U.S. patent application number 12/094568 was filed with the patent office on 2009-01-01 for motor/pump assembly with improved sealing.
Invention is credited to Horst Steegmuller, Matthias Tupy.
Application Number | 20090004035 12/094568 |
Document ID | / |
Family ID | 37651066 |
Filed Date | 2009-01-01 |
United States Patent
Application |
20090004035 |
Kind Code |
A1 |
Steegmuller; Horst ; et
al. |
January 1, 2009 |
Motor/Pump Assembly With Improved Sealing
Abstract
A motor/pump assembly, in particular for a motor vehicle braking
apparatus is fixed axially on an end face of the pump housing. The
brush plate forms the termination face of the motor with respect to
the pump housing. The boundary area of the motor housing which
faces the pump housing and that area of the brush plate which is
radially adjacent to the boundary area of the motor housing each
have a seal-accommodating step, into which a seal is inserted which
is compressed axially by the pump housing being fixed to the
motor.
Inventors: |
Steegmuller; Horst;
(Wurzburg, DE) ; Tupy; Matthias; (Oberkotzau,
DE) |
Correspondence
Address: |
BAKER BOTTS L.L.P.;PATENT DEPARTMENT
98 SAN JACINTO BLVD., SUITE 1500
AUSTIN
TX
78701-4039
US
|
Family ID: |
37651066 |
Appl. No.: |
12/094568 |
Filed: |
October 23, 2006 |
PCT Filed: |
October 23, 2006 |
PCT NO: |
PCT/EP06/67664 |
371 Date: |
September 11, 2008 |
Current U.S.
Class: |
417/423.14 ;
29/888.02; 417/423.7 |
Current CPC
Class: |
B60T 8/368 20130101;
H02K 5/10 20130101; F04B 1/0448 20130101; F04B 17/03 20130101; Y10T
29/49236 20150115; H02K 7/075 20130101 |
Class at
Publication: |
417/423.14 ;
417/423.7; 29/888.02 |
International
Class: |
F04B 17/03 20060101
F04B017/03 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 24, 2005 |
DE |
10 2005 056 082.2 |
Claims
1. A motor/pump unit comprising: a motor having a pot-shaped motor
housing and a brush plate provided in the motor housing, and a pump
having a pump housing, wherein the motor is secured axially to an
end face of the pump housing, the brush plate forms the terminating
face of the motor with respect to the pump housing, the edge region
of the pot-shaped motor housing facing the pump housing has a
seal-accommodating stage, the region of the brush plate radially
adjacent to the edge region of the motor housing likewise has a
seal-accommodating stage, and inserted into said seal-accommodating
stages is a seal which is axially compressed through securing of
the pump housing on the motor.
2. The motor/pump unit according to claim 1, wherein the
seal-accommodating stage of the brush plate is slanted so that the
seal-accommodating stage has sides that enclose an angle less than
90.degree..
3. The motor/pump unit according to claim 1, wherein the
seal-accommodating stage of the motor housing has a slant on which
is provided a monitoring area at which the presence of the seal is
detected.
4. The motor/pump unit according to claim 1, wherein the motor is
secured axially to an end face of the pump housing by means of a
screw connection.
5. The motor/pump unit according to claim 1, wherein a rotor shaft
of the motor is ducted through a bearing into the pump housing and
secured to the pump housing in a bearing of the pump.
6. The motor/pump unit according to claim 2, wherein the
seal-accommodating stage has sides that enclose an angle of about
45.degree..
7. The motor/pump unit according to claim 1, wherein the seal is
circumferential sealing washer.
8. A method for sealing motor/pump unit comprising the steps of:
providing a motor having a pot-shaped motor housing and a brush
plate provided in the motor housing, and providing a pump having a
pump housing, wherein the brush plate forms the terminating face of
the motor with respect to the pump housing, the edge region of the
pot-shaped motor housing facing the pump housing and the region of
the brush plate radially adjacent to the edge region of the motor
housing form a mutually adjacent seal-accommodating stage;
inserting a seal into the mutually adjacent seal-accommodating
stage; securing the motor axially to an end face of the pump
housing.
9. The method according to claim 8, wherein the seal-accommodating
stage of the brush plate is slanted so that the seal-accommodating
stage has sides that enclose an angle less than 90.degree..
10. The method according to claim 8, wherein the seal-accommodating
stage of the motor housing has a slant on which is provided a
monitoring area at which the presence of the seal is detected.
11. The method according to claim 8, wherein the motor is secured
axially to an end face of the pump housing by means of a screw
connection.
12. The method according to claim 8, wherein a rotor shaft of the
motor is ducted through a bearing into the pump housing and secured
to the pump housing in a bearing of the pump.
13. The method according to claim 9, wherein the seal-accommodating
stage has sides that enclose an angle of about 45.degree..
14. The method according to claim 9, wherein the seal is
circumferential sealing washer.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a U.S. national stage application of
International Application No. PCT/EP2006/067664 filed Oct. 23,
2006, which designates the United States of America, and claims
priority to German Application Number 10 2005 056 082.2 filed Nov.
24, 2005, the contents of which are hereby incorporated by
reference in their entirety.
TECHNICAL FIELD
[0002] The invention relates to a motor/pump unit.
BACKGROUND
[0003] Known from EP-B1-0 645 875 is a motor/pump unit that is in
particular a motor vehicle anti-locking braking device. Said known
unit contains a motor housing, a pump housing, and an electronics
housing. The motor housing is located with one of its end faces in
front of one of the pump housing's end faces. The electronics
housing is located with one of its end faces in front of the pump
housing's other end face. Connecting leads are ducted through the
end faces situated one in front of the other and through the pump
housing as electric power supply or control leads between in each
case the interior of the motor housing on the one hand and that of
the electronics housing on the other. The end faces situated one in
front of the other are sealed one from the other, particularly
radially outward, by means of circumferential seals situated
between them. Said seals are generally produced by silicone rubber
overmolding.
[0004] A further motor/pump unit is known from DE-C1-101 62 247.
Said known unit is also a motor vehicle braking device. Said device
contains a motor housing, a pump housing, and an electronics
housing located axially one behind the other in a sandwich
arrangement. At least two mutually electrically insulated plug-type
power supply or control leads are ducted from the motor housing to
the electronics housing. The plug-type power supply or control
leads are fastened on the motor housing side in a base, in
particular a brush plate, are embodied axially rigidly, and are
free to move transversely to their longitudinal direction at least
in terms of tolerance compensation. The plug-type power supply or
control leads can with axial support with respect to the motor
housing be plug-contacted with an electronics unit in the
electronics housing. With the unit assembled, the brush plate can
be supported by at least one supporting rib, located on the outer
edge, on the motor housing's outer circumferential surface counter
to the power supply and control leads' plug-in direction by means
of a press fit taking all tolerances into account.
[0005] Known from EP-A1-1 341 290 is a further motor/pump unit that
is in particular a motor vehicle braking device. Said known unit
has an electric motor and a pump located axially behind it and
driven thereby. Provided between the electric motor and pump is a
drive link having a universal joint. The connection is made via a
coupling part having a form-fitting plug-in receptacle for a rotor
shaft end of the electric motor on the driven side and for a pump
shaft end of the pump on the drive side. The plug-in receptacle is
embodied axially conically. The rotor shaft end and pump shaft end
are mutually axially pretensioned to insure rotational compliance
that is free from play.
[0006] When the motor housing is in the known units sealed from the
pump block and surroundings using silicone rubber overmolding, then
highly complex tools as well as a highly complex process will be
required for doing so. A high error rate will furthermore have to
be accepted. The tool and handling costs will likewise be high.
[0007] It is furthermore already known how to use what are termed
CIPG (cured in place gaskets) seals or wet seals which are injected
onto the hydraulic block or motor while the motor is being
assembled. Motor reworking is problematic when such seals are used
because the motors can no longer be detached from the pump block
and replaced without damaging the seal. The necessary scrapping
entails high costs. The assembly process is also cost-intensive,
complex, and prone to errors.
[0008] It is furthermore already known how to use a plurality of
individual seals, for example O-rings or form rings, for sealing
the motor housing from the pump housing and surroundings. A
disadvantage associated therewith is that the individual seals are
easily lost. That makes checking for the individual seals' presence
unavoidable. The assembly process is more complex. The handling of
parts is time-consuming. Using a plurality of individual seals
increases overall costs.
SUMMARY
[0009] According to an embodiment, a motor/pump unit may comprise a
motor having a pot-shaped motor housing and a brush plate provided
in the motor housing, and a pump having a pump housing, wherein the
motor is secured axially to an end face of the pump housing, the
brush plate forms the terminating face of the motor with respect to
the pump housing, the edge region of the pot-shaped motor housing
facing the pump housing has a seal-accommodating stage, the region
of the brush plate radially adjacent to the edge region of the
motor housing likewise has a seal-accommodating stage, and inserted
into said seal-accommodating stages is a seal which is axially
compressed through securing of the pump housing on the motor.
[0010] According to a further embodiment, the seal-accommodating
stage of the brush plate can be slanted so that the
seal-accommodating stage has sides that enclose an angle less than
90.degree..
[0011] According to a further embodiment, the seal-accommodating
stage of the motor housing may have a slant on which is provided a
monitoring area at which the presence of the seal is detected.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Further advantageous characteristics of the invention will
emerge from its exemplary elucidation with reference to the
figures, in which:
[0013] FIG. 1 is a partial sectional representation of a motor/pump
unit according to an embodiment,
[0014] FIG. 2 is an enlarged representation of detail X shown in
FIG. 1 with the seal not yet in the compressed condition, and
[0015] FIG. 3 is another enlarged representation in which sealing
is shown in the compressed condition.
DETAILED DESCRIPTION
[0016] According to various embodiments, both the sealing function
will be improved and the seal's service life extended because the
seal's tensioned or compressed condition acts in one direction
only. No silicone rubber overmolding is needed for insuring the
sealing function. That function can be brought about simply and
economically by inserting a seal into the motor housing's and brush
plate's mutually adjacent seal-accommodating stages during assembly
of the motor/pump unit, which seal will then be automatically
compressed in the axial direction when the pump housing is secured
to the motor. Sealing surfaces reliably preventing an ingress of
brake fluid from the pump side will thereby be created where the
seal makes contact with the brush plate's seal-accommodating stage.
Sealing surfaces sealing the motor housing's interior from the
surroundings will furthermore be created where the seal makes
contact with the motor housing's seal-accommodating stage. A robust
sealing effect will consequently be achieved with just one sealing
component.
[0017] Using a single seal will reduce the number of components
compared with known units where a plurality of seals is used.
[0018] A further advantage is that securing of the brush plate in
the motor/pump unit will also be improved by the seal's axial
compression.
[0019] A further advantage is increased overall system resistance
to aging effects, for example in the case of storage at different
temperatures. Undesired aging effects of the plastic end shield are
particularly avoided. Coarser tolerances at the plastic end shield
will also be possible as well as a reduction in the individual
components' complexity. That will reduce costs.
[0020] More stringent customer requirements in terms of sealing
functionality can furthermore be met by means of the various
embodiments.
[0021] FIG. 1 is a partial sectional representation of a motor/pump
unit according to an embodiment. An electric motor M and a pump P
belong to said motor/pump unit. It can be used, for example, in a
motor vehicle as an anti-locking braking device.
[0022] The motor M has a pot-shaped motor housing 1. A rotor shaft
3 is supported therein in bearings 4 and 5. Rotor laminations 8 are
permanently connected to said shaft so that they turn with the
rotor shaft during operation. Secured to the motor housing's
interior sides are magnetic shells 7 serving when the motor is
operating to energize the rotor winding belonging to the rotor
laminations 8. The rotor winding is connected to a commutator 9
that is likewise secured to the rotor shaft 3 and connected to
brushes secured in a brush plate 11. The brush plate 11 forms the
terminating face of the motor M with respect to the pump housing 2.
The motor M is axially secured to an end face of the pump housing
2, for example through a screw connection. The rotor shaft 3 of the
motor M is ducted through the bearing 9 into the pump housing 2 and
secured there in a bearing 6 on the pump side.
[0023] Provided between the motor housing 1 and pump housing 2 is a
seal 12, preferably a circumferential sealing washer. Said seal
both seals the motor housing 1 from the surroundings and seals the
motor housing 1 against an ingress of brake fluid discharging
undesirably from the pump housing 2.
[0024] FIG. 2 is an enlarged representation of detail X, shown in
FIG. 1, in which the seal 12 and associated accommodating elements
are contained in the motor housing 1 and brush plate 11.
[0025] It can be seen from said figure that the pot-shaped motor
housing 1 has a seal-accommodating stage 1a in its edge region
facing the pump housing 2. The region of the brush plate 11
radially adjacent to the edge region of the motor housing 1 is,
likewise, also provided with a seal-accommodating stage 11a.
[0026] The seal 12 is first inserted into the mutually adjacent
seal-accommodating stages 1a and 11a during assembly of the motor
housing 1 and pump housing 2. It can be seen that the seal 12, not
yet being in the compressed condition, protrudes in the axial
direction from the motor housing 1 after being inserted into the
seal-accommodating stages.
[0027] The monitoring area 16 shown in FIG. 2 has an assisting
function during the assembly process. Force monitoring can
advantageously be performed to determine whether a seal is present
or not. It can thereby be insured that the motor housing is not
inadvertently permanently connected to the gear housing without a
seal's first having been inserted into the seal-accommodating
stages 1a and 11a.
[0028] The seal can in the region of the monitoring area 16
furthermore be slightly compressed in the radial direction when the
seal 12 is inserted into the seal-accommodating stages 1a and 11a
in order to fix the seal somewhat in position so that it cannot
immediately drop out of the seal-accommodating stages 1a, 11a after
being inserted. A sealing function in the radial direction, though,
is not associated therewith.
[0029] FIG. 3 is another enlarged representation in which the seal
12 is shown in the compressed condition. Said compressed condition
is brought about by pressing the pump housing 2 in the axial
direction against the motor housing 1 then securing it in position
thereon using, for example, screws. The seal 12 is compressed in
the axial direction while being thus pressed, as illustrated in
FIG. 3 by the small arrows. The seal 12 is pressed into the
seal-accommodating stages 1a and 11a through being thus compressed
in the axial direction. Sealing surfaces 13 and 14 are created
between the pump housing 2 and brush plate 11 through the seal's
being thus pressed in. Said surfaces will prevent an ingress of
brake fluid undesirably discharged from the pump housing 2 and
located in the groove 17 into the motor housing's interior. A
sealing surface 15 is furthermore created through the seal's being
thus axially pressed into the seal-accommodating stages. Said
surface seals the motor housing 1 from its surroundings so that
nothing from there can penetrate into the interior of the motor
housing 1.
[0030] The sides of the seal-accommodating stages 1a and 11a are
slightly slanted to improve the sealing effect, particularly
against an ingress of brake fluid into the interior of the motor
housing 1. The slant of the brush plate's seal-accommodating stage
11a is therein such that the seal-accommodating stage has sides
enclosing an angle .alpha. that is less than 90.degree. and
preferably approximately in the 45.degree. range.
[0031] Owing to the seal's being compressed exclusively in the
axial direction a single-axis tensioned or compressed condition is
insured that will have a more favorable impact on the seal's
sealing function and service life than an overlaid tensioned or
compressed condition where the seal is compressed in the axial and
radial direction and in the case of which the groove would fill to
a higher level and increased relaxation of tension or, as the case
may be, accelerated material aging hence result.
[0032] In contrast to known methods, sealing of the motor housing
according to various embodiments will also fulfill enhanced
specification requirements in terms of storage at different
temperatures and temperature-change tests of the kind imposed of
late.
[0033] A further major advantage is a simplified assembly process
for the brush system. There is a robust brush system design. There
is no need for silicone rubber overmolding as employed widely
hitherto.
* * * * *