Abstract
The invention relates to a drive unit for a device for lifting and transporting loads, which is attached or to be attached to a further device. A drive device according to the invention for the lateral movement of at least two load lifting elements of a device for lifting and transporting loads for mounting on a movable or stationary device comprises a first drive element and a second drive element, wherein the first load lifting element is movable by the first drive element and the second load lifting element is movable by the second drive element laterally in the axial direction of a first guide profile of the device for lifting and transporting loads, wherein the at least two load lifting elements are supportable by the first guide profile. The two drive elements can be driven by exactly one drive unit, the exactly one drive unit being positioned between the two drive elements.
Claims
1. Drive device for the lateral movement of at least two load lifting elements of a device for lifting and transporting loads for mounting on a movable or stationary device, comprising a first drive element and a second drive element, wherein a first load lifting element is movable by the first drive element and a second load lifting element is movable by the second drive element laterally in the axial direction of a first guide profile of the device for lifting and transporting loads, wherein the at least two load lifting elements can be carried by the first guide profile, wherein the two drive elements can be driven by exactly one drive unit, wherein the exactly one drive unit is positioned between the two drive elements, the exactly one drive unit having an internal and continuous output shaft, the first output shaft end being operatively connected in a rotationally fixed manner to the first drive element and the second output shaft end being operatively connected in a rotationally fixed manner to the second drive element, and the axis of the output shaft and the axes of the drive elements lying on one line, wherein in addition, the exactly one drive unit is at least partially integrated in the first guide profile.
2. Drive device according to claim 1, wherein at least one drive element has a spindle or each drive element has a spindle with a different direction of rotation.
3. Drive device according to claim 1, wherein each of the two drive elements has a double spindle with a different direction of rotation.
4. Drive device according to claim 1, wherein each drive element can be operatively connected to at least one load lifting element.
5. Drive device according to claim 1, wherein the first guide profile comprises a hollow profile and in the first guide profile a drive element is at least partially integrated, wherein the first guide profile comprises a longitudinal slot through which a holder for a load lifting element protrudes.
6. Drive device according to claim 1, wherein the exactly one drive unit has a gear wheel, which gear wheel can be driven and which gear wheel is operatively connected in a rotationally fixed manner to the output shaft.
7. Drive device according to claim 1, wherein at least one drive element has a shiftable gear for reversing the direction of movement of at least one load lifting element.
8. Drive device according to claim 1, wherein bearings are provided in the drive device, which are designed to absorb lateral forces of the drive elements.
9. Drive device according to claim 1, wherein the drive unit has a housing, wherein axial forces of the drive elements can be transmitted via the housing to the device for lifting and transporting loads.
10. Drive device according to claim 1, wherein the drive device has at least one first connecting element and one second connecting element for receiving the at least two load lifting elements, where the first connecting element can be operatively connected to a first bushing and the second connecting element can be operatively connected to a second bushing having internal threads, the first bushing being operatively connected to the first drive element and the second bushing being operatively connected to the second drive element, the drive elements each having an end stop, a spring being provided between the bushings and the respective end stop.
Description
IN THE FIGURES
[0034] FIG. 1 shows a three-dimensional representation of a drive device with load lifting elements in a position of maximum width
[0035] FIG. 2 shows a three-dimensional representation of a drive device with load lifting elements in a maximally narrow position
[0036] FIG. 3 shows a three-dimensional representation of a drive device with connecting elements in a position of maximum width
[0037] FIG. 4 shows a three-dimensional representation of a drive device with load lifting elements in an intermediate position
[0038] FIG. 5 shows a three-dimensional representation of a drive device in a sectional view
[0039] FIG. 6 shows a sectional plan view of a drive device
[0040] FIG. 1 shows a three-dimensional representation of a drive device 100 with load lifting elements 191, 192 suspended in connecting elements 125, 136. The first and second drive elements are located on a plane and, in this embodiment, below a first guide profile 120 (not shown in FIG. 1, see FIGS. 4, 5 and 6) and a fork carrier bar 124, respectively, on which the drive device 100 is mounted. Alternatively, the drive device may also be arranged above the first guide profile 120. Furthermore, the drive device can also be integrated in the lifting frame (not shown) of an industrial truck by connecting the mast cheeks of the industrial truck (not shown) directly to the frame structure, which means that a fork carrier bar can be dispensed with. The load lifting elements 191, 192 are suspended from the first guide element 120 and are supported by the latter. The load lifting elements 191, 192 are also supported by a second guide profile 140. Between the first drive element 121 and the second drive element 131 there is a drive unit 160 in a housing 165. This drive unit 160 can be, for example, an electric motor or a fluid motor, for example a hydraulic motor. The drive unit 160 rotationally drives both the first drive element 121 and the second drive element 131, which are located on a continuous shaft. The drive elements 121, 131 are spindles, for example recirculating ball screws or threaded spindles. Bushings 121h, 131h, to which connecting elements 125, 135 are attached, are moved via the drive elements 121, 131. Integrated in the drive elements 121, 131 can be gears (not shown in the Fig.), which are switchable and can reverse the direction of rotation of a drive element 121, 131, so that both a sideshift movement, in which the connecting elements 125, 135 are moved in parallel and in the same direction, and an opposite direction movement of the connecting elements 125, 135, as required for adjusting the distance of the load lifting elements 191, 192, are possible. In FIG. 1, the connecting elements 125, 135 and thus the load lifting elements 191, 192 are in the position of maximum width.
[0041] In FIG. 2, the drive device 100 from FIG. 1 is shown in a maximally narrow position. The two connecting elements 125, 135 are therein moved up to a stop (not shown) on the drive unit 160.
[0042] FIG. 3 shows a drive device 100 according to the invention with connecting elements 125, 135 in a position of maximum width in a three-dimensional representation detached from an assembly situation. The connecting elements 125, 135 are attached to the bushings 121h, 131h driven by the drive elements 121, 131. The drive unit 160 is arranged centrally between the bushings 121h, 131h.
[0043] FIG. 4 shows a further three-dimensional representation of a drive device 100 with load lifting elements in connecting elements 125, 135 in an intermediate position. The drive elements 121, 131 are integrated into the first guide element 120, which is designed as a hollow profile, and are therefore not visible in this illustration. Due to the integration into the first guide profile 120, the drive elements 121, 131 are protected against damage to the greatest possible extent. The drive unit 160 of this embodiment has a hydraulic motor. The hydraulic connections 200 point upwards out of the first guide profile 120 through openings in the housing 165, so that the hydraulic connections 200 and hydraulic hoses attached thereto (not shown) do not interfere with the load lifting and also the free view for an operator of a device for lifting and transporting loads, on which the drive device is mounted, is not restricted.
[0044] FIG. 5 shows a three-dimensional cross-sectional view of a drive device 100. Bearings 162 are provided in the drive unit 160, which are designed to absorb lateral forces of the drive elements 121, 131. The lateral forces of the drive elements 121, 131 can result from the sideshift movement and are composed, for example, of inertial forces of the moved masses, friction and possibly forces due to the lateral displacement of loads with a load lifting element 191, 192. By providing bearings 162, such forces can be absorbed. The drive unit 160 has a housing 165, where axial forces of the drive elements 121, 131 can be transmitted via the housing 165 to the device for lifting and transporting loads on which the drive device 100 is mounted. The first connecting element 121 has a first bushing 121h and the second connecting element 131 has a second bushing 131h with an internal thread, the first bushing 121h being operatively connected to the first drive element 121 and the second bushing 131h being operatively connected to the second drive element 131, the drive elements 121, 131 each having an end stop 300, a spring 400 being provided between the bushings 121h, 131h and the respective end stop 300. Connecting elements 125, 135 can be fastened to the bushings 121h, 131h and can be moved laterally, for example by rotation of the drive elements 121, 131 via the bushings 121h, 131h, where the lateral movements can take place in opposite directions or in the same direction. The spring 400 can be used to prevent the respective drive element i121, 131 from jamming in the respective bushing 121h, 131h on the end stop 300. If the bushing 121h, 131h moving on the respective spindle 121i, 131i approaches an end stop 300, the spring 400 first comes under pressure. The counterforce built up by the spring 400 grows slowly with further progress of the respective bushing 121h, 131h on the respective spindle 121i, 131i, so that the bushing 121h, 131h on the spindle 121i, 131i does not suddenly jam, thereby applying a high tension force in the thread of the spindle 121i, 131i. In addition, the release force required later when the spindle 121i, 131i is turned back to release the bushing 121h, 131h is supported by the spring 400. In other words, the spring 400 acts here as a force accumulator. The spring 400 may be arranged at the end stop 300 on the spindle 121i, 131i and/or partially in the bushing 121h, 131h. In the embodiment shown in the figure, the spring 400 in the first drive element 121 is arranged on the spindle 121i in such a way that it can engage between the drive element 160 and the bushing 121h, while the spring 400 in the second drive element 131 is arranged in the bushing 131h in such a way that it can engage between the bushing 131h and the end stop 300.
[0045] FIG. 6 shows a sectional view of an embodiment of the drive device 100 of FIG. 5 in a plan view. The drive unit 160 has a gear wheel 161 on an output shaft 170, via which the output shaft 170 can be driven. The output shaft 170 has a first output shaft end 171, via which the output shaft 170 is connected to the first drive element 121 in a rotationally fixed manner. Furthermore, the output shaft 170 has a second output shaft end 172, via which the output shaft 170 is connected to the second drive element 131 in a rotationally fixed manner. The drive unit 160 has two bearings 162, via which lateral forces introduced by the drive elements 121, 131 are absorbed by the housing 165 without putting stress on the gear wheel 161 or other components of the drive unit 160. One spring 400 is installed for each direction of movement. Both springs 400 are installed in opposite directions and are also provided with only a slight offset, so that both springs 400 cannot be brought to a stop at the same time. As a result, only one spring 400 brakes in each direction. Since the output shaft 170 in the drive unit 160 is continuous, the entire output shaft 170 and thus the two drive elements 121, 131 brake in each direction of movement when a stop 300 is approached. In the embodiment shown, helical springs are used as springs 400. In principle, all known suitable springs 400, such as helical, disc, coil, ring, gas pressure, rubber or air springs can be used.
LIST OF REFERENCE NUMBERS
[0046] 100 drive device [0047] 120 first guide profile [0048] 121 first drive element [0049] 121h first bushing [0050] 121i first spindle [0051] 124 fork carrier bar [0052] 125 first connecting element [0053] 131 second drive element [0054] 131h second bushing [0055] 131i second spindle [0056] 135 second connecting element [0057] 160 drive unit [0058] 161 gear wheel [0059] 162 bearing [0060] 165 housing [0061] 170 output shaft [0062] 171 first output shaft end [0063] 172 second output shaft end [0064] 191 first load lifting element, first fork arm [0065] 192 second load lifting element, second fork arm [0066] 200 hydraulic port [0067] 300 end stop [0068] 400 spring
