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CN-122011630-A - Engine crankshaft rear oil seal and preparation method thereof

CN122011630ACN 122011630 ACN122011630 ACN 122011630ACN-122011630-A

Abstract

The application relates to the technical field of sealing materials, and particularly discloses an engine crankshaft rear oil seal and a preparation method thereof. The preparation raw materials of the engine crankshaft rear oil seal comprise fluororubber, modified filler, toner, processing aid, stabilizer, vulcanizing agent and vulcanizing aid, wherein the preparation raw materials of the modified filler comprise silica, aminosilane, allyl-2, 3-glycidyl ether and fluoroolefin monomers, and the mass ratio of the silica to the aminosilane to the allyl-2, 3-glycidyl ether to the fluoroolefin monomers is 1 (0.1-0.2) (0.3-0.5) (0.2-0.3). The application can effectively improve the wide-temperature stability of the crankshaft rear oil seal, ensure the stable sealing effect of the crankshaft rear oil seal under complex working conditions and prolong the sealing life of the crankshaft rear oil seal.

Inventors

  • ZHOU WENTAO
  • WANG HONGLIANG

Assignees

  • 广东亿达汽车密封件股份有限公司

Dates

Publication Date
20260512
Application Date
20260323

Claims (10)

  1. 1. The rear oil seal of the engine crankshaft is characterized by being prepared from the following raw materials in parts by weight: 80-100 parts of fluororubber, 14-16 parts of modified filler, 7-9 parts of color powder, 1.8-2.8 parts of processing aid, 7-10 parts of stabilizer, 1.7-2.3 parts of vulcanizing agent and 2-4 parts of vulcanizing aid; The preparation raw materials of the modified filler comprise silica, aminosilane, allyl-2, 3-glycidyl ether and fluoroolefin monomers, wherein the mass ratio of the silica to the aminosilane to the allyl-2, 3-glycidyl ether to the fluoroolefin monomers is 1 (0.1-0.2) (0.3-0.5) (0.2-0.3).
  2. 2. The engine crankshaft rear oil seal according to claim 1, wherein the preparation method of the modified filler comprises the steps of: Adding a first solvent and aminosilane into silica, heating and stirring for reaction, filtering to remove filtrate, washing, and drying to obtain a surface modified filler; Adding a second solvent and allyl-2, 3-epoxypropyl ether into the surface modified filler, stirring for reaction, filtering to remove filtrate after the reaction is finished, washing, and drying to obtain an intermediate modified filler; Adding the intermediate modified filler and a third solvent into a reaction kettle, vacuumizing, heating, pumping fluoroolefin monomers and an initiator, stirring for reaction, and performing aftertreatment after the reaction is completed to obtain the modified filler.
  3. 3. The engine rear crankshaft oil seal according to claim 1, wherein the fluorine-containing olefin monomer includes one or both of perfluorobutyl ethylene and hexafluoropropylene ‌.
  4. 4. The engine rear crankshaft oil seal of claim 1, wherein the aminosilane comprises one or both of 3-aminopropyl trimethoxysilane and 3-aminopropyl triethoxysilane.
  5. 5. The engine crankshaft rear oil seal according to claim 1, wherein the fluororubber comprises FEPM type fluororubber and perfluoroether rubber in a mass ratio of 1 (0.15-0.25).
  6. 6. The engine crankshaft rear oil seal of claim 1, wherein the vulcanizing agent comprises one or more of vulcanizing agent DCP, vulcanizing agent DHBP, vulcanizing agent BIBP.
  7. 7. The engine rear crankshaft oil seal according to claim 1, wherein the vulcanization aid comprises one or both of triallyl isocyanurate and triallyl cyanurate.
  8. 8. The engine rear crankshaft oil seal of claim 1, wherein the processing aid comprises one or more of polyethylene wax, palm wax, WS-280, and rein Aflux.
  9. 9. The engine crankshaft rear oil seal according to claim 1, wherein the stabilizer comprises magnesium oxide and calcium hydroxide in a mass ratio of 1 (0.7-0.9).
  10. 10. A method for preparing an engine crankshaft rear oil seal according to any one of claims 1 to 9, comprising the steps of: (1) Adding fluororubber into an internal mixer for banburying for 3-6min at an initial temperature of 70-80 ℃, sequentially adding a processing aid, a stabilizer, a modified filler and color powder, heating to 100-120 ℃, fully mixing for 6-10min, and discharging rubber to obtain a rubber compound; (2) Loading and unloading the rubber compound on an open mill, cooling the rubber compound to 50-60 ℃, adding a vulcanizing agent and a vulcanizing aid, wrapping with a triangular bag for 3-5 times, passing through the rubber compound for 5-8 times, rolling, and unloading to obtain rubber compound for later use; (3) Preforming the sizing material in a precise preforming machine to obtain a rubber strip or a rubber ring; (4) The skeleton is dip-coated with adhesive after surface treatment, pre-cured, and then bonded with adhesive tape or adhesive ring by hot vulcanization to obtain the rear oil seal of the engine crankshaft.

Description

Engine crankshaft rear oil seal and preparation method thereof Technical Field The invention relates to the technical field of sealing materials, in particular to a rear oil seal of an engine crankshaft and a preparation method thereof. Background With the rapid development of the automobile industry, the engine is continuously iterated towards the directions of high power density, high rotating speed and long service life, and the performance requirements on all parts of the engine are also increasingly stringent. Among them, the crankshaft rear oil seal is a vital component in the engine sealing system, and its performance is directly related to the reliability, emission level and service life of the engine. The crankshaft rear oil seal is mainly made of fluororubber, the fluororubber has excellent high-temperature resistance, oil resistance, chemical medium resistance and other performances, and the sealing material taking fluororubber as a matrix can adapt to the requirements of different working conditions to a large extent. However, fluororubber has higher rigidity due to the fact that the rotation of bonds is limited by strong attractive force between fluorine atoms of main chains or side chains, when the fluororubber is in a low-temperature environment, the fluororubber is easy to become brittle and crack, and when the fluororubber is exposed to a high-temperature environment for a long time, the fluororubber is aged and hardened, elasticity is lost, and the oil seal of a crankshaft loses the original sealing performance. Disclosure of Invention In order to solve the problem of insufficient heat resistance and cold resistance of fluororubber, the application provides an engine crankshaft rear oil seal and a preparation method thereof. In a first aspect, the application provides an engine crankshaft rear oil seal, which adopts the following technical scheme: The rear oil seal of the engine crankshaft is prepared from the following raw materials in parts by weight: 80-100 parts of fluororubber, 14-16 parts of modified filler, 7-9 parts of color powder, 1.8-2.8 parts of processing aid, 7-10 parts of stabilizer, 1.7-2.3 parts of vulcanizing agent and 2-4 parts of vulcanizing aid; The preparation raw materials of the modified filler comprise silica, aminosilane, allyl-2, 3-glycidyl ether and fluoroolefin monomers, wherein the mass ratio of the silica to the aminosilane to the allyl-2, 3-glycidyl ether to the fluoroolefin monomers is 1 (0.1-0.2) (0.3-0.5) (0.2-0.3). By adopting the technical scheme, the C-F bond energy in the fluororubber is higher, and fluorine atoms have a stronger shielding effect on a polymer main chain, so that the material is endowed with better heat resistance, oil resistance and chemical medium resistance. According to the application, by introducing the modified filler with a specific proportion, after the surface of the silica is modified by the aminosilane, the surface amino groups of the silica can react with the epoxy groups of the allyl-2, 3-epoxypropyl ether, and the fluorine-containing olefin monomer is further grafted, so that the surface of the modified filler has fluorine-containing groups, the interface compatibility with a fluororubber matrix is enhanced, and physical or chemical crosslinking points can be formed between the modified filler and fluororubber molecular chains under the vulcanization effect. Meanwhile, the bond angle and the rotational freedom degree of ether bond contained in the allyl-2, 3-epoxypropyl ether are higher, the interaction force between the modified filler and the fluororubber molecular chain can be reduced, the excessive rigidity of the molecular chain is effectively inhibited, the brittle failure tendency at low temperature is reduced, when the modified filler is in a low-temperature environment, the disperse phase of the modified filler can play a role in toughening, under the high-temperature condition, the fluorine-containing group in the modified filler and the fluororubber matrix are in synergistic effect, the thermal stability is improved, the aging and hardening process is delayed, and therefore the wide-temperature stability of the oil seal after a crankshaft is obviously improved, and the sealing life is prolonged. In addition, the synergistic effect of the vulcanizing agent and the vulcanizing aid further optimizes the processability and the vulcanizing system of the sizing material, and ensures that the oil seal keeps a stable sealing effect under a complex working condition. Preferably, the preparation method of the modified filler comprises the following steps: Adding a first solvent and aminosilane into silica, heating and stirring for reaction, filtering to remove filtrate, washing, and drying to obtain a surface modified filler; Adding a second solvent and allyl-2, 3-epoxypropyl ether into the surface modified filler, stirring for reaction, filtering to remove filtrate after the reaction is finished, washing, and drying to