FR2612566A1 - WATER PUMP FOR COOLING CIRCUITS OF INTERNAL COMBUSTION ENGINES - Google Patents

Abstract

THIS WATER PUMP FOR COOLING CIRCUITS OF INTERNAL COMBUSTION ENGINES FOR AUTOMOTIVE VEHICLES PRESENTS A ROTOR 3 WHICH INCLUDES A HUB 4 HAVING AN END 4A ARRANGED IN FRONT SLIDING CONTACT WITH A DYNAMIC CONTACT RING 8 WHICH APPEARS ANNULAR SEAL 7 INTERPOSED BETWEEN SHAFT 5 OF ROTOR 3 AND BODY 1 OF THE PUMP. BETWEEN THIS END 4A OF THE HUB 4 OF THE ROTOR 3 AND THE BUSH 8 ARE INTERPOSED ANTI-WEAR MEANS CONSTITUTED BY A DEPOSIT OF HIGH HARD MATERIAL 9 DEPOSITED ON THE SURFACE OF THE said END 4A OF THE HUB 4 BY PROJECTION IN THE FORM OF PLASMA.

Description

The present invention relates in a way

  water pumps for cooling circuits

  internal combustion engines for self-propelled

  mobile. The invention relates more particularly to

  pump of the type comprising a body which defines a chamber

  pumping station in which a rotor with

  with a hub mounted on a driving shaft which exits into the pumping chamber, a seal

  ring between the shaft and the body and includes

  a dynamic contact ring disposed in forward sliding contact with the end of the hub

  said lining, and anti-wear means

  axially between said end of the hub and said

dynamic contact ring.

  According to the best known technique, these means

  anti-wear consists of an element of

  ramique attached to the dynamic contact ring of the

  this, on the one hand, to improve

  the rotor and the ring and, on the other hand, to ensure a long life at the interface thanks to limited wear

  surfaces that are in dynamic contact.

  This solution, however, had the disadvantage

  deny a significant increase in the

  axially the packing, as well as a significant increase in the difficulties and costs of manufacturing and

pump assembly.

  The object of the present invention is to obviate the above-mentioned drawback and this goal is achieved by virtue of

  said anti-wear means interposed between

  the end of the hub and the dynamic contact ring

  of the filling consist of a deposit of one

  of high hardness which is deposited on the surface of said end of the hub, by projection in the form of

plasma.

  With this principle of solution, an effective seal and limited wear of the interface between the hub of the rotor and the dynamic contact ring of said lining is obtained, by appreciably reducing the axial size of the lining, as well as the corresponding costs of manufacturing and assembly compared to the prior art described above. This is also due to the fact that direct deposition of the anti-wear material on the rotor hub, which

  normally cast iron, avoids the need for

  special hardening and finishing conditions

the rotor hub.

  According to the invention, the deposition deposited by projec-

  in the form of plasma is made of a ceramic material

  in one or more layers, with possible intermediate layers of attachment or, alternatively, it may consist of metallo-ceramic compounds

  deposited by the technique mentioned above.

  Other features and advantages of the

  will be better understood when reading the description of

  following description of an example of

  the attached drawing which represents an axial section

  schematic and partial diagram of a water pump according to the invention.

  tion. In the drawing, it is schematically indicated in 1 a part of the body of a water pump for circuits of

  cooling of internal combustion engines for

  automobile hides. The body 1 defines a pumping chamber 2 in which is housed a finned rotor 3,

  normally made of cast iron, sheet or plastic, which

  sede a tubular hub 4, come from a single piece or rap-

  door. The hub 4 is keyed on an end portion a of a drive shaft 5 supported free to rotate by the

  1, with the aid of bearings 6 and controlled by rotating

  tion, in a manner known per se, by the engine of the vehicle.

the.

2 6 1 2 5 6

3 2612566

  In 7, a seal has been indicated

  annular, also of classical type, interposed coaxially

  between the driving shaft 5 and the body 1 in the

  in which the end portion 5a of the shaft 5 exits into the pumping chamber 2. The seal 7 is also associated, in a manner known per se, with a dynamic contact ring 8, normally made of graphite, which makes facing the end 4a

  hub 4 facing towards the lining 7.

  Between the graphite ring 8 and the end 4a

  of the hub 4, is interposed an anti-annular portion

  wear 9 against which this ring 8 is applied in con-

frontal sliding tact.

  According to the invention, the anti-wear part 9 consists of a deposit of high hardness material which

  is directly applied to the end 4a of the hub 4.

  This material, which can be constituted by a cerami-

  or by metallo-ceramic compounds or metal carbides, is deposited in one or more

  layer (s) on the surface of the end 4a by a technique

  known in itself projection in the form of plasma.

  The function of the deposit 9 is to reduce the frictional wear between the graphite ring 8 and the hub 4 of the rotor 3, so as to give the interface a longer duration. The conditions of realization of this deposit 9 allow-- on the other hand to limit the clutter

  axial axis of the assembly constituted by the gasket 7, the

  8 and the rotor 3, as well as to reduce the costs of

manufacturing and assembly.

  Of course, various modifications may be made by those skilled in the art to the device which

  just described as a non-limiting example.

  mitative, without departing from the scope of the invention.

R E V E N D I CATIONS

  1 - Water pump for cooling circuits

  internal combustion engines for self-propelled

  mobile devices, comprising a body which defines a pumping chamber in which is disposed a rotor having a hub fixed on a drive shaft which exits into the pumping chamber, an annular sealing gasket interposed between the shaft and the body and which comprises a dynamic contact ring disposed in sliding contact

  front end with the end of the hub facing towards

  the packing, and anti-wear means arranged axially-

  between said end of the hub and said dynamic contact ring, characterized in that said anti-wear means are constituted by a deposit of a material of

  high hardness (9) deposited on the surface of said end

  tee (4a) of the hub (4) of the rotor (3) by projection under

  Plasma form in one or more layers.

  2 - Pump according to claim 1, characterized

  in that the deposit (9) deposited by projection under

  Plasma form is made of a ceramic material.

  3 - Pump according to claim 1, characterized

  in that the deposit (9) deposited by projection under

  The plasma form consists of metal compounds

ceramics.