Chain drive arrangement and lifting equipment with double chain wheel

Abstract

To achieve weight and size savings on a chain drive and on the whole of a lifting mechanism.SOLUTION: A lifting mechanism device having an electric or pneumatic motor and two link members has two chain wheels (R11, R12), which are arranged beside each other on a shaft (d), which is driven by the motor, wherein each chain wheel is used to guide in each case a portion of a link chain with alternately horizontal links (L) and vertical links (T), that is to say, having pockets for receiving horizontal links and having a groove which extends in the circumferential direction for receiving vertical links. The chain wheels (R11, R12) are arranged in a rotationally secure manner with respect to each other in an angular position in the same direction in which the angle pockets of the two chain wheels are located offset with respect to each other by only a distance parallel with the shaft, but are not rotated with respect to each other.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a lifting mechanism having a double chain wheel in which two or more link chains are used as carrier means. In particular, the present invention is a chain drive device having a chain drive on a chain drive shaft that can be driven by a motor, the chain drive device being capable of guiding at least two link chain strands via the chain drive, and a lifting mechanism device directly or communicatively connected to the motor. The present invention further relates to a lifting mechanism system including a lifting mechanism device, a link chain strand guided via the chain drive of the lifting mechanism device, and a stop device that can be attached to the end of the link chain strand.

Background Art

[0002] In the type of lifting mechanism being considered here (this term also includes chain drive devices, lifting mechanism devices, and systems), link chains, particularly industrial round steel chains or profile steel chains, are used as carrier means for lifting and / or moving loads. In this case, the chain links of the chain strand are guided via a chain wheel (also called a chain sprocket), and the links of the chain strand are alternately directed vertically and horizontally on the outer surface of the chain wheel. Preferably, the chain drive has two chain wheels arranged adjacent to each other on the shaft of the chain drive, and in each case, each of the chain wheels for guiding a part of the link chain strand is configured with alternating horizontal and vertical links, that is, with pockets for receiving horizontal links and grooves extending circumferentially for receiving vertical links.

Summary of the Invention

Problems to be Solved by the Invention

[0003] In elevator devices and stop devices, it goes without saying that durability and reliability against chain breakage are particularly important. For example, when it is intended to double the load-bearing capacity of an electric or manual lifting gear, a chain drive of a lifting gear with a single chain strand can be converted, for example, using a deflection roller for deflecting the chain, into a two-strand chain configuration of a link chain according to the pulley principle. It is also possible to configure a plurality of strands so as to triple or double the load-bearing capacity. However, in this case, it is disadvantageous that the chain under full load capacity must also be guided over the deflection wheel. In a double-chain chain drive, this triples the load angle of the chain for each lifting cycle on the chain wheels involved (once on the drive chain wheel and twice on the deflection chain wheel). This leads to a substantial shortening of the service life of the chain, thereby reducing the service life to substantially one-third. The lifting speed of a multi-strand chain drive also decreases inversely with the number of strands. The inventors recognize the often quite significant space requirements of the chain wheels as a further disadvantage.

Means for Solving the Problem

[0004] Summary of the Invention To overcome these drawbacks, according to the present invention, in a chain drive, it is proposed that the chain drive has two or more chain wheels arranged adjacent to each other so as to be able to rotate reliably on the shaft of the chain drive, and the two chain wheels are arranged at angular positions in the same direction relative to each other. At this angular position in the same direction, the angular pockets of the two chain wheels are offset from each other by a distance parallel to the shaft.

[0005] This solution according to the present invention provides several advantages. As a result of the use of double (or multiple) chain wheels and correspondingly multiplexed chains, the load of the lifting mechanism (without additional chain angles per chain) can be doubled or multiplexed, and the adverse effect on the service life of the chains is avoided. The present invention also enables the use of chains with relatively small strand cross-sections for the chain links and chain wheels with relatively small diameters. The possibility of using smaller chains (with the same load-bearing capacity per chain) is even more advantageous with regard to the service life of the chains. The small chain dimensions provide an advantage with regard to the wear service life compared to larger chains. This is because the ratio of the chain surface to the chain volume is improved.

[0006] In a chain drive with a double chain wheel, the diameter of the chain used can be reduced by a factor of √2 with the same load-bearing capacity (this corresponds to two chains with half the load-bearing capacity). As a result, the required segmentation of the chain and the size of the chain wheel are reduced by the same factor. Consequently, with the same load-bearing capacity, a double chain drive can be reduced by a factor of 1 / √2 = 0.71 with respect to the diameter compared to a chain drive with a single chain.

[0007] As a result of this reduction in the size of the chain wheel, the drive torque required in the associated lifting mechanism can also be reduced by this factor. As a result, the chain drive in the lifting mechanism device can be made overall smaller. As a further result, a smaller drive torque is required, and as a result, the weight of the chain drive with a double chain drive can also be reduced compared to a chain drive with individual chains for the same load. Thereby, the linear dimensions of the chain drive are reduced by approximately 11% (in accordance with the cube root of 0.71). As a result of the savings in weight and size of the chain drive and the entire lifting mechanism, there are further significant savings in terms of cost and materials.

[0008] A further advantage has been found to be an improvement in safety against chain failure, particularly breakage of the chain as a result of the use of two or more chains extending in parallel. If a chain ceases to function (breaks), the load does not fall nevertheless, and if the other chain is configured, for example, with four-fold safety, it can still support the load.

[0009] In an advantageous further development of the invention, the lifting mechanism device is further provided with a motor which is directly or transmission-connected to the chain drive shaft. This results in particular advantages in the case of small mechanical lifting mechanisms used in lifting systems such as cranes, for example. In these lifting mechanisms and the systems in which they are installed, it is also advantageous that not only a more compact structural type can be achieved, but also further components such as gear mechanisms or brake devices (safety brakes) can be made smaller. This is because, due to the consistent load-bearing capacity, the dimensions of the chain strands can be made to depend on (not the overall configuration of the chain hoist) the size of the individual link chain strands. Thus, the size of the motor and, where applicable, the associated gear mechanism and / or the associated brake device can correspond to the size of the individual link chain strands. This is particularly true when the motor operates electrically or pneumatically.

[0010] In particular, by replacing a (single) chain wheel with a double chain wheel, with respect to the same load-bearing capacity of the compact lifting gear, the size of the chain (size of the chain links) and the chain wheel can be made smaller, and as a result of the smaller diameter of the chain wheel, less torque is generated, which can in turn result in smaller dimensions in the brake (safety brake), the motor gear mechanism, and ultimately the motor (with the same power but at a higher speed). Furthermore, a smaller housing can be provided and overall weight can be saved. Overall, the invention leads to significant cost savings, particularly with respect to electric lifting mechanisms.

[0011] Preferably, the chain wheels can be arranged directly adjacent to each other on the shaft, preferably integrally formed, and / or the chain wheels are spaced apart from each other on the shaft. A particularly advantageous configuration is provided with a chain drive having two chain wheels. These may be formed mirror-symmetrically to each other.

[0012] To improve the guidance of the chain via the chain wheel, it is advantageous to have a housing that surrounds the chain wheel and radially limits the movement space of the chain links on the chain wheel inside. In this case, it may be advantageous for the housing to have two grooves adjacent to each other on the inside, and in these grooves, the vertical links of the link chain strand running on the chain wheel are guided.

[0013] The aforementioned advantages also particularly occur with respect to a lifting mechanism system that, in addition to a lifting mechanism device of the aforementioned type, comprises a link chain strand guided via a chain drive of the lifting mechanism device and a stop device having two connection positions arranged adjacent to each other for one end member of each link chain strand and having a connection portion for the load on the side facing away from the link chain strand, the connection positions being arranged at the same height with respect to the load direction (i.e., a direction parallel to the extension direction of the link chain strand). Preferably, the connection portion may comprise a load hook. This may be supported by the stop device so as to be rotatable about an axis parallel to the load direction. The present invention will be described in more detail below in connection with several exemplary embodiments shown in the drawings, with further details and preferences, all of which are purely illustrative and not limiting of the present invention.

Brief Description of the Drawings

[0014]

Figure 1a

Figure 1b

Figure 2

Figure 3

Figure 4a

Figure 4b

Figure 4c

Figure 5a

Figure 5b

Figure 5c

Figure 6a

Figure 6bc

Figure 7a

Figure 7b

DETAILED DESCRIPTION OF THE INVENTION

[0015] In the figures, for clarity, the same elements are given the same reference numerals. The reference numerals in the claims are merely intended to enhance understanding and are in no way intended to limit each embodiment. The drawings show exemplary embodiments, and in these embodiments, it is not intended that the present invention be construed as limiting. The load is supported against gravity, and as a result, the load direction b corresponds to the vertical direction (see FIGS. 1 and 3). However, in other applications, for example, when transporting a load along a track, the load direction may be differently oriented, and in this case, it is clear that the load direction generally corresponds to the extent direction of the path. Generally, the chain used as a load means in a chain hoist extends substantially symmetrically in the load direction in the loaded operating state. Terms such as "upper region", "downward", or "lower side" are intended to be understood in this context, that is, with respect to the direction corresponding to the conceptual load direction in the vertical direction.

[0016] The exemplary embodiment shown below relates to a chain drive configured for a round steel chain in which individual chain links are rotated relative to each other by 90° around the extending direction of the chain. Also, the chain may be other forms of chain links, such as a profile steel chain, and those skilled in the art can easily perform the corresponding adaptation of the chain wheel according to the present invention and the chain drive system for these types of chains. The chain is generally manufactured from steel, such as case-hardened steel, but hardened and tempered steel may also be advantageously used.

[0017] When the link chain is guided over the chain wheel of the chain drive according to the present invention, the individual chain links are held thereon, and thus are alternately guided in the vertical direction T and the horizontal direction L (for example, see FIGS. 3 and 4a) on each chain wheel. The terms "vertically" and "horizontally" have the meanings that are already customary in the prior art in this case. The vertical chain link T is a chain link supported by only one leg. The eye of the chain link perpendicular to the chain wheel is oriented substantially parallel to the axis of rotation of the chain wheel. On the chain wheel, this leg of the vertical chain member is often located in a groove that extends in the circumferential direction of the chain wheel and determines the position of the chain link. The horizontal chain link L is a chain link, and its two legs are placed adjacent to each other. The eye of the horizontal chain link on the chain wheel is oriented substantially radially with respect to the axis of rotation of the chain wheel. In the chain wheel considered in this case, generally, a chain pocket for receiving the horizontal chain link is provided in any case.

[0018] FIG. 1 shows a lifting mechanism system 10 according to a first embodiment of the present invention. The lifting mechanism system includes a chain drive system having a double chain 11 and a double chain wheel 12 according to the present invention, and an electric drive motor 13 that drives a shaft 15, that is, the shaft on which the double chain wheel of the chain drive system 11 is arranged, via a gear mechanism 14. A connection cable 19 serves to electrically supply power to the electric motor 13.

[0019] The motor 13, the gear mechanism 14, and the upper part of the chain drive system 11 (in particular the double chain wheel 12) are housed in a housing 16 that opens downward at least in the area of the chain drive. The housing 16 may be held and positioned on its upper side, for example, by an assembly hook 17 that is mounted and fixed in place, on a carrier (not shown) or a crane boom or the like. The operation of the hoisting mechanism system 10, in particular the electric motor 13, is controlled and monitored in a manner known per se, for example via a manual operation unit 18.

[0020] FIG. 3 is a perspective view of an embodiment of a chain drive system K that can be used, in particular, as the chain drive system 11 of the system of FIG. 1. The chain drive system K includes a chain drive in the form of a double chain wheel D1, together with two chain strands S11, S12 of a chain hoist on which a stop device A1 is further fixed at its end and is guided thereon. As can be seen in FIG. 3, the two chain strands S11, S12 are each guided around one of the two chain wheels R11, R12 of the double chain wheel D1, and the individual chain members are held and thus guided alternately in the vertical direction T and the horizontal direction L on the respective chain wheels R11, R12.

[0021] In FIG. 2, for comparison, a conventional elevator mechanism system 20 with individual chains 21 and chain wheels 22 is shown. In this case, since the load intended to be lifted is held and moved by the individual chains, the chains 21 are dimensioned to be correspondingly larger, and the sizes of the motor 23 and gear 24 mechanisms follow the size of the chains 21. In contrast, the two chains 11 of the elevator mechanism system 10 in FIG. 1 can be configured to be smaller in this case, since the load intended to be lifted is distributed across the strands of the two chains. This also allows for a smaller form of the gear mechanism 14 and, if applicable, a smaller form of the motor 13. Thus, overall, there is a reduced and more economical form of the elevator mechanism system 10 with smaller space requirements - a smaller housing 16 - and a lighter weight elevator mechanism compared to previous elevator mechanisms. Furthermore, as a result of the multiple form of the chains and the mutual redundancy of the chain strands, the reliability against breakage of the chain strands is improved.

[0022] For example, compared to a conventional chain drive with a simple chain wheel, a chain drive with a double chain wheel can have a technical configuration as shown in Table 1.

Table 1

[0023] FIG. 4 shows further details of the chain wheel (double chain wheel D1) of the chain drive in FIG. 3 without the chain links arranged. In this case, FIG. 4a shows a front view, FIG. 4b shows a longitudinal sectional view along a section passing through the rotation axis d of the chain drive, FIG. 4c shows a sectional view of the chain wheel R11 along the central plane m1 (viewing direction along the rotation axis d), which corresponds exactly to the sectional view of the other chain wheel R12 along the central plane m2.

[0024] In FIG. 5, the chain drive system K is shown as three other views (FIGS. 5a-5c), namely, a plan view (FIG. 5a; viewing direction along the load direction b), a front view (FIG. 5b), and a side view (FIG. 5c; viewing direction parallel to the rotation axis d of the chain wheel). In FIGS. 3-5, the chain drive is shown without the housing so that the chain wheel and the chain strand guided within the chain wheel can be better seen. The housing E1 is optional and will be described below with reference to FIG. 6.

[0025] Referring to FIGS. 4a to 4c, each of the chain wheels R11, R12 is in the form of a so-called pocket chain wheel. Thus, the chain wheel has a pocket H that is adapted to the elliptical link shape and has a substantially flat support surface (pocket base) for the horizontal chain link L in any case (see FIG. 5a). Where applicable, at the longitudinal center of the pocket, a recess that functions to receive a potential weld bead (not shown) around the leg of the chain link may be further formed so that the horizontal chain link L can be flatly placed on the support surface of the pocket H even if such a weld bead exists. The pockets of the chain wheel are defined relative to each other by webs G, and each web is divided by a groove F to receive the vertical link T within the central planes m1, m2 of the chain wheels R11, R12 such that the web G is divided into two teeth Z (on the left and right of the central plane m1 or m2 in any case). In this exemplary embodiment, the chain wheel has a pentagonal shape (number of pockets z = 5) with five pockets H in side view and thus five webs G that define them relative to each other, but it is clear that the chain wheel can easily have more or fewer pockets and webs. The web G has a convex side that connects directly to the flat support surface of the pocket H at the "inner" edge (i.e., closest to the axis of rotation d), preferably with a prominent transition edge. The preferably flat base of the groove F for the vertical leg T has, between the teeth Z, a depression that serves the same purpose as the aforementioned recess in the pocket base, i.e., to receive a potential weld bead (not shown) of the vertical leg T and may be further formed so that it can be flatly placed or supported on the groove base on the flat outer side of its inner leg. This is because during the pivoting operation, the horizontal link L is self-supported on the vertical Ts, thereby facilitating the pivoting of the horizontal chain link to the correct position on each pocket base, and thus supporting the vertical link T on the groove base of the groove F is very important for the function of the chain drive or wheel.As a result of this configuration of the chain wheel, both the horizontal link L and the vertical link T, that is, the horizontal link L with most of its side on the support surface of the pocket and the vertical link T with the outer surface of the inner leg on the groove base, are supported flatly.

[0026] In the double chain wheel D1, two chain wheels R11, R12 adjacent to each other are connected to each other so that they can rotate coaxially and reliably. According to the present invention, the chain wheels are arranged relative to each other without a relative angular offset, that is, when viewed along the rotation axis d, the chain pockets of one chain wheel R11 are positioned directly adjacent to the chain pockets of the other chain wheel R12. In a similar manner, this can also be referred to the web G, that is, when viewed in the direction along the rotation axis d, the web G of one chain wheel R11 is positioned directly adjacent to the web G of the other chain wheel R12. According to another aspect, it can also be considered that the two chain wheels R11, R12 are configured symmetrically with respect to each other about the central plane m0. The two chain wheels may be integrally formed in the double chain wheel D1, or may be in the form of individual components R11 and R12 connected to each other in a suitable manner so that they can rotate reliably, for example, by connection pins or by welding.

[0027] Referring again to FIGS. 1 to 3, a load (not shown) intended to be supported by the lifting mechanism is connected at the ends of the two chains S11, S12 using a stop device A1 having connection positions for the chain strands, and these connection positions are arranged at the same height relative to each other in the load direction. The stop device A1 includes a stop component C1 having a load hook B1. The stop component C1 is formed by a body configured in a socket shape and provided with connection positions C11, C12 in its "upper" region. By these connection positions C11, C12 provided inside the body, the respective end members of the chain strands are arranged and fixed, for example, with bolts (not shown).

[0028] The load hook B1 is located on the "lower side" of the body of the stop component C1 and is preferably supported so as to be rotatable about an axis parallel to the load direction b. However, in a variant, the load hook B1 may be attached so as to be reliably rotatable with respect to the body of the stop component C1.

[0029] Generally, the stopping device has, on the opposite side of the connection part, two (or more, if applicable) connection positions arranged adjacent to each other for the end members of each link chain, and these connection positions are preferably arranged at the same height when viewed in the load direction.

[0030] Figure 6 shows an example of a lifting mechanism device W2 in which a double-chain wheel D1 is rotatably supported within a chain drive housing E1 (components for holding the housing are omitted in Figure 6 for clarity). In this case, Figure 6a shows a front view, Figure 6b shows a longitudinal section along a "horizontal" plane of section 6-6 passing through the rotation axis d of the double-chain wheel D1, and Figure 6c shows a sectional view along the central plane m1 of the chain wheel R11. The housing E1 surrounds the chain wheels R11, R12 and defines radially inward the movement space of the link chain on the chain wheels. The double-chain wheel D1 is concentrically supported within the housing E1 by a shaft (extending along the rotation axis d) and its holding member (not shown) such that the wheel D1 can rotate within the housing without contacting the housing and is rotatably fixed within the housing. As can be seen particularly in the sectional view of Figure 6b, the housing has two grooves F1, F2 adjacent to each other on the inside, and within these grooves, the vertical links of the link chain running on the chain wheels are guided. An inner part J2, also called a wiper, may be further provided to close the chain drive on the output side, and the inner part J2 can further guide the chain part when entering the chain drive, particularly during the release ("discharge") of the chain from the chain wheel and when leaving the chain drive. The housing E1 and the inner part J2 are held, for example, within a motor housing.

[0031] Another exemplary embodiment of the present invention is the pneumatic actuated lifting mechanism system 70, shown in FIG. 7. This lifting mechanism system 70 also includes a chain drive system with the double chain 11 and double chain wheel 12 according to the present invention, but also includes a motor 73 that is driven by compressed air, controlled and monitored, for example, by a manual operation unit 78, and supplied with compressed air via a compressed air line 79. The pneumatic embodiment features further space and weight savings for the motor 73 and the gear mechanism 74 so that the housing 76 is also more compact. Further, this embodiment corresponds to the embodiments described above in connection with FIGS. 1 and 3 - 6.

[0032] Of course, those skilled in the art can modify the present invention in light of the illustrated embodiments and description to fit a given requirement. Therefore, the technical structure of the present invention is not limited to the illustrated embodiments. Instead, the present invention extends to the entire scope of protection derived from the following claims.

Claims

1. a chain drive having a chain drive (D1) on a chain drive shaft which can be driven by a motor, through which at least two link chain strands (S11, S12) can be guided, said chain drive has at least two chain wheels (R11, R12; R61, R62) arranged adjacent to each other on a shaft of said chain drive, each of said chain wheels being adapted to guide a portion of a link chain strand with alternating horizontal links (L) and vertical links (T), i.e. having pockets (H) for receiving said horizontal links and having circumferentially extending grooves (F) for receiving said vertical links, said two chain wheels (R11, R12; R61, R62) are arranged so as to be able to rotate reliably relative to each other in the same angular direction, with the angular pockets of said two chain wheels being offset relative to each other by a distance parallel to said shaft; Chain drive.

2. 2. A chain drive according to claim 1, characterized in that the chain wheels (R11, R12) are arranged directly adjacent to one another on the shaft and are preferably constructed integrally.

3. 2. A chain drive according to claim 1, characterized in that the chain wheels (R61, R62) are spaced apart from one another on the shaft.

4. 4. The chain drive according to claim 1, wherein the chain drive comprises two chain wheels arranged mirror-symmetrically with respect to each other.

5. 5. A chain drive according to claim 1, characterized by a housing (E1) surrounding the chain wheel and defining radially inside the movement space of the chain links on the chain wheel.

6. 6. A chain drive according to claim 5, wherein the housing has two grooves (F1, F2) on the inside, adjacent to each other, in which the vertical links of the link chain strand running on the chain wheels are guided.

7. 7. A lifting mechanism device comprising a chain drive according to any one of claims 1 to 6 and a motor directly or transmissively connected to the chain drive shaft, the motor being electrically or pneumatically operated.

8. 8. A lifting mechanism device according to claim 7, wherein the size of the motor and, where applicable, the associated gear mechanism and / or the associated brake device corresponds to the size of the individual link chain strands.

9. A lifting mechanism system comprising a lifting mechanism device as described in claim 7, link chain strands (S11, S12) guided through the chain drive of the lifting mechanism device, and a stop device having connection positions (C11, C12) arranged adjacent to each other for end links of each link chain strand for fixing the ends of the link chain strands (S11, S12) and having a connection member (B1) for a load on the side facing away from the link chain strands, the connection positions being arranged at the same height in the load direction.

10. 10. A lifting mechanism system according to claim 9, wherein the connecting member comprises a load hook preferably rotatably supported on the stop device about an axis parallel to the load direction (b).

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