gearbox

Abstract

The present application relates to a gear box comprising: a case; a rotating shaft; a bearing (12) rotatably supporting the rotating shaft in the case; and an end cover (20) fixed to the case, the end cover having a shaft hole (15) allowing the rotating shaft to project out of the case, the end cover (20) further formed with an oil inlet hole (25) for introducing lubricating oil and an oil guide groove (40) on an inner side facing the bearing (12) and communicating with the oil inlet hole (25), and the gear box further comprising a cover plate (50) fixed to the end cover (20) to cover the oil guide groove (40), the cover plate (50) comprising an oil injection hole (55) communicating with the oil guide groove (40) through the cover plate (50) so that the lubricating oil in the oil guide groove (40) is injected toward the bearing (12).

Description

Technical Field

[0001] This application relates to a gearbox, particularly a wind turbine gearbox. Background Technology

[0002] The motor side of the wind turbine gearbox includes a high-speed output shaft, bearings supporting the output shaft, an end cover located axially outside the bearing, and optional bearing bushings located radially outside the bearing. Both the end cover and the bearing bushing are fixed to the gearbox housing. Lubricating oil for the bearings is first introduced into the end cover, and then sprayed onto the bearings through a separate oil pipe located within the gearbox, via a nozzle at the end of the pipe. This bearing lubrication structure using oil pipes occupies a large space within the gearbox, resulting in a large gearbox size, particularly in the axial dimension. Utility Model Content

[0003] The purpose of this application is to improve the bearing lubrication structure of the gearbox in order to reduce the size of the gearbox.

[0004] A gearbox according to this application includes: a housing; a rotating shaft; a bearing rotatably supporting the rotating shaft in the housing; and an end cover fixed to the housing, the end cover having a shaft hole allowing the rotating shaft to pass through and extend out of the housing, the end cover also forming an oil inlet for introducing lubricating oil and forming an oil guide groove communicating with the oil inlet on the inner side facing the bearing, and the gearbox further includes a cover plate fixed to the end cover to cover the oil guide groove, the cover plate including an oil spray hole communicating with the oil guide groove through the cover plate to guide the lubricating oil in the oil guide groove to be sprayed toward the bearing.

[0005] In some embodiments, the opening of the oil injection hole to the oil outlet of the bearing is lower than the opening to the oil inlet of the oil guide groove.

[0006] In some embodiments, the injection port is a single injection port or a plurality of injection ports extending to different locations on the oil guide groove.

[0007] In some embodiments, the oil guide groove is an arcuate groove extending around the shaft hole, the cover plate is an arcuate plate, and the oil injection holes are two oil injection holes extending to opposite ends of the oil guide groove, respectively.

[0008] In some embodiments, the oil guide groove has widened regions at opposite ends, and the two oil injection holes are respectively connected to a corresponding widened region.

[0009] In some embodiments, the central angle corresponding to the oil guide groove is between 60 degrees and 120 degrees.

[0010] In some embodiments, the end cap is positioned such that one end of the oil guide groove is directly above the rotating shaft.

[0011] In some embodiments, the cover plate is connected to the end cap using fasteners, and / or the cover plate is bonded to the end cap around the oil guide groove.

[0012] In some embodiments, the end cap includes on its inner side: an annular portion for axially positioning the outer ring of the bearing, and an annular zone located radially inward of the annular portion, wherein the oil guide groove is disposed on the annular zone, and wherein the annular zone is axially recessed into the end cap relative to the annular portion in a manner further away from the bearing to form a gap between the end cap and the bearing, the cover being accommodated within the gap.

[0013] In some embodiments, the cover plate includes a thinner outer annular portion and a thicker inner annular portion, with the oil injection hole opening onto the bearing on the inner annular portion.

[0014] In some embodiments, the gearbox further includes a first set of fasteners, each extending into the end cap through a through hole provided on the outer annular portion; and a second set of fasteners, each extending into the end cap through a countersunk hole provided on the inner annular portion.

[0015] In some embodiments, the gearbox is a wind turbine gearbox, and the rotating shaft is the output shaft of the wind turbine gearbox.

[0016] According to the gearbox of this application, an oil guide groove is formed on the surface of its end cover facing the bearing. The oil guide groove is covered and sealed by a separately provided cover plate. An oil spray hole passing through the cover plate communicates with the oil guide groove, thereby guiding and spraying high-pressure lubricating oil in the oil guide groove onto the bearing. This bearing lubrication method eliminates the need for a separate oil pipe inside the gearbox. Compared to the space required for installing an oil pipe, providing a recessed oil guide groove on the end cover and sealing the oil guide groove with a cover plate of relatively small thickness (dimension in the axial direction) can save internal space of the gearbox and reduce the axial dimension of the gearbox.

[0017] More preferably, the end cover includes a positioning annular portion for axially positioning the outer ring of the bearing, and an oil-guiding annular zone located radially inward of the positioning annular portion and axially recessed into the end cover relative to the annular portion (thus forming a gap between the end cover and the bearing). An oil-guiding groove is provided on the oil-guiding annular zone, and a cover plate is provided in the gap. The recess size of the oil-guiding annular zone from the positioning annular portion (or the resulting gap) is designed such that the cover plate and the fasteners securing the cover plate to the end cover are accommodated within the gap, and the oil injection hole is close to the bearing raceway. This further reduces the axial dimension of the gearbox.

[0018] By rationally designing the details of the oil guide groove and the position and number of oil injection holes on the cover plate, the lubricating oil in the oil guide groove can be guided to one or more desired injection positions. More advantageously, the oil injection holes are designed to slope downwards through the cover plate, that is, the opening (or oil outlet) of the injection hole into the bearing raceway is lower than the opening (or oil inlet) into the oil guide groove. This allows the lubricating oil to be sprayed onto the bearing raceway at a greater pressure, enhancing lubrication and cooling effects. The bearing lubrication structure of this application is simple, has low component processing difficulty, and low cost, meeting both the axial space requirements of the gearbox and the cost control requirements. Attached Figure Description

[0019] Figure 1 A partially enlarged cross-sectional view of a gearbox according to an embodiment of this application is shown.

[0020] Figure 2 This is a three-dimensional view of the end cap.

[0021] Figure 3 This is a 3D view of the cover plate. Detailed Implementation

[0022] The principle of this application is described in detail below using the output shaft of the high-speed stage (i.e., the one connected to the generator side) of a wind turbine gearbox as an example. However, it should be understood that the principle of this application is not only applicable to wind turbine gearboxes, nor only to the output shaft of the high-speed stage of a wind turbine gearbox, but can be applied to any similar rotating shaft of any gearbox.

[0023] Figure 1 This is the portion of the wind turbine gearbox in a longitudinal sectional view relevant to the improvements described in this application. The figure shows the high-speed stage output shaft 10 of the wind turbine gearbox, which is supported within the housing (not shown) via bearing 12 (e.g., the illustrated tapered roller bearing) and bearing bushing 14. In the description of this application, the direction in which the output shaft 10 extends is referred to as the axial direction.

[0024] As shown in the figure, the bearing 12 axially positions or fixes its inner ring 121 to the output shaft 10 via its outer collar 16 and lock nut 18. The outer ring 123 of the bearing 12 is positioned by the end cover 20. The output shaft 10 extends out of the gearbox housing through the shaft hole 15 at the center of the end cover 20.

[0025] The end cover 20 of the gearbox is fixed to the gearbox housing. The end cover 20 can be directly fixed to the housing or indirectly fixed to the housing in any way (as illustrated in the embodiment). In the illustration, the bearing bushing 14 is directly fixed to the housing housing, and the end cover 20 is fixed to the bearing bushing 14. For example, Figure 1 The image shows fasteners 11 (e.g., bolts) that secure the end cap 20 to the bearing bushing 14. Figure 2This shows the through hole 13 on the end cap 20 for the fastener 11.

[0026] The end cap 20 has an inner side located inside the gearbox or facing the bearing 12, and an outer side on the opposite side. A recessed peripheral region 27 is provided on the outer side of the end cap 20, in which a plurality of circumferentially spaced through holes 13 are arranged, so that the fasteners 11 do not protrude from the peripheral region 27 or from the outermost end face of the end cap 20. Although not shown in the figure, it can be understood that the bearing bushing 14 itself is also connected to the housing by fasteners such as bolts.

[0027] On the inner side of the end cover 20, the end cover 20 has: an outermost annular region 31 (for connection) located radially, which is used to fix and connect to the bearing bushing 14; an innermost annular region 33 (for positioning) located radially, which is used to abut, contact or position the outer ring 123 of the bearing 12 axially; and an innermost annular zone 35 (for oil guiding) located radially, which corresponds axially to the raceway 125 of the bearing 12. Optionally, but not necessarily, the end cover 20 also includes an innermost annular region 37 located radially inside the annular zone 35 to receive and accommodate a portion of the lock nut 18. The annular zone 35 is axially recessed into the end cover from the annular region 33, forming a gap 30 between the end cover 20 and the bearing 12, and the innermost annular region 37 is axially recessed further away from the bearing 12 than the annular zone 35.

[0028] The oil guide groove 40 is formed on the annular zone 35 (for oil guiding) of the end cover 20. The cover plate 50 covering the oil guide groove 40 and the fasteners that fix the cover plate 50 to the end cover 20 are accommodated in the gap 30, which can further reduce the axial dimension of the gearbox.

[0029] like Figure 2 In the circumferential direction surrounding the axial direction, the oil guide groove 40 extends a portion of the annular zone 35. Other portions of the annular zone 35, besides forming the portion of the oil guide groove 40, may form process recesses 39 to reduce part weight; this part will not be described in detail. As an example, the oil guide groove 40 is an arcuate groove corresponding to a central angle of approximately 90 degrees, i.e., extending one-quarter of the circumference. Alternatively, the central angle corresponding to the oil guide groove 40 may be between 60 and 120 degrees. This application does not limit the oil guide groove 40 to be an arcuate groove, nor does it limit the cross-sectional shape and / or size of the oil guide groove 40.

[0030] As shown in the figure, as a non-limiting example, the oil guide groove 40 has substantially consistent parameters or dimensions (e.g., radial width, depth, etc.) along its circumferential length, but has widened end regions 40a and 40b at opposite ends.

[0031] An oil inlet 25 is located near one of the end regions 40a. The oil inlet 25 can penetrate the thickness of the end cap 20, introducing lubricating oil from the outside of the end cap 20 into the gearbox. The oil inlet 25 can extend directly to the oil guide groove 40, guiding lubricating oil directly from the outside of the end cap into the oil guide groove 40. Optionally, the specific design of the oil inlet 25 can be modified according to actual needs, as long as the oil inlet 25 communicates with the oil guide groove 40. The oil inlet 25 does not have to be any shape of hole, but rather refers to any form of channel that allows lubricating oil to flow. The oil inlet 25 does not necessarily have to penetrate the thickness of the end cap 20 from the outside to the inside of the end cap 20. Depending on the oil passage configuration of other parts of the gearbox, the oil inlet 25 can be designed to extend from any other location (e.g., from the radially outer side, such as from the bearing bushing 14) to an annular zone 35 inside the end cap 20, or to the oil guide groove 40.

[0032] Corresponding to the arc-shaped groove of the oil guide groove 40, the cover plate 50 is also an arc-shaped plate. The cover plate 50 is secured by a set of fasteners (e.g., bolts) 51 located radially outward of the oil guide groove 40. Figure 1 The end cap 20 is fastened to the oil guide groove 40 and a set of fasteners (e.g., bolts, not shown in the figure) located radially inside the oil guide groove 40. Figure 2 and 3 The holes for these fasteners (threaded holes 51a / 53a on end cap 20 and smooth holes 51b / 53b on cover plate 50) are shown in the figure. Although not shown, an adhesive seal is also provided between the opposing surfaces of cover plate 50 and end cap 20 to prevent lubricating oil leakage through the surfaces of cover plate 50 and end cap 20. In some embodiments, cover plate 50 may be secured to end cap 20 by adhesive sealing only around oil guide groove 40. Any other structure that can achieve the function of securing cover plate 50 to end cap 20 may be used.

[0033] The cover plate 50 is provided with two oil injection holes 55, which penetrate the thickness of the cover plate 50. When the cover plate 50 is fixed to the end cover 20, the oil injection holes 55 communicate with the oil guide groove 40, and in particular with the two widened end regions 40a and 40b of the oil guide groove 40. This allows the high-pressure lubricating oil introduced into the oil guide groove 40 to be automatically sprayed into the raceway 125 of the bearing 12 through the oil injection holes 55.

[0034] from Figure 1 and Figure 3As can be seen, the cover plate 50 includes a thinner outer arc-shaped portion 52 and a thicker inner arc-shaped portion 54. Holes 51b for the first set of fasteners 51 are formed on the outer arc-shaped portion 52, and holes 53b for the second set of fasteners are formed on the inner arc-shaped portion 54. To minimize the axial dimension of the gearbox, the holes 53b for the second set of fasteners are countersunk holes. On the side of the inner arc-shaped portion 54 facing the support, each hole 53b has a countersunk recess 57b, as shown... Figure 3 As shown.

[0035] This application employs a bearing lubrication structure with an oil guide groove 40 and a cover plate 50, which significantly saves internal space in the gearbox and reduces its size compared to arranging oil pipes inside the gearbox. More preferably, the annular region 35 of the oil guide groove 40 is recessed into the end cover 20, allowing the cover plate 50 and the fasteners securing the end cover 20 to be accommodated within the formed gap 30. The gap 30 is sized to allow the oil injection hole 55 to approach the bearing raceway 125 at a small, appropriate distance, ensuring optimal lubrication and cooling when the lubricating oil is sprayed onto the bearing raceway 125.

[0036] Although the illustration shows two injection holes 55, this application does not limit the number of injection holes 55 (e.g., one or more than two), or the position of the injection holes 55 along the circumferential direction.

[0037] Preferably, such as Figure 1 As shown, the oil injection hole 55 has an orifice (or inlet) 55a leading to the oil guide groove 40 and an orifice (or outlet) 55b leading to the bearing raceway 125. The orifice 55b is lower than the orifice 55a, meaning that the oil injection hole 55 extends downwards through the cover plate 50. This allows lubricating oil to be sprayed onto the bearing raceway 125 at a higher or higher pressure, which is beneficial for improving lubrication and cooling effects.

[0038] During use, the gearbox is in such a state as Figure 1 As shown in the horizontal orientation, the output shaft 10 is horizontal. The oil guide groove 40 is located above the central axis of the output shaft 10. As an example, the opposite ends of the oil guide groove 40 are located substantially directly above the output shaft 10 (i.e., at the 12 o'clock position) and horizontally (i.e., at the 3 o'clock or 9 o'clock position), respectively, but this is not the case. Figure 2 The image shows the oil return hole 41 on the end cap 20.

[0039] The principles of this application have been described in detail above with reference to the accompanying drawings. Those skilled in the art should understand that this application is not limited to the details shown in the figures and described above. Without departing from the essence of this application, those skilled in the art can make any modifications, and all such modified technical solutions are within the protection scope of this application.

Claims

1. A gearbox, comprising: Box; Rotation axis; The rotating shaft is rotatably supported in the housing by a bearing (12); and an end cap (20) is fixed to the housing, the end cap having a shaft hole (15) that allows the rotating shaft to pass through and extend out of the housing, characterized in that... The end cap (20) also has an oil inlet (25) for introducing lubricating oil and an oil guide groove (40) communicating with the oil inlet (25) is formed on the inner side facing the bearing (12). The gearbox also includes a cover plate (50) fixed to the end cap (20) to cover the oil guide groove (40), the cover plate (50) including an oil injection hole (55) that passes through the cover plate (50) and communicates with the oil guide groove (40) to guide the lubricating oil in the oil guide groove (40) to be sprayed toward the bearing (12).

2. The gearbox according to claim 1, characterized in that, The opening of the oil injection hole (55) to the oil outlet (55b) of the bearing (12) is lower than the opening to the oil inlet (55a) of the oil guide groove (40).

3. The gearbox according to claim 1, characterized in that, The oil injection hole (55) is a single oil injection hole or multiple oil injection holes that extend to different positions of the oil guide groove (40).

4. The gearbox according to claim 1, characterized in that, The oil guide groove (40) is an arc-shaped groove extending around the shaft hole, the cover plate (50) is an arc-shaped plate, and the oil injection hole (55) is two oil injection holes extending to opposite ends of the oil guide groove (40).

5. The gearbox according to claim 4, characterized in that, The oil guide groove (40) has widened areas at opposite ends, and the two oil injection holes are respectively connected to a corresponding widened area.

6. The gearbox according to claim 4, characterized in that, The central angle corresponding to the oil guide groove (40) is between 60 degrees and 120 degrees.

7. The gearbox according to claim 4, characterized in that, The end cap (20) is positioned such that one end of the oil guide groove (40) is directly above the rotating shaft.

8. The gearbox according to claim 1, characterized in that, The cover plate (50) is connected to the end cap (20) by fasteners, and / or the cover plate (50) is bonded to the end cap (20) around the oil guide groove (40).

9. The gearbox according to any one of claims 1-8, characterized in that, The end cap (20) includes on its inner side an annular portion (33) for axially positioning the bearing outer ring (123) of the bearing (12), and an annular zone (35) located radially inside the annular portion. The oil guide groove (40) is disposed on the annular zone (35), and The annular zone (35) is axially recessed into the end cap (20) relative to the annular portion (33) in a manner further away from the bearing (12) to form a gap (30) between the end cap (20) and the bearing (12), and the cover plate (50) is accommodated in the gap.

10. The gearbox according to claim 9, characterized in that, The cover plate (50) includes a thinner outer annular portion (52) and a thicker inner annular portion (54), and the oil injection hole (55) is opened to the bearing (12) on the inner annular portion (54).

11. The gearbox according to claim 10, characterized in that... Also includes: The first set of fasteners (51) each extends through a through hole provided on the outer annular portion (52) into the end cap (20); The second set of fasteners, each extending through a countersunk hole provided on the inner annular portion (54) into the end cap (20).

12. The gearbox according to any one of claims 1-8, characterized in that, The gearbox is a wind turbine gearbox, and the rotating shaft is the output shaft (10) of the wind turbine gearbox.

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