JP5937844B2 - mechanical seal - Google Patents

Description

  The present invention relates to a mechanical seal, and more particularly to a mechanical seal for an automobile water pump.

  Especially in the case of automobile water pumps, mechanical seals for shafts are known and have been used successfully for many years. Due to constant efforts in weight reduction design, especially in the case of automobile water pumps, the water pump housing is gradually made of plastic rather than metal to reduce fuel consumption. The mechanical seal is press-fitted into the housing. However, the disadvantage of such a combination is that, in the long run, there is a gap between the mechanical seal and the water pump plastic housing due to the different thermal expansion, resulting in a tightness of the mechanical seal. ) Is lost.

  The present invention relates to the problem of providing an improved or at least an alternative embodiment of a general purpose mechanical seal, in particular a mechanical seal characterized by durability and a strong connection with a water pump housing.

  The above problems are solved by the subject matter of the independent claims according to the present invention. Advantageous embodiments are the subject matter of the dependent claims.

  The present invention is based on the technical idea of forming a housing for a sealing device, preferably a mechanical seal, through which the sealing device is fixed to a bearing casing of a water pump. This housing is not made of metal as conventionally known, but is made of plastic. Such a plastic housing is connected to the bearing casing of the water pump in a durable and secure manner, and the bearing casing is also made of plastic. Guaranteed over a period, preferably beyond the total useful life. By selecting the same material or at least the material of which the thermal expansion coefficient of the bearing casing of the water pump is approximately the same as that of the housing of the mechanical seal, undesirable sealing caused over a long period of time due to different thermal expansion coefficients The problem can be avoided. The material preferably comprises a suitable plastic such as, for example, a fiber reinforced thermoplastic or a fiber reinforced thermosetting plastic. Furthermore, by making the housing of the mechanical seal from plastic, a flexible and cost-effective housing can be obtained, and can be connected to the bearing casing of the water pump in various different ways, for example Adhesion and welding are possible.

  An advantageous improvement of the problem solving means of the present invention is that the mechanical seal further comprises the following configuration. A receptacle coupled in a manner that is rotatably fixed to a shaft for sealing; a sealing ring; a counter ring interacting with the sealing ring; a spring; and a rubber bellows. Yes. The sealing ring and / or counter ring may be composed of ceramics, in particular silicon carbide or graphite. During the operation of the mechanical sealing, the sealing ring and the counter ring come into contact with each other to form a sealing surface, which is usually connected in a manner that is rotatably fixed to the housing of the mechanical seal, so that the water pump The counter ring is usually connected to the receptacle in such a way that it is rotatably fixed to the bearing casing, so that it is rotatably fixed to the shaft of the water pump. Connected in a way. Silicon carbide and graphite each have independent properties different from each other, for example, graphite exhibits low friction loss. In contrast, silicon carbide has a very high hardness and a high melting point, and is particularly suitable for use as so-called engineering ceramics. Furthermore, it goes without saying that typical sealing materials (not described here) are also conceivable.

  In a possible improvement of the solution according to the invention, a possible sealing concept, such as a sealing lip, is provided when the material of the bearing housing and housing of the sealing device has at least approximately the same, preferably the same coefficient of thermal expansion. Can be done. The material preferably comprises a suitable resin such as, for example, fiber reinforced thermoplastic or fiber reinforced thermosetting plastic.

  Further important features and advantages of the invention result from the subclaims, the drawings and the associated description of the shapes based on the drawings.

  It goes without saying that the above-described features and the features described below can be used not only in the above-described combinations, but also in other combinations or alone without departing from the scope of the present invention.

  More preferred exemplary embodiments of the invention are illustrated in the drawings and explained in more detail in the following description. The same reference numbers refer to the same, similar or functionally identical configurations.

It is a section perspective view of the mechanical seal concerning the embodiment of the present invention. It is a cross-sectional perspective view of the water pump incorporating a mechanical seal.

  As shown in FIGS. 1 and 2, the mechanical seal 1 according to the embodiment of the present invention includes a housing 2, and the mechanical seal 1 is fixed to the bearing casing 3 of the water pump 4 (see FIG. 2) via the housing 2. sell. Since the bearing casing 3 of the water pump 4 is made of plastic, the housing 2 of the mechanical seal 1 is also made of plastic according to the present invention. The material preferably comprises a suitable plastic such as, for example, a fiber reinforced thermoplastic or a fiber reinforced thermosetting plastic. Thereby, especially in the long term, it is possible to avoid a difference in thermal expansion coefficient that causes different thermal expansion and thereby water leakage. In addition, the mechanical housing 1 can be produced flexibly and cost-effectively by the plastic housing 2. Usually, the mechanical seal 1 separates the water transport part and the hollow part in the water pump 4.

  Furthermore, the mechanical seal 1 has the following configuration.

  That is, the mechanical seal 1 includes a receptacle 6 connected in a manner that is rotatably fixed to the shaft 5 to seal the water pump 4, a sealing ring 7, and a counter ring 8 that interacts with the sealing ring 7, A spring 9 and a rubber bellow 10 are provided.

  The sealing ring 7 and / or the counter ring 8 are made of ceramics, in particular silicon carbide or graphite. The sealing ring 7 is made of ceramics, for example, and the counter ring 8 engaged with the sealing ring 7 is made of graphite. The counter ring 8 is connected to the receptacle 6 by a method of being rotatably fixed, and the sealing ring 7 is connected to the housing 2 by a method of being rotatably fixed, and the bearing casing of the water pump 4 is further connected via the housing 2. 3 is connected in a manner that is rotatably fixed.

  The spring 9 is composed of, for example, a disc spring or a wave spring, and plays a role of applying a load to the sealing ring 7 in advance with respect to the counter ring 8. The mechanical seal 1 is firmly connected to the bearing casing 3 of the water pump 4 via the housing 2, and is particularly connected to the bearing casing 3 by welding, adhesion, or press fitting.

  Referring to FIG. 1, it is clear that the spring 9 is pre-loaded with one side relative to the housing 2 and the other side relative to the pot 11, where the pot 11 is connected to the outer ring of the rubber bellows 10 and The sealing ring 7 is supported. Here, the rubber bellows 10 is held radially inward in the housing 2 by a protrusion 12 (nose). Instead of the receptacle 6, the counter ring 8 and the sealing ring 7, the mechanical seal 1 may include a radial shaft seal (not shown).

  The configuration according to the invention of the plastic housing 2 of the mechanical seal 1 makes it possible in particular to avoid the gap between the housing 2 of the mechanical seal 1 and the bearing casing 3 of the water pump 4 which occurs as a result of different coefficients of thermal expansion. Thus, the long-term sealing property of the mechanical seal 1 is ensured.

1 Mechanical seal 2 Housing 3 Bearing casing 4 Water pump 5 Shaft 6 Receptacle 7 Sealing ring 8 Counter ring 9 Spring 10 Rubber bellows

Claims (5)

Water pump (4), especially a mechanical seal for automobile water pumps,
With a housing (2),
The mechanical seal is fixed to the bearing casing (3) of the water pump (4) through the housing (2),
The housing (2) is made of plastic ,
A receptacle (6) connected in a rotatably fixed manner to the shaft (5) to be sealed;
Sealing ring (7),
A counter ring (8) interacting with the sealing ring (7);
A spring (9) for applying a load to the sealing ring (7) in advance with respect to the counter ring (8),
The counter ring (8) is connected to the receptacle (6) in a manner that is rotatably fixed,
The mechanical seal, wherein the sealing ring (7) is connected to the housing (2) by a method of being rotatably fixed . The mechanical seal according to claim 1,
A mechanical seal further comprising a rubber bellows (10). In the mechanical seal according to claim 1 or 2,
The mechanical seal characterized in that the sealing ring (7) and / or the counter ring (8) are made of ceramics, in particular made of silicon carbide or graphite. The mechanical seal according to any one of claims 1 to 3 ,
The mechanical seal, wherein the spring (9) is configured as a wave spring or a disc spring. An automobile water pump,
A plastic bearing casing (3);
A plastic housing (2), and a sealing device fixed to the bearing casing (3) of the water pump (4) through the housing (2),
The bearing casing (3) and the housing (2) are made of a plastic having at least approximately the same thermal expansion coefficient ,
5. The automobile water pump according to claim 1, wherein the sealing device is the mechanical seal according to claim 1 .

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