DRIVE UNIT

Description

[0001] The invention relates to a drive unit with the features of claim 1 and a lifting and tilting device with such a drive unit.

[0002] To ensure the functionality of transmission components is not impaired, it is important to protect them from contamination. Otherwise, there is a risk that the accumulation of dust, dirt, and other debris will impair their mobility or cause them to become blocked, preventing them from fulfilling their intended purpose.

[0003] German patent application DE 10 2019 131 986 A1 discloses a gear unit with an elongated gear section used to operate a lifting and tipping mechanism of a refuse collection vehicle. Two gear sections work together to perform the lifting and tipping motion of a pallet truck. A carriage moves relative to the elongated gear section, which is thus relatively unprotected and exposed to environmental influences. Contamination can prevent the lifting and tipping mechanism from functioning properly, as the gear unit becomes blocked. To prevent contamination, a protective sleeve is provided that surrounds the elongated gear section when necessary. Disadvantages of this design include its large installation space requirement, which causes the protective sleeve to protrude beyond the frame of the lifting and tipping mechanism, and its limited flexibility. Because the protective sleeve protrudes beyond the frame, at least temporarily, there is also a risk of injury to operators and passersby.

[0004] It is therefore the object of the present invention to propose a drive unit whose functionality is not impaired by environmental influences.

[0005] This problem is solved by a drive unit with the features according to claim 1. Advantageous further developments are the subject of the dependent claims.

[0006] The invention relates to a drive unit with a slide and a gear unit moving the slide, wherein the gear unit has an elongated gear part which is movable in its longitudinal direction in a guide channel of the slide relative to the slide, wherein a length-variable cover element surrounding the gear part is arranged at at least one opening of the guide channel.

[0007] The carriage acts as a support element for a component to be moved. This could, for example, be the shaft of a lifting and tilting device to which a pallet truck is attached. The carriage moves relative to the elongated gear section via the gear unit. This section is moved out of the guide channel and would then be exposed to environmental influences, at least temporarily. The cover element surrounds the elongated gear section, thus protecting it from dust, dirt, and splashing water. Because its length is variable, it can be adjusted to the section of the elongated gear section not protected by the guide channel. This has the advantage over a rigid, tube-like cover element that less installation space is required.Often, a drive unit according to the invention is arranged in a frame in which there is no space for a rigid cover element whose length cannot be changed. Such a cover element would have to protrude beyond the frame in certain situations and could then pose a risk of injury. A length-variable cover element, on the other hand, can be designed so that its smallest dimension is such that the available installation space can be utilized.

[0008] The cover element can be extended to a fully extended position when the elongated transmission component moves out of the guide channel relative to the carriage, and retracted to a fully retracted position when the elongated transmission component moves into the guide channel relative to the carriage. This ensures that the elongated transmission component is always adequately covered. For example, in the case of a lifting and tilting device, this means that when the carriage moves upwards in its installed position (i.e., in the vehicle's vertical direction), the transmission component moves out of the guide channel. During this movement, the length-adjustable cover element extends and increases in length. When the carriage moves downwards, the transmission component moves into the guide channel, and the length-adjustable cover element retracts again.

[0009] According to the invention, the cover element is designed as a spiral spring element. In the retracted state, it is under preload, so that it is automatically moved into the extended state by releasing the preload.

[0010] Another advantageous embodiment provides that the cover element is hollow-cylindrical or hollow-conical in the extended state. This allows the elongated gear section to be completely enclosed and protected from contamination on all sides. The cover element is particularly preferably designed as a cylinder or conical spiral.

[0011] Preferably, the slide has a receiving space for the cover element in the area of ​​the guide channel opening. This allows the cover element to be held in place and prevents it from slipping.

[0012] Preferably, the guide channel has an enlarged diameter in the area of ​​the opening to form the receiving chamber. This makes the receiving chamber particularly easy to create during manufacturing, and inserting the cover element into the receiving chamber is also very easy to assemble. Furthermore, the enlarged diameter of the receiving chamber is preferably two to ten millimeters, particularly three to four millimeters, larger than the normal diameter of the guide channel. Most preferably, the enlarged diameter of the receiving chamber is two to ten millimeters, particularly three to four millimeters, larger than the local diameter of the cover element.

[0013] Preferably, the cover element is made of a metallic material. This makes the cover element very dimensionally stable and prevents the risk of the cover element buckling during operation and blocking the gearbox unit. Furthermore, a metallic cover element is more resistant to wear and damage.

[0014] The invention provides that a support is positioned against a free end of the cover element. The support prevents the cover element from expanding or contracting uncontrollably, thus preventing damage. Simultaneously, it serves as a stop element and can assist or even drive the insertion of the variable-length cover element.

[0015] Preferably, the abutment comprises a rod arranged on the elongated gear part, and a plate arranged in an end region of the rod and in contact with the free end of the cover element.

[0016] Preferably, the rod extends within the cover element. The cover element is then held between the abutment and the slide. The plate, serving as a stop element, moves uniformly with the elongated gear section away from and towards the slide. This allows it to drive the change in length of the cover element by exerting tension on it or pushing against it.

[0017] If the cover element is designed as a coil spring element, the plate resists the spring force of the cover element. As the plate, guided by the rod and the elongated gear section, moves away from the slide, the cover element expands due to the force generated by its preload. Conversely, the plate exerts pressure on the cover element, reducing its size. The elongated gear section and the slide, in effect, generate the length variation of the cover element through their intended relative movement.

[0018] Preferably, the rod has a thread at least in some sections. This allows the individual components to be easily connected and aligned. For example, the end sections of the rod can have a thread to connect the rod to the gear part and the plate.

[0019] Furthermore, the rod is held in an end pocket of the elongated gearbox section. This allows for easy assembly of the rod on the gearbox section. Advantageously, both the pocket and the rod are threaded, allowing the rod to be screwed into the pocket. In addition to easy assembly, the rod's length can also be easily adjusted.

[0020] Preferably, the plate has an opening through which the rod passes. This also allows for easy assembly, and the position of the plate on the rod can be easily adjusted. This allows the longitudinal extension of the cover element to be fixed. In particular, if the rod and the opening in the plate are threaded, the distance between the plate and the gear component can be adjusted very easily. The position of the plate can also be easily secured with nuts.

[0021] In a further advantageous embodiment of the invention, the plate has a base and a projection extending from it, which engages in an interior space of the cover element. This allows the cover element to be held in position on the plate and prevents it from slipping during movement of the retainer perpendicular to the cover element. Furthermore, the plate seals the interior space of the cover element, preventing the ingress of dirt, dust, and splashing water.

[0022] Particularly preferred is the diameter of the projection, which is two to ten millimeters, particularly three to four millimeters, smaller than the diameter of the base of the plate. Most preferred is the diameter of the projection, which is two to ten millimeters, particularly three to four millimeters, smaller than the local diameter of the cover element.

[0023] Preferably, the cover element is arranged to be freely movable within the receiving space and / or on the abutment. This means that the cover element is not fixed within the receiving space and / or on the abutment, but rather, for example, is capable of rotational movement around its longitudinal axis. This prevents damage to the cover element, as it can deflect to a certain extent from adverse forces. In the case of a design as a coil spring element, the free mounting also facilitates the smooth expansion and contraction of the cover element.

[0024] Preferably, the elongated transmission part is a rack and pinion.

[0025] Furthermore, the elongated gear part preferably works together with a second gear part arranged on the slide.

[0026] Furthermore, the second transmission part is preferably a gear.

[0027] The invention further relates to a lifting and tipping device, particularly for a waste collection vehicle, with a drive unit for a lifting truck as described above. Lifting and tipping devices are constantly exposed to environmental influences such as dust, dirt, and precipitation. At the same time, it is essential that they function as reliably as possible to avoid disrupting waste collection operations. The use of a drive unit according to the invention in a lifting and tipping device counteracts contamination of the drive unit, thereby preventing device failures caused by contamination. Furthermore, safety for operators and passersby is increased because the entire device, due to its compact size, can be housed within the frame of the lifting and tipping device, and no elements protrude beyond it, at least temporarily.

[0028] Further features of the invention can be seen from the figures and the accompanying description.

[0029] They show: Figure 1 shows a drive unit in use with a lifting and tilting device with the cover element retracted; Figure 2 shows a drive unit in use with a lifting and tilting device with the cover element extended; Figure 3 shows a drive unit in perspective view with the cover element retracted; Figure 4 shows a drive unit in perspective view with the cover element extended; Figure 5 shows a drive unit in sectional view with the cover element retracted; Figure 6 shows a drive unit in sectional view with the cover element extended; Figure 7 shows a detailed cross-sectional view of the cover element.

[0030] The Figure 1 and 2Figure 1 shows a lifting and tilting device 1 for a waste collection vehicle, equipped with a drive unit 2 according to the invention. The drive unit 2 comprises a carriage 3, which is guided on guide rods 4 in the vehicle's vertical direction X. A shaft rotatable about its longitudinal axis is arranged on the carriage 3, which carries a lifting carriage (not shown in detail here). A waste container to be emptied is suspended from the lifting carriage.

[0031] The drive unit 2 further comprises a gear unit with a first elongated gear part 5, which here is designed as a rack, and a second gear part 6, here a gear, arranged on the slide 3. The elongated gear part 5 and the second gear part 6 interact through their interlocking teeth.

[0032] In Figure 1The carriage 3 is in a lower position at the beginning of an emptying cycle. The rack 5 is located, at least partially, in a guide channel 7 formed in the carriage 3. A lifting mechanism raises the carriage 3, and thus the pallet truck with the waste container, upwards. The rack 5 and the carriage 3 are initially raised parallel to each other and move uniformly upwards in the vehicle direction X. The upward movement of the rack 5 is then blocked by driving it against a stop. This causes the gear 6 to roll over the rack 5 while the carriage 3 continues to move upwards. The rotation of the gear 6 is transmitted to the shaft and the pallet truck, so that the waste container is turned upside down, allowing the waste it contains to fall into a collection container. The upward movement of the carriage 3 ends in an upper position, as described in Figure 2is shown.

[0033] After the rack 5 is locked, it and the slide 3 move relative to each other. The rack 5 moves in its longitudinal direction L in a guide channel 7 of the slide 3. During the upward movement of the slide 3, the rack 5 slides out of the lower opening 8 of the guide channel 7.

[0034] During the downward movement, the sequence of motion reverses. The carriage 3 moves downwards along the vehicle's vertical direction X, and the gear 6 rolls down the rack 5 in the opposite direction of rotation. This rotates the pallet truck with the waste container back into its starting position. The rack 5 moves relative to the carriage 3 back into the guide channel 7 of the carriage 3.

[0035] A length-variable cover element 9 is arranged at the lower opening 8 of the guide channel 7. The length of the cover element 9 can be increased or decreased and surrounds the rack 5 when it is moved out of the guide channel 7. Inside the guide channel 7, the rack 5 is largely protected from contamination. Outside, this function is performed by the cover element 9. It increases in length to an extended state ( Figures 2 , 4 and 6 ), when the rack 5 is moved out of the guide channel 7. Conversely, the cover element shrinks into a retracted state ( Figure 1 , 3 and 5 ), when the rack 5 moves into the guide channel 7. The cover element 9 has a hollow conical shape, with the rack 5 located in the interior 16 of the cover element 9.

[0036] With its first end 10, the cover element 9 is arranged in a receiving space 11 on the slide 3. With its second, free end 12, the cover element 9 is in contact with an abutment 13.

[0037] The abutment 13 comprises a rod 14 and a plate 15 and is in Figure 7 The rod 13 is shown in detail. Each end of the rod has a thread. One end is screwed into a corresponding recess 20 of the rack 5. The plate 15 is located at the opposite end of the rod 14, which passes through an opening in the plate 15, and is secured with nuts. In this configuration, the rod 14 and plate 15 can be easily assembled and adjusted.

[0038] The plate 15 has a base 17 and a projection 18 extending from it, which engages in the interior 16 of the cover element 9. In this embodiment, the base 17 is circular and the projection 18 is cylindrical, matching the hollow-conical shape of the cover element 9. However, the geometry of the individual components can be adapted to one another. The plate 15 covers the opening of the free end 12 of the cover element 9, preventing dirt from penetrating. Because the projection 18 engages in the interior 16, the plate 15 and the cover element 9 are held relative to each other, for example, during lateral movements of the cover element 9, so that the interior 16 always remains sealed.

[0039] The cover element 9 is designed as a spiral spring element, more precisely as a cylindrical spiral, and is made of a metallic material. In the retracted state, the coils of the cover element 9 lie one above the other, and its longitudinal extension is determined solely by the width of the metal strip. In the retracted state, the cover element 9 is under a preload that, when installed, acts in the vehicle's vertical direction X. Without any further force being applied, this preload is released, and the cover element 9 extends longitudinally, driven by the spring force, into its hollow-conical extended shape.

[0040] The combination of cover element 9 and abutment 13 according to the invention makes use of this effect. In the retracted state, the plate 15 of the abutment 13 holds the cover element 9 in the retracted state and under preload. When the rack 5 moves out of the guide channel 7, the plate 15, which is connected to the rack 5 via the rod 14, moves away from the slide 3 with the rack 5. This allows the cover element 9 to expand under spring force and, in a sense, automatically covers the rack 5 over its entire exposed length.

[0041] In the reverse movement sequence, the rack 5 retracts into the guide channel 7, causing the plate 15 to move towards the slide 3. In doing so, it exerts a force on the cover element 9 against the spring force, pressing it back into its retracted position. The rack 5 itself causes the cover element 9 to shrink in size through its own movement.

[0042] This embodiment of the invention offers the advantage that no additional actuators are required to vary the length of the cover element 9. The individual components interact passively with each other in this respect. The arrangement is therefore easy to assemble and maintain.

[0043] Furthermore, the cover element 9 requires only minimal installation space, as it adapts its length to the available space. Even its dimensions in the retracted state can be adjusted to the available installation space within certain limits.

[0044] The cover element 9 is also kink-resistant, thus preventing slippage or jamming during operation. It is also wear-resistant and long-lasting.

[0045] The receiving chamber 11 in the slide 3 is created by widening the guide channel 7 in the area of ​​its opening 8. In other words, the guide channel 7 has a larger cross-sectional diameter in the area of ​​its opening 8 than in its other sections. The resulting step forms a stop 19 against which the cover element 9 abuts and rests. The diameter of the receiving chamber 11 is approximately 3 to 4 millimeters larger than the outer diameter of the cover element 9 in its retracted state, ensuring that a sufficiently wide stop 19 is formed so that the cover element does not slip into the guide channel 7. The cover element 9 sits loosely and is free to move within the receiving chamber 11.This freedom of movement is necessary due to the design as a spiral spring element, which in particular requires rotational mobility so that the extension and retraction can take place without blocking or jamming.

[0046] For the same reason, the free end 12 of the cover element 9 is also loosely and freely movable on the abutment 13, more precisely its plate 15. The diameter of the projection 18 of the plate 15 is 3 to 4 millimeters smaller than the diameter of the cover element 9 at its free end 12. This results in a good balance between the mobility of the cover element 9 and its sealing. Reference sign

[0047] 1 Lifting and tilting device 2 Drive unit 3 Slide 4 Guide rod 5 Rack, elongated gear part 6 Gear, second gear part 7 Guide channel 8 Opening of 7 9 Cover element 10 First end of 9 11 Receiving space 12 Second end of 9 13 Abutment 14 Rod 15 Plate 16 Interior of 9 17 Base area of ​​15 18 Projection of 15 19 Stop 20 Pocket L Longitudinal direction of 5 X Vehicle vertical direction

Claims

1. Drive unit (2) comprising a slide (3) and a gear unit that moves the slide (3), wherein the gear unit has an elongate gear part (5) which is movable in a guide channel (7) of the slide (3) in its longitudinal direction and relative to the slide, wherein a length-variable cover element (9) for the gear part (5), which is designed as a spiral spring element and surrounds the gear part (5), is arranged at at least one opening of the guide channel (7), characterized in that an abutment (13) abuts a free end (12) of the cover element (9).

2. Drive unit (2) according to claim 1, characterized in that the cover element (9) is designed to be hollow-cylindrical or hollow-conical in an extended state.

3. Drive unit (2) according to claim 1 or 2, characterized in that the slide (3) has a receiving space (11) for the cover element (9) in the region of the opening (8) of the guide channel (7).

4. Drive unit (2) according to claim 3, characterized in that the guide channel (7) has a larger diameter in the region of the opening (8) in order to form the receiving space (11).

5. Drive unit (2) according to at least one of the preceding claims, characterized in that the cover element (9) is made of a metal material.

6. Drive unit (2) according to at least one of the preceding claims, characterized in that the abutment (13) comprises a rod (14) which is arranged on the elongate gear part (5), and a plate (15) which is arranged in an end region of the rod (14) and which abuts the free end (12) of the cover element (9).

7. Drive unit (2) according to claim 6, characterized in that the rod (14) has a thread at least in portions.

8. Drive unit (2) according to claim 6 or 7, characterized in that the rod (14) is held in a recess (20) at the end of the elongate gear part (5).

9. Drive unit (2) according to at least one of claims 6 to 8, characterized in that the plate (15) comprises a through-hole through which the rod (14) passes.

10. Drive unit (2) according to at least one of claims 6 to 9, characterized in that the plate (15) has a base surface (17) and a projection (18) protruding therefrom, which engages in an interior space (16) of the cover element (9).

11. Drive unit (2) according to at least one of the preceding claims, characterized in that the cover element (9) is arranged to be freely movable in the receiving space (11) and / or on the abutment (13).

12. Drive unit (2) according to at least one of the preceding claims, characterized in that the elongate gear part (5) is a gear rack.

13. Drive unit (2) according to at least one of the preceding claims, characterized in that the elongate gear part (5) interacts with a second gear part (6) arranged on the slide (3).

14. Drive unit (2) according to claim 13, characterized in that the second gear part (6) is a pinion.

15. Lifting and tilting device (1), in particular for a waste collection vehicle, comprising a drive unit (2) for a lift truck according to at least one of the preceding claims.