U.S. patent application number 09/456271 was filed with the patent office on 2001-12-06 for clamping spring ring.
Invention is credited to BRATTHALL, JOHAN, OGREN, LARS, STAHL, BORJE.
Application Number | 20010048844 09/456271 |
Document ID | / |
Family ID | 25681380 |
Filed Date | 2001-12-06 |
United States Patent
Application |
20010048844 |
Kind Code |
A1 |
BRATTHALL, JOHAN ; et
al. |
December 6, 2001 |
CLAMPING SPRING RING
Abstract
The invention concerns a device for mutual locking of two
concentric cylindrical parts such as parts to be used in a
submersible pump unit. One outer part (10) and two inner parts (6)
and (7) are locked mutually by help of a circumferential locking
element (12) having resilient abilities and which is arranged at
the intersectional point between the three parts (6), (7) and
(10).
Inventors: |
BRATTHALL, JOHAN;
(SALTSJO-BOO, SE) ; STAHL, BORJE; (KISTA, SE)
; OGREN, LARS; (TABY, SE) |
Correspondence
Address: |
MENOTTI J LOMBARDI
ITT FLUID TECHNOLOGY
10 MOUNTAINVIEW ROAD
UPPER SADDLE RIVER
NJ
07458
|
Family ID: |
25681380 |
Appl. No.: |
09/456271 |
Filed: |
December 7, 1999 |
Current U.S.
Class: |
403/326 |
Current CPC
Class: |
H02K 5/1732 20130101;
H02K 5/15 20130101; Y10T 403/602 20150115; Y10T 403/60
20150115 |
Class at
Publication: |
403/326 |
International
Class: |
F16B 001/00; F16D
001/00; B25G 003/00; F16G 011/00; B25G 003/18; F16B 021/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 23, 1998 |
SE |
9804525-5 |
Claims
1. A device for mutual axial and radial locking and securing of
cylindrical details, especially an outer detail (10) and two
adjacent internal details (6) and (7) respectively, the lathers
having the same outer diameters which equals the inner diameter of
the outer detail (10), characterized in, that a locking ring
designed as a spring element having an elastically deferrable cross
section, such as a helical spring (12), or a rigid element having a
layer of a resilient material, is compressed in a preferably
circumferentially formed channel which is established in the
intersection between the three details (10), (6) and (7).
2. A device according to claim 1, characterized in, that the outer
detail (10) is a stator housing in an electric motor and that the
inner details (6) and (7) respectively, are a bearing housing and a
bearing cover respectively, said cover being attached to said
bearing housing, the housing as well as the cover being provided
with collars which extend outwards to the stator housing (10).
3. A device according to claim 1, characterized in, that the detail
(10) is provided with an internal groove (11), prefearably around
its entire periphery, which groove accomodates the spring element
(12) in the intersection between the three details (10), (6) and
(7).
4. A device according to claim 1, characterized in, that the detail
(6) and/or alternatively the detail (7) are provided with chamfers
(8) and (9) respectively, facing each other, for accomodating the
spring element (12) in the intersection between the three details
(10), (6) and (7).
5. A device according to claim 1, characterized in, that the
clamping spring (12) is a spiral spring having a diameter
corresponding with the cross section of said channel or channels in
the intersection between the three details (10), (6) and (7), the
ends of said spring being united, thus creating a ring having a
diameter corresponding with the inner diameter of the outer detail
(10).
Description
[0001] The invention concerns a device for mutual locking of
concentric cylindrical parts such as parts in a submersible pump
unit.
[0002] A machine of this type normally includes an electrically
driven motor and a hydraulic unit with a rotating impeller
connected to the motor via a rotary driving shaft.
[0003] In order to prevent the medium within the hydraulic unit
from penetrating the motor along the driving shaft, one or two
seals are normally arranged between the motor and the hydraulic
unit. A common type of seal is the so-called mechanical face seal,
which includes one seal ring rotating with the shaft and one
stationary seal ring attached to the surrounding housing. The two
seal rings are pressed against each other by a spring, thus
preventing medium from entering between the seal surfaces.
[0004] A pump unit of the above mentioned type will thus include an
electric motor, a seal housing and a hydraulic unit with an
impeller connected to the motor via a central rotary shaft.
[0005] In order to keep the different parts together into one unit
there are several solutions. Big machines are normally kept
together by help o flanges provided with a number of bolts along
their circumferences. Smaller machines may be connected by help of
long bolts around the periphery which bolts press the outer parts
towards each other, thus locking the intermediate part
therebetween.
[0006] Examples of such solutions are shown in SE-415 696 and DE-1
653 726.
[0007] A disadvantage with these known solutions is that they are
relatively expensive because of costly materials and because of the
fact that the mounting time could be extensive. The problem to be
solved is thus to obtain a slim design without any outer details
which add to its diameter.
[0008] A device for obtaining a an axial locking between a,
concentric details is disclosed in SE-399 745. An element 6 is here
arranged within grooves in the concentric details thus establishing
an axial mutual locking. A disadvantage however, is that said
element 6 is rigid, which means that the concentric details are not
allowed to come into contact with each other. The result will be
that the mutual location of the details is not defined, but may
vary depending on the dimension of the element 6. In addition there
is no locking aginst mutual rotation.
[0009] The invention is described more closely below with reference
to the enclosed drawings that show a cut through a pump according
to the invention, and a locking coil spring.
[0010] In FIG. 1, 1 and 2 stand for the rotor and the stator
respectively in an electric motor, 3 a driving shaft, 4 and 5
bearings, 6 a bearing housing, 7 a bearing cover, 8 and 9 chamfers
on the peripheries of the bearing housing and the bearing cover
respectively. 10 a capsule surrounding the stator, 11 an internal
groove in said capsule and 12 a locking coil spring.
[0011] FIG. 2 shows the spring 12, in the straight and united
configurations.
[0012] The machine thus comprises an electric driving unit
consisting of a rotor 1 and a stator 2. A driving shaft 3 is
supported in an upper bearing 4 and a lower bearing 5 respectively,
said lower bearing being mounted in a bearing housing 6 having a
cover 7. The machine also comprising a seal housing and a pump
housing with an impeller connected to the lower end of the driving
shaft 3.
[0013] The driving shaft 3 is subject to strong axial forces during
operation and it is thus very important that it is correctly locked
axially in relation to the stator 2. According to the invention,
the lower bearing 5 is supported in a housing 6 which locks the
bearing and prevents it from being moved upwardly or to the side.
The bearing housing 6 is further provided with a collar, the
periphery of which extends out to the stator capsule 10. The
bearing is locked to the housing by a cover 8 which is pressed
against the underside of the bearing and is fixed to the bearing
housing by screws. The periphery of the cover 7 having the same
diameter as the collar on the bearing housing.
[0014] According to the invention the lower bearing 5 is fixed in
the bearing housing 6 in the capsule 10 by help of a special
design. According to a preferred embodiment the capsule 10 is being
provided with an internal circumferential groove 11. The
peripheries of the collar on the bearing housing as well as the
cover 7 are provided with chamfers 8 and 9 respectively. These
create together a ring formed channel on the inside of the capsule.
This channel is utilized for mutual locking of the details in the
following way:
[0015] When the details are mounted the bearing housing 6 is slid
onto the shaft 3 into a position decided by a shoulder on the
shaft. The periphery of the collar on the bearing housing will then
be positioned opposite the groove 11 in the capsule 10. In the ring
formed channel or channels established between the groove 11 and
the chamfer 8 on the periphery of the collar, a looking coil spring
12, having an elastically deformable cross section, is mounted.
Said spring being preferably designed like a spiral spring with its
ends being united thus forming a ring with a diameter mainly the
same as that of the inner wall of the capsule 10. The dimension of
the spring 12 being such that it can be accomodated within the
channel or channels.
[0016] The bearing 5 is then slid onto the shaft and mounted in the
bearing housing 6 and the cover 7 is pressed into alignment with
the underside of the bearing and attached to the bearing housing by
help of axial screws. The chamfer 9 on the periphery of the cover 7
the closes the ring formed channel where the spring 12 has been
inserted. Said spring, the dimension of which being such that it
fills up the channel, then obtains an effective mutual axial as
well as radial locking of the bearing housing and the capsule 10
and consequently also an axial locking of the bearing and the
shaft. The capsule 10 in its turn being pressed around the stator 2
which means that a well connected package is obtained.
[0017] A condition for obtaining a sufficient strength of the
joint, without the demand for extreme manufacturing tolerances, is
that the detail used in the channel must be resilient, but at the
same time sufficiently rigid. A correctly dimensioned spiral spring
is then a perfect solution. By choosing a suitable relationship
between compressing strain and the spring constant in the locking
spring, a butt contact between the bearing housing 6 and the
bearing cover 7 is secured over a a certain tolerance range. A
rigid ring such as a lock ring, demands very high tolerances and an
o-ring is too flexible to obtain a sufficient strength when the
joint is subject to high stress. A rigid ring having a coating of
resilient material could be used and is within the scope of the
invention
[0018] In the description above and in the enclosed drawing the
preferred embodiment is described as a mutual locking between a
bearing housing and a surrounding stator capsule in a submersible
pump. The invention is however not limited to this field, but
possible to apply in general for mutual locking of concentric
details
[0019] Other embodiments within the scope of the invention can be a
division of the groove 11 into several parts. Further variants are
that only one of the parts bearing housing or bearing cover is
provided with a chamfer 8 or 9, or that the room for accommodation
of the coil spring is established by the groove 11 only. According
to still another alternative, the groove is eliminated and the room
for the coil spring is established by one or two chamfers on the
bearing housing and/or the bearing cover.
* * * * *