U.S. patent application number 16/639159 was filed with the patent office on 2020-07-09 for oscillating piston pump for fluids.
The applicant listed for this patent is NIDEC GPM GmbH. Invention is credited to Conrad Nickel, Franz Pawellek.
Application Number | 20200217314 16/639159 |
Document ID | / |
Family ID | 62916697 |
Filed Date | 2020-07-09 |
![](/patent/app/20200217314/US20200217314A1-20200709-D00000.png)
![](/patent/app/20200217314/US20200217314A1-20200709-D00001.png)
![](/patent/app/20200217314/US20200217314A1-20200709-D00002.png)
![](/patent/app/20200217314/US20200217314A1-20200709-D00003.png)
United States Patent
Application |
20200217314 |
Kind Code |
A1 |
Nickel; Conrad ; et
al. |
July 9, 2020 |
OSCILLATING PISTON PUMP FOR FLUIDS
Abstract
The invention relates to an oscillating piston pump for liquid
and gaseous fluids, comprising: a pump housing having at least two
sector-shaped working chambers, which are diametrically opposed
relative to a pivot axis arranged in-between; an oscillating
piston, having at least two displacement portions which extend
diametrically relative to the pivot axis and are each received
pivotably in one of the working chambers; an electric drive, which
moves the oscillating piston alternately on a pivot movement
between two turning points delimited within the working chambers; a
group of outlet valves, which ensure the discharge of a volume
displaced from the working chambers to a pump outlet; and a group
of inlet valves, which ensure the entry of a volume flowing into
the working chambers from a pump inlet. The group of outlet valves
or inlet valves is arranged on both sides of each working chamber
and communicates through the pump housing with the pump outlet or
the pump inlet. The other group of inlet valves or outlet valves is
arranged in the oscillating piston and communicates via a cavity in
the oscillating piston with the pump inlet or the pump outlet.
Inventors: |
Nickel; Conrad; (Troistedt,
DE) ; Pawellek; Franz; (Lauertal, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NIDEC GPM GmbH |
Auengrund Ot Merbelsrod |
|
DE |
|
|
Family ID: |
62916697 |
Appl. No.: |
16/639159 |
Filed: |
July 16, 2018 |
PCT Filed: |
July 16, 2018 |
PCT NO: |
PCT/EP2018/069248 |
371 Date: |
February 14, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04C 15/064 20130101;
F04C 9/00 20130101; F04C 2240/603 20130101; F04C 21/00 20130101;
F04C 2240/40 20130101; F04C 2240/60 20130101; F04C 9/002 20130101;
F04C 2240/20 20130101 |
International
Class: |
F04C 9/00 20060101
F04C009/00; F04C 15/06 20060101 F04C015/06 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 28, 2017 |
DE |
10 2017 122 611.7 |
Claims
1. A swivel piston pump for liquid and gaseous fluids, comprising:
a pump housing having at least two sector-shaped working chambers
opposing each other diametrically with respect to a pivot axis
positioned therebetween; a swivel piston having at least two
displacement sections which extend diametrically with respect to
the pivot axis and which are each received in a swiveling manner in
one of the working chambers; an electrical drive which moves the
swivel piston alternately between two turning points on a pivoting
motion contained within the working chamber; a set of outlet valves
which allow a volume displaced from the working chambers to exit
toward a pump outlet; and a set of inlet valves which allow a
volume flowing into the working chambers to enter from a pump
inlet; wherein at least one of the set of outlet valves and set of
inlet valves) is arranged on both sides of each working chamber and
communicates with one of the pump outlet or and pump inlet through
the pump housing; and configured such that the other set of the
inlet valves or set of the outlet valves is disposed in the swivel
piston and communicates with the pump inlet or pump outlet via a
cavity in the swivel piston.
2. The swivel piston pump according to claim 1, wherein the cavity
of the swivel piston is opened towards an axial side relative to
the pivot axis, and an orifice of the pump inlet or pump outlet
facing the swivel piston is formed in the pump housing so as to
overlap an opened cross-section of the cavity).
3. The swivel piston pump according to claim 1, wherein the opened
cross-section of the cavity extends annularly around the pivot
axis, and the orifice of the pump inlet or pump outlet is disposed
centrally with respect to the pivot axis.
4. The swivel piston pump according to claim 1, wherein the cavity
takes the form of a hollow space matching the outer contour of the
swivel piston.
5. The swivel piston pump according to claim 1, wherein the swivel
piston is produced as a molded plastic part having an overmolded
steel shaft as the pivot axis.
6. The swivel piston pump according to claim 1, wherein the outlet
valves are formed by flexible lock vanes which release an outlet
side of a valve opening.
7. The swivel piston pump according to claim 1, wherein the inlet
valves are each formed by an arrangement of prisms of triangular
cross-section which are flexibly movable with respect to each
other, said prisms being disposed with an apex edge of the
cross-section facing a flow direction and being disposed
perpendicularly facing a shut-off direction with a lateral side of
the cross-section.
8. The swivel piston pump according to claim 1, wherein the
electrical drive is configured as a rotary solenoid drive having an
armature which can be pivoted electromagnetically around a pivot
axis between two working points, and is fixed non-rotatably with
the swivel piston.
9. The swivel piston pump according to claim 1 7, wherein the
electrical drive is configured as an electrically rotating motor
that is coupled to the swivel piston via an eccentric actuator
mechanism.
10. A method of using a swivel piston pump according to claim 1 for
pumping liquid and/or gaseous fluids.
11. A method of using a swivel piston pump according to claim 1 as
a lubricating oil pump for a transmission.
Description
[0001] The present invention relates to an electric swivel piston
pump for liquid and gaseous fluids, which may be applied
universally for different applications, e. g., as an oil pump or as
a compressor.
[0002] For this purpose, primarily revolving displacement pumps,
for example, vane pumps or rotary vane pumps, are known in the
related art, which are widely used for liquid as well as gaseous
fluids. During production, a great number of components, such as
vanes, springs and seals, must be installed at such vane pumps due
to their configuration. Furthermore, in order to ensure a long
durability, numerous fits relevant for sliding or sealing must be
manufactured with great dimensional accuracy at vanes, sliding slit
pockets and the like, because occasional tolerance deviations limit
the functionality.
[0003] In addition, non-revolving displacement pumps with
oscillating pump components, such as swivel piston pumps or
pendulum piston pump, are known from other applications, e.g.
oil-free vacuum pumps, which are able to operate with gasses
without a lubrication supply, the pistons of the pendulum running
up against an air cushion at a stationary chamber wall. The pump
assembly of such swivel piston pump may include relatively few
components, i.e., a piston capable of swinging or a pendulum, and a
pump chamber with valves, to be more precise.
[0004] The patent application DE 10 2016 119 985.0 of the same
applicant, which was not yet published on the date of filing of the
present patent application, describes a pendulum piston pump in an
exemplary application as an oil-free vacuum pump at a break booster
of a vehicle.
[0005] This pendulum piston pump includes a pendulum, a pump
housing, a plurality of check valves, intake ports and an eccentric
driving mechanism. The pendulum is pivotable around a pivot point
and has two pistons. The pump housing has two sector-shaped pump
chamber segments and lateral run-up surfaces that respectively
limit outer-most positions of the pivoting motion of the pendulum
at each piston. Check valves unblock a connection to the outside
when receiving pressure from the pump chamber segments. Intake
ports of the inlet are closed against the pump chamber segments
during the pivoting motion of the pendulum due to an overlap with
the respective piston. They are unblocked in a turning area when
passing through the outermost position of the piston. An eccentric
driving mechanism is provided between the pendulum and an electric
motor.
[0006] Such pendulum piston pumps or swivel piston pumps are
relatively compact and powerful and have a simple assembly with few
individual pump components. However, they are limited to the supply
of gasses, i.e., compressible mediums.
[0007] The object of the present invention is to provide another
compact pump with an economic assembly that is also suitable for
supplying fluids or liquid mediums.
[0008] This object is achieved according to the present invention
with a swivel piston pump having the features of claim 1 for liquid
and gaseous fluids.
[0009] The electrically driven swivel piston pump comprising, among
other elements, a swivel piston having displacement sections which
extend diametrically and which are received in sector-shaped
working chambers of a pump housing, as well as a set of inlet
valves or outlet valves arranged on both sides of the working
chambers, is particularly characterized by the fact that the other
set of the inlet valves or outlet valves is disposed in the swivel
piston and communicates with the pump inlet or the pump outlet via
a cavity in the swivel piston.
[0010] The invention thus provides, for the first time, a swivel
piston pump of which the inlet guide or outlet guide opens into the
working chamber through the pump housing on the one hand and
through the swivel piston on the other hand.
[0011] In conventional assemblies, in which the inlet guide as well
as the outlet guide open into the working chamber through the pump
housing, an orifice, usually the one of the inlet guide, is covered
by the piston and only temporarily unblocked. A charge exchange
with the working chamber may thus only take place during a part of
the piston stroke. In order to configure a volumetrically efficient
operating path of the piston effectively in favor of the
displacement volume for each piston stroke, a corresponding ability
for charge exchange only extends to the turning area of the piston.
Due to the short available time frame for filling or taking in a
pumping medium in an emptied working chamber, such swivel piston
pumps or pendulum piston pumps are only suitable for an efficient
operation with compressible, gaseous mediums.
[0012] By means of the assembly according to the present invention,
the orifice of the inlet guide and the orifice of the outlet guide
guarantee a continual charge exchange across the entire piston
stroke, which enables a volumetrically efficient operation to be
realized with incompressible, liquid mediums or a fluid with any
arbitrary ratio of gas phase to liquid phase, in addition to
compressible, gaseous mediums.
[0013] Compared with revolving displacement pumps, such as vane
pumps, which are suitable for supplying liquid mediums, the swivel
piston pump according to the present invention achieves an improved
performance-dimension ratio.
[0014] In addition, the assembly of the swivel piston pump
according to the present invention includes fewer components
compared to vane pumps and fewer sliding contact surfaces, such
that it may be produced more economically with respect to assembly
work and choice of materials.
[0015] Advantageous further embodiments of the swivel piston pump
according to the present invention are the object of the dependent
claims.
[0016] According to an aspect of the invention, the cavity of the
swivel piston is opened towards an axial side relative to the pivot
axis, and an orifice of the pump inlet or pump outlet facing the
swivel piston may be formed in the pump housing so as to overlap an
opening cross-section of the cavity.
[0017] Due to a corresponding end-face intersection of the inlet
guide or the outlet guide between the housing wall and the moved
piston, a flow connection may be realized by means of a gap seal or
the like without interfering with the piston motion. Compared to a
flexible passage or the like, a non-fatiguing flow connection is
thus provided.
[0018] According to an aspect of the invention, the opening
cross-section of the cavity may extend annularly around the pivot
axis, and the orifice of the pump inlet or the pump outlet may be
disposed centrally with respect to the pivot axis.
[0019] This configuration achieves a regular flow cross-section at
the intersection between the pump housing and the swivel piston
across the entire pivoting motion.
[0020] According to an aspect of the invention, the cavity takes
the form of a hollow space matching the outer contour of the swivel
piston.
[0021] Due to this configuration, the flow cross-section is
maximized in the swivel piston. At the same time, the oscillating
mass of the swivel piston and the necessary material usage is
minimized, which lowers a drive power and material costs.
[0022] According to an aspect of the invention, the swivel piston
may be produced as a moulded plastic part having an overmoulded
steel shaft as a pivot axis.
[0023] This choice of materials further favors the goals of a low,
oscillating mass as well as an economic implementation of the
swivel piston as a molding piece.
[0024] According to an aspect of the invention, the outlet valves
may be formed by flexible lock vanes that release an outlet side of
a valve opening.
[0025] Due to this configuration, the valves of the pump are
provided as economic bent sheet-metal parts or other flexible
materials as a single part, which are, for example, punched out in
the shape of a brace or the like, formed, and inserted into a
receptacle of the pump housing.
[0026] According to an aspect of the invention, the inlet valves
are each formed by an arrangement of prisms of triangular
cross-section which are flexibly movable with respect to each
other, said prisms being disposed facing a flow direction with an
apex edge of the cross-section and being disposed perpendicularly
facing a shut-off direction with a lateral side of the
cross-section.
[0027] Due to this configuration, the valves of the pump are
manufactured by selecting a material of suitable elasticity as a
molded piece or even integrally with the molded piece of the swivel
piston. The flow-effective shape and alignment of such flexible,
prismatic valve elements causes the same to automatically spread or
press together as a function of the flow-through direction. In the
shown application as inlet valves at a swivel piston, the
functionality of closing and opening is additionally,
simultaneously supported by the mass inertia of the flexible valve
elements in the oscillating acceleration progression of the
piston.
[0028] According to an aspect of the invention, the electric drive
may be configured as a rotary solenoid drive, the armature of which
may be pivoted electromagnetically around the pivot axis between
two working points, and is fixed non-rotatably with the swivel
piston.
[0029] The drive concept of a rotary solenoid drive is ideal for
the operating mode of an oscillating displacement piston, because
the generated and the required torque progression are not constant
but increase equally towards the working points of the rotary
solenoid or towards the turning points of the swivel piston.
[0030] In addition, a direct drive connection may be configured by
means of a shaft without eccentric kinematics or the like. In
addition, more economic control electronics may be implemented as
an ECU common in the related art for a brushless dc motor.
[0031] According to an aspect of the invention, the electric drive
may be configured as an electrically rotating motor that is coupled
to the swivel piston via an eccentric actuator mechanism.
[0032] In the case of this alternative, an available variety of
economic standard drives may be used at least with respect to the
electric motor.
[0033] The invention is described below in detail based on one
exemplary embodiment with reference to the drawings. They show:
[0034] FIG. 1 a cross-section through the swivel piston pump
according to the present invention with a plan view of the swivel
piston, the working chambers and the valves;
[0035] FIG. 2 a perspective view of the swivel piston pump
according to the present invention with a central intake port and a
pressure socket;
[0036] FIG. 3 a longitudinal section through the swivel piston pump
according to the present invention with a rotary solenoid
drive.
[0037] First, the structure of an exemplary embodiment of the
swivel piston pump according to the present invention designed to
be used as an oil pump in a low-pressure lubricant system, e.g.,
for supplying lubrication oil to gears in a transmission will be
described with reference to FIG. 1.
[0038] In FIG. 1, at the top left and lower right of a pivot axis
12, two sector-shaped working chambers 10 opposing each other
diametrically are illustrated that extend inside the pump housing 1
on one plane with the pivoting motion of the swivel piston 2. The
flanks of the working chamber 10 form run-up surfaces for the
swivel piston 2.
[0039] Illustrated at the top right and lower left of the pivot
axis 12, two areas of a pump outlet 14 connected via a bow-shaped
channel in the pump housing 1 are arranged between the working
chambers 10. Between the working chambers 10 and the pump outlet
14, valve openings are formed in the run-up surfaces of the working
chambers 10. The valve openings, together with clasp-like, flexible
lock vanes 40 that respectively cover a side lying on the outside
with respect to the working chamber 10, of the valve opening, form
outlet valves 4 of the swivel piston pump.
[0040] The swivel piston 2 is fixed on the pivot axis 12 which is
simultaneously a drive shaft of the electric drive 3. The swivel
piston 2 includes two displacement sections 20 which are
alternately pivoted in the working chambers 10 over a rotational
angle of approximately 90.degree., as shown by the double arrow.
Between the displacement sections 20, the swivel piston 2 has a
circular outer contour. The inside of the swivel piston 2 is a
hollow part and opened to the side of the viewer of the
illustration, which results in a cavity 25. The cavity 25 surrounds
an accommodation of the pivot axis 12 and extends into the
displacement sections 20.
[0041] Inlet valves 5 of the swivel piston pump are provided in the
flanks of the displacement sections 20 that are pivoted towards the
run-up surfaces of the working chambers 10. The inlet valves 5 are
formed by prismatic sections 50 and openings in the area of the
wall of the swivel piston 2 lying therein between. The prismatic
sections 50 have a triangular cross-section and are formed
integrally with the swivel piston 2 at one end. Due to the fact
that in the exemplary embodiment it is inlet valves 5 which allow a
sucked-in delivery flow to pass through from the cavity 25 into a
working chamber 10 and which are supposed to block in the reverse
direction, all triangular cross-sections are arranged in a
flow-efficient manner such that they point towards the cavity 25
with an apex and point towards the pump chamber 10 with a surface
or hypotenuse of the triangle.
[0042] The prismatic sections 50 have a free end towards the open
side of the cavity 25, such that they may incline at the free end
like cantilevers clamped in on one side when a material with
sufficient elasticity is chosen, particularly a plastic material.
When the pump medium flows through, the prismatic sections 50 are
thus flexibly inclined, either spreading apart at the free end or
pressing together depending on the flow direction due to the
different flow resistance of the triangular cross-section. A
passage function and a blocking function thus result in opposing
flow directions.
[0043] In the exemplary embodiment of the swivel piston pump, which
is configured for use as a lubrication oil pump, that is, for
pumping mediums of higher viscosity, a sufficient valve function
may already be achieved by means of the illustrated arrangement of
three prismatic sections 50 with a central, larger cross-section,
and two smaller cross-sections offset thereto, the blocking
function being improved by selecting different cross-section
sizes.
[0044] In FIG. 2, an outer side of a pump cover 11 of the swivel
piston pump is illustrated at which an intake port of the pump
inlet 15 and a pressure socket of the pump outlet 14 are apparent.
The intake port of the pump inlet 15 is arranged centrally with
respect to the pivot axis 12 in the pump cover 11, such that it
opens directly into the cavity 25 within the circular outer contour
of the swivel piston 2, independently of its position. As is
apparent from FIGS. 1 and 2, the pressure socket of the pump outlet
14 opens into the area of the pump outlet 14 illustrated at the
lower left of the pivot axis 12.
[0045] As shown in FIG. 3, the pump housing 1 furthermore includes
a flange section, in which an electric drive 3 is accommodated,
directed in the direction of the working chamber 10. At a side of
the pump housing 1 shown on the right, another flange section
closed by a cover 13 is provided in which a control circuit 34 of
the electric drive 3 is accommodated. Lead terminals leading
towards solenoids 30 of the electric drive 3 exit from the pump
housing 1 through a socket illustrated as being directed
upwards.
[0046] In the shown embodiment, the electric drive 3 is provided by
what is called a bistable rotary solenoid including two solenoids
30 and an armature 32. The solenoids 30 are axially separated from
one another and are in contact with two pole rings 31, which are
also axially separated, and with a coaxial ferrite core 33. The
armature 32 is pivotable on the pivot axis 12 and has two armature
bodies which each have a diametrically longer extension of the
circumference and, offset by 90.degree. thereto, a diametrically
shorter extension of the circumference, i.e., for example, a
circular area with two ring segments recessed at the inside
opposite of one another. The armature bodies are each accommodated
and mounted in a central recess of a pole ring 31. Each recess of
the pole rings 31 has two opposing pole shoes.
[0047] When one of the solenoids 30 is supplied with current, the
armature 32 pivots into a position by means of a reluctance force,
in which the corresponding armature body aligns itself with its
longer diametric extension between the pole shoes of the recess of
the corresponding pole ring 31 in order to decrease the air gap and
thus the magnetic resistance in a magnetic circuit passing through
the solenoid 30, the ferrite core 33, the pole ring 31 and the
armature body.
[0048] The pole shoes of the two pole rings 31 or the two armature
bodies of the armature body 32 are off-set to one another by
90.degree.. Thus an alternating pivoting motion of the pivot axis
12 by 90.degree. is generated when the two solenoids 30 are
alternately supplied with current by the control circuit 34.
[0049] In the following, the functionality of the swivel piston
pump will be explained.
[0050] When the swivel piston 2 moves from the initial position
shown in FIG. 1 in a counterclockwise direction, a volume of the
pumping medium is displaced in front of the swivel piston 2 or
discharged from the working chambers 10. The flexible lock vanes 40
of the outlet valves 4 are thereby pushed in an outward direction
at the pressure side of the swivel piston 2 in the pump housing 1
and unblock the valve openings. The prismatic sections 50 of the
inlet valves 5 at the front pressure side of the swivel piston 2
are press against one another at the free ends and block a passage
to the cavity 25.
[0051] At the same time, negative pressure is generated in a
section of the working chamber 10 at the rear side of the swivel
piston 2 such that a volume of the pumping medium sucked in through
the pump inlet 15 follows and flows into the working chamber 10.
Prismatic sections 50 of the inlet valves 5 at the rear intake side
of the swivel piston 2 are thereby spread apart the the free ends
by the delivery flow taken in and open for a flow from the cavity
25 into the working chamber 10. The flexible lock vanes 40 of the
outlet valves 4 are pulled against the valve openings in the pump
housing 1 at the intake side of the swivel piston 2 and block the
outlet valves 4.
[0052] The same functionality is provided in a reverse pivoting
motion back to the initial position of the swivel piston 2 in FIG.
1. The swivel piston pump is thus a double-stroke pump.
* * * * *