U.S. patent application number 13/393217 was filed with the patent office on 2012-11-08 for tracking device.
This patent application is currently assigned to Robert Bosch GmbH. Invention is credited to Harald Vogt.
Application Number | 20120279489 13/393217 |
Document ID | / |
Family ID | 43242158 |
Filed Date | 2012-11-08 |
United States Patent
Application |
20120279489 |
Kind Code |
A1 |
Vogt; Harald |
November 8, 2012 |
Tracking Device
Abstract
A tracking device is disclosed for a unit, in particular a solar
collector, to be directed toward a moving object. The tracking
device has a bracket, which carries the unit and which is
accommodated on a shaft that can be rotated about an azimuth axis
by means of a hydraulic azimuth drive. Furthermore, the tracking
device has a hydraulically adjustable tilting device for tilting
the bracket, wherein a support of the shaft and the azimuth drive
are arranged on or in a housing. At least one section of the shaft
having the support thereof, the azimuth drive, and a pressure
medium tank having pressure medium for supplying the azimuth drive
and the tilting device are arranged in a common cavity of the
housing.
Inventors: |
Vogt; Harald; (Jakarta,
ID) |
Assignee: |
Robert Bosch GmbH
Stuttgart
DE
|
Family ID: |
43242158 |
Appl. No.: |
13/393217 |
Filed: |
July 27, 2010 |
PCT Filed: |
July 27, 2010 |
PCT NO: |
PCT/EP2010/004579 |
371 Date: |
July 15, 2012 |
Current U.S.
Class: |
126/606 |
Current CPC
Class: |
F24S 2030/115 20180501;
Y02E 10/47 20130101; F24S 30/452 20180501 |
Class at
Publication: |
126/606 |
International
Class: |
F24J 2/54 20060101
F24J002/54 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 29, 2009 |
DE |
10 2009 039 341.2 |
Claims
1. A tracking device for a unit to be directed toward a moving
object, comprising: a hydraulic azimuth drive; a shaft having a
bearing assembly, the shaft being configured to be rotated about an
azimuth axis by the hydraulic azimuth drive; a bracket which
carries the unit and which is mounted on the shaft; a hydraulically
adjustable tilting device configured to tilt the bracket; a housing
defining a cavity; and a pressure medium tank configured to contain
pressure medium for supplying the azimuth drive, wherein the
bearing assembly of the shaft and the azimuth drive are arranged on
or in the housing, and wherein at least one section of the shaft
and the bearing assembly thereof, and the pressure medium tank and
the tilting device are arranged in the cavity of the housing.
2. The tracking device as claimed in patent claim 1, wherein the
azimuth drive has a worm gear, which is arranged in the housing and
the worm of of the worm gear meshes with a worm wheel arranged on
the shaft, wherein the worm is driven by a hydraulic motor.
3. The tracking device as claimed in patent claim 2, wherein the
hydraulic motor is an axial piston motor, which is secured on an
outer wall of the housing and the hydraulic ports of which are
arranged on an end facing the housing.
4. The tracking device as claimed in patent claim 2, wherein the
worm is formed on a worm spindle which is accessible on both sides
of the housing and on the first end section of which the hydraulic
motor is arranged and on the second end section of which a
rotational speed sensor is arranged.
5. The tracking device as claimed in patent claim 1, wherein the
tilting device has a hydraulic cylinder, which engages on the
bracket and engages directly or indirectly on the shaft and which
is configured to be supplied with pressure medium by a hydraulic
pump arranged on the housing.
6. The tracking device as claimed in patent claim 5, wherein the
azimuth drive is supplied by the hydraulic pump and an electric
motor, which drives the hydraulic pump.
7. The tracking device as claimed in patent claim 6, wherein the
electric motor is a synchronous motor, and the hydraulic pump is a
gear pump, both of which are placed against the housing in a radial
direction with respect to the shaft.
8. The tracking device as claimed in patent claim 7, wherein a tank
port and a pressure port are arranged on a side of the gear pump
which faces the housing.
9. The tracking device as claimed in patent claim 8, wherein a
lateral wall section of the housing forms a wall of the gear pump,
and wherein the tank port and the pressure port are through holes
in the wall section.
10. The tracking device as claimed in claim 1 further having a
control block with an electronic control unit and/or valves for
controlling the supply to the azimuth drive and the tilting
device.
11. The tracking device as claimed in claim 1, wherein the shaft
has a section which projects from the housing toward the
bracket.
12. The tracking device as claimed in patent claim 10, wherein the
control block is arranged adjacent to the projecting section of the
shaft on an upper side of the housing, said upper side facing the
bracket, or is arranged laterally on the housing or in the
housing.
13. The tracking device as claimed in patent claim 1, further
comprising a dirt seal, which rests against the shaft, and is
fitted on the housing.
14. The tracking device as claimed in patent claim 1, wherein at
least the section of the shaft which is accommodated in the housing
is hollow.
15. The tracking device as claimed in patent claim 1, wherein the
bearing assembly of the shaft has an axial bearing and a radial
bearing, wherein the axial bearing is arranged between the radial
bearing and the bracket, and wherein both bearings are immersed in
the pressure medium.
16. The tracking device as claimed in patent claim 15, wherein the
housing is a casting, through the upper side of which the shaft can
be inserted and on the underside of which, which faces away from
the bracket, there is arranged an opening, through which the axial
bearing and the radial bearing can be inserted and which can be
closed by a housing cover.
17. The tracking device as claimed in patent claim 1, wherein the
shaft carries a pivot bearing of the bracket, and wherein the pivot
of the pivot bearing lies in a radial plane of the shaft.
18. The tracking device as claimed in claim 4, wherein the
rotational speed sensor is a potentiometer.
19. The tracking device as claimed in claim 1, wherein the unit is
a solar collector.
Description
[0001] The invention relates to a tracking device in accordance
with the preamble of patent claim 1.
[0002] The publication DE 100 22 236 B4 shows a hydraulically
driven, two-axis tracking device of this kind for a solar panel, in
which the hydraulically driven actuators are mounted on the head of
a mast. A miniature hydraulic unit with a tank integrated therein
supplies the actuators with hydraulic oil. A support bracket for
the solar panel is mounted within the mast head so as to be
rotatable about a vertical azimuth axis. A bearing housing is
filled with bearing oil, which is separated from the hydraulic oil
by seals.
[0003] The disadvantage with tracking devices of this kind is the
outlay for the separate lubrication of the various rolling contact
bearings and of the rack of the azimuth adjustment system, which is
provided by grease in an upper region and by an oil bath
underneath, the latter being separated from the hydraulic oil.
[0004] Given this situation, it is the underlying object of the
invention to provide a tracking device in which the outlay in terms
of apparatus and maintenance is reduced.
[0005] This object is achieved by means of a tracking device as
claimed in patent claim 1.
[0006] The tracking device according to the invention for a unit,
in particular a solar collector, to be directed toward a moving
object, has a bracket, which carries the unit and which is mounted
on a shaft that can be rotated about an azimuth axis by means of a
hydraulic azimuth drive. The tracking device furthermore has a
hydraulically adjustable tilting device for tilting the bracket,
wherein a bearing assembly of the shaft and the azimuth drive are
arranged on or in a housing. In this arrangement, at least one
section of the shaft with the bearing assembly thereof and a
pressure medium tank containing pressure medium for supplying the
azimuth drive and the tilting device are arranged in a common
cavity of the housing. Since the pressure medium (hydraulic oil)
lubricates the bearing assembly, the outlay in terms of apparatus
and maintenance for the tracking device according to the invention
is reduced.
[0007] Further advantageous embodiments of the invention are
described in the dependent patent claims.
[0008] In a preferred development, the azimuth drive has a worm
gear, which is arranged in the housing and the worm of which meshes
with a worm wheel arranged on the shaft, wherein the worm is driven
by means of a hydraulic motor. Since the pressure medium (hydraulic
oil) lubricates the worm gear, there is a further reduction in the
outlay in terms of apparatus and maintenance.
[0009] In a preferred development, the hydraulic motor is an axial
piston motor, which is secured on an outer wall of the housing and
the hydraulic ports of which are arranged on an end facing the
housing.
[0010] In this case, the worm can be formed on a worm spindle which
is accessible on both sides of the housing and on the first end
section of which the hydraulic motor is arranged and on the second
end section of which a rotational speed sensor is arranged. The
latter is preferably a potentiometer, by means of which a high
resolution and an absolute angle indication can be achieved at low
cost.
[0011] In a particularly preferred development, the tilting device
has a hydraulic cylinder, which engages on the bracket and engages
directly or indirectly on the shaft and which can be supplied with
pressure medium by means of a hydraulic pump arranged on the
housing.
[0012] For the sake of a compact construction of the tracking
device according to the invention, the azimuth drive, like the
tilting device, is preferably also supplied by means of the
hydraulic pump and an electric motor, which drives the hydraulic
pump.
[0013] The electric motor can be a robust synchronous motor and the
hydraulic pump can be a gear pump, both of which are placed against
the housing in a radial direction with respect to the shaft.
[0014] In order to shorten or even completely eliminate piping, a
tank port and a pressure port can be arranged on a side of the gear
pump which faces the housing.
[0015] If a lateral wall section of the housing simultaneously
forms a wall of the gear pump, one end wall of the gear pump can be
omitted. If the tank port and the pressure port are through holes
in the wall section, no piping is required for this purpose.
[0016] A preferred development has a control block with an
electronic control unit and/or valves for controlling the supply to
the azimuth drive and the tilting device.
[0017] The mounting of the bracket on the shaft is simplified if
the shaft has a section which projects from the housing (toward the
bracket).
[0018] The control block can be arranged adjacent to the projecting
section of the shaft on an upper side of the housing, said upper
side facing the bracket, or can be arranged laterally on the
housing or in the housing. The latter integration offers particular
protection from external influences.
[0019] In order to protect the pressure medium in the cavity of the
housing from contamination, it is preferred if a dirt seal, which
rests against the shaft, is fitted on the housing.
[0020] In order to maximize the cavity or tank volume, at least the
section of the shaft which is accommodated in the housing can be
made hollow.
[0021] Preference is given to a bearing assembly of the shaft with
an axial bearing for supporting the weight of the bracket and of
the unit and with a radial bearing, wherein the axial bearing is
arranged between the radial bearing and the bracket. According to
the invention, both bearings are immersed in the pressure medium in
order to minimize friction.
[0022] For the sake of simple manufacture and assembly, the housing
can be a casting, through the upper side of which the shaft can be
inserted and on the underside of which, which faces away from the
bracket, there is arranged an opening, through which the axial
bearing and the radial bearing can be inserted. The opening on the
underside can be closed by a housing cover. A casting of this kind
can be machined before assembly, in particular to provide for the
two bearing seats, the dirt seal and the bearing area for the
housing cover.
[0023] In a development, the shaft carries a pivot bearing of the
bracket, and the pivot of the pivot bearing lies in a radial plane
of the shaft.
[0024] An embodiment of the invention is described in detail below
with reference to the figures, in which:
[0025] FIG. 1 shows an embodiment of a tracking device according to
the invention in a side view;
[0026] FIG. 2 shows the embodiment of the tracking device according
to the invention in a section from the side; and
[0027] FIG. 3 shows the azimuth drive of the embodiment of the
tracking device according to the invention in a sectioned plan
view.
[0028] FIG. 1 shows an embodiment of a tracking device according to
the invention for a flat solar collector or solar panel 12 in a
side view. An approximately cuboidal housing 2 is mounted on a mast
1, of which only the upper end section is shown in FIG. 1.
Projecting from the upper side 4 of said housing is a shaft 6, to
the upper end of which a pivot bearing 8 is welded. By means of the
pivot bearing 8, which has a pivot perpendicular to the plane of
the drawing, the shaft 6 is connected to a bracket 10. The solar
panel 12 is secured on the side of the bracket 10 which is at the
top (FIG. 1), and the intention is to align and adjust the
large-area upper side 14 of said panel perpendicularly to the sun.
For this purpose, the shaft 6 is mounted so as to be rotatable
about a vertical azimuth axis 16, taking the solar panel 12 along
during a rotary motion by means of the pivot bearing 8 and the
bracket 10. By means of this rotary motion, the solar panel 12 can
follow a movement of the sun from east to west.
[0029] The tracking device can follow the vertical direction of
movement of the sun by tilting the solar panel 12 about the pivot
bearing 8, assuming the position illustrated in broken lines in
FIG. 1, for example. A hydraulic cylinder 18 is provided for this
tilting movement, said cylinder being attached pivotably to the
shaft 6 by means of a joint 20, on the one hand, and to an edge
section of the bracket 10 or of the solar panel 12 by means of a
joint 22, on the other hand. The edge section can be lowered by
retracting a piston rod 24, while the edge section can be raised
(into the position shown in FIG. 1, for example) by extending the
piston rod 24.
[0030] The rotation of the shaft 6 about the azimuth axis 16 is
accomplished by means of a hydraulic motor 26 and of an azimuth
drive, which is explained with reference to FIGS. 2 and 3.
[0031] Both hydraulic actuators 18, 26 are supplied with pressure
medium by means of a gear pump 30 driven by a synchronous motor 28.
A control block 32, which has an electronic control unit and valves
for controlling and supplying pressure medium to the two actuators
18, 26, is furthermore arranged on the upper side 4 of the housing
2.
[0032] FIG. 2 shows the embodiment in accordance with FIG. 1 in a
section from the side. The shaft 6 is embodied as a hollow shaft
and has a circumferential section 34 which is stepped back radially
at a step 40, on which section an axial bearing 36 and a radial
bearing 38 are arranged. By means of these two bearings 36, 38, the
shaft 6 and hence the solar panel 12 are mounted so as to be
rotatable about the azimuth axis, wherein the shaft 6 is supported
relative to the housing 2 along the azimuth axis 16 by means of the
step 40 on the shaft, the axial bearing 36, a sleeve 42, an outer
bearing ring of the radial bearing 38 and a housing cover 44. The
housing cover 44 is secured and sealed off on an underside of the
housing 2 by means of screws.
[0033] A cavity, which serves as the tank T of the tracking device,
is provided within the housing 2 and the shaft 4. The hydraulic oil
contained therein is drawn in by gearwheels 46, 48 of the gear pump
30 via a tank port 49 and is delivered to the hydraulic cylinder 18
and/or to the hydraulic motor 26 (neither of which is shown in FIG.
2) via a pressure port 51 and via valves of the control block
32.
[0034] An annular dirt seal 53, which rests against the shaft 6 and
protects the pressure medium in the tank T from contamination, is
inserted into an encircling recess on the upper side 4 of the
housing 2.
[0035] The hydraulic motor 26 drives a worm 50, which imparts
rotation, via a worm wheel 52, to the shaft 6 attached thereto. The
worm wheel 52 is secured on the circumferential section 34 of the
shaft 6 between the two bearings 36, 38.
[0036] FIG. 3 shows the azimuth drive of the embodiment in
accordance with FIG. 1 and FIG. 2 in a sectioned plan view. The
hollow shaft 6 is driven by the hydraulic motor 26 by means of a
worm spindle 54, the worm 50 secured thereon and the worm wheel 52
meshing therewith. The worm spindle 54 is supported in a through
aperture 60 in the housing 2 by means of two rolling contact
bearings 56, 58. The worm spindle 54 is stepped back radially in
the region of the bearings 56, 58, while the through aperture 60 is
widened radially in the region of the bearings 56, 58. The rolling
contact bearings 56, 58 can thus each be inserted into the through
aperture 60 in the housing 2 from outside (from above and below in
FIG. 3) during the assembly of the tracking device according to the
invention. On one side (at the bottom in FIG. 2), the through
aperture 60 is closed by the hydraulic motor 26, while a
potentiometer 62 is arranged on the other side (the upper side in
FIG. 3) of the through aperture 60, said potentiometer serving as a
rotational speed sensor or rotational position sensor for the worm
spindle 54, the worm 50 and the hydraulic motor 26.
[0037] A disclosure is made of a tracking device for a unit, in
particular a solar collector, to be directed toward a moving
object, which device has a bracket, which carries the unit and
which is mounted on a shaft that can be rotated about an azimuth
axis by means of a hydraulic azimuth drive. The tracking device
furthermore has a hydraulically adjustable tilting device for
tilting the bracket, wherein a bearing assembly of the shaft and
the azimuth drive are arranged on or in a housing. At least one
section of the shaft and the bearing assembly thereof, the azimuth
drive and a pressure medium tank containing pressure medium for
supplying the azimuth drive and the tilting device are arranged in
a common cavity of the housing.
LIST OF REFERENCE SIGNS
[0038] 1 mast
[0039] 2 housing
[0040] 4 upper side
[0041] 6 shaft
[0042] 8 pivot bearing
[0043] 10 bracket
[0044] 12 solar panel
[0045] 14 upper side
[0046] 16 azimuth axis
[0047] 18 hydraulic cylinder
[0048] 20, 22 joint
[0049] 24 piston rod
[0050] 26 hydraulic motor
[0051] 28 synchronous motor
[0052] 30 gear pump
[0053] 32 control block
[0054] 34 circumferential section
[0055] 36 axial bearing
[0056] 38 radial bearing
[0057] 40 step
[0058] 42 sleeve
[0059] 44 housing cover
[0060] 46, 48 gearwheel
[0061] 49 tank port
[0062] 50 worm
[0063] 51 pressure port
[0064] 52 worm wheel
[0065] 53 dirt seal
[0066] 54 worm spindle
[0067] 56, 58 rolling contact bearing
[0068] 60 through aperture
[0069] 62 potentiometer
[0070] T tank
* * * * *