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CN-121993603-A - Sealing device for tractor and working method thereof

CN121993603ACN 121993603 ACN121993603 ACN 121993603ACN-121993603-A

Abstract

The invention belongs to the technical field of general vehicles, and particularly relates to a sealing device for a tractor and a working method of the sealing device, wherein the sealing device for the tractor comprises a protective sleeve, an isolating lip, a wear-resistant ring, an elastic sealing piece and a communicating opening, wherein the outer end of the protective sleeve extends outwards and surrounds a driving shaft, the isolating lip is arranged on the side wall of the inner end of the protective sleeve and protrudes towards the driving shaft, the wear-resistant ring is arranged on the side wall of the inner end of the protective sleeve and is parallel to the isolating lip, the elastic sealing piece is fixed on the side wall of the inner end of the protective sleeve, the outer wall of the elastic sealing piece is abutted with the outer wall of the driving shaft so that three mutually isolated lubrication chambers are formed among the wear-resistant ring, the elastic sealing piece and the isolating lip, and the communicating opening is formed on the elastic sealing piece, wherein when the driving shaft rotates at a high speed, the driving shaft extrudes the elastic sealing piece to elastically deform so that the communicating opening is opened, and three mutually isolated lubrication chambers are mutually communicated.

Inventors

  • BAI YANFEI
  • LIU TIANYU
  • ZHANG MUHUI

Assignees

  • 徐州徐工港口机械有限公司

Dates

Publication Date
20260508
Application Date
20260305

Claims (11)

  1. 1. A sealing device for a tractor, comprising: A protective sleeve (2) provided with a framework (20) inside to maintain the shape, and the outer end of the protective sleeve extends outwards and surrounds the driving shaft (1); The isolating lip (3) is arranged on the side wall of the inner end of the protective sleeve (2) and protrudes towards the driving shaft (1); The wear ring (4) is arranged on the side wall of the inner end of the protective sleeve (2) and is parallel to the isolation lip (3); The elastic sealing piece (5) is fixed on the side wall of the inner end of the protective sleeve (2), and the outer wall of the elastic sealing piece (5) is abutted with the outer wall of the driving shaft (1) so as to form three mutually isolated lubrication chambers among the wear-resistant ring (4), the elastic sealing piece (5) and the isolation lip (3); A communication port (6) which is arranged on the elastic sealing element (5); when the driving shaft (1) rotates at a high speed, the driving shaft (1) extrudes the elastic sealing piece (5) to enable the elastic sealing piece to elastically deform, so that the communication port (6) is opened, and three mutually isolated lubrication chambers are mutually communicated.
  2. 2. The tractor seal of claim 1, wherein, The communication port (6) is closed by the self-body structure of the elastic sealing element (5) when the elastic sealing element (5) is in an initial position without deformation.
  3. 3. The tractor seal of claim 1, wherein, The cross section of the communication port (6) is conical, and the conical small end of the communication port faces the outer wall of the driving shaft (1).
  4. 4. The sealing device for a tractor of claim 3, wherein, The included angle alpha between the axial lead of the communication port (6) and the axial lead of the driving shaft (1) is 30-60 degrees.
  5. 5. The tractor seal of claim 4, wherein, The included angle beta between the axis of the communication port (6) and the conical surface is 45-60 degrees.
  6. 6. The tractor seal of claim 1, wherein, The two ends of the elastic sealing piece (5) are respectively arranged at the connection parts of the isolation lip (3) and the inner wall of the protective sleeve (2) and the wear-resisting ring (4).
  7. 7. The tractor seal of claim 1, wherein, The outer wall of the protective sleeve (2) is also provided with a sealing spring (7), and the sealing spring (7) pushes the isolation lip (3) to move towards the driving shaft (1).
  8. 8. The tractor seal of claim 1, wherein, The elastic sealing piece (5) is made of oil-resistant rubber or fluororubber, and the deformation part of the elastic sealing piece is configured to elastically deform when the rotating speed of the driving shaft (1) reaches a preset threshold value.
  9. 9. The tractor seal of claim 5, wherein, The opening area of the communication port (6) is positively correlated with the rotational speed of the drive shaft (1).
  10. 10. The tractor seal of claim 1, wherein, The number of the communication ports (6) is two, and the two communication ports (6) are arranged at the position, close to the protective sleeve (2), of the elastic sealing piece (5).
  11. 11. A method of operating a sealing device for a tractor according to any one of claims 1 to 10, the method comprising: When the driving shaft (1) rotates at a low speed, the outer wall of the elastic sealing piece (5) is abutted with the outer wall of the driving shaft (1), and lubrication chambers among the wear ring (4), the elastic sealing piece (5) and the isolation lip (3) are isolated from each other; when the driving shaft (1) rotates at a high speed, the driving shaft (1) presses the elastic sealing piece (5) to enable the elastic sealing piece to elastically deform, so that the communication port (6) is opened, and three mutually isolated lubrication chambers are mutually communicated.

Description

Sealing device for tractor and working method thereof Technical Field The invention belongs to the technical field of general vehicles, and particularly relates to an axle assembly, in particular to a sealing device for a tractor and a working method thereof. Background The reliability of the sealing performance of the drive shaft as a core power transmission component of a heavy vehicle transmission system directly determines the transmission efficiency, the maintenance cost and the service life of the whole vehicle. In practical conditions, the rotational speed range of the drive shaft varies greatly, from start-up, low-speed creep to high-speed cruise, and there is an inherent contradiction between lubrication and sealing requirements, which puts a distinct and nearly opposite requirement on the sealing device. At low speeds (e.g., start-up, low speed travel), the drive shaft and seal are in a "boundary lubrication" condition. At this time, only one layer of extremely thin oil film firmly adsorbed on the surface of the shaft is needed to prevent dry friction, and the lubrication requirement is low. The main aspect of the technical contradiction at this time is "leakage prevention", in which the sealing device needs to be kept in close contact with the surface of the drive shaft, generating a high radial pressure to actively suppress the flow and leakage of the lubricating grease. If the sealing gap is too large or the grease mobility is too strong, leakage is directly caused. However, when the drive shaft enters a high-speed rotation state, a large amount of heat is generated between the friction pairs. If the close contact state is maintained at a low speed, frictional heat is rapidly accumulated, and the aging, hardening and even ablation failure of the seal lip material (such as rubber) due to high temperature are easily caused in a short time. At this time, the main aspect of the technical contradiction is converted into heat dissipation and cooling, and the core requirement is to take away the friction heat. This requires a transition from "boundary lubrication" to "hydrodynamic lubrication" and allows a sufficient amount of grease to flow, causing the drive shaft to "float" on a thicker dynamic oil film, achieving near non-contact operation, thereby greatly reducing the coefficient of friction and the amount of heat generated. Existing sealing techniques, whether single-backbone oil seals, labyrinth seals, or simple combinations thereof, are static and fixed in nature. Once installed, the amount of interference between the seal lip and the journal, the preload and the flow path of the lubricating oil are determined and cannot be dynamically adjusted during operation according to the change in rotational speed. This inherent structural defect makes it difficult to address the conflicting requirements of accelerated performance decay of conventional sealing materials, especially in high temperature, high humidity, dusty environments, further amplifying the contradiction and further reducing the reliability of the system. Therefore, how to meet different sealing requirements of the driving shaft under the high-speed and low-speed working conditions is a technical problem to be solved in the field. It should be noted that the above information disclosed in this background section is only for understanding the background of the inventive concept and therefore the above description is not to be construed as constituting information of the related art. Disclosure of Invention The embodiment of the disclosure at least provides a sealing device for a tractor and a working method thereof. In a first aspect, embodiments of the present disclosure provide a sealing device for a tractor, comprising: A protective sleeve having a skeleton provided therein to maintain a shape, the outer end of which extends outwardly and surrounds the driving shaft; The isolating lip is arranged on the side wall of the inner end of the protective sleeve and protrudes towards the driving shaft; The wear ring is arranged on the side wall of the inner end of the protective sleeve and is parallel to the isolation lip; The elastic sealing piece is fixed on the side wall of the inner end of the protective sleeve, and the outer wall of the elastic sealing piece is abutted with the outer wall of the driving shaft so as to form three mutually isolated lubrication chambers among the wear-resistant ring, the elastic sealing piece and the isolation lip; the communication port is arranged on the elastic sealing element; When the driving shaft rotates at a high speed, the driving shaft extrudes the elastic sealing element to enable the elastic sealing element to elastically deform, so that the communication port is opened, and three mutually isolated lubrication chambers are mutually communicated. In an alternative embodiment, the communication port is closed by the self-structure of the elastic seal when the elastic seal is in the initial undef