Double-shaft-seal structure and sealing device

Abstract

The utility model discloses a double shaft seal structure and a sealing device, the double shaft seal structure comprises a first shaft seal and a second shaft seal which are sleeved on a driving shaft, the first shaft seal is located in a shaft seal cover plate, and the second shaft seal is tightly attached to the inner side end face of the shaft seal cover plate; a guide groove is formed in the end face of the inner side of the shaft seal cover plate, a chamfer is arranged on the edge of a boss, making contact with the shell, of the shaft seal cover plate, a cavity between the first shaft seal and the second shaft seal is communicated with a chamfer area through the guide groove, and the chamfer area is communicated with an exhaust channel in the shell. Two-way sealing can be achieved by arranging the two shaft seals, it is guaranteed that hydraulic oil in the pump / motor cannot leak into the working device connected in series, oil in the working device can be prevented from jumping into the pump / motor, and therefore the pump / motor and the working device can operate normally, and meanwhile it is guaranteed that air pressure between the two shaft seals is kept balanced.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of shaft seal structure, concretely relates to a double shaft seal structure and sealing device. BACKGROUND

[0002] The statements herein merely provide background information related to the utility model and do not necessarily constitute the prior art.

[0003] During the operation of the plunger pump / motor, there is a pressure of 1-3 bar in the shell, and an axle seal is usually installed at the input / output end of the driving shaft to prevent the hydraulic oil in the shell from leaking out. The axle seal is usually designed to have only one-way sealing performance, and the axle seal is installed in the axle seal cover plate to only prevent the oil from leaking out. However, in engineering practice, the plunger pump / motor needs to be connected in series with other working devices, and the oil in the two cannot be mixed. The existing structure using the axle seal for sealing only has one-way sealing effect, and can only prevent the oil in the plunger pump / motor shell from leaking out, but cannot prevent the oil in the other working devices connected in series with the plunger pump / motor from entering the shell, which leads to the mixing of the oil, and seriously affects the service life of the pump and motor. SUMMARY

[0004] The utility model aims at providing a double shaft seal structure and sealing device, which can ensure that the oil in the pump / motor and the oil in the connected working device are not mixed, and at the same time, the air pressure between the two axle seals is kept balanced.

[0005] In order to achieve the above-mentioned purpose, the utility model is implemented by the following technical scheme:

[0006] In the first aspect, the embodiments of the utility model provide a double shaft seal structure, which comprises a first axle seal and a second axle seal sleeved on a driving shaft, the first axle seal is located in an axle seal cover plate, and the second axle seal is tightly attached to the inner side end face of the axle seal cover plate. A guide groove is arranged on the inner side end face of the axle seal cover plate, and the boss edge of the axle seal cover plate in contact with the shell is provided with a chamfer, the cavity between the first axle seal and the second axle seal is communicated with the chamfer area through the guide groove, and the chamfer area is communicated with the exhaust passage on the shell.

[0007] As a further technical scheme, the exhaust passage comprises a first exhaust passage and a second exhaust passage, wherein the opening of the first exhaust passage is directed to the gap position between the shell and the axle seal cover plate, and the opening of the second exhaust passage is directed to the chamfer area on the axle seal cover plate.

[0008] As a further technical scheme, the first exhaust passage is connected to the second exhaust passage and communicated with the second exhaust passage, and the first exhaust passage and the second exhaust passage are in Y shape.

[0009] As a further technical scheme, the outlet of the second exhaust passage is provided with a screw plug.

[0010] As a further technical scheme, the first exhaust passage and the second exhaust passage are both arranged obliquely, and the first exhaust passage and the second exhaust passage are located at the lower part in the shell.

[0011] As a further technical scheme, the guide groove is provided with two guide grooves which are arranged symmetrically at the center.

[0012] As a further technical scheme, the guide groove is in an arc shape.

[0013] As a further technical scheme, the shaft seal cover plate is provided with a plurality of first threaded holes and a plurality of second threaded holes, bolts are mounted in the first threaded holes, the shaft seal cover plate is fixed on the shell through the bolts, and the shaft seal cover plate is pried out of the shell through the second threaded holes.

[0014] As a further technical scheme, an O-shaped sealing ring is arranged between the end faces of the shaft seal cover plate and the shell which are in contact.

[0015] In a second aspect, the utility model provides a sealing device which comprises the double shaft seal structure of the first aspect.

[0016] The utility model has the advantages of the following embodiments:

[0017] The first shaft seal prevents the leakage of external hydraulic oil, gear oil and the like into the shell, the second shaft seal prevents the axial movement of the shaft seal cover plate and the leakage of oil in the pump / motor to the outside of the shell, the first shaft seal and the second shaft seal ensure that the oil in the pump / motor and the related serial working devices is not mixed, and thus the respective operation in the suitable working environment is ensured.

[0018] Considering that there is a cavity between the first shaft seal and the second shaft seal, the utility model is provided with an exhaust passage on the shell and a guide groove and a chamfer on the shaft seal cover plate, so that the cavity between the two shaft seals is communicated through the guide groove and the chamfer, when the temperature of the working environment changes and causes the change of the air pressure between the two shaft seals, the gas can be discharged or the hydraulic oil can be absorbed through the exhaust passage, so that the air pressure between the shaft seals is balanced, the expansion or compression of the gas between the shaft seals is prevented, and thus the service life of the shaft seal is affected.

[0019] The screw plug arranged below the second exhaust passage can prevent the dust in the external environment from entering the cavity between the shaft seals, prevent the dust from scratching the shaft seal or the driving shaft, and affect the service life of the machine. BRIEF DESCRIPTION OF DRAWINGS

[0020] The drawings constituting a part of the present application serve to provide further understanding of the present application, and the illustrative embodiments of the present application and their descriptions serve to explain the present application, and do not constitute improper limitation on the present application.

[0021] Figure 1 is a schematic view of the double shaft seal structure of the present application;

[0022] Figure 2 is a structural schematic view of the chamfer and guide groove on the shaft seal cover plate of the present application;

[0023] Figure 3 is a partial enlarged view of the exhaust passage position on the housing of the present application;

[0024] Figure 4 is a schematic view of the shaft seal cover plate of the present application installed on the housing.

[0025] The schematic view is only for illustration of use;

[0026] Wherein, 1, shaft seal cover plate; 2, O-shaped sealing ring; 3, housing; 4, bearing; 5, driving shaft; 6, first shaft seal; 7, second shaft seal; 8, first exhaust passage; 9, second exhaust passage; 10, screw plug; 11, guide groove; 12, chamfer; 13, first threaded hole; 14, second threaded hole; 15, bolt. DETAILED DESCRIPTION

[0027] It should be noted that the following detailed description is exemplary, and is intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used in the present application have the same meaning as that generally understood by those skilled in the art to which the present application belongs.

[0028] Related term explanation:

[0029] Plunger pump: axial plunger hydraulic pump, used to provide high-pressure liquid to the hydraulic motor of the engineering machinery.

[0030] Plunger motor: a device for converting the hydraulic energy of high-pressure hydraulic oil into mechanical energy.

[0031] Shaft seal: a component for sealing the rotating shaft and the fixed housing, preventing liquid from leaking out of the gap on the shaft, and preventing external impurities from entering the bearing or hydraulic oil, to ensure the normal operation of the mechanical equipment.

[0032] Example 1

[0033] In a typical embodiment of the present application, as Figures 1 to 4As shown, a double shaft seal structure is provided, comprising a first shaft seal 6 and a second shaft seal 7 sleeved on the driving shaft 5, the first shaft seal 6 is located in the shaft seal cover plate 1, and the second shaft seal 7 is close to the inner side end surface of the shaft seal cover plate 1; a guide groove 11 is arranged on the inner side end surface of the shaft seal cover plate 1, and the boss edge of the shaft seal cover plate 1 in contact with the shell 3 is provided with a chamfer 12, the cavity between the first shaft seal 6 and the second shaft seal 7 is communicated with the chamfer area through the guide groove 11, and the chamfer area is communicated with the exhaust passage on the shell 3.

[0034] The double seal structure can realize bidirectional sealing, can prevent the hydraulic oil in the pump / motor from leaking to the connected working device, and can prevent the oil in the working device from entering the pump / motor, so that the pump / motor and the working device can normally operate. Specifically, the first shaft seal 6 can prevent external hydraulic oil, gear oil and the like from leaking into the shell, the inner side end surface of the shaft seal cover plate is abutted against the second shaft seal 7 to prevent axial movement of the second shaft seal 7, and the oil in the pump / motor is prevented from leaking to the outside of the shell, the first shaft seal 6 and the second shaft seal 7 can ensure that the oil in the pump / motor and the related connected working device is not mixed, so that each can operate in a suitable working environment.

[0035] As shown in Figure 1 and Figure 3 , the exhaust passage comprises a first exhaust passage 8 and a second exhaust passage 9, wherein the opening of the first exhaust passage 8 is directed to the gap position between the shell 3 and the shaft seal cover plate 1, and the opening of the second exhaust passage 9 is directed to the chamfer area on the shaft seal cover plate 1.

[0036] Further, the first exhaust passage 8 is connected to and communicated with the second exhaust passage 9, the first exhaust passage 8 and the second exhaust passage 9 are in Y shape, and the outlet of the second exhaust passage 9 is provided with a screw plug.

[0037] The cavity between the first shaft seal 6 and the second shaft seal 7 is communicated with the chamfer area through the guide groove 11, and the chamfer area is communicated with the second exhaust passage 9. During the installation of the shaft seal, the two shaft seals extrude the middle cavity, the pressure in the cavity is increased, and the gas can be discharged through the guide groove 11 to the chamfer 12, and then through the second exhaust passage 9 or the first exhaust passage 8. After the installation of the shaft seal and the shaft seal cover plate is completed, the second exhaust passage 9 will be plugged by the screw plug 10 to prevent dust in the external environment from entering the exhaust hole and the cavity between the shaft seals, and to ensure the normal cooperation of the shaft seal and the driving shaft.

[0038] In the embodiment, the first exhaust passage 8 and the second exhaust passage 9 are both inclined, and the first exhaust passage 8 and the second exhaust passage 9 are located in the lower part of the shell 3.

[0039] As shown in Figure 2As shown, the guide groove 11 is provided with two, two guide groove 11 center symmetry, the guide groove 11 is arc-shaped.

[0040] As shown in the figure, Figure 2 and Figure 4 As shown, the shaft cover plate 1 is provided with a plurality of first threaded holes 13 and a plurality of second threaded holes 14, the first threaded hole 13 is installed with a bolt 15, the shaft cover plate 1 is fixed on the shell 3 through the bolt 15, the second threaded hole 14 is screwed into the bolt 15, and the shaft cover plate 1 is ejected from the shell 3.

[0041] In this embodiment, the end surface of the shaft cover plate 1 and the shell 3 is provided with an O-shaped sealing ring 2, which is used to realize the sealing between the shaft cover plate 1 and the shell 3.

[0042] The working principle of the double shaft seal structure provided by the embodiment is:

[0043] When the working environment temperature rises or the machine continues to run, the gas between the two shaft seals expands due to heating, and the gas can pass through the guide groove 11 to the chamfer 12, and then be discharged through the second exhaust passage 9 or the first exhaust passage 8. The gas in the first exhaust passage 8 is discharged through the gap between the shaft cover plate 1 and the shell 3. When the ambient temperature is low or the machine stops running, the gas in the cavity between the two shaft seals, the first exhaust passage 8 and the second exhaust passage 9 is compressed due to cooling, and the oil in the serial working device will seep into the first exhaust passage 8 through the gap between the shaft cover plate 1 and the shell 3, and then into the second exhaust passage 9, so that the gas pressure is balanced. The first exhaust passage 8 and the second exhaust passage 9 are arranged below the machine and the first exhaust passage 8 is downwardly inclined, so that the seeped oil will stay at the bottom of the second exhaust passage 9 and will not jump into the two shaft seals, so as not to mix the oil in the working device and the pump motor.

[0044] By providing an exhaust passage on the shell, when the working environment temperature changes and the gas pressure between the two shaft seals changes, the gas can be discharged or the hydraulic oil can be sucked in through the exhaust passage, so that the gas pressure between the two shaft seals is balanced, preventing the shaft seal from being deformed due to the expansion or compression of the gas between the two shaft seals, thereby affecting the service life of the shaft seal.

[0045] A screw plug is arranged below the second exhaust passage 9, which can prevent dust in the external environment from entering the cavity between the two shaft seals, preventing the dust from scratching the shaft seal or the driving shaft and affecting the service life of the machine.

[0046] Embodiment 2

[0047] In a typical embodiment of the present application, a sealing device is provided, which comprises the double shaft seal structure of embodiment 1.

[0048] The above merely describes preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A double shaft seal structure characterized by, The double shaft seal structure comprises a first shaft seal and a second shaft seal, the first shaft seal is located in a shaft seal cover plate, and the second shaft seal is close to an inner side end surface of the shaft seal cover plate; a guide groove is arranged on the inner side end surface of the shaft seal cover plate, a boss edge of the shaft seal cover plate in contact with the shell is provided with a chamfer, a cavity between the first shaft seal and the second shaft seal is communicated with the guide groove and the chamfer area, and the chamfer area is communicated with an exhaust passage on the shell.

2. The dual shaft seal structure of claim 1, wherein The exhaust passage comprises a first exhaust passage and a second exhaust passage, an opening of the first exhaust passage is located at a gap position between the shell and the shaft seal cover plate, and an opening of the second exhaust passage is located at the chamfer area on the shaft seal cover plate.

3. The double shaft seal structure of claim 2, wherein The first exhaust passage is connected to the second exhaust passage and is communicated with the second exhaust passage, and the first exhaust passage and the second exhaust passage are in a Y shape.

4. The double shaft seal structure of claim 3 wherein, A screw plug is arranged at an outlet of the second exhaust passage.

5. The double shaft seal structure of claim 3 wherein, The first exhaust passage and the second exhaust passage are both arranged in an inclined manner, and the first exhaust passage and the second exhaust passage are located in a lower part of the shell.

6. The dual shaft seal structure of claim 1 wherein, The guide groove is provided with two guide grooves which are symmetrically arranged at the center.

7. The dual shaft seal structure of claim 1 wherein, The guide groove is in an arc shape.

8. The dual shaft seal structure of claim 1 wherein, A plurality of first threaded holes and a plurality of second threaded holes are arranged on the shaft seal cover plate, a bolt is arranged in the first threaded hole, the shaft seal cover plate is fixed on the shell through the bolt, and a bolt is screwed into the second threaded hole to push the shaft seal cover plate out of the shell.

9. The dual shaft seal structure of claim 1 wherein, An O-shaped sealing ring is arranged between the end surfaces of the shaft seal cover plate and the shell in contact with each other.

10. A sealing device, characterized by The double shaft seal structure comprises the double shaft seal structure according to any one of claims 1-9. The double shaft seal structure comprises the double shaft seal structure according to any one of claims 1-9.

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