U.S. patent application number 14/520908 was filed with the patent office on 2015-04-23 for hydraulic piston pump having distribution through a bi-directional port plate.
The applicant listed for this patent is HYDRO LEDUC. Invention is credited to Francois POREL.
Application Number | 20150110656 14/520908 |
Document ID | / |
Family ID | 49667491 |
Filed Date | 2015-04-23 |
United States Patent
Application |
20150110656 |
Kind Code |
A1 |
POREL; Francois |
April 23, 2015 |
HYDRAULIC PISTON PUMP HAVING DISTRIBUTION THROUGH A BI-DIRECTIONAL
PORT PLATE
Abstract
A hydraulic pump having a plurality of pistons sliding in bores
formed in a barrel mounted in rotation in a casing of the pump, the
barrel bearing against a distribution port plate borne by a
cylinder head. Two drainage channels place an inner space of the
casing in respective communication with two suction/delivery
orifices of the cylinder head. Each drainage channel is provided
with a valve able to close the drainage channel in response to an
overpressure in the suction/delivery orifice such that, according
to the direction of rotation of the pump, the inner space of the
casing is in communication through one of the drainage channels
with the suction line; whereas the communication through the other
drainage channel between the delivery side and the inner space of
the casing is closed.
Inventors: |
POREL; Francois; (Sainte
Pole, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HYDRO LEDUC |
Azerailles |
|
FR |
|
|
Family ID: |
49667491 |
Appl. No.: |
14/520908 |
Filed: |
October 22, 2014 |
Current U.S.
Class: |
417/538 |
Current CPC
Class: |
F04B 1/122 20130101;
F04B 53/04 20130101; F04B 1/2042 20130101; F04B 1/24 20130101; F03C
1/0642 20130101; F03C 1/14 20130101; F04B 49/22 20130101 |
Class at
Publication: |
417/538 |
International
Class: |
F04B 1/12 20060101
F04B001/12; F04B 49/22 20060101 F04B049/22 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 22, 2013 |
FR |
1360278 |
Claims
1. A hydraulic piston pump of the type having a plurality of
pistons sliding in bores formed in a barrel mounted in rotation in
a casing of the pump, said barrel bearing against a distribution
port plate borne by a cylinder head, said distribution port plate
being provided with two symmetrical crescents serving alternately
as a suction crescent and a delivery crescent according to the
direction of rotation of the pump, in which the cylinder head is
provided with two drainage channels placing an inner space of the
casing in respective communication with two suction/delivery
orifices of said cylinder head; each drainage channel being
provided with a valve, wherein the valve has in each case a
compression spring housed in the drainage channel so as to maintain
the valve in an open position by default, the valve being able to
close the drainage channel in response to an overpressure in the
suction/delivery orifice such that, according to the direction of
rotation of the pump, the inner space of the casing is in
communication through one of the drainage channels with the suction
line; whereas the communication through the other drainage channel
between the delivery side and the inner space of the casing is
closed.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS AND CLAIM TO PRIORITY
[0001] This application claims priority to Patent Application No.
1360278 filed Oct. 22, 2013 in France, the disclosure of which is
incorporated herein by reference and to which priority is
claimed.
FIELD OF THE INVENTION
[0002] The present invention relates to a hydraulic piston pump and
more particularly a hydraulic piston pump in which distribution
takes place by means of a port plate.
BACKGROUND OF THE INVENTION
[0003] To allow a piston pump having distribution through a port
plate to be able to rotate either to the right or to the left, it
is necessary to construct this pump, on the one hand, by designing
a symmetrical distribution port plate such that the delivery zone
of the pump can become a suction zone and vice versa and, on the
other hand, by incorporating orifices in the pump which can receive
either a suction connection or a delivery connection.
[0004] According to the direction of rotation of the pump, each of
the two orifices of the pump will become either a suction orifice
or a delivery orifice.
[0005] In such an arrangement, the leaks of the distribution port
plate on the delivery side of the pump, which is the pressure side,
will be collected by the casing of the pump.
[0006] To evacuate these leaks, it is necessary to provide a
connection of the casing of the pump toward the supply reservoir of
the pump by installing a drainage circuit.
[0007] This need to have a drainage circuit is a disadvantage.
[0008] FR-A-2988143 describes a hydraulic motor with internal
drainage. The hydraulic motor has a drainage orifice communicating
with an inner space of the casing of the motor, an intermediate
pipe into which the drainage orifice of the casing opens, a first
nonreturn valve arranged between the intermediate pipe and a first
bi-directional hydraulic port and able to open under the effect of
a positive pressure differential between the intermediate pipe and
the first bi-directional hydraulic port, and a second nonreturn
valve arranged between the intermediate pipe and a second
bi-directional hydraulic port and able to open under the effect of
a positive pressure differential between the intermediate pipe and
the second bi-directional hydraulic port. Such an arrangement makes
it possible for the liquid arising from the internal leaks of the
motor to be evacuated from the casing through the one of the two
nonreturn valves which is connected to the return port of the
motor. In this device, the valves are closed by default.
SUMMARY OF THE INVENTION
[0009] The object of the present invention is to produce a piston
pump which can rotate either to the right or to the left without
having to put in place a specific pump drainage circuit.
[0010] To achieve this aim, the pump according to the present
invention has a plurality of pistons sliding in bores formed in a
barrel mounted in rotation in a casing of the pump, said barrel
bearing against a distribution port plate borne by a cylinder head,
said distribution port plate being provided with two symmetrical
crescents serving alternately as a suction crescent and a delivery
crescent according to the direction of rotation of the pump, and is
characterized in that the cylinder head is provided with two
drainage channels placing an inner space of the casing in
respective communication with two suction/delivery orifices of said
cylinder head; each drainage channel being provided with a valve
able to close the drainage channel in response to an overpressure
in the suction/delivery orifice such that, according to the
direction of rotation of the pump, the inner space of the casing is
in communication through one of the drainage channels with the
suction line; whereas the communication through the other drainage
channel between the delivery side and the inner space of the casing
is closed.
[0011] According to one embodiment, the valve has in each case a
compression spring housed in the drainage channel so as to maintain
the valve in an open position by default.
[0012] The invention will be better understood, and other aims,
details, features and advantages thereof will become more clearly
apparent during the following description of a number of particular
embodiments of the invention given purely by way of nonlimiting
illustrative example with reference to the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] In these drawings:
[0014] FIG. 1 is a view in longitudinal section of a known type of
hydraulic piston pump.
[0015] FIG. 2 is a view in section on line D-D of FIG. 1.
[0016] FIG. 3 is a perspective view of the pump of FIG. 1 rotating
to the right.
[0017] FIG. 4 is a perspective view of the pump of FIG. 1 rotating
to the left.
[0018] FIG. 5 is a partial view, in longitudinal section,
illustrating the operation of the suction zone of the pump
according to the invention.
[0019] FIG. 6 is a partial view, in longitudinal section,
illustrating the operation of the delivery zone of the pump
according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
[0020] FIG. 1 shows a hydraulic piston pump having a drive shaft 1
provided with a plate 2 against which there bear a plurality of
pistons 3 which slide in bores 4 formed in a barrel 5 housed in a
casing 6 provided with a drainage orifice 8 closed by a cap. The
barrel 5 bears against a distribution port plate 7 borne by a
cylinder head 9.
[0021] In FIG. 2, which is a view in section on D-D of FIG. 1, it
can be seen that, in a known way, the distribution port plate 7 has
two crescents 10 and 11 which are bean-shaped openings and which
are symmetrical. According to the direction of rotation of the
shaft 1, these crescents will serve alternately for suction or for
delivery.
[0022] FIG. 3 shows the position of the suction pipe A when the
drive shaft 1 is rotating to the right (or clockwise
direction).
[0023] FIG. 4 shows the position of this suction pipe A when the
drive shaft is rotating to the left (or counter clockwise
direction).
[0024] A delivery line B, not shown in FIGS. 3 and 4, is connected
to the other orifice of the cylinder head 9.
[0025] During the operation of the pump, hydraulic liquid leaks
occur on the delivery side of the pump. These leaks are collected
in the casing 6 and will be evacuated through the drainage orifice
8, which can be connected to a drainage circuit to return the
liquid arising from the leaks to the reservoir.
[0026] One aim of the present invention is to dispense with this
drainage circuit.
[0027] To achieve this aim, the cylinder head 9 is provided with
two nonreturn valves 12 communicating with the suction/delivery
orifices 20.
[0028] The effect of these two valves 12 is: [0029] on the one
hand, to allow the inner space 17 of the casing 6 to communicate
freely through one of the valves 12 with the suction orifice 20 and
the suction line A, as is illustrated in FIG. 5, thereby placing
the inner space 17 of the casing 6 in connection with the suction
side of the pump and implementing the drainage of the pump; [0030]
on the other hand, closing, through the other valve 12, the
communication of the delivery orifice 20 with the inner space 17 of
the casing 6, as is illustrated in FIG. 6.
[0031] More precisely, the nonreturn valve has a helical spring 13,
a ball 12 serving as a valve, and a channel 14 formed in the
cylinder head 9 so as to connect in each case the suction/delivery
orifice 20 to the inner space 17 of the casing 6 of the pump. The
channel 14 opens into the casing 6 in line with a peripheral
portion of the distribution port plate 7 which has a fluid passage
toward the inner space 17 of the casing 6.
[0032] The spring 13 is housed in a wide section of the channel 14,
bearing between a shoulder of the channel 14 on the casing side and
the ball 12 on the cylinder head side. By default, the spring 13
maintains the ball 12 at a distance from a valve seat 18
surrounding the inlet of the channel 14. Thus, the channel 14 is
open unless there is an overpressure in the suction/delivery
orifice 20 with respect to the inner space 17, which is normally at
atmospheric pressure. The valve 12 is therefore a valve which is
open by default and which closes the channel 14 in response to an
overpressure in the suction/delivery orifice 20 of the cylinder
head.
[0033] Although the invention has been described in conjunction
with a number of particular embodiments, it is clearly obvious that
it is in no way limited thereto and that it encompasses all the
technical equivalents of the means described and combinations
thereof where these fall within the scope of the invention.
[0034] The use of the verb "have", "comprise" or "include" and its
conjugated forms does not exclude the presence of elements or steps
other than those stated in a claim. Unless stated otherwise, the
use of the indefinite article "a" for an element does not exclude
the presence of a plurality of such elements.
[0035] In the claims, any reference sign between parentheses should
not be interpreted as a limitation of the claim.
* * * * *