular groove and the third lubricating oil outlet 8-1 in sequence to lubricate the tooth surfaces of the internal gear ring 7 and the planetary gear 8. During the flow process, the lubricating oil finally flows out of the third lubricating oil outlet 8-1 to lubricate the tooth surfaces under the combined action of oil pressure, the oil's own gravity, the dynamic pressure effect of the planetary gear mounting shaft 6 and centrifugal force, thereby reducing the oil loss along the stroke and improving the problem of poor end lubricating oil supply capacity that is common in long and narrow stroke lubricating oil supply structures.

[0036] On the other hand, the use of various lubricating oil inlets, outlets, and annular grooves replaces the commonly used planetary carrier lubricating oil channel design, solving the problem of difficult machining of slender oil holes inside the planetary carrier. While ensuring the strength of the planetary carrier, the weight of the planetary carrier is effectively reduced. Secondly, the main heat source during operation comes from the relative frictional motion between contacting surfaces (such as gear meshing surfaces, sliding bearings and journals). The external oil supply pipe 5 reduces the number of internal structural components in the housing, increases the contact area between the lubricating oil and splashes inside the housing, and improves the heat exchange effect between the oil supply pipe 5 and the external air, which can reduce the lubricating oil temperature entering the inner cavity of the planetary gear mounting shaft 6 to a certain extent.

[0037] The two ends of the sun gear oil injection pipe 10 are respectively inserted into the hollow input shaft 1 and the second planetary carrier 11-2. Several fourth lubricating oil outlet holes 10-1 are opened on the outer circumference of the sun gear oil injection pipe 10. The fourth lubricating oil outlet holes 10-1 face the tooth surface of the sun gear 9 and are evenly distributed along the length of the sun gear oil injection pipe 10. The fourth lubricating oil outlet holes 10-1 are connected to the first lubricating oil outlet hole 1-2.

[0038] Specific Implementation Method Two: Combining Figure 1 and Figure 4 In this embodiment, both ends of the oil supply pipe 5 are welded with straight pipe joints 5-1. Preferably, a standard welded straight pipe joint (JBT966-1977) is selected. Both ends of the oil supply pipe 5 are connected to the first lubricating oil outlet 1-2 and the second lubricating oil inlet 6-2 through the straight pipe joints 5-1.

[0039] One end of the straight pipe connector 5-1 is welded to the oil supply pipe 5. The other end of the straight pipe connector 5-1 is coated with thread sealant and then threaded to the first lubricating oil outlet 1-2 or the second lubricating oil inlet 6-2. This arrangement achieves a seal and prevents lubricating oil leakage.

[0040] The other components and connections are the same as in Specific Implementation Method 1.

[0041] Specific implementation method three: Combining Figures 1 to 6 In this embodiment, the oil supply pipe 5 is made of stainless steel, preferably 06Cr19Ni10 stainless steel.

[0042] Furthermore, both the first planetary carrier 11-1 and the second planetary carrier 11-2 are made of low-carbon steel.

[0043] Furthermore, the sun gear oil injection pipe 10 is made of brass alloy, preferably CuAl9Fe4Ni4 brass alloy. This design utilizes the difference in ductility and thermal expansion characteristics between brass alloy and low carbon steel to fix the sun gear oil injection pipe 10 and prevent oil leakage. This greatly simplifies the oil supply structure while meeting the lubrication requirements of the sun gear tooth surface during the operation of the planetary gear transmission device.

[0044] The other components and connections are the same as in specific implementation method one or two.

[0045] Working principle

[0046] Combination Figures 1 to 6 Explanation of the working principle of this invention:

[0047] An external oil station supplies oil to the input shaft bearing housing 4. The sliding bearing 3 and the input shaft bearing housing 4 have oil supply holes. The inner circumferential surface of the input shaft bearing housing 4 has an oil supply annular groove. The lubricating oil flows through the oil supply hole, the oil supply annular groove and the first lubricating oil inlet hole 1-1 and then enters the first annular groove.

[0048] The lubricating oil in the first annular groove enters the oil supply pipe 5 and the sun gear injection pipe 10 through the first lubricating oil outlet holes 1-2, respectively.

[0049] The lubricating oil flowing from the oil supply pipe 5 flows sequentially through the second lubricating oil inlet 6-2, the second lubricating oil outlet 6-3, the second annular groove, the third annular groove, and the third lubricating oil outlet 8-1, and then lubricates the tooth surfaces of the internal gear ring 7 and the planetary gear 8.

[0050] The lubricating oil flowing from the sun gear oil injection pipe 10 is sprayed out through the fourth lubricating oil outlet 10-1 and then lubricates the tooth surface of the sun gear 9.

[0051] The present invention has been disclosed above with reference to preferred embodiments, but it is not intended to limit the present invention. Any simple modifications, equivalent changes and alterations made by those skilled in the art to the above embodiments without departing from the technical solution of the present invention, based on the technical essence of the present invention, shall still fall within the scope of the technical solution of the present invention.

Claims

1. A lubrication circuit structure for a planetary gear transmission device, comprising a transmission unit; The transmission unit includes a hollow input shaft (1), an internal gear ring (7), a sun gear (9), a first planet carrier (11-1), a second planet carrier (11-2), several planet gears (8), and several planet gear mounting shafts (6). The hollow input shaft (1) is fixedly connected to the first planetary carrier (11-1). The hollow input shaft (1) is rotatably connected to the input shaft bearing seat (4) through the sliding bearing (3). The sliding bearing (3) and the input shaft bearing seat (4) are provided with oil supply holes, and the inner circumferential surface of the input shaft bearing seat (4) is provided with an oil supply annular groove. The internal gear ring (7) and the planet gear (8) are both arranged between the first planet carrier (11-1) and the second planet carrier (11-2), and the internal gear ring (7) and the sun gear (9) are both meshed with the planet gear (8); The planetary gear (8) is rotatably connected to the planetary gear mounting shaft (6), and the two ends of the planetary gear mounting shaft (6) are respectively inserted into the first planetary carrier (11-1) and the second planetary carrier (11-2); Its features are: It also includes a connecting sleeve cup (2), an oil supply pipe (5), and a sun gear injection pipe (10); The connecting sleeve (2) is coaxially installed in the inner hole of the hollow input shaft (1). A first annular groove is opened on the outer circumferential surface of the connecting sleeve (2). A first lubricating oil inlet (1-1) and a first lubricating oil outlet (1-2) are opened on the hollow input shaft (1). The first lubricating oil outlet (1-2) is connected to the first lubricating oil inlet (1-1) through the first annular groove. The first lubricating oil inlet (1-1) is connected to the oil supply hole. The planetary gear mounting shaft (6) includes an end cap (6-1), and a blind hole is opened on the end face of the planetary gear mounting shaft (6). The end cap (6-1) is threadedly connected to the blind hole. The end cap (6-1) has a second oil inlet hole (6-2), the outer circumferential surface of the planetary gear mounting shaft (6) has a second oil outlet hole (6-3) and a second annular groove, the inner circumferential surface of the planetary gear (8) has a third oil outlet hole (8-1) and a third annular groove, and the third oil outlet hole (8-1) is connected to the second oil inlet hole (6-2) through the second oil outlet hole (6-3); The two ends of the oil supply pipe (5) are respectively connected to the first lubricating oil outlet (1-2) and the second lubricating oil inlet (6-2). The oil supply pipe (5) is made of stainless steel. Both ends of the oil supply pipe (5) are welded with straight pipe joints (5-1). Both ends of the oil supply pipe (5) are connected to the first lubricating oil outlet (1-2) and the second lubricating oil inlet (6-2) through straight pipe joints (5-1). The two ends of the sun gear oil injection pipe (10) are respectively inserted into the hollow input shaft (1) and the second planetary carrier (11-2). The outer circumferential surface of the sun gear oil injection pipe (10) has a fourth lubricating oil outlet (10-1), which is connected to the first lubricating oil outlet (1-2).

2. The lubrication circuit structure for a planetary gear transmission device according to claim 1, characterized in that: The sun gear fuel injector (10) is made of brass alloy.

3. The lubrication circuit structure for a planetary gear transmission device according to claim 2, characterized in that: The first planetary carrier (11-1) and the second planetary carrier (11-2) are both made of low-carbon steel.

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