Note: Descriptions are shown in the official language in which they were submitted.
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TRANSMISSION ASSEMBLY, POWER
UNIT AND LIFTING CABINET
FIELD OF THE INVENTION
The following relates to the field of cabinets, and more particularly to a
transmission
assembly, a power unit, and a lifting cabinet.
BACKGROUND OF THE INVENTION
With the development of urbanization, most of the residential buildings are
small-
sized. In order to ensure enough storage space, people often make good use of
the unused
upper space, for example, a hanging wall-mounted cabinet or storage chamber is
mounted in
the house to improve the space utilization. However, it is very troublesome to
take items out
from or put them in the cabinet or storage chamber which is located in a high
place, and this
cannot perfectly meet the needs of people of different heights.
To solve the problems above, an automatically lifting cabinet comprises a
cabinet body
having an openable bottom, from where a lifting shelf installed inside the
body can be lowered
out. The lifting cabinet in the prior art operates by raising and lowering a
lifting shelf by a belt
pulley which is driven by a motor. Due to the heavy load on the lifting shelf,
a motor with
greater power is required to be equipped within the lifting cabinet such that
smooth raising and
lowering of the lifting shelf can be ensured if the shelf is loaded. However,
the motor with
greater power has a relatively larger dimension and occupies more space which
results in less
space for storage in the cabinet.
SUMMARY OF THE INVENTION
It is an objective of the invention to provide a transmission assembly of a
lifting
cabinet so that a small motor can be used in the lifting cabinet instead of a
large motor.
A transmission assembly is provided for a lifting cabinet, comprising a first
transmission unit with a screw rod which is connected with a driving device
and a sliding
piece which is connected with the lifting shelf
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The sliding piece is coupled to the screw rod.
The screw rod rotates under the action of the driving device and drives the
sliding
piece to move back and forth along the axis of the screw rod, thereby the
sliding piece drives
the lifting shelf to move up and down.
The transmission assembly of the lifting cabinet according to the present
invention
converts a rotary motion outputted from the driving device into a linear
motion through the
cooperation between the screw rod and the sliding piece, and the driving
device outputting
greater axial force consequently. Thus, a relatively small motor with a lower
output torque
can be used in the lifting cabinet to drive a lifting shelf of the same weight
when compared to
the conventional lifting cabinet, and the problem of large motor in
conventional lifting cabinet
taking up too much space is thereby solved.
In one embodiment, the screw rod is a ball screw, and the sliding piece is a
transmission nut. A ball passage is formed between the ball screw and the
transmission nut,
and a plurality of balls are arranged therein.
In the transmission assembly of the lifting cabinet according to the present
invention,
the screw rod is a ball screw, the sliding piece is a transmission nut, and a
plurality of balls are
arranged in a ball passage formed between the ball screw and the transmission
nut. Compared
with the prior art where a gear drives a transmission shaft and the
transmission shaft drives a
belt pulley to rotate, a greater output axial thrust is created from the first
transmission unit if
the same torque is outputted, through the cooperation between the ball screw
and the
transmission nut, so that a smaller motor is sufficient to be used in the
lifting cabinet.
Further, the sliding piece is further configured with a transmission wheel,
and a
flexible connecting piece is coiled on the transmission wheel for connecting
with the lifting
shelf
When the transmission wheel moves along with the sliding piece, the flexible
connecting piece drives the lifting shelf to move up and down.
The transmission assembly of the lifting cabinet according to the present
invention
operates by providing transmission wheels on the sliding piece and coiling a
flexible
connecting piece for connecting the lifting shelf on the transmission wheel.
When the sliding
piece moves back and forth driven by the ball screw, the transmission wheel
moves along with
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it as well, meanwhile, the lifting shelf is thereby driven by the flexible
connecting piece to
move as the transmission wheel moves. Moreover, the transmission wheel bears
constant pull
by the flexible connecting piece when the load on the lifting shelf stays
unchanged, so that the
lifting shelf moves more smoothly.
Further, the transmission assembly of the lifting cabinet also comprises a
fixture which
is secured inside the cabinet body of the lifting cabinet. One end of the
flexible connecting
piece is secured to the fixture, and the other end is secured to the lifting
shelf.
The transmission assembly of the lifting cabinet according to the present
invention
operates by fixing a fixture inside the cabinet body of the lifting cabinet,
and securing the two
ends of the flexible connecting piece to the lifting shelf and the fixture
respectively, so that the
pull of the flexible connecting piece is partly transferred to the cabinet
body of the cabinet, in
order to prevent the flexible connecting piece detaching from the lifting
shelf.
Further, a steering wheel is further provided on the fixture.
The sliding piece is configured with two transmission wheels, each of which is
configured with one set of flexible connecting piece coiled thereon, and
wherein one of the
sets of the flexible connecting pieces is coiled on the steering wheel to make
a turn.
In the transmission assembly of the lifting cabinet according to the present
invention, it
is provided a steering wheel on the fixture and two transmission wheels on the
sliding piece;
two sets of flexible connecting piece connecting with the lifting shelf are
coiled on the two
transmission wheels respectively, and one set of the flexible connecting piece
makes a turn by
being coiled on the steering wheel, so that the two sets of flexible
connecting piece are
connected to the two sides of the lifting shelf respectively, and the two
sides of the lifting shelf
are subjected to identical pull force in a same direction, thus the lifting
shelf moves more
smoothly.
Further, the transmission assembly of the lifting cabinet further comprises a
second
transmission unit, the input of which is connected with the driving device and
the output is
connected with the first transmission unit;
The second transmission unit is used for receiving a first torque outputted
from the
driving device and outputting a second torque to the first transmission
assembly according to
the first torque.
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The directions of the first torque and the second torque are different.
The transmission assembly of the lifting cabinet according to the present
invention
operates by providing a second transmission unit between the driving device
and the first
transmission unit, and the second transmission unit outputting a second torque
in a different
direction from the first torque, so that the first transmission unit and the
driving device can be
arranged in the same plane, and the first transmission unit and the driving
device can be
connected in a shape of "L", thus a reasonable layout and space saving is
achieved.
Specifically, the second transmission unit comprises a second gear with first
and
second gear rings being coaxially arranged thereon.
The first gear ring is connected with the driving device, and the second gear
ring is
connected with a cone gear arranged on the screw rod.
Specifically, a first gear is connected between the first gear ring and the
driving device.
Preferably, the second torque is greater than the first torque.
In the transmission assembly of the lifting cabinet according to the present
invention,
the second transmission assembly outputs a greater second torque compared with
a first torque
outputted from the driving device, so that a greater axial force outputted
from the first
transmission unit is achieved.
Another objective of the invention is to provide a power unit for a lifting
cabinet,
comprising a driving device and the transmission assembly of lifting cabinet
as described
above.
Another objective of the invention is to provide a lifting cabinet, comprising
a power
unit as described above.
Embodiments of the invention will be described in detail, with references to
the
following figures, for a better understanding and practice.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a top view of an embodiment of the lifting cabinet with the roof
removed
according to the present invention;
Figure 2 is a structural schematic view of an embodiment of the power unit for
the
lifting cabinet according to the present invention.
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Figure 3 is a structural schematic view of an embodiment of the lifting
cabinet with the
front cabinet door and roof removed according to the present invention.
List of reference numbers:
10 first transmission unit
11 screw rod
12 sliding piece
13 transmission wheel
14 flexible wire rope
15 fixture
16 steering wheel
second transmission unit
21 first gear
22 second gear
15 23 cone gear
driving device
31 motor
32 gear box
shelf
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of the invention will be described in detail in purpose of
explanation,
with references to the following figures.
As illustrated in Figure 1, a transmission assembly for a lifting cabinet,
comprises a
first transmission unit 10. As illustrated in Figure 2, the first transmission
unit 10 comprises a
screw rod 11 which is connected with a driving device 30, and a sliding piece
12 which is
connected with a lifting shelf 40. The sliding piece 12 is coupled to the
screw rod 11.
The screw rod 11 rotates under the action of the driving device 30 and drives
the
sliding piece 12 to move back and forth linearly along the axis of the screw
rod 11. The sliding
piece 12 drives the lifting shelf 40 to move up and down.
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In an embodiment, the transmission assembly of the lifting cabinet according
to the
present invention converts a rotary motion created by the driving device into
a linear motion
through the cooperation between the screw rod and the sliding piece, and a
greater axial thrust
is thereby outputted. Thus, a relatively small motor with a lower output
torque can be used in
the lifting cabinet to drive a lifting shelf of the same weight when compared
to the
conventional lifting cabinet, and the problem of large motor in conventional
lifting cabinet
taking up too much space is thereby solved.
Specifically, the screw rod 11 is a ball screw, and the sliding piece 12 is a
transmission
nut, a ball passage is formed between the ball screw and the transmission nut,
and a plurality
of balls are arranged therein. It should be noted that, the ball passage and
the balls are not
shown in the accompanying drawings without causing any misunderstanding.
For the transmission assembly of the lifting cabinet according to the present
invention,
a greater output axial thrust is created from the first transmission unit if
the same torque is
outputted, through the cooperation between the ball screw and the transmission
nut, so that a
smaller motor is sufficient to be used in the lifting cabinet.
In the prior art, a motor drives a gear, which thereby drives a belt pulley to
rotate. The
axial force F1 produced by the belt pulley complies with the formula F1 = ¨T,
wherein the T is
ti
the torque of the belt pulley, 11 is the arm of force on the belt pulley. If T
= 5 N = m, 11 =
5mm, the axial force (i.e. the pull force exerted on the lifting shelf)
produced by the belt
pulley will be 1000 N.
In comparison, the axial force F2 produced by cooperation between the ball
screw and
transmission nut complies with the formula F2 = 1-1=2 , wherein the p is the
lead of the ball
screw (i.e. a distance that the transmission nut travels after it rotates in
one complete circle
relative to the ball screw). If p = 5mm, and the transmission efficiency is
80%, the axial force
produced by the cooperation between the ball screw and the transmission nut
will be 5024 N.
It can be seen that the axial force produced by the cooperation between the
ball screw
and the transmission nut will be at least 5 times the axial force that
produced by the belt
pulley, if the torque is the same.
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,
Preferably, the sliding piece 12 is further configured with transmission
wheels 13, as
illustrated in Figure 1 and Figure 2, and a flexible connecting piece 14
coiled or wrapped on
the transmission wheel 13 is provided for connecting with the lifting shelf
40.
When the transmission wheel moves along with the sliding piece, the flexible
connecting piece drives the lifting shelf to move up and down.
Specifically, the flexible connecting piece 14 is a steel wire rope or cable.
The transmission assembly of the lifting cabinet according to the present
invention
operates by providing transmission wheels 13 on the sliding piece 12 and
coiling a flexible
connecting piece 14 for connecting the lifting shelf on the transmission
wheel. When the
sliding piece 12 moves back and forth driven by the ball screw 11, the
transmission wheel 13
moves along with it as well, meanwhile, the lifting shelf is thereby driven by
the flexible
connecting piece 14 to move as the transmission wheel moves. Moreover, the
transmission
wheel 13 bears constant pull by the flexible connecting piece 14 when the load
on the lifting
shelf stays unchanged, so that the lifting shelf moves more smoothly.
Preferably, as illustrated in Figure 2, the transmission assembly of the
lifting cabinet
further comprises a fixture 15 which is secured inside the cabinet body 40 of
the lifting
cabinet. One end of the flexible connecting piece 14 is secured to the fixture
15, and the other
end is secured to the lifting shelf 40.
The transmission assembly of the lifting cabinet according to the present
invention
operates by fixing the fixture 15 inside the cabinet body of the lifting
cabinet, and securing the
two ends of the flexible connecting piece 14 to the lifting shelf and the
fixture respectively, so
that the pull of the flexible connecting piece is partly transferred to the
cabinet body of the
cabinet, in order to prevent the flexible connecting piece 14 detaching from
the lifting shelf.
Preferably, as illustrated in Figure 2, a steering wheel 16 is further
provided on the
fixture 15.
The sliding piece 12 is configured with two transmission wheels 13, each of
which is
configured with a set of flexible connecting piece 14 coiled thereon, and one
set of the flexible
connecting piece 14 is coiled on the steering wheel 16 to make a turn.
In the transmission assembly of the lifting cabinet according to the present
invention, it
is provided a steering wheel 16 on the fixture 15 and two transmission wheels
13 on the
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sliding piece 12; two sets of flexible connecting piece 14 connecting with the
lifting shelf are
coiled on the two transmission wheels 13 respectively, one set of the flexible
connecting piece
14 makes a turn by being coiled on the steering wheel 16, so that the two sets
of flexible
connecting pieces 14 are connected to the two sides of the lifting shelf
respectively, and the
two sides of the lifting shelf are subjected to identical pull force in a same
direction, thus the
lifting shelf moves more smoothly.
Preferably, the transmission assembly of the lifting cabinet further comprises
a second
transmission unit 20, the input of which is connected with the driving device
and the output is
connected with the first transmission unit 10.
The second transmission unit 20 is used for receiving a first torque outputted
from the
driving device 30 and outputting a second torque to the first transmission
unit 10 according to
the first torque, wherein the directions of the first torque and the second
torque are different.
The transmission assembly of the lifting cabinet according to the present
invention
operates by providing a second transmission unit 20 between the driving device
30 and the
first transmission unit 10, and the second transmission unit 20 outputting a
second torque in a
different direction from the first torque, so that the first transmission unit
10 and the driving
device 30 can be arranged in the same plane, and the first transmission unit
10 and the driving
device 30 can be connected in a shape of "L", thus a reasonable layout and
space saving is
achieved.
Specifically, the second transmission unit 20 comprises a second gear 22 with
first and
second gear rings being coaxially arranged thereon.
The first gear ring is connected with the driving device 30, and the second
gear ring is
connected with a cone gear 23 arranged on the screw rod 11, in order to change
the direction
of the output torque.
Specifically, a first gear 21 is connected between the first gear ring and the
driving
device 30.
The first gear 21 has a larger diameter than the output gear in the reduction
gearbox for
the driving device 30, therefore, the first gear 21 outputs a greater torque
than the reduction
gearbox for the driving device.
Preferably, the second torque is greater than the first torque.
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Date Recue/Date Received 2021-09-14
In the transmission assembly of the lifting cabinet according to the present
invention,
the second transmission assembly outputs a greater second torque compared with
a first torque
outputted from the driving device, so that a greater axial force output from
the first
transmission unit is achieved.
Moreover, the second gear 22 has both straight teeth and conical teeth, and
the second
gear 22 is engaged with the first gear 21 and the cone gear 23 which is
connected to the screw
rod 11, respectively, in this way, the direction of the output torque from the
driving device is
changed.
A power unit for a lifting cabinet is provided in an embodiment, comprising a
driving
device 30 and transmission assembly as described above.
Specifically, the driving device 30 comprises a small motor 31 and a reduction
gearbox
32 connected thereto.
A lifting cabinet is provided in an embodiment, comprising a power unit for
the lifting
cabinet as described above
As illustrated in Figure 3, the lifting cabinet comprises a cabinet body 50
and a lifting
shelf 40 sliding inside the cabinet body 50.
The upper space in the cabinet body 50 is partitioned to form an installation
space
where the power unit is arranged, two sets of steel wire ropes 14 extend out
from the two sides
of the installation space and connect to the two sides of the lifting shelf
40, for driving the
lifting shelf to move up and down.
It will be appreciated that one skilled in the art may incorporate or combine
different
embodiments or examples, or technical features of different embodiments or
examples
disclosed in the description together if there are no contradictions.
In the description of the present invention, it should be understood that the
terms
"longitudinal", "lateral", "front", "back", "left", "right", "vertical",
"horizontal", "top",
"bottom", "inner", and "outer", etc., indicate direction or position relation
based on the
direction or position relation shown in figures, and is only for convenience
of describing the
present invention and simplifying the description, rather than indicating or
implying that the
indicated apparatus or parts must be configured or operated in specific
direction. Therefore,
these terms should not be deemed as a limit to the content protected by the
present invention.
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Date Recue/Date Received 2021-04-16
If the terms "first", "second", etc. are used herein to define a component,
one skilled in
the art should understand that usage of terms "first" and "second" is only for
the convenience
of describing the present invention and simplifying the description. Unless
otherwise stated,
the terms hereinbefore have no specific meanings.
The present invention is not limited to the above embodiments. Any variations
or
modifications without departing from the spirit and scope of the invention and
within the
scope of claims and equivalent technology of the present invention will be
also contained in
the present invention.
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