FR2633016A1 - PALLET ROTARY LOW GENERATOR - Google Patents

Abstract

The invention relates to vacuum generators. This apparatus comprises a body 2 in which rotates a rotor 13 provided with vanes 15 which slide in slots 14 and form variable volume chambers 48 in a cavity 10. This cavity has an air suction opening 24 and an opening 44 for delivering air and lubricating oil, which communicates with a delivery duct 41 formed in the body 2. This opening 44 is formed directly in the bottom 64 of the cavity 10 and has a greater angular width than the inlet 41 of the discharge pipe. Main applications: supplying servo-brakes for diesel motor vehicles.

Description

l 2 2633016

  The present invention relates to a general

  rotary vane depression, which can advantageously

  It can be used in diesel vehicles to generate the vacuum that is needed, especially for servo-brake operation. As is well known, these generators of

  rotary depression include a supporting body of

  designed to support a shaft driven by the engine

  serves to drive in rotation an eccentric rotor housed.

  in a working cavity, and which carries a plurality of vanes sliding in cavities in the rotor and into which pressurized oil is introduced, so that the outer end of the vanes is applied in contact with the inner surface of the working cavity, which cavity is

  divided by said pallets into different chambers

  workloads with variable volume. The great psychological push

  drastically acting on the inner ends of the pallets, which is antagonistic to the retraction force of

  pallets in the rotor exerted by the rotational sliding

  on the inner surface of the outer working cavity

  centric with respect to the rotor, has the effect that the

  are subject to sudden oscillations and

  shocks on the surface of the working cavity, which

  drags an accentuated and irregular wear of this surface.

  this. The purpose of the present invention is to provide a rotary vane rotary vacuum generator of the type

  above, but perfected so as to avoid this

  convenient, with a particularly simple realization

and therefore economical.

  According to the invention, a generator of

  rotary vane depression comprising a support body

  port for supporting a shaft for rotating a rotor which carries a plurality of pallets slidable in cavities in said rotor, and whose outer end is applied in contact with an inner surface of a working cavity

  formed in said body so as to form chambers

  of variable volume work between said pallets

  this cavity having respective openings for air suction and air discharge and lubricating oil, said discharge opening being in communication with a discharge pipe practiced

  in said support body, characterized in that

  the discharge opening is formed in said support body and that the angular dimension of said discharge opening is greater than that of the

  initial portion of said discharge conduit.

  Figures in the attached drawing, given only

  as an example, will make clear how the in--

  vention can be realized. In these drawings, FIG. 1 is a side view of the generator

  rotary-vane depression according to the present invention.

  tion; Figures 2 and 3 are sectional views of the rotary vacuum generator of Figure 1, in planes whose traces are respectively indicated in II-II and III-III; and FIG. 4 is a sectional view of the rotary vacuum generator of FIG. 3, according to a plane of which

  the trace is indicated in IV-IV of Figure 1.

  As can be seen in FIGS. 1 to 4, the rotary vane depression generator indicated by FIG.

  reference 1 comprises a support body 2, advantageously

  it is made of aluminum by die casting, which is closed in its front region by a cover 3, which is fixed on the body 2 by three bolts 4, with

  interposition of an annular lining 5. At its end

  rear tee, which is the opposite of the closed one

  by the cover 3, the body 2 has a part 6

  mant collar which is intended to be fixed on a motor block (of known type and not shown). This body 2 has, in its center, a zone 8 of reduced section

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  and then it widens towards the lid 3 by forming a bucket-shaped portion 9 which internally forms

  a working cavity 10. Zone 8 of the body plays the role of

  the support for a shaft 11 which protrudes beyond the flange portion 6 to one end, through a lining ring 7 which is itself housed

  in an end portion 12 of the body 2, and this shaft

  flange 61 provided with fingers 62 so as to be

  dragged in rotation, in a manner known by the movement

  of the motor. At its other end, the shaft 11 is

  in a rotor 13 housed in the working cavity 10 and which has four slots 14 in which are housed respective pallets 15 which slide in these slots 14 to rely on the

  inner surface of the cavity 10 by their outer end.

  pool. Inside the shaft 11, from its central part

  up to the end on which the rotor 13 is placed

  Manché, is formed an axial channel 16 which gives passage to the lubricating oil under pressure. Near the blind interior bottom of channel 16, four

  radial holes 17, uniformly spaced 90, which

  channel 16 in communication with an annul-

  18 formed on the outer outer surface of the shaft 11, the right of the housing formed in the zone 8 of the body 2. In this zone 8 is further formed a conduit

  63 which leads to the outside through a threaded segment tan-

  say that, inside, it comes out in the area of the

  annular chamber 18 (Figure 2). Moreover, in the former

  Open end of channel 16, is fitted a cup

  19 having an axial hole which puts channel 16 in

  with a circular chamber 20 formed in the

  upper surface of the rotor 13 which looks towards the neck

  3, and this chamber 20 is in communication with the bottom portion of the slots 14. In the bottom wall 64 of the working cavity 10, opens a suction opening 24 located at the end of a conduit 65 which, at its other end, opens out perpendicularly into a lateral zone (FIG. 2) of a duct 66 which

  is practiced in the zone 8 of the body 2, perpendicular-

  the axis of this body 2 and communicates with the outside world.

  by means of a connecting pipe 23. This pipe contains advantageously and of a

  known manner in its interior volume, a check valve

  return that allows only the suction of air from an external pipe, known and not shown. In the support body 2 is provided, in a lower portion 25 which is oriented downwardly when the vacuum generator 1 is disposed of.

  shown in FIG. 1, a discharge pipe

  26 whose end opening is delimited by a small disk 37 provided with a central pipe 30, and which is fixed at its periphery by the crimping of an annular edge 38 of the part 25 and with the interposition of a Sealing ring 36. A duct 40 starts from this duct 26 in an upwardly inclined direction, and opens out beyond the flange portion 6, in the recess of FIG.

  the part 12 in which is housed the annular seal

7.

  According to the improvement which is the object of the present invention, a first segment 41 of the delivery conduit is formed between the bottom wall 64 of the working cavity 10 and the conduit 26 while, in this bottom wall 64 (FIG. 6) is formed a cavity

  44 having a channel profile, and which constitutes the

  discharge opening of the working cavity 10 of the

  In particular, this openness

  reproach 44 is in communication with the first

  first segment 41 of the discharge pipe and, thus,

  As can be seen in Figure 3, it has a

  significantly higher angular the 3-dimensional

  angle of this discharge opening 44 is in fact

  fet substantially equal to the angular distance measured between the ends of two successive sliding vanes. This discharge opening 44 has

  a relatively small section so as not to be

  interested only in the outer end

  pallets 15 and has a larger

  section only in front of the first segment 41 of the con-

  discharge, so as to establish communica- tion. This first segment 41 is in an intermediate position of the angular dimension of the opening

  discharge 44; more specifically, this segment is

  a little beyond the middle of the opening.

  The operation of the vacuum generator 1

  according to the invention is the following. Under the influence of

  of the shaft 11, the rotor 13 is rotated,

  so that the vanes 15 define in a way that

  rooms 48 of variable volume, which believes that

  from the discharge opening 44 to the

  suction line 24, then decreases to a minimum located in the right of the discharge opening 44. There is therefore a suction of air through the opening 24 and the conduits 65 and 66 of the connecting tube 23 ,

  and a backflow of air through the discharge opening

  44, the first segment 41, the conduit 26 and the tubular

  In addition, pressurized oil is added through the conduit 63 and the radial holes 17, in the

  channel 16 formed in the shaft 11 and this oil, in step

  through the hole in the cup 19 and the cir-

  20, pushes, in their rear area, the pallets

  15 who are in this way kept in contact

  with the inner surface of the working cavity 10.

  in the return phase of pallets 15, light oil

  burriante fate outward of the rotor 13, so that this oil is also expelled at the same time

  air through the discharge opening 44 and, by

  30, according to the improvement of the present invention, as shown in FIG. 3, when a pallet 15 passes through the zone o is the suction opening 24, it encloses

  a variable-volume chamber indicated at 48 in

  a progressive compression action and, after a brief rotation, the pallet 15 which forms the front limit of this chamber 48 reaches the right of the initial segment 45 of the discharge opening 44 thus putting the chamber 48 in communication with the first segment 41 of the discharge pipe; in this way, we avoid the detrimental overpressure of the oil on the

  pallets 15, so that the latter are no longer

  abrupt oscillations and that they can slip smoothly on the inner surface of the

  working chamber 10, thus reducing considerably

  wear, which therefore becomes uniform. The form of

  The addition of this channel-like discharge opening 44, which has been described, also has the effect that the initial segment of the opening which communicates with the

  segment 41 of the discharge pipe is of relative section

  the reduction of the internal pressure of the chamber 48. The advantages of simplicity of realization and efficiency

  operation of the vacuum generator of the pre-

  This invention is therefore evident from this

which has been described.

  It goes without saying that modifications and variants may be made to the device that has just been a non-limiting example, in particular by substituting the equivalent technical means, without departing from the scope of the invention. Among others, the segment 41 of the discharge pipe may not be

of circular section.

Claims (5)

R E V E N D I C A T I ONS   1 - Rotating vane vacuum generator   (1) comprising a support body (2) for supporting   a shaft (11) to rotate a rock   tor (13) which carries a plurality of vanes (15) which slide in cavities (14) in said rotor (13) and whose outer end is applied   in contact with the inner surface of a working cavity   vail (10) formed in said body (2) so as to form   sea working rooms (48) with variable volume between   said pallets (15), this cavity having openings   respective openings for sucking in air (24) and for   air and lubricating oil (44), said opening   discharge nozzle (44) being in communication with a delivery pipe (41, 26) formed in said   support body (2), characterized in that said opening   outlet (44) is formed in said support body (2) and that the angular dimension of said discharge opening (44) is greater than that * of   the initial portion (44) of said discharge conduit.   2 - Vacuum generator according to the claim   1, characterized in that said refolding opening   (44) has an angular dimension substantially equal to the angular distance between the ends of the successive pallets (15).   3 - Vacuum generator according to the claim   1 or 2, characterized in that   the discharge opening (44) is formed in the bottom wall (64) of the working cavity (10) of said support body (2); said discharge duct (41) opening into said bottom wall (64), in the zone   of said discharge opening (44).   4 - Vacuum generator according to one of the   preceding claims, characterized in that said   discharge opening (44) has a profile of nal. 8 2633016   - Vacuum generator according to the claim   4, characterized in that said refolding opening   (44) has a relatively small section,   to be interested solely in the part of the ex-   outer end of said pallets (15), and one more   large section only to the right of flow (41).   6 - Vacuum generator according to one of the   preceding claims, characterized in that said   discharge pipe (41) is practiced at a point where   of the angular decrease of the said opening repression (44).