Screw conveyor with two-point bearing

Abstract

A screw conveyor suitable for installation in a pressure housing / cutting-separating drum, designed for axially rotatable bearing, with the bearing provided at least at two points. Furthermore, a bearing device and a device for grinding foodstuffs.

Description

[0001] The present invention relates to an improved conveyor screw, particularly for use in a food chopping device, which ensures efficient and reliable storage. It also relates to a storage device and a device for chopping food itself. State of the art

[0002] The design of a food-grinding device, such as a meat grinder, typically includes a conveyor screw installed in a pressure housing or a cutting-and-separating drum. This conveyor screw is used to transport pieces of food through rotation and simultaneously grind them by forcing the food through holes in the pressure housing and shearing them off by the conveyor screw's flight.

[0003] In conventional designs, the screw conveyor is often mounted in a single location, which can lead to uneven loading and potential wear. Vibrations and imbalances can also occur, impairing the efficiency of the shredding process. A reliable and stable bearing is therefore crucial to ensure the long-term, effective operation of the shredding device.

[0004] The current state of the art, as described in patent DE 102017003407 B3, discloses a screw conveyor installed in a pressure housing or cutting-separating drum. This screw conveyor is mounted for axial rotation, with the bearing relative to the pressure housing being provided at only one point on the left by means of a centering insert. On the right side, there is a centering sleeve, but this does not serve to support the screw conveyor. Through the opening in this sleeve, the screw conveyor is connected directly or indirectly to a motor drive; therefore, a bearing is not necessarily required. Disclosure of the invention

[0005] The present invention aims to overcome the disadvantages of the prior art by providing an improved bearing for the screw conveyor. The screw conveyor is now supported at at least two locations, which allows for a more even distribution of load and increases stability during operation. This arrangement can help extend the service life of the screw conveyor and improve the efficiency of the overall comminution process. Furthermore, the bearing is preferably located exclusively relative to a single, other machine part, which not only enables more precise guidance with less play in the pressure housing, but also simplifies the design and facilitates assembly and maintenance.

[0006] This includes or comprises a conveyor screw device suitable for installation in a pressure housing / cutting-separating drum, designed for axially rotatable mounting. The conveyor screw is mounted at at least two locations.

[0007] Advantageously, the mobility of the screw conveyor is limited to one degree of freedom, preventing unwanted movement. This arrangement achieves a more even distribution of the load, resulting in increased stability and a longer service life for the screw conveyor. Force effects and one-sided wear on the screw conveyor or pressure housing, for example, due to unevenly fed food, are avoided.

[0008] In a special design of the conveyor screw, the bearings at all points are mounted exclusively opposite a single / one-piece, other machine part.

[0009] Advantageously, if all bearing points are aligned relative to a single machine part, the play between the screw conveyor and that machine part can be minimized. For example, if one bearing is mounted relative to the pressure housing and a second relative to the meat grinder, the play created by the mounting between the pressure housing and the meat grinder will undesirably increase.

[0010] The key here is to minimize play, which can be achieved by making the other machine part a single piece. Alternatively, fixed connections such as screw joints can also be considered.

[0011] In a special design of the screw conveyor, the bearings of the screw conveyor are located exclusively directly opposite the pressure housing.

[0012] Advantageously, the only machine part in this specific implementation is the pressure housing, since the freewheel must be precisely coordinated between the conveyor screw and the pressure housing.

[0013] Alternatively, the bearings between the screw conveyor and the pressure housing are mounted using a bearing device / bracket. This ensures only a quasi-one-piece design, but the brackets are firmly connected to the pressure housing and have as little play as possible. Advantageously, manufacturing and maintenance / cleaning are significantly simplified compared to if the brackets were formed integrally with the pressure housing. Since the force paths are transferred directly to the pressure housing via the brackets, this is an advantage compared to, for example, a one-sided bearing opposite the meat grinder housing.

[0014] The bracket includes an outer bearing shell and keeps the pressure housing at a distance from the conveyor screw.

[0015] In a special design of the conveyor screw, the bearings are arranged radially outwards.

[0016] Advantageously, the support is positioned radially outward from the screw conveyor, ensuring stable and smooth rotation of the screw conveyor, as this corresponds to the direct flow of force and avoids / minimizes shear stresses during mounting. This would not be the case if the support were positioned opposite a machine part (e.g., the meat grinder) that is not radial to the direction of rotation. This design allows for even load distribution across the entire length of the screw conveyor and reduces the risk of bending and torsional forces that could compromise its structural integrity.

[0017] In a special embodiment of the conveyor screw, one receptacle on the conveyor screw is positioned for the first storage location (near) an input end and the second receptacle for the second storage location (near) an output end.

[0018] The receptacles can have the shape of pins that are rotationally symmetrical.

[0019] Advantageously, the at least two bearings are located at widely spaced locations, e.g., directly at or near the ends of the screw conveyor, or at the level of the ends of the pressure housing. This minimizes shear forces.

[0020] Alternatively, the mounts, or rather their surfaces, directly form the inner bearing shells. These can optionally be hardened.

[0021] In a special embodiment of the conveyor screw, at least one or both of the receptacles are provided to form a positive or non-positive connection with a bearing bush, alternatively a hardened bearing bush.

[0022] Typically, one of the two bearing shells of a bearing is harder than the other to provide indirect lubrication. Hardening the inner bearing, which is located on the screw conveyor, causes little wear, so the inner bearing shell does not need to be replaced or serviced frequently due to reduced wear.

[0023] Furthermore, the invention includes or comprises a bearing device comprising, in at least two embodiments, a bearing bushing forming an inner bearing shell, intended for immovable connection to a screw conveyor. Furthermore, a holder forming an outer bearing shell. The holder is not formed integrally with the pressure housing and is suitable for keeping the pressure housing spaced apart from the screw conveyor.

[0024] In a particular embodiment of the bearing device, at least one of the bearing bushes and / or at least one of the bearing shells consists of hardened material.

[0025] Both components can also be made of hardened material to improve the durability and resistance of the bearing.

[0026] This advantageously creates a plain bearing that is easy to clean compared to a ball bearing, for example.

[0027] In an alternative design, a ball bearing is also conceivable, which advantageously promises better running properties.

[0028] Furthermore, the invention includes or comprises a device for comminuting food, comprising a conveyor screw as described above, and a pressure housing as described above, which is spaced apart and guided by a bearing as described above. The conveyor screw can thus rotate about an axis centrally within the pressure housing.

[0029] The advantages of the individual measures come into play in the overall system.

[0030] In one embodiment, the invention comprises a device for comminuting foodstuffs, wherein the conveyor screw has a first bearing on a first input-side receptacle with a fixed, preferably hardened bearing bush, which forms a sliding bearing for the axial rotation of the conveyor screw with a first (front) holder, wherein the first holder is releasably connected to the pressure housing in a force-locking or form-locking manner. Furthermore, the conveyor screw has a second bearing on a second output-side receptacle with a fixed, preferably hardened bearing bush, which forms a sliding bearing for the axial rotation of the conveyor screw with a second (rear) holder, wherein the second holder is releasably connected to the pressure housing in a force-locking or form-locking manner. According to one embodiment, the conveyor screw and bearing bush(s) can also be manufactured as a single piece.

[0031] Further embodiments are described and explained in more detail below with reference to the attached figures.

[0032] They show: Fig. 1 a device for chopping food; Fig. 2 a perspective view of a screw conveyor with bracket in half section; Fig. 3 a pressure housing and brackets Fig. 4 A cross-sectional view of the pressure housing, as well as a conveyor screw and bearing shells.

[0033] As in Fig. 1 As shown, a device for chopping foodstuffs is equipped with a feed screw 1 which, by rotating on the inlet side, feeds the foodstuff concentrically to the conveyor screw 7 so that it is received in the cavities between the threads.

[0034] A holder for a standard tool carrier 2 can be provided, which simplifies the installation in a machine housing 19.

[0035] The screw conveyor 7 is rotatably mounted in the pressure housing 8. Bearing bushings 4, 9 are mounted on a journal on the inlet and outlet sides, each with a receptacle 16a, 16b. These form the inner bearing shells and can optionally be hardened.

[0036] Likewise, the correct distance between the screw conveyor, or rather its journals, and the pressure housing is ensured by inlet and outlet brackets 3, 12. These brackets also have bushings 3a, 10, which form the outer bearing shells.

[0037] The conveyor screw 7 is connected or mounted to the pressure housing 8 by the brackets 3, 12. The mounting of the pressure housing 8 to the machine housing 19 (e.g., meat grinder) can be achieved by a screw connection on the input side. An (at least partially) circumferential spring 17a enables the mechanical engagement of a union nut 6, which is screwed onto an external thread on the machine housing. The axial force exerted by the nut 6 on the spring 17a fixes the pressure housing 8 in the machine housing 19. According to one embodiment, this clamps the bracket against the pressure housing. This arrangement is particularly effective because it simultaneously fixes the pressure housing 8 to the machine housing 19 and, at the same time, fixes the bracket 3 to the pressure housing. Thanks to the solution with the two brackets 3, 12, these two wearing parts can be replaced by loosening only two union nuts.

[0038] On the output side, an ejection screw 14 is located adjacent to the conveyor screw 7, which transports unwanted food residue to an ejection valve 15. The ejection device has a conical end 13, which is engaged by a second union nut 11, similar to the spring 17a. The second union nut 11 is screwed onto a thread 17b located at the end of the pressure housing 8. This connection of the nut and the assembly secures the bracket and bearing bushings. This screw connection enables easy assembly and maintenance and simplifies cleaning.

[0039] In rotating systems, there is a risk that components will become loose and rotate unintentionally or no longer rotate. To prevent the pressure housing 8 from rotating relative to the machine housing 19, a tongue and groove combination can prevent these two components from rotating relative to each other. In one embodiment, the pressure housing 8 has a groove in the axial direction, which is placed on a tongue or locking pin 5 during assembly.

[0040] In the present drawings, the input-side bracket 3 is mounted on the front side of the pressure housing 8. The input-side bracket 3 has an outer diameter equal to or larger than that of the pressure housing 8. Advantageously, this allows the distance between the two bearings to be increased even further.

[0041] At the same time, this allows a locking pin 3b to engage in a hole / recess in the pressure housing 8. In addition to the anti-twist feature, this also serves as an assembly lock; the holder can no longer be installed the wrong way round (end faces swapped) because the pin 3b would not find space in the machine housing 19.

[0042] In the illustration, the output-side holder 10 has a smaller diameter than the outer diameter of the pressure housing 8. In particular, however, it is larger than the inner diameter of the pressure housing 8, so that a recess must be provided in the pressure housing 8 into which the holder 10 can be inserted.

[0043] The conveyor screw 7 can be solid. Alternatively, a recess / cavity 18 can be provided in the screw to save weight and reduce the inertia. The cavity can be created by drilling a hole on one side to a certain depth. This would then leave space on the other side for the standard tool carrier 2. Alternatively, a through hole can be drilled if the tool carrier is not required, which simplifies manufacturing and maximizes weight savings.

[0044] In Fig. 2 A perspective view of the screw conveyor with cut-away brackets is shown.

[0045] In Fig. 3The components of the pressure housing 8 and the brackets 3, 12 are shown. The previously described locking pin 3b is visible, as well as a groove that, when the input-side bracket is mounted on the front, extends the groove in the pressure housing. The spring 5 in the machine housing 19 thus engages in both grooves.

[0046] In Fig. 4The components are shown partially assembled. The upper sectional drawing shows the pressure housing with the brackets 3 and 12 in the assembled state. In this illustration, it can be seen that the pressure housing, according to one embodiment, has one or more helical grooves in the inner surface. These, in conjunction with the conveyor screw, improve the feed of the food intended for comminution. On the right side of the pressure housing 8, holes can be provided through which liquid and / or food intended for comminution / separation can be pressed and cut off. Figure 4It is clearly visible that, according to one design, one or more helical grooves can be arranged on the inner surface of the bearing shells 4, 10. This allows fluid / grease to enter the bearing and serves as lubrication. The grease or fluid is provided by the food being ground or separately supplied to the bearings. In the latter case, it must be food-safe.

[0047] The radial sectional view of the input side of the conveyor screw 7 shows the mount of the standard tool holder / feed screw pin 2 with which the feed screw 1 is connected to the conveyor screw 7. For this purpose, a shaft milled on both sides and corresponding recesses in the mount can be provided.

[0048] By using such a standardized connection 16c, the conveyor screw can also be used for purposes other than rotation in a pressure housing or for grinding food. Such a standardized connection makes the conveyor screw much more versatile and can be used regardless of the adjustment accuracy of the feed screw. List of reference symbols

[0049] 1 Feed screw 2 Standard tool carrier 3 Input / first bracket 3a Input / first outer bearing shell / bushing 3b Locking pin (bracket) 3c Screw channel - internal spiral for lubrication 4 Input / first inner bearing shell / bushing 5 Locking pin (housing) 6 First union nut 7 Feed screw 8 Pressure housing 9 Output / second inner bearing shell / bushing 10 Output / second outer bearing shell / bushing 10a Screw channel - internal spiral for lubrication 11 Second union nut 12 Output / second bracket 13 Conical end 14 Ejection screw 15 Ejection valve 16a Input / first receptacle 16b Output / second receptacle 16c Connection 17a Tension spring 17b Thread 18 Cavity 19 Machine housing

Claims

1. Conveyor screw (7), suitable for installation in pressure housing / cutting-separating drum (8), designed for axially rotatable bearing, characterized in that storage takes place in at least two locations.

2. Conveyor screw (7) according to claim 1, characterized in that the bearings at all points are positioned exclusively opposite a single, other machine part.

3. Conveyor screw (7) according to claim 1 or 2, characterized in that the bearing of the conveyor screw takes place exclusively directly opposite the pressure housing (8) or by means of a bearing device / holder (3, 10).

4. Conveyor screw (7) according to one of the preceding claims, characterized in that the bearing is arranged radially outwards.

5. Conveyor screw (7) according to one of the preceding claims, characterized in thata receptacle (16a) on the conveyor screw (7) for the first storage location is positioned (near) an input end and the second receptacle (16b) for the second storage location is positioned (near) an output end.

6. Conveyor screw (7) according to claim 5, characterized in that at least one or both of the receptacles (16a, 16b) are connected to a bearing bush (4, 9) or a hardened bearing bush (4, 9) via a positive or non-positive connection or at least one of the receptacles (16a, 16b) is hardened.

7. Bearing device, comprising in at least two embodiments: a bearing bush (4, 9) forming an inner bearing shell, provided for immovable connection to a conveyor screw (7) and a holder (3, 12) forming an outer bearing shell, which is not formed integrally with the pressure housing (8) and is suitable for keeping the pressure housing (8) at a distance from the conveyor screw (7).

8. Storage device according to claim 7, characterized in that the bearing bush (4, 9) and / or at least one of the bearing shells is made of hardened material.

9. Device for chopping foodstuffs, comprising a conveyor screw (7) according to claim 1, and a pressure housing (8) according to claim 7, spaced apart and guided by a bearing according to claim 5, so that the conveyor screw (7) can rotate about an axis centrally in the pressure housing (8).

10. Device for comminuting foodstuffs, wherein the conveyor screw (7) has, on a first input-side receptacle (16a), a first bearing with a bearing bush (4) which is firmly seated on the conveyor screw and which, with a first (front) holder (3), forms a sliding bearing for the axial rotation of the conveyor screw (8), wherein the first holder is releasably connected to the pressure housing (8) in a force-locking or form-locking manner, and furthermore the conveyor screw (7) has, on a second output-side receptacle (16b), a second bearing with a firmly seated second bearing bush (9), which, with a second (rear) holder (12), forms a sliding bearing for the axial rotation of the conveyor screw (8), wherein the second holder is releasably connected to the pressure housing (8) in a force-locking or form-locking manner.

11. Device according to claim 10, characterized in thatthe second holder (12) is directly non-positively connected to the pressure housing (8) via a union nut (11) and the first holder (3) is indirectly non-positively connected to the pressure housing (8) by clamping the pressure housing against the machine housing (19) of the meat grinder with the aid of a union nut (6) and thereby clamping the holder (3), which is supported against the housing (19) or the feed screw (1), against the pressure housing (8).

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