U.S. patent application number 10/381836 was filed with the patent office on 2004-02-12 for hydraulic aggregate for the leakage cavity of a pump.
Invention is credited to Hotzel, Joachim, Schmitt, Stefan A.
Application Number | 20040028544 10/381836 |
Document ID | / |
Family ID | 26007183 |
Filed Date | 2004-02-12 |
United States Patent
Application |
20040028544 |
Kind Code |
A1 |
Schmitt, Stefan A ; et
al. |
February 12, 2004 |
Hydraulic aggregate for the leakage cavity of a pump
Abstract
The present invention relates to a hydraulic aggregate for a
hydraulic controlling and/or regulating device, including a pump
having a pump housing that includes a leakage chamber with a
leakage bore opening into a hollow space of a lid fixed to the pump
housing, said hollow space having a pressure-fluid connection to
the atmosphere. The leakage bore is connected to the atmosphere by
way of a float valve open in its basic position, and the float
valve effects closure of the leakage bore under the effect of
hydrostatic pressure in lid.
Inventors: |
Schmitt, Stefan A;
(Johannesberg, DE) ; Hotzel, Joachim; (Franfurt/M,
DE) |
Correspondence
Address: |
RADER, FISHMAN & GRAUER PLLC
39533 WOODWARD AVENUE
SUITE 140
BLOOMFIELD HILLS
MI
48304-0610
US
|
Family ID: |
26007183 |
Appl. No.: |
10/381836 |
Filed: |
July 23, 2003 |
PCT Filed: |
September 19, 2001 |
PCT NO: |
PCT/EP01/10810 |
Current U.S.
Class: |
417/435 ;
137/205 |
Current CPC
Class: |
F15B 1/26 20130101; Y10T
137/3109 20150401; B60T 8/368 20130101; F16K 31/22 20130101; F04B
53/04 20130101 |
Class at
Publication: |
417/435 ;
137/205 |
International
Class: |
F04B 039/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 27, 2000 |
DE |
100 47 765.8 |
Mar 2, 2001 |
DE |
101 10 072.8 |
Claims
1. Hydraulic aggregate for a hydraulic controlling and/or
regulating device, including a pump having a pump housing that
includes a leakage chamber with a leakage bore opening into a
hollow space of a lid fixed to the pump housing, said hollow space
having a pressure-fluid connection to the atmosphere, characterized
in that the leakage bore (1) is connected to the atmosphere by way
of a float valve (2) open in its basic position, and in that the
float valve (2) effects closure of the leakage bore (1) under the
effect of hydrostatic pressure in lid (3).
2. Hydraulic aggregate as claimed in claim 1, characterized in that
the float valve (2) comprises a valve sleeve (4) which is slidably
arranged in a tubular socket (5) that is inserted into the leakage
bore (1) and extends into the hollow space (6) of the lid (3).
3. Hydraulic aggregate as claimed in claim 1 or 2, characterized in
that at least one leakage channel (7) is interposed between the
tubular socket (5) and the valve sleeve (4), said leakage channel
allowing leakage fluid out of the leakage chamber (8) of the pump
to propagate into the hollow space (6) of lid (3) when the float
valve (2) adopts its open position.
4. Hydraulic aggregate as claimed in any one of the preceding
claims, characterized in that for forming several leakage channels
(7) the valve sleeve (4) includes a square outside profile having
an end that includes a collar (9) whereat an annular seal (10) is
arranged for forming a valve seat, said seal (10) abutting on the
tubular socket (5) and closing the leakage channel (7) under the
effect of hydrostatic pressure.
5. Hydraulic aggregate as claimed in claim 4, characterized in that
the end of the valve sleeve (4) remote from the collar (9) has a
gas-permeable, but fluid-impermeable diaphragm (11) that
fluid-tightly isolates the leakage chamber (8) in the pump housing
from the hollow space (6) in lid (3) when the float valve adopts
its closed position.
6. Hydraulic aggregate as claimed in any one of the preceding
claims, characterized in that the tubular socket (5) in conjunction
with the float valve (2) forms a pre-assembled and pre-adjusted
independently operable assembly, with sections of the tubular
socket (5) being pressed into the leakage bore (1) for the purpose
of adjusting the float valve (2).
7. Hydraulic aggregate as claimed in any one of the preceding
claims 1 to 6, characterized in that there is an axial distance
between the tubular socket (5) and the inside wall of the lid (3)
which is at least as large as the working stroke of the float valve
(2), the said float valve (2) in its open position being supported
with its collar (9) on the inside wall of the lid (3).
Description
[0001] The present invention relates to a hydraulic aggregate for a
hydraulic controlling and/or regulating device according to the
preamble of claim 1.
[0002] DE 198 51 762 A1 discloses a hydraulic aggregate of the type
mentioned hereinabove. The hydraulic aggregate includes a pump
having a leakage chamber that is permanently connected to a hollow
space of a lid by way of a pipe in a leakage bore. Under
unfavorable operating conditions of the hydraulic aggregate, this
arrangement does not always ensure functionally proper ventilation
and venting or a functionally proper leakage discharge of the pump
out of the leakage chamber into the hollow space of the lid. In
addition, the pipe is subject to very close manufacturing
tolerances, especially when the opening of the pipe has a small
design, which may lead to blocking of the pipe passage.
[0003] Therefore, an object of the present invention is to improve
upon a hydraulic aggregate of the generic type in such a way as to
avoid the above-mentioned shortcomings.
[0004] According to the present invention, this object is achieved
for a hydraulic aggregate of the above-mentioned type by way of the
characterizing features of patent claim 1.
[0005] Further features, advantages and possible applications of
the present invention can be taken in the following from the
description of an embodiment making reference to several
accompanying drawings.
[0006] In the drawings,
[0007] FIG. 1 is a sectional view of the relevant components for a
hydraulic aggregate.
[0008] FIG. 2 is a partial view of the hydraulic aggregate
according to FIG. 1 in the closing function of the float valve of
the invention.
[0009] FIG. 3 is a partial view of the hydraulic aggregate
according to FIG. 1 in the partially open position of the float
valve.
[0010] FIG. 4a is an enlarged cross-sectional side view of a valve
sleeve.
[0011] FIG. 4b is a top view of the valve sleeve.
[0012] FIG. 1 shows the principal illustration of a hydraulic
aggregate for a hydraulic controlling and/or regulating device,
including a pump with a pump housing 12 that has a leakage chamber
8 with a leakage bore 1 opening into a hollow space 6 of a lid 3
fixed to the pump housing 12, said hollow space having a
pressure-fluid connection 13 to the atmosphere. According to the
invention, the leakage bore 1 includes a float valve 2, which
either effects ventilation under atmospheric pressure in lid 3 or
closure of the leakage bore 1 under the effect of a hydrostatic
pressure in lid 3. In the illustration shown the float valve 2 is
in its open position under the effect of gravity, the arrangement
of the hydraulic aggregate as depicted contributing to this end. In
detail, the hydraulic aggregate includes a block-shaped pump
housing 12 into which an electric motor with an eccentric is fitted
from above, said electric motor being used to drive a plurality of
pump pistons (not shown in the drawing) in the pump housing 12.
Thus, the leakage chamber 8 generally corresponds to the crank
chamber for receiving the pump drive. Succeeding at the bottom of
the leakage chamber 8 in the direction of the lid 3 is the leakage
bore 1 in the form of a through-bore. Consequently, lid 3 is
disposed below the block-shaped pump housing 12. Ventilation and
venting of the hollow space 6 and the leakage chamber 8 is ensured
by way of the lateral pressure fluid connection 13 disposed at the
deepest point of lid 3, to what end the float valve 2 in the open
position, due to its weight, is supported on the elevated inside
wall of lid 3. This illustrated position of the float valve 2 not
only permits unimpeded ventilation and venting of the hollow spaces
(leakage chamber 8, hollow space 6) being interconnected due to the
generously sized radial distance between the tubular socket 5 and
the valve sleeve 4 of the float valve 2 slidable herein. It
additionally allows unimpeded passage of the pump fluid out of the
leakage chamber 8 into the hollow space 6 of lid 3 so that the
possibly existing pump leakage due to the effect of gravity may
propagate along the inside wall of the lid 3 to the lateral
pressure fluid connection 13 and from there may be discharged out
of lid 3, if so required. This renders an exchange of fluid and gas
along the periphery of the float valve 2 possible at any time, as
long as the float valve 2 keeps assuming the open position
according to the drawing. On the other hand, the function of the
through-opening in the valve sleeve 4 is exclusively limited to the
exchange of gas between the hollow space 6 and the leakage chamber
8 because a fluid-impermeable diaphragm 11 is fitted to valve
sleeve 4, what will be dealt with in the description of the float
valve 2 according to FIGS. 4a, 4b.
[0013] According to the drawing, lid 3 is flanged from below to the
frontal end of pump housing 12. If required, lid 3 accommodates
electrical and/or electronic controlling and regulating elements
for operating the electric motor and, if required, for operating
several solenoid valves arranged in the pump housing 12.
[0014] Different from the open position of the float valve 2 of
FIG. 1, FIG. 2 now shows the closed position of the float valve 2
because the hydraulic unit is in an immersed situation where water
has entered through the pressure fluid connection 13 into the
hollow space 6 of lid 3. Under the effect of the hydrostatic
buoyancy at the float valve 12, the annular seal 10 arranged
between the tubular socket 5 and the collar 9 at float valve 2
closes the slot (leakage channel 7 in FIGS. 4a, 4b) disposed
between the tubular socket 5 and the valve sleeve 4 in a
fluid-tight fashion.
[0015] Due to the valve construction chosen, an air bubble 14
simultaneously remains inside the float valve 2 and assists the
closing movement of the float valve 2. The air bubble 14 in the
float valve 2 is disposed between the water level and the diaphragm
11 fitted at the frontal end of the float valve 2. When the
hydraulic aggregate cools down, the air volume in the leakage
chamber 8 experiences a vacuum effect, since the diaphragm wetted
by water prevents pressure balance. Consequently, the float valve 2
remains without change in the desired closed position until the
immersion action is terminated.
[0016] FIG. 3 shows the float valve 2 at the beginning of opening
when, after termination of the immersion action, the water in the
hollow space 6 is able to exit again to the atmosphere through the
pressure fluid connection 13, whereby the hydrostatic buoyancy at
the float valve 2 collapses. The subsequently dominating weight of
the float valve 2 again offers the possibility of discharging the
pump leakage out of the leakage chamber 8 through the peripheral
leakage channel 7 in the direction of the hollow space 6, while
additionally an exchange of gas can take place via the diaphragm 11
between the leakage chamber 8 or the adjoining housing of the
electric motor and the atmosphere. With a decreasing fluid level in
the hollow space 6, the valve sleeve 4 due to the effect of gravity
and, as the case may be, additionally due to vibrations of the
hydraulic aggregate, will move into the fully opened valve
position, which can already be taken from the illustration of FIG.
1.
[0017] Based on the preceding explanations, FIG. 4a shows an
enlarged side view of the valve sleeve 4 that is preferably made up
of a particularly light material, e.g. of polypropylene, on the
surface whereof a disc-shaped diaphragm 11 is arranged. Said
diaphragm is permeable to gas, but prevents the exchange of fluid,
and it is preferably welded to the valve sleeve 4. What can be
easily seen in this side view are the leakage channels 7 that
extend on either side of the valve sleeve member similar to a
longitudinal groove. Adjacent to channels 7 is an annular seal 10
that is carried by a collar 9 shaped below the tubular portion in
the way of a seat valve.
[0018] Based on FIG. 4a, FIG. 4b shows the top view of the valve
sleeve 4 from which the square outside profile of the valve sleeve
4 becomes clearly apparent, permitting an unhindered gas exchange
and fluid discharge in the open position of the float valve 2. The
diaphragm 11 illustrated as net or mesh can be seen coaxially to
the cross-section of the valve sleeve 4 (e.g. `Goretex` diaphragm),
while the annular seal 10 is retained at collar 9.
[0019] Thus, the present invention describes an automatic float
valve 2 ensuring in its normally open position the ventilation of
the electric motor and the unimpeded leakage discharge out of the
leakage chamber 8 of the pump. In the case of an immersion
situation, the float valve 2 closes automatically and, hence,
situation, the float valve 2 closes automatically and, hence,
prevents the ingress of water into the leakage chamber 8 and into
the electric motor. The use of the gas-permeable diaphragm 11 shall
be noted which, after the immersion situation, renders possible a
pressure balance between the inside chamber of the electric motor
and the atmosphere. The pressure balance is the condition for an
automatic opening of the float valve 2.
[0020] A particularly simple construction is achieved for the float
valve 2 when it is configured as a valve sleeve 4 arranged in a
tubular socket 5 slidable in the leakage bore 1, with sections of
said tubular socket 5 extending into the hollow space 6 of the
cover 3. Between the tubular socket 5 and the valve sleeve 4 at
least one leakage channel 7 is necessary which discharges leakage
fluid out of the leakage chamber 8 of the pump into the hollow
space 6 of the lid 3 when the float valve 2 adopts its open
position.
[0021] A manufacture of several leakage channels 7, which is
especially favorable under the aspects of construction, is possible
when the valve sleeve 4 is designed as square outside profile whose
end portion passes over into a collar 9 at which the annular seal
10 is arranged to form a valve seat. The annular seal closes the
tubular socket 5 and, thus, the leakage channels 7 under the effect
of the hydrostatic lifting force.
[0022] As mentioned already, the end of the valve sleeve 4 remote
from the collar 9 has a special significance because it receives
the gas-permeable but fluid-impermeable diaphragm 11 separating the
leakage chamber 8 in the pump housing in a fluid-tight manner from
hollow space 6 and lid 3 when the float valve 2 assumes its closed
position.
[0023] The construction presented hereinabove renders it possible
that the tubular socket 5 with the float valve 2 forms a
pre-assembled and pre-adjusted, independently operable assembly
having sections of tubular socket 5 pressed by a defined standard
into the leakage bore 1 for the purpose of adjusting the float
valve 2.
[0024] Under construction aspects care must be taken that an axial
distance is provided between the tubular socket 5 and the inside
wall of the lid 3 which is at least as large as the working stroke
of the float valve 2, said float valve 2, in its open position,
being supported with its collar 9 on the inside wall of lid 3.
1 List of Reference Numerals 1 leakage bore 2 pump housing 3 lid 4
valve sleeve 5 tubular socket 6 hollow space 7 leakage channel 8
leakage chamber 9 collar 10 annular seal 11 diaphragm 12 pump
housing 13 pressure fluid connection 14 air bubble
* * * * *