JP2011252497A - Sealing device for water pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing device for water pumps to seal hermetically sealed fluid such as LLC, while improving rust proofing property of components, pressure resistance and wear resistance.SOLUTION: The sealing device 1 is composed of a rubber ring 11 and a resin ring 21. The rubber ring 11 integrates a cylindrical fixing part 12, a flange part 13, and a seal lip 14. The resin ring 21 integrally has a fixing ring part 22, a flange part 26, and a backup ring part 23. The resin ring 21 includes a recess 27 surrounded by the fixing ring part 22, flange part 26, and backup ring part 23. The lip base part 17 having a substantially U-section is fitted into the recess 27 from the inside of the machine, thereby setting a laminate structure formed of alternate rubber and resin.

Description

  The present invention relates to a sealing device according to a sealing technique, and more particularly to a sealing device suitable for use in a shaft seal portion of a water pump. The sealing device of the present invention is used for, for example, a water pump for cooling an automobile engine, or used for other cooling water pumps.

  2. Description of the Related Art Conventionally, as a sealing device used in this type of water pump, a sealing device 51 shown in FIG. 2 is known. This sealing device 51 is fixed to a housing 52 and seals slidably in contact with a shaft 53. By arranging a plurality of lips 54 side by side, a sealing fluid such as LLC is sealed so as not to leak from the inside A to the outside B. The seal lip 54 is made of a rubber-like elastic body, and this rubber-like elastic body is adhered (vulcanized and bonded) to the metal reinforcing ring 55.

However, since the above-described prior art has the metal reinforcing ring 55 as its component, rust is likely to be generated in the reinforcing ring 55, and thus there is a difficulty in rust prevention of the part. As a sealing device for water pumps, it is necessary to pay attention to the following points in addition to the rust prevention of the parts.
(1) Since a pressure of about 0.2 MPa acts from the inside as the sealing fluid pressure, it is necessary to consider pressure resistance.
(2) Since the seal lip is easily worn by water lubrication, it is necessary to consider wear resistance.
(3) Since foreign matters such as cast sand, rust, or sand particles existing in the pump are mixed in the water and easily wear the seal lip, it is necessary to consider wear resistance also in this respect.

JP 2002-310095 A

  In view of the above, the present invention provides a sealing device for a water pump that seals a sealing fluid such as the above-mentioned LLC, which can improve rust prevention, pressure resistance and wear resistance of components. For the purpose.

  To achieve the above object, a sealing device according to claim 1 of the present invention is a water pump sealing device mounted between a housing and a shaft so that a sealing fluid such as LLC does not leak from the inside of the machine to the outside of the machine. The rubber ring is provided in a radially inward direction at the inner end of the cylindrical fixing portion and the cylindrical fixing portion that is fitted to the inner periphery of the housing. A flange portion and a seal lip that is provided at an inner peripheral end portion of the flange portion and that is slidably in close contact with the shaft are integrally formed, and the resin ring is an inner periphery of a cylindrical fixing portion of the rubber ring. And a fixing ring portion that presses the rubber ring firmly against the housing by the fitting allowance, and a flange portion that is provided radially inward at an outer end of the fixing ring portion. And a back-up ring portion that is provided at an inner peripheral end portion of the flange portion and is disposed on the back side of the seal lip to suppress excessive deformation of the seal lip, and the fixing ring portion and the flange portion And an annular recess surrounded by the backup ring portion is formed in the resin ring, and a lip base portion of the seal lip having a substantially U-shaped cross section is fitted into the recess from the inside of the machine, whereby an inner portion of the sealing device is A rubber / resin alternate lamination in which a cylindrical fixing portion of the rubber ring, a fixing ring portion of the resin ring, a lip base portion of the rubber ring, and a backup ring portion of the resin ring are arranged in a row in a radial direction over a peripheral portion The structure is set.

  Further, the sealing device according to claim 2 of the present invention is the sealing device according to claim 1, wherein the flange-shaped inward engagement portion for preventing the resin ring from coming off in the axial direction is fixed to the rubber ring in a cylindrical shape. It is characterized by being integrally provided at the outer end of the machine.

  According to a third aspect of the present invention, there is provided a sealing device according to the first or second aspect, wherein a lip-shaped inner peripheral seal portion slidably in close contact with the peripheral surface of the shaft is a backup in the resin ring. It is the machine outer side end part of a ring part, Comprising: It has integrally provided in the inner peripheral part of the flange part.

  The sealing device of the present invention having the above-described configuration has a component that is a combination of a rubber ring and a resin ring and does not have a metal reinforcing ring that easily generates rust. It is possible to improve.

  Also, the rubber ring that is one component has a cylindrical fixing portion that is fitted to the inner periphery of the housing, whereas the resin ring that is the other component is a cylindrical shape of the rubber ring. Because it has a fixing ring part that is fitted to the inner periphery of the fixing part and strongly presses the rubber ring against the housing by its fitting allowance, the rubber ring and the entire sealing device should be firmly fixed to the housing Is possible. Therefore, even if the metal reinforcing ring is omitted, there is no problem in the mounting property.

  Also, the rubber ring that is one component has a seal lip that is slidably in close contact with the shaft, whereas the resin ring that is the other component is disposed on the back side of the seal lip. In addition, since the backup ring portion that suppresses excessive deformation of the seal lip is provided, it is possible to suppress excessive deformation of the seal lip and improve its pressure resistance. If the pressure resistance is improved, the seal lip is not excessively pressed against the shaft, so that the wear resistance can be improved.

  Therefore, as described above, according to the intended purpose of the present invention, a sealing device capable of improving the rust prevention, pressure resistance and wear resistance of components in a sealing device for water pumps that seals a sealing fluid such as LLC. Can be provided.

  In addition, since the lip base of the rubber ring is fitted from one side in the axial direction into the annular recess surrounded by the cylindrical fixing part, flange part and backup ring part of the resin ring, the lip base fitted in the recess is a resin ring. Therefore, even if the sealing fluid pressure acts, it hardly deforms. Accordingly, it is possible to stabilize the contact posture of the lip tip portion connected to the lip base with respect to the shaft, and from this point, the pressure resistance and wear resistance of the seal lip can be improved.

  In addition, when a flange-shaped inward engagement portion is integrally provided at the outer end of the tubular fixing portion of the rubber ring, the resin ring can be prevented from falling off in the axial direction. When the lip-shaped inner seal part is integrally provided on the outer peripheral end of the backup ring part and the inner peripheral part of the flange part, foreign matter such as dust on the outer side of the backup ring part Intrusion can be suppressed.

Sectional drawing of the principal part of the sealing device which concerns on the Example of this invention. Sectional drawing of the sealing device which concerns on a prior art example

  Next, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a cross section of a main part of a sealing device 1 according to an embodiment of the present invention. The sealing device 1 according to the embodiment includes a water pump for cooling an automobile engine so that LLC (long life coolant) as a sealing fluid (liquid) does not leak from the inside (sealing fluid side) A to the outside (atmosphere side) B. And is configured as follows.

  That is, the sealing device 1 according to the embodiment includes a rubber ring 11 made of a predetermined rubber material and a resin ring 21 made of a predetermined resin material, and is configured by a combination of these two parts.

  The rubber ring 11, which is one component, is integrally formed with a flange portion 13 inward in the radial direction at the end of the inner side of the cylindrical fixing portion 12 fitted to the step portion 3 on the inner periphery of the shaft hole of the housing 2. A seal lip 14 is integrally formed at the inner peripheral end of the flange portion 13 so as to be slidably in close contact with the peripheral surface of the shaft 4, and the seal lip 14 has its pressure receiving surface 14a at the inner side A. The pressure receiving surface 14a is pressed against the peripheral surface of the shaft 4 when receiving the sealing fluid pressure.

  The seal lip 14 has a substantially U-shaped lip base 17 integrally formed at the inner peripheral end of the flange portion 13, and a lip tip integrally formed obliquely inward at the inner peripheral end of the lip base 17. A garter spring 19 may be fitted to the latter lip tip 18 to adjust the tightening allowance for the shaft 4 as shown in the figure.

  In addition, a flange-shaped inward engagement portion 15 is formed integrally with the outer end of the cylindrical fixing portion 12 inward in the radial direction, and this engagement portion 15 engages with the resin ring 21. By doing so, the resin ring 21 is configured not to fall off in the axial direction.

  The resin ring 21 which is the other component has a fixing ring portion 22 which is fitted to the inner periphery of the cylindrical fixing portion 12 of the rubber ring 11, and the fixing ring portion 22 has rubber due to its fitting margin. The cylindrical fixing portion 12 of the ring 11 is configured to be strongly pressed against the inner peripheral surface of the shaft hole of the housing 2.

  In addition, a flange portion 26 is integrally formed at the outer end of the fixed ring portion 22 inward in the radial direction, and a backup ring portion 23 is integrally formed at the inner peripheral end of the flange portion 26 toward the inner side A. Has been. The backup ring part 23 is arranged on the back side (machine outside B) of the seal lip 14 and on the inner peripheral side of the lip base part 17 so as to suppress excessive deformation of the seal lip 14 by backing up the seal lip 14. It is configured.

  Further, a lip-shaped inner peripheral seal portion 25 is integrally formed obliquely inwardly on the inner peripheral portion of the flange portion 26 at the outer end portion of the backup ring portion 23, and the inner peripheral seal portion 25. Is configured to prevent foreign matter such as dust on the outside B from entering the inner periphery of the backup ring portion 23 by being slidably in close contact with the peripheral surface of the shaft 4.

  Further, as described above, since the resin ring 21 integrally includes the fixing ring portion 22, the flange portion 26, and the backup ring portion 23, an annular concave portion 27 surrounded by them is formed, and the concave portion 27 is formed with rubber. The lip base 17 of the seal lip 14 in the ring 11 is configured to be fitted from the machine inner side A. Therefore, as a result of fitting the lip base 17 into the recess 27 in this way, from the outer peripheral part to the inner peripheral part of the sealing device 1, the cylindrical fixing part 12 of the rubber ring 11, the fixing ring part 22 of the resin ring 21, A rubber / resin alternate laminated structure is set in which the lip base portion 17 of the rubber ring 11 and the backup ring portion 23 of the resin ring 21 are arranged in a row in the radial direction.

  The rubber ring 11 and the resin ring 21 are each manufactured separately and assembled without using an adhesive.

  The sealing device 1 having the above configuration is mounted on the shaft seal portion of the water pump so that the LLC, which is a sealing fluid, does not leak from the inside A to the outside B as described above. It is characterized by its effectiveness.

  That is, first, the sealing device 1 having the above-described configuration is a combination of a rubber ring 11 and a resin ring 21 and does not have a metal reinforcing ring that easily generates rust. Therefore, it is not necessary to be concerned about the occurrence of rust even when used in a water pump, and thus it is possible to improve the rust prevention properties of parts.

  In addition, the rubber ring 11 that is one component has the cylindrical fixing portion 12 that is fitted to the inner periphery of the shaft hole of the housing 2, whereas the resin ring 21 that is the other component is the resin ring 21. Since the rubber ring 11 has a fixing ring portion 22 that is fitted to the inner periphery of the cylindrical fixing portion 12 and presses the rubber ring 11 firmly against the inner peripheral surface of the shaft hole of the housing 2 by the fitting allowance. The rubber ring 11 and the entire sealing device 1 can be firmly fixed to the housing 2 by the resin ring 21. Therefore, even if the metal reinforcing ring is omitted, the sealing device 1 can be firmly fixed to the housing 2 and its mounting property can be ensured.

  The rubber ring 11 as one component has a seal lip 14 that is slidably in close contact with the peripheral surface of the shaft 4, whereas the resin ring 21 as the other component is a seal. Since the backup ring portion 23 is disposed on the back side of the lip 14 and suppresses excessive deformation of the seal lip 14, the backup lip portion 23 can back up the seal lip 14. The seal lip 14 is elastically deformed so as to be pressed against the peripheral surface of the shaft 4 by being pressed by the sealing fluid pressure, but the elastic deformation of the seal lip 14 is restricted by the backup ring portion 23. Further, since the rubber ring 11 is backed up by the fixing ring portion 22 of the resin ring 21 with respect to the flange portion 13, the flange portion 13 is not deformed so as to fall into the outer side B, so that the flange portion 13 falls down. The seal lip 14 is not excessively deformed. Therefore, deformation of the seal lip 14 can be suppressed, and the pressure resistance can be improved. Since the contact surface pressure is suppressed unless the seal lip 14 is strongly pressed against the shaft 4, its wear resistance (sliding wear resistance) can be improved.

  Further, since the lip base portion 17 of the rubber ring 11 is fitted from one axial direction into the annular concave portion 27 surrounded by the fixing ring portion 22, the flange portion 26 and the backup ring portion 23 of the resin ring 21, The inserted lip base 17 is held by the resin ring 21, and therefore hardly deforms even when a sealing fluid pressure acts. Therefore, the contact posture of the lip tip 18 connected to the lip base 17 with respect to the shaft 4 can be stabilized. Therefore, the pressure resistance and wear resistance of the seal lip 14 can be improved also in this respect.

  Note that a pumping mechanism including a screw groove may be provided on the inner peripheral surface of the backup ring portion 23.

DESCRIPTION OF SYMBOLS 1 Sealing device 2 Housing 3 Step part 4 Shaft 11 Rubber ring 12 Cylindrical fixing part 13, 26 Flange part 14 Seal lip 14a Pressure receiving surface 15 Inward engagement part 17 Lip base part 18 Lip tip part 19 Garter spring 21 Resin ring 22 fixation Ring part 23 Backup ring part 25 Inner peripheral seal part 27 Recessed part A Machine inside B Machine outside

Claims (3)

In a water pump sealing device (1) mounted between a housing (2) and a shaft (4) so that a sealing fluid such as LLC does not leak from the inside (A) to the outside (B),
It consists of a combination of a rubber ring (11) and a resin ring (21),
The rubber ring (11) has a cylindrical fixing portion (12) fitted to the inner periphery of the housing (2), and is directed radially inward to the machine inner end of the cylindrical fixing portion (12). And a flange portion (13) provided integrally with a seal lip (14) provided at an inner peripheral end of the flange portion (13) and slidably in close contact with the shaft (4),
The resin ring (21) is fitted to the inner periphery of the cylindrical fixing portion (12) of the rubber ring (11), and the rubber ring (11) is strongly pressed against the housing (2) by the fitting margin. A fixing ring portion (22), a flange portion (26) provided radially inward at an outer end portion of the fixing ring portion (22), and an inner peripheral end portion of the flange portion (26). A backup ring portion (23) that is provided on the back side of the seal lip (14) and suppresses excessive deformation of the seal lip (14);
An annular recess (27) surrounded by the fixing ring portion (22), the flange portion (26) and the backup ring portion (23) is formed in the resin ring (21), and the sealing lip having a substantially U-shaped cross section ( The lip base (17) of 14) is fitted into the recess (27) from the inner side (A), whereby the cylinder of the rubber ring (11) extends from the outer periphery to the inner periphery of the sealing device (1). Radial fixing portion (12), fixing ring portion (22) of resin ring (21), lip base portion (17) of rubber ring (11) and backup ring portion (23) of resin ring (21) A water pump sealing device characterized in that a laminated structure of rubber and resin alternately arranged in a row is set. The sealing device according to claim 1.
A flange-shaped inward engagement portion (15) for preventing the resin ring (21) from coming off in the axial direction is integrally provided at the outer end of the tubular fixing portion (12) of the rubber ring (11). A sealing device for a water pump. The sealing device according to claim 1 or 2,
A lip-shaped inner peripheral seal portion (25) that is slidably in close contact with the peripheral surface of the shaft (4) is an outer end portion of the backup ring portion (23) in the resin ring (21) and a flange portion (26 The water pump sealing device is provided integrally with the inner periphery of the water pump.

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