AXIALLY BIASED SHAFT SEAL

JOINT A COMPRESSION AXIALE POUR ARBRE

English Abstract

ABSTRACT
A shaft seal for a shaft extending through a
bearing eye in a separation wall between a drive motor
space on one side of the wall and a working space on the
other side of the wall, such as in a multipurpose kitchen
machine. A plastic case surrounds the shaft and extends
through a bearing eye in the separation wall, and the
case cooperates with a sealing bell which is engaged by
a sealing ring positioned between the bell and the bearing
eye. The construction is simpler than that utilized in
known devices and avoids the previously usually close
tolerances and resulting higher costs present in known
devices.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A shaft seal for a shaft extending through
a bearing eye in a separation wall between a drive motor
space on one side of the wall and a working space on the
other side of the wall, said seal including a plastic sleeve
surrounding said shaft in one of said spaces and having
an end projecting through said bearing eye with a clearance
between said sleeve and said bearing eye, said end being
secured to said shaft, a sealing bell in the other of said
spaces having an internal opening engaging the end of said
sleeve, said bell having a flared portion defining an
outer surface, a seal member located between said flared
portion and said bearing eye and engaging said outer surface.
2. In a multipurpose kitchen device with an electric
driving motor, a driveshaft penetrating a separation wall
between a motor receiving space and a working space of the
device, where said driveshaft is equipped with a plastic
casing, characterized by said plastic casing being formed
in the area of the separation wall in such a manner that,
in collaboration with a sealing bell, it forms a seal,
appropriate for its use, of the shaft penetration, which
consists of a bearing eye on the one hand and of the drive-
shaft which penetrates it with a certain amount of play on
the other hand, a sealing bell being set on the motor space
side against the bearing eye, which is formed onto the
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separation wall, with a ring seal being placed in between.
3. In a multipurpose kitchen machine according
to claim 2, further characterized by the plastic casing
surrounding the driveshaft as a component of the shaft
penetration and having formed therein a collar with an
annular groove serving to receive a lubricant which at
the same time has a sealing action, where said collar, under
the axial action of the driveshaft, presses the sealing bell
including the ring seal against the bearing eye.
4. In a multipurpose kitchen machine according to
claim 2 or 3, characterized by the circumference of the
casing, which surrounds the driveshaft and a boring which is
associated with the bearing eye, on the one hand, as well
as between the bearing eye and the sealing bell, which is
turned towards it at a small distance, on the other hand,
forming free spaces for receiving the lubricant that is
stored in the annular groove of the collar.
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Description

~7877
This invention relates to a seal, and more particularly
to a seal for use in a multipurpose kitchen machine with an
electric drive motor, whose driveshaft is equipped with a
plastic casing, and wherein the driveshaft penetrates a
separation wall ~etween th.e motor receiving space and the working
space of the machine.
With multipurpose kitchen machines, it is known that
the driveshaft, which can be coupled with different tools and
which protrudes into the working space of the device, can be
sealed bv shaft seals in a manner that is in itself well known,
for example by shaft sealing rings, glands, labyrinth seals,
in the area of the shaft penetrationO In this way, the liquid
or doughy mass which is situated in the working space of the
kitchen appliance is prevented from penetrating into the motor
receiving space of the kitchen machine. One presupposition for
this is that the driveshaft will be ma-tched exactly to the
penetration which is associated with it and which is situated
within the separation wall ~etween the working space and the
motor receiving space of the kitchen machine. This requirement
requires a relatively expensive.mountiny of the driveshaft and
suitable pairings of materials (metal-plastic) in the area of
the separation wall, resulting in relatively high manufacturing
costs.
The purpose of the present invention is to design the
penetration of the driveshaft, which is located in the area of
the separation wall between the motor receiving space and the
working space of the multipurpose kitchen machine, much simpler
than previously, while avoiding the previously usual close
tolerances, which cause an increase in costs, whereby now as

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before a seal, appropriate to its usel of -the workinc~ space
as against the motor receiving space of the appliance is
quaranteed.
The seal according to the invention has a plastic
casing in the area of the separation wall and is shaped in such
a manner that, in collaboration with a sealing bell, it forms
a seal, appropria-te to its use, of the shaft pene-tration, which
consists of the bearing eye on the one han~ and of the drive-
shaft which penetrates it with a certain amount of play, on
; 10 the other hand. Here, the sealing bell is set on the mo~o~
space side against the bearing eye which is formed onto the
separation wall, while a sealing ring is pl~ced in ~etween.
The present invention generally relates to a shaft
seal for a shaEt extending through a bearing eye in a
separation wall between a drive motor space on one side of the
wall and a working space on the other side of the wall. The
shaft seal has a plastic sleeve surrounding t~e shaft in one
of the spaces and having an end projecting through the bearing
eye with a clearance between the sleeve and the bearing eye.
The end of the plastic sleeve is secured to the shaftr and a
sealing bell is provided in the other of the spaces having an
internal opening engaging the end of the sleeve. The bell
; has a flared portion deEining an outer surface, and a seal
member is located between the flared portion and the bearing
eye and engages the outer surEace.
The invention is explained in more de~ail with
reference to an embodiment that is shown in cross-sectional
view of the single Eigure in the accompanyin~ drawing.

l377
As the single figure shows, -the driveshaft 1 of
the household appliance ls mounted in the mot,or receiving
.space 2 by ~eans of the bearin~s 3 and d, which are
cor~lercial units and which are disposed so as -to be fixed
in the device. Each of these bearin~s - as can be seen from
the representation of beariny 3 - has a ball-like ~asing 3.1
and is taken up by housiny shell 5 ~hich has a concave shape.
The bearing 3 is pxessed against this housiny sheel through
a flexible pressure ring 5.1 which is fastened at the shell 5,
A sealing ring made of steel 1.2 with a contact
surface consisting of an ela~t,ic material 1.3 i5 used, in
a manner that is in itself well known, to provide an axial
securiny of the driveshaft 1 with respect to the two
bearings 3 and 4 which receive said driveshaft 1 and which
are fixed in the device.
, In the area of the working space 6 of the household
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appliance~ the driveshaft 1 is surrounded with an electrically
insulating casing 7 made of plastic. This casi:ny extends as far
as the area of the penetration, associated with the driveshaft 1,
within the device-side sepa.ration wall 8 between the working
space 6 and the motor receiving space 2 of the household appliance.
This penetration here cons1sts of a boring 8.1 in the separation
wall 8 of the device housing, where said boring 8.1 surrounds
with some play the driveshaft 1 including the casing 7 that is
set upon it. To seal the working space 6 against the motor
receiving space 2, a collar 7.1 has now been formed onto the
casing 7 in the area o the penetration 8.1. This collar 7~1 is
provided with an annular groove 7.2, which is provided to receive
a lubricant which at the same time has a sealing action.
As can be seen from the drawing, the boring 8.1 is
associated with a bearin.g eye 8.~ of the separation wall 8,
where said bearing eye 8.2 has a bell-shaped design. A sealing
bell 9 now comes to lie against this bearing eye, where said
sealing bell 9 is set upon the collar 7.1 of the casing 7. A
; ring seal 10 is disposed between .the sealing bell 9 and the
~0 bearing eye 8.2. This sealing ring 10 consists of an elastic
organic material, for example sponge rubber.
The sealing bell 9 preerably consists of a material
that has a high inherent elasticity. The sealing bell 9 is
pressed against the sealing ring 10 by means of the collar 7.1
which with the casing 7 that is pressed together
with the driveshaft 1, where said casing 7 itself is seated on
a bond 1.1 that is formed onto the driveshaft 1 and thus is
retained in its functionally proper position with respect to
the drivesha:Et 1.
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setween the circu~ference of the casing 7 and the
boring 8.1 of the bearing eye 8.2 on the one hand, as well as
between the bearing eye 8.2 and the sealing bell 9 on the other
hand, there arise free spaces. Here, the sealing bell 9 is
turned towards the bearing eye 8.2 at a small distance due to
the ring seal 10 which lies in between. The resulting free
spaces fill with the lubricant that is stored in the annular
groove 7.2 of the collar 7.1 and thus, to a significant extent,
cause the sealing of the shaEt penetration that is formed in
this way.
The sealing bell 9 collaborates with the bearing eye
8.2 including the intermediate sealing ring 10 on the one hand
and with the collar 7.1, which i5 formed onto the casing 7 and
which has a circular groove 7.2, on the other hand, with
inclusion of the lubricant that is stored in the annular groove
7.2. Despite the relatively large tolerances between the
outside diameter of the protective casing 7 which is associated
with the driveshaft 1, and the boring 8.1 of the separation
wall 8, this collaboration creates a seal, appropriate for its
use, of the shaft penetration of the household appliance in
accord with the innovation, where said shaft penetration extends
from the motor receiving space 2 into the working space 6.
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