Gearbox sealing structure

Abstract

The invention relates to a gearbox sealing structure, and belongs to the technical field of vehicle transmission. Comprising a gearbox body for supporting an axle through a bearing in a bearing seat, a collector ring box fixedly connected to the outer side of the bearing seat, and a sealing end cover, the axle is sleeved with a collector ring located in the collector ring box. A sealing ring tightly sleeved on the axle is arranged between the collector ring and the inner ring of the bearing; the collecting ring box is fixedly installed on the sealing end cover and located on the motor side of the box body, a gap is formed between the sealing end cover and the collecting ring box, and a gap cavity is reserved between the sealing end cover and the collecting ring box; the outer circle surface of the sealing ring forms a sealing gap with the bearing seat and the sealing end cover respectively; the bearing seat is provided with an oil return channel communicated with an oil return hole of the box body, and the oil return channel is communicated with the bearing seat, the sealing ring and the sealing end cover. According to the invention, carbon powder in the collector ring box can be effectively prevented from being entrained by airflow and entering the gearbox to pollute lubricating oil, so that long-term normal operation of a vehicle is facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of gear box sealing, and in particular to a gear box sealing structure. Background Art

[0002] The existing subway gearbox structure independently developed by the applicant is as follows: Figure 1 As shown, the box body composed of the upper box body and the lower box body 1 supports the axle 4 through the bearing installed in the bearing seat 2 fixedly connected thereto. In order to ensure reliable grounding of the axle, a collector ring box 5 is fixedly installed on the outer side of the bearing seat 2, and a grounding device is installed on the collector ring box 5. The axle 4 is fixedly connected to the collector ring 6 located in the collector ring box. The carbon brush of the grounding device maintains long-term contact with the collector ring for conductive grounding, which will continuously rub and generate carbon powder and be discharged through the powder discharge duct 6.0 below the collector ring box.

[0003] The gearbox adopts a small gap labyrinth seal structure. The sealing ring 7, the collector ring 6 and the bearing inner ring 2.1 are interference-fitted on the axle as rotating parts, and the collector ring box 5, the bearing inner ring 2.2 and the bearing seat 2 are assembled on the box body as stationary parts. Through the relative movement of the stationary parts and the rotating parts, the slit throttling effect of the small sealed gap and its friction effect and the dissipation effect of the sealed cavity are utilized to prevent the gearbox lubricating oil from leaking and the carbon powder of the grounding device from entering the gearbox.

[0004] During the operation of the vehicle, as the temperature of the gearbox rises, the internal pressure gradually increases, and the gearbox adjusts the balance of internal and external pressures through dynamic seals and breathers, which is referred to as zero-pressure working conditions. When the vehicle enters a tunnel, the airflow under the vehicle is affected by the closed space of the tunnel, and the pressure rises sharply, while the internal pressure of the gearbox cannot be immediately balanced with the external pressure, resulting in the external pressure being greater than the internal pressure, and the external airflow is squeezed into the gearbox, which is referred to as negative pressure working conditions.

[0005] The collector ring box of the gearbox in the prior art is part of the sealing structure. Under zero-pressure conditions, the internal fluid of the seal mainly enters the external environment through the carbon exhaust duct of the lower cover of the collector ring box, inhibiting the inhalation of carbon powder at the sealing end; but under negative pressure conditions, the carbon powder that has not been discharged from the inner cavity of the collector ring box will be carried by the airflow and enter the gearbox through the small gap C of the labyrinth seal and the oil return hole, causing the lubricating oil to turn black, causing great trouble to the normal operation and maintenance of the train. Figure 2 Therefore, a gearbox sealing structure with a collector ring box is needed to solve the problem that when the existing gearbox sealing structure with a collector ring box is under negative pressure, the carbon powder in the collector ring box will enter the gearbox and contaminate the lubricating oil, thereby affecting the operation of the vehicle. Summary of the invention

[0006] The object of the present invention is to provide a gear box sealing structure to solve the problems raised in the above background technology.

[0007] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a gearbox sealing structure, comprising a gearbox housing supporting an axle through a bearing in a bearing seat, a collector ring box and a sealing end cover fixedly connected to the outside of the bearing seat; the axle sleeve is provided with a collector ring located in the collector ring box; a sealing ring tightly fitted on the axle is installed between the collector ring and the inner ring of the bearing; the collector ring box is fixedly installed on the sealing end cover, located on the motor side of the housing, and a gap is set between the sealing end cover and the collector ring box, leaving a gap cavity between them; the outer cylindrical surface of the sealing ring forms a sealing gap with the bearing seat and the sealing end cover respectively; the bearing seat has an oil return channel connected to the oil return hole of the housing, and the oil return channel is connected to the matching gap between the bearing seat, the sealing ring and the sealing end cover.

[0008] Preferably, the sealing end cover is fixedly installed on the motor side of the box body, and a plurality of bosses are provided at intervals along the cover body of the sealing end cover. When the collector ring box is fixedly installed on the sealing end cover, the end face of the collector ring box facing the sealing end cover abuts against the bosses, forming a gap cavity therebetween.

[0009] Preferably, the inner hole of the collector ring box includes end sections whose shapes match the two ends of the collector ring and a middle section connecting the two end sections. The middle section and the collector ring form a powder collecting cavity, and the powder collecting cavity is connected to a powder discharge duct.

[0010] Preferably, the end section of the collector ring box facing the gap cavity side is provided with a step-shaped bending portion, and the end of the collector ring corresponding to the bending portion is provided with a bending end bent toward the bending portion, and an axial labyrinth powder discharge channel is formed between the bending portion and the bending end; the powder discharge channel is connected to the powder collecting cavity.

[0011] Preferably, the outer ring of the bearing is installed on the motor side of the output end of the box through the inner step of the bearing seat, and the axle is further supported by the inner ring of the bearing; two spaced reducing rings extend axially outward from the middle part of the outer step of the bearing seat, and two expanding rings extend axially outward from the middle section of the sealing ring to form sealing gaps corresponding to the two reducing rings of the bearing seat.

[0012] Preferably, two reducing rings and two expanding rings form a sealing gap section connected to the oil return channel of the bearing seat, forming an oil return pressure relief chamber; the sealing gap section between the reducing ring of the bearing seat and the expanding ring of the sealing ring and the bearing forms an oil storage chamber.

[0013] Preferably, the box body is composed of an upper box body and a lower box body which are coupled and fixedly connected.

[0014] Preferably, the side surface of the sealing end cover facing the bearing seat is provided with a plurality of first protrusions facing the bearing seat at radial intervals, and the sealing ring is provided with second protrusions with a shape matching the first protrusions at positions corresponding to the plurality of first protrusions. A labyrinth structure is formed between the plurality of first protrusions and the second protrusions to constitute a radial labyrinth sealing section of the sealing gap, and the radial labyrinth sealing section is connected to the oil return channel of the bearing seat.

[0015] Preferably, a groove is provided in the radial direction on the inner hole surface of the sealing end cover to form a debris cavity between the sealing ring and the debris cavity, which is connected with the radial labyrinth sealing section along the sealing ring, and the sealing end cover where the debris cavity is located is provided with a connecting debris discharge hole toward the gap cavity.

[0016] Preferably, the gearbox sealing structure further comprises a box body wheel side sealing assembly, comprising a first bearing seat, a first sealing ring and a first sealing end cover; the first bearing seat is mounted on the box body, supports the axle through the bearing in the first bearing seat, and is fixedly connected to the first sealing end cover on the outer side of the first bearing seat, and a first sealing ring tightly sleeved on the axle is arranged between the first bearing seat and the first sealing end cover; the outer circumferential surface of the first sealing ring forms a first sealing gap with the first bearing seat and the first sealing end cover respectively; the first bearing seat has a first oil return channel connected to the oil return hole of the box body, and the first oil return channel is connected to the matching gap between the first bearing seat, the first sealing ring and the first sealing end cover; the first sealing gap has the same structure as the sealing gap, and the first oil return channel has the same structure as the oil return channel; A first groove is radially provided on the inner hole surface of the first sealing end cover to form a first impurity cavity between the first sealing ring and the first impurity cavity. The first impurity cavity is connected with the first sealing gap along the first sealing ring, and the first sealing end cover where the first impurity cavity is located is provided with a first row of impurity holes connected toward the outside of the first sealing end cover. Beneficial Effects

[0017] The gearbox of the present invention is achieved by fixing the collector ring box on the outer end side of the box body away from the bearing seat, and a sealing end cover is installed between the box body and the collector ring box, and a gap is set between the sealing end cover and the collector ring box, leaving a gap cavity between them. The output end motor side of the gearbox of the present invention is provided with a grounding device, and the grounding device is installed on the collector ring box. In order to realize the gearbox of the present invention, an external collector ring box is used, which does not participate in the gearbox sealing. Since the collector ring box and the gearbox sealing structure are completely open, the gap cavity between the two is directly connected to the outside world, so that the carbon powder will be directly discharged without being affected by the working condition, and cannot enter the box body, thereby fundamentally solving the problem of carbon powder entering the gearbox.

[0018] On the basis of the above, the sealing structure formed by the sealing gap and the oil return channel on the output motor side of the gearbox of the present invention is the same as the sealing structure formed by the first sealing gap and the first oil return channel on the output wheel side. The sealing end cover on the motor side forms a radial labyrinth seal section between the side of the bearing seat and the sealing ring. This is the same as the role of the existing gearbox with a small gap labyrinth seal structure in the prior art. The slit throttling effect of the small gap and its friction effect and the dissipation effect of the sealing cavity are used to prevent the gearbox lubricating oil from leaking and the carbon powder of the grounding device from entering the gearbox. This sealing structure has been used in large quantities, and its structure is mature and its application experience is reliable. On this basis, the present invention extends two spaced reducing rings axially outward from the middle of the outer step of the bearing seat, and the middle section of the sealing ring extends two expanding rings axially outward to form sealing gaps corresponding to the two reducing rings of the bearing seat, so as to form a return oil pressure relief chamber and an oil storage chamber, so as to further increase the dissipation effect of the sealing cavity, and effectively prevent external impurities from entering the lubricating oil channel. Similarly, the output end wheel side of the gearbox of the present invention also adopts the same first sealing gap and first oil return channel structure to prevent the lubricating oil of the wheel side box from leaking and external impurities from entering the gearbox.

[0019] On the basis of the above, the sealing end cover on the motor side of the gearbox of the present invention is provided with a debris cavity on the side of the gap cavity facing the collector ring box, which can contain impurities such as water or air dust and re-discharge them through the debris discharge hole, effectively preventing the radial labyrinth seal gap section along the sealing ring from entering the gearbox. Similarly, the first sealing end cover on the wheel side of the present invention is also provided with a first debris cavity, which plays the same role as the sealing end cover on the motor side, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the sealing structure of the gear box in the prior art; Figure 2 for Figure 1 The enlarged schematic diagram of point B in the middle; Figure 3 A schematic structural diagram of a gearbox sealing structure of an embodiment; Figure 4 Schematic diagram of the structure of the gear box of the embodiment. DETAILED DESCRIPTION

[0021] The technical solution of the present invention is described in detail below with reference to the accompanying drawings, but the protection scope of the present invention is not limited to the embodiments.

[0022] See also Figure 3-Figure 4, this embodiment provides a gearbox sealing structure, including a gearbox housing 1 supporting an axle 4 through a bearing 3 in a bearing seat 2, a collector ring box 5 fixedly connected to the outside of the bearing seat 2, and a sealing end cover 11; the axle 4 is sleeved with a collector ring 6 located in the collector ring box; the output motor side of the gearbox of this embodiment is provided with a grounding device 9, which is installed in the collector ring box, and the carbon brush of the grounding device contacts the collector ring to ensure reliable grounding of the axle. A sealing ring 7 tightly sleeved on the axle is installed between the collector ring 6 and the inner ring 3-1 of the bearing 3, and the housing 1 is composed of upper and lower housings 1-1, 1-2 that are matched and fixedly connected. The housing 1 supports the axle 4 through the bearing 3 installed in the bearing seat 2 fixedly connected thereto. The specific structure is that the output motor side of the housing is installed with the outer ring 3-2 of the bearing through the inner step 2-1 of the bearing seat 2, and then supports the axle through the inner ring 3-1 of the bearing. The collector ring box 5 is fixedly installed on the sealing end cover 11, which is located on the motor side of the box body, and there is a gap between the sealing end cover and the collector ring box, leaving a gap cavity A between them; specifically, the sealing end cover 11 of this embodiment is fixedly installed on the motor side of the box body, and a plurality of bosses 10 are provided at intervals along the cover body of the sealing end cover. When the collector ring box is fixedly installed on the sealing end cover, the end face of the collector ring box facing the sealing end cover abuts against the boss 10, forming a gap cavity A between them.

[0023] The outer circumferential surface of the sealing ring 7 of this embodiment forms a sealing gap with the bearing seat 2 and the sealing end cover 11 respectively; the bearing seat has an oil return channel connected to the oil return hole 1-3 of the housing, and the oil return channel is connected to the matching gap between the bearing seat 2, the sealing ring 7, and the sealing end cover 11. Specifically, two spaced reducing rings 2-2.1 and 2-2.2 are extended axially outward from the middle of the outer step 2-2 of the bearing seat, wherein in order to facilitate the processing of the outer shrinking ring 2-2.2 of the bearing seat, the outer side of the bearing seat is processed inwardly into a groove, and a sealing retaining ring 12 is provided, and an oil return through hole connected to the oil return channel is opened on the sealing retaining ring to form a reducing ring 2-2.2. The middle section of the sealing ring 7 extends axially outward to form two expanding rings 7-2.1 and 7-2.2 that correspond to the two reducing rings 2-2.1 and 2-2.2 of the bearing seat 2 to form a sealing gap; the two reducing rings 2-2.1 and 2-2.2 and the two expanding rings 7-2.1 and 7-2.2 form a sealing gap section that is connected to the oil return channel 2-3 of the bearing seat 2, forming an oil return pressure relief chamber 8. The sealing gap section between the reducing ring 2-2.1 of the bearing seat 2 and the expanding ring 7-2.1 of the sealing ring 7 and the bearing 2 forms an oil storage chamber 8'.

[0024] The inner hole of the collector ring box 5 of this embodiment includes end sections 5.1 and 5.2 whose shapes match the two ends of the collector ring and a middle section 5.3 connecting the two end sections. The middle section 5.3 and the collector ring 6 form a powder collecting cavity, and the powder collecting cavity is connected to a powder discharge duct 5.4. At the same time, the end section of the collector ring box facing the gap cavity side is provided with a step-shaped bending portion 5.5, and the end of the collector ring corresponding to the bending portion is provided with a bending end 5.6 bent toward the bending portion, and an axial labyrinth powder discharge channel X is formed between the bending portion 5.5 and the bending end 5.6; the powder discharge channel is connected to the powder collecting cavity. The axial labyrinth powder discharge channel X of this embodiment and the powder discharge duct 5.4 form a self-airflow reflux effect to maintain the pressure balance inside and outside the collector ring box, guide the undischarged carbon powder in the collector ring box to be discharged from the powder discharge channel, and improve the powder discharge effect.

[0025] In this embodiment, the sealing end cover 11 is provided with a plurality of first protrusions facing the bearing seat 2 at intervals along the radial direction on the side of the sealing end cover 11 facing the bearing seat 2, and the sealing ring is provided with a second protrusion whose shape matches the first protrusion at the position corresponding to the plurality of first protrusions, and a labyrinth structure is formed between the plurality of first protrusions and the second protrusions to form a radial labyrinth seal section Y of the sealing gap, and the radial labyrinth seal section Y is connected with the oil return channel 2-3 of the bearing seat. In addition, a groove is provided along the radial direction on the inner hole surface of the sealing end cover, and a miscellaneous cavity Z is formed between the sealing ring, and the miscellaneous cavity Z is connected with the radial labyrinth seal section Y along the sealing ring, and a miscellaneous cavity Z is provided in the miscellaneous cavity toward the gap cavity, and a miscellaneous cavity Z1 is provided toward the gap cavity along the outer end side of the box body toward the gap cavity. In this embodiment, the miscellaneous cavity is provided in the sealing end cover, and the miscellaneous cavity is provided with a miscellaneous cavity to achieve pressure balance adjustment at the inlet side of the radial labyrinth seal section Y, thereby avoiding the external impurities being carried into the gearbox by the airflow when negative pressure is generated at the inlet side of the radial labyrinth seal section.

[0026] In addition, the gearbox sealing structure of the present embodiment further comprises a box body wheel side sealing assembly (not shown), comprising a first bearing seat, a first sealing ring and a first sealing end cover; the first bearing seat is mounted on the box body, supports the axle through the bearing in the first bearing seat, and is fixedly connected to the first sealing end cover on the outer side of the first bearing seat, and a first sealing ring tightly sleeved on the axle is arranged between the first bearing seat and the first sealing end cover; the outer circumferential surface of the first sealing ring forms a first sealing gap with the first bearing seat and the first sealing end cover respectively; the first bearing seat has a first oil return channel connected to the oil return hole of the box body, and the first oil return channel is connected to the matching gap between the first bearing seat, the first sealing ring and the first sealing end cover; the first sealing gap has the same structure as the sealing gap, and the first oil return channel has the same structure as the oil return channel; A first groove is radially provided on the inner hole surface of the first sealing end cover to form a first impurity cavity between the first sealing ring and the first impurity cavity. The first impurity cavity is connected with the first sealing gap along the first sealing ring, and the first sealing end cover where the first impurity cavity is located is provided with a first row of impurity holes connected toward the outside of the first sealing end cover.

[0027] Working principle: The gearbox sealing structure provided in this embodiment is provided with a sealing end cover on the outer motor side of the gearbox housing away from the bearing seat, and a boss is provided between the sealing end cover and the collector ring box to form a gap cavity, so that the collector ring box is externally mounted on the housing and does not participate in the sealing of the gearbox, and a sealing ring with the same structure as the wheel side is used as the seal between the housing bearing seat and the collector ring. A mature and reliable sealing structure is used to ensure the stable operation of the gearbox. The collector ring box and the gearbox sealing structure of this embodiment are completely separated, and the gap cavity between the two is directly connected to the outside world. The carbon powder in the collector ring box is not affected by changes in the working condition and can be directly discharged to the outside world and cannot enter the housing, thereby fundamentally solving the problem of carbon powder entering the housing and polluting the lubrication system.

[0028] As above, although the present invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the present invention itself. Various changes may be made to it in form and detail without departing from the spirit and scope of the present invention defined in the appended claims.

Claims

1. A gearbox sealing structure, comprising a gearbox housing supporting an axle through a bearing in a bearing seat, a collector ring box fixedly connected to the outer side of the bearing seat, and a sealing end cover; the axle sleeve is provided with a collector ring located in the collector ring box; a sealing ring tightly sleeved on the axle is installed between the collector ring and the inner ring of the bearing; characterized in that: The collector ring box is fixedly installed on the sealing end cover, which is located on the motor side of the box body, and there is a gap between the sealing end cover and the collector ring box, leaving a gap cavity between them; the outer cylindrical surface of the sealing ring forms a sealing gap with the bearing seat and the sealing end cover respectively; the bearing seat has an oil return channel connected to the oil return hole of the box body, and the oil return channel is connected to the matching gap between the bearing seat, the sealing ring and the sealing end cover.

2. A gearbox sealing structure according to claim 1, characterized in that: The sealing end cover is fixedly installed on the motor side of the box body, and a plurality of bosses are arranged at intervals along the cover body of the sealing end cover. When the collector ring box is fixedly installed on the sealing end cover, the end surface of the collector ring box facing the sealing end cover abuts against the bosses, forming a gap cavity therebetween.

3. A gearbox sealing structure according to claim 1, characterized in that: The inner hole of the collector ring box includes end sections whose shapes match the two ends of the collector ring and a middle section connecting the two end sections. The middle section and the collector ring form a powder collecting cavity, and the powder collecting cavity is connected to a powder discharge duct.

4. A gearbox sealing structure according to claim 3, characterized in that: The end section of the collector ring box facing the gap cavity is provided with a step-shaped bending portion, and the end of the collector ring corresponding to the bending portion is provided with a bending end bent toward the bending portion, and an axial labyrinth powder discharge channel is formed between the bending portion and the bending end; the powder discharge channel is connected to the powder collecting cavity.

5. A gearbox sealing structure according to claim 2, characterized in that: The output end motor side of the box body installs the outer ring of the bearing through the inner step of the bearing seat, and then supports the axle through the inner ring of the bearing; two spaced reducing rings are extended axially outward from the middle part of the outer step of the bearing seat, and two expanding rings are extended axially outward from the middle section of the sealing ring to form sealing gaps corresponding to the two reducing rings of the bearing seat.

6. A gearbox sealing structure according to claim 5, characterized in that: The two reducing rings and the two expanding rings form a sealing gap section connected to the oil return channel of the bearing seat, forming an oil return pressure relief chamber; the sealing gap section between the reducing ring of the bearing seat and the expanding ring of the sealing ring and the bearing forms an oil storage chamber.

7. A gearbox sealing structure according to claim 1, characterized in that: The box body is composed of an upper box body and a lower box body which are coupled and fixedly connected.

8. The gearbox sealing structure according to claim 1, characterized in that: The side surface of the sealing end cover facing the bearing seat is radially spaced apart with a plurality of first protrusions facing the bearing seat, and the sealing ring is provided with second protrusions whose shapes match the first protrusions at positions corresponding to the plurality of first protrusions. A labyrinth structure is formed between the plurality of first protrusions and the second protrusions to constitute a radial labyrinth sealing section of the sealing gap, and the radial labyrinth sealing section is connected to the oil return channel of the bearing seat.

9. A gearbox sealing structure according to claim 8, characterized in that: The inner hole surface of the sealing end cover is provided with a groove along the radial direction to form a debris cavity between the sealing ring and the sealing ring. The debris cavity is connected with the radial labyrinth sealing section along the sealing ring, and the sealing end cover where the debris cavity is located is provided with a communicating debris discharge hole toward the gap cavity.

10. A gearbox sealing structure according to claim 1, characterized in that: The gearbox sealing structure also includes a box wheel side sealing assembly, including a first bearing seat, a first sealing ring and a first sealing end cover; the first bearing seat is installed on the box body, supports the axle through the bearing in the first bearing seat, and is fixedly connected to the first sealing end cover on the outer side of the first bearing seat, and a first sealing ring tightly sleeved on the axle is installed between the first bearing seat and the first sealing end cover; the outer cylindrical surface of the first sealing ring forms a first sealing gap with the first bearing seat and the first sealing end cover respectively; the first bearing seat has a first oil return channel connected to the oil return hole of the box body, and the first oil return channel is connected to the matching gap between the first bearing seat, the first sealing ring and the first sealing end cover; the first sealing gap has the same structure as the sealing gap, and the first oil return channel has the same structure as the oil return channel; A first groove is radially provided on the inner hole surface of the first sealing end cover to form a first impurity cavity between the first sealing ring and the first impurity cavity. The first impurity cavity is connected with the first sealing gap along the first sealing ring, and the first sealing end cover where the first impurity cavity is located is provided with a first row of interconnected impurity holes toward the outside of the first sealing end cover.

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