EP3846925B1 - Mixer with arm - Google Patents

Description

The invention relates to a mixer, in particular a building material mixer such as an asphalt or concrete mixer, according to the preamble of claim 1.

Mixers generally consist of a container with at least one driven shaft, to which mixing arms carrying blades are fastened approximately perpendicularly to the shaft or at a defined angle to the shaft at a distance from one another. The blades are arranged at a distance from the inner wall of the container. The mixing arms preferably have an inner part connected to the shaft and an outer part carrying the blades. These two parts can preferably be connected to one another by means of an adjustable connecting device having screws.

In known building material mixers, as z. B. are described in the following publications ( WO2006/007778A1 , EP0111148A2 , EP2007275700 , US3738774 , US5061082 , DE9410951U1 , US3773436 , US3773436A , CH408743A ), the replacement of worn elements, such as the shaft or the mixing arms, is associated with a considerable amount of time, since all screw connections of the mixing arms - a building material mixer usually has a large number of mixing arms - have to be actuated at least once. If the parts are also worn, stuck together due to adhering mix or welded together through use, additional measures (e.g. cutting torch or cut-off grinder) must be taken to equip the building material mixer with new mixing elements, since the fastening elements can no longer be loosened with conventional tools.

From the EP0976442 a mixing device is known with a mixing drum and a mixing shaft mounted at the ends of the mixing drum, the mixer shaft having blade arms extending radially outwards, at the ends of which blade blades are arranged which reach close to the wall of the mixing drum. The paddle blades and the mixer shaft have wear protection.

Proceeding from the above prior art, the object of the invention is to provide a mixer whose components are particularly resistant to abrasion.

According to the invention, the object is achieved by a mixer having the characterizing features of claim 1.

Advantageous embodiments of the present invention are specified in the dependent claims.

The present invention is at least realized when preferably detachable fastening elements between the individual components such as the shaft and/or mixing arm and/or blade are surrounded by a protective part, either as a whole or in each case. A guard may be a clamp or casing that encloses the individual sections or shaft/fasteners/mixing arms in their entirety. The protective part should reliably protect the areas underneath from abrasion, but it should also be easy to remove from them. In particular, a welding or other permanent connection to the areas to be protected should be avoided, which only allows the protective part to be detached from the areas to be protected if the same are destroyed.

A protective part can be any element which protects from abrasion and surrounds the essential components, in particular the shaft and/or the mixing arm which supports the blade. The protective part can be made of any resistant material, in particular a metal, a metal alloy, a plastic or a ceramic. Although the protective part can in principle have any external shape, a shape in which the protective part snugly surrounds the shaft and/or fastening elements and/or the mixing arms is particularly preferred. In addition to the supple design, the protective part can have functional areas which, for example, also have a mixing function (e.g. wings, scrapers or a shovel-like structure).

The protective part is provided according to the invention in any case if it preferably surrounds the above-mentioned components in a protective manner and/or can be easily attached to the parts and/or can be easily removed for replacement, even with possible destruction of the protective part. For the Protection of the components can be provided in one-part or, according to the invention, multi-part protective part segments, which in their entirety can form the protective part.

A multi-part structure according to the invention involves shell parts that jointly surround at least one area of the mixer (arm and/or arm mount and/or mixer shaft). The shell parts of a given area are held in place by a protective portion of an adjacent area. For example, a (multi-part) casing as a protective part of the mixer shaft is held by protective parts of adjacent arm mounts provided at the ends of the mixer shaft. For this purpose, a receptacle can be provided, in particular on the protective parts of adjacent arm mounts, on or behind or in which the casing can be accommodated as a protective part of the mixer shaft (shaft).

The components can in particular be referred to as driven mechanical means for carrying out the mixing process, with stirring tools (e.g. mixing arm/shovel) sweeping through the material being provided.

The protective part should preferably be arranged and/or removed without the use of tools (particularly those that cause danger), such as cut-off grinders or cutting torches. The fastening elements in a mixer, which connect the individual components to one another, are particularly susceptible to abrasion caused by the mixed material. In addition, however, load-bearing elements such as the shaft or the mixing arms can also be subject to significant wear and tear, especially in the case of long-term use. By arranging a protective part on these elements, a long-term use is made possible according to the invention without the need to replace these sometimes quite heavy components. Wear protection elements can be provided here as a protection party segments, which preferably Length are formed in one piece or in several parts, in particular in two parts or three parts.

For this purpose, a protective part segment, which in particular protects the mixing arm, can be fixed between blade and shaft or between blade and fastening element of the mixing arm. The protective part segment of the mixing arm is particularly preferably fixed between the blade of the mixing arm and the protective part segment of the fastening element. A (further) protective part segment, which protects a fastening element, can be detachably connected to it, in particular connected to it by means of detachable plug-in, snap-in, snap-in and/or bayonet connections. A guard segment, which protects at least part of the shaft, can be fixed between the guard segments of two adjacent mixing arms and/or between the guard segments for fasteners of adjacent mixing arms.

The protective part segments on the mixing arm and fastening element, on the mixing arm, fastening element and shaft or on the fastening element and shaft are a functional unit and preferably form a continuous protection between these elements.

Such an arrangement of individual protective part segments of the protective part according to the invention, which preferably depends on one another, makes it possible for the protective armor to be detached particularly easily around the individual elements.

If the shovel is removed from the mixing arm, the protective part segment surrounding the mixing arm can be stripped off or pulled down from the protective arm in a simple manner. The detachable connection of the protective part segment for the respective fastening element can be in the operating state be provided protected beneath the guard segment for the mixing arm or an extension thereof, thereby protecting it from abrasion.

The guard segment of a fastening element can be formed in two parts, a first part preferably facing the mixing arm being held in position by the guard segment by the guard segment of the mixing arm, preferably in combination with the mixer blade. The first part can be fixed between the guard segment of the mixer arm and the fastening element.

A second part of the protective part segment of the same fastening element, which can face away from the associated mixer arm, can be connected to the fastening element, preferably via a latching or snap connection. The connection of the second part of the guard segment to the fastener may be sheltered beneath the first part or sheltered between the first and second parts. This can prevent the connection from being actuated and/or released accidentally.

If the protective part segment for the mixing arm and/or for the fastening elements of the individual mixing arms is removed, the protective part segment of the shaft that is preferably held (locked), preferably fixed, on these protective part segments can be removed. The protective part segment(s) for the respective mixing arm and/or for the respective fastening elements of the individual mixing arms can accordingly hold the protective part segment(s) of the shaft in position on the shaft. Preferably, the protective part segment(s) of a shaft segment/shaft section between two mixing arms is/are on the protective part segments of adjacent/adjacent mixing arms and/or on adjacent/adjacent ones Fastening elements of the individual mixing arms fixed to the shaft (in the longitudinal direction of the shaft).

The respective segments can be arranged around the component to be protected and enclose it at least along one direction/side.

The individual segments can be collar-shaped and surround the respective components of the mixer according to the invention in the manner of a collar. In this context, collar-shaped is intended to refer in particular to a partially or completely enclosing arrangement of the protective part segments on the mixer. The arrangement of the individual protective part segments around the component of the mixer to be protected in each case can also be form-fitting.

According to a preferred development of the present invention, it is provided that the protective part segment for the shaft is provided as a cladding in some areas, which is arranged around the shaft between two adjacent mixing arms. In principle, the protective part segment for the shaft can be designed in one piece and can preferably be arranged at the factory around the shaft between two adjacent mixing arms when the mixer is assembled. In order to simplify the assembly and disassembly of the segments, however, it is preferably provided that the casing around the shaft is designed in several parts, preferably in two parts, with the individual parts of the multi-part casing having a contact area with one another along the longitudinal axis of the shaft or jointly enclosing the shaft .

In principle, a protective part segment for the shaft can have any number of casing components. It is particularly useful, however, that the cladding of the shaft is provided as a protective part segment of two, preferably identical, half-shells, which are each over the length between extends two adjacent mixing arms. At least in an inner area of the casing, these can each depict a partial area, in particular half, of the circumference of the area of the shaft to be protected, whereby the protective part segment for the shaft can be arranged in a form-fitting manner on the outer circumference of the shaft in the operating state. In principle, the protective part segment for the shaft can also be provided at a distance, in particular without a form fit with an outer contour of the shaft, from the same in the operating state.

According to a preferred development, it is provided that the protective part segment for a mixing arm is designed in one piece. This protective segment can preferably be sleeve-shaped and have a shape on its inner wall which corresponds approximately to the outer contour of the mixing arm. The resulting form fit between the mixing arm and the protective part segment for the mixing arm prevents wear and tear on the mixing arm as a result of a possible rotary movement of the protective element around the mixing arm. This applies in particular when the mixing arm has a non-rotationally symmetrical shape in the longitudinal direction.

The protective part segment for the mixing arm is particularly preferably provided at least between the blade and the shaft or between the blade and the fastening element, preferably between the blade and the protective part of the fastening element. Insofar as the shovel is arranged on the mixing arm, this can prevent the protective part segment for the mixing arm from detaching from the same, since the shovel blocks the way.

According to a preferred development of the present invention, it is provided that the mixer has a fastening element for the respective mixing arm, by means of which the mixing arm is fastened to the shaft, preferably detachably, and/or that the protective part segment for the mixing arm has an extension in the area of the fastening element, in which at least a part of the fastening element can be placed, preferably the part which is arranged on a side of the shaft facing the mixing arm.

In principle, the extension can be made in one piece with the protective part segment for the mixing arm, but it can also be made in several pieces. In this case, the expansion can in particular relate to an expansion of the segment by the said functionality and/or to an area of the protective part segment for the mixing arm that increases in diameter. The extension can serve in particular to protect against wear of at least part of the fastening element.

According to the invention, a mixing arm can therefore also be understood to mean a combination of a fastening device for the mixing arm and the mixing arm itself.

Particularly preferably, the above-mentioned extension is designed on its inner circumference as a semicircular/half-shell-shaped element or at least has such a shape on its inner circumference that it corresponds to the outer contour of the fastening element in the area which faces the mixing arm on the shaft and which is covered by the extension is. As a result, a form fit with the fastening element can be provided.

On its outer circumference, the aforementioned extension preferably has a smooth, in particular rounded, shape. This can in particular prevent excessive abrasion.

An expedient development of the present invention is that the mixer has a fastening element for the mixing arm, by means of which the mixing arm is fastened to the shaft and that the fastening element is on a the mixer arm opposite side of the shaft has a fastener guard segment which at least partially surrounds the fastener.

The (separate) extension can also be referred to as a shell or half-shell, the inner contour of which is adapted to at least part of the fastening element. The shell or half-shell can have a connection or contact area to the protective arm guard segment, so that they form a form-fitting protective arm guard unit and fastening element.

The extension of the mixer arm guard segment may also be referred to as the first part of the fastener guard segment.

The fastener guard segment may also be referred to as the second part of the fastener guard segment.

The first part and the second part can completely surround the fastening element at (a portion of) the outer circumference.

In the operating state, the expansion of the protective part segment for the mixing arm and the fastening element protective part segment preferably form a rounded or/or closed outer contour which can correspond approximately to the shape of a hollow cylinder coaxial to the shaft. To protect the fastening element, this cylindrical shape, arranged axially at the end, can have radially inwardly projecting areas on the side of the fastening element, which can form a positive fit with the shaft inside the fastening element or the protective part segment of the shaft.

Provision is particularly preferably made for the first part of the protective part segment for the fastening element and/or the second part of the protective part segment for the fastening element to have a receptacle or receptacle parts in which the protective part segment(s) of the shaft can be fixed.

The extension of the mixing arm guard segment (the first part of the fastener guard segment) and/or the fastener guard segment (the second part of the fastener guard segment) may each individually have a receptacle which radially engages the shaft guard segment and/or axially relative to the shaft. To this end, the receptacles of the extension of the mixing arm guard segment and the fastener guard segment may together form an interrupted or uninterrupted, preferably approximately circular, collar. In which the shaft guard segment may be axially receivable and radially securable to the shaft.

Preferably, one of the extensions of the protective part segment for the mixing arm and the fastening element protective part segment has an uninterrupted or interrupted, preferably approximately semicircular, i.e. part-circular, receptacle, the inner contour of which corresponds approximately to the outer contour of a multi-part casing of the protective part segment for the shaft .

It is expediently provided that the protective part segment of the shaft, which is provided in some areas between two adjacent mixing arms, is fixed between the protective part segment for the mixing arm in the area of the fastening element and/or the fastening element protective part segment of the adjacent mixing arms.

If the expansion of the protective part segment for the mixing arm and the fastening element protective part segment are arranged on the fastening elements of two adjacent mixing arms, these elevations projecting axially to the shaft can provide a receptacle for the protective part segment for the shaft.

The individual casing parts (so-called wave protectors) are thus fixed between the individual protective section segments of two adjacent mixing arms. In order to remove the casing parts forming the protective part segment, it may therefore be necessary to first detach at least one of the protective part segments from the mixing arm and/or the fastening element.

In a preferred manner, the protective part or the individual protective part segments should thus be achieved in a protective manner at least surrounding connecting means and/or connecting parts of the shaft with the mixing arm and/or the mixing arm with the blade.

With regard to the above statements, the receptacle on the extension of the protective part segment for the mixing arm can also be provided directly on the protective part segment for the mixing arm.

A protective part is characterized in that it surrounds the mixing arm and/or the fastening element and/or the shaft at least in regions. The device according to the invention preferably forms a complete encasing of the above-mentioned assemblies of a building material mixer, so that approximately only the blade and the wear protection itself is exposed to significant abrasion during operation. Since the wear protection is preferably only plugged or pushed onto the existing components, this allows a high level of temporal efficiency in the operational Restoration of the building material mixer can be achieved since only the guards and the blade itself need to be replaced, not the arm, attachment and shaft assemblies.

In principle, the fastening element can be part of the mixing arm. The protective part is intended to prevent abrasion of fastening elements between shaft and mixing arm or mixing arm and shovel. In principle, however, the protective part can also be provided in such a way that it protects flat areas of the shaft, fastening element and/or mixing arm from abrasion during operation of the mixer.

The protective part can be made of a particularly abrasion-resistant material, such as a particularly hard steel or cast alloy. In addition or as an alternative to this, the protective part can have armored elements, which additionally protect areas of the protective part that are particularly at risk of abrasion.

As a result, the protective part can be provided with a lower overall weight or overall volume, since the armor can be provided particularly there where the abrasion or the abrasive influences of mixed material on the elements described according to the invention occur particularly severely.

A correspondingly thinner-walled material can be used in other areas of the protective part, which experience has shown to be less subject to abrasion.

In principle, the protective part can surround the shaft and/or fastening element and/or the mixing arms in the operating state like a second skin, whereby at least these areas of the mixer's inner workings, which are particularly sensitive to abrasion, are protected.

If the mixer does not have any mixing arms, but instead the blades are attached directly to the shaft via fastening elements, the protective part segments can also be provided only on the fastening elements and/or the shaft.

The method for protecting the shaft, mixing arms and/or fastening elements of the same from closing in a mixer is characterized in that a protective element is arranged on the shaft and/or mixing arm and/or fastening element in the manner described above.

Fig. 1

eine schematische Darstellung eines erfindungsgemäßen Mischer in Querschnittsansicht,

Fig. 2

eine Explosionsdarstellung eines erfindungsgemäßen Mischarms mit Schaufel und Befestigungselement für eine Befestigung des Mischarms an der Welle sowie entsprechenden einem Schutzpartiesegment für den Mischarm mit Erweiterung für das Befestigungselement von beiden Seiten an der Welle,

Fig. 3

eine Seitenansicht eines Ausschnitts der erfindungsgemäßen Schutzpartie, welche zumindest zwei Mischarme und einen entsprechenden Wellenabschnitt umgibt,

Fig. 4

eine perspektivische Ansicht der Figur 3 ohne Welle.

Preferred embodiments of the present invention are explained below with reference to the attached drawing. Show it:

1

a schematic representation of a mixer according to the invention in cross-sectional view,

2

an exploded view of a mixing arm according to the invention with blade and fastening element for fastening the mixing arm to the shaft and a corresponding protective part segment for the mixing arm with an extension for the fastening element from both sides on the shaft,

3

a side view of a section of the protective part according to the invention, which surrounds at least two mixing arms and a corresponding shaft section,

4

a perspective view of the figure 3 without wave.

In figure 1 a schematic cross-sectional view through a mixer 10 according to the invention is shown. This has a housing 50 in which a shaft 40 is provided so that it can be driven in rotation.

A plurality of mixing tools 60 can be arranged on the shaft 40, which can have at least one blade 30 and/or a mixing arm 20, wherein the mixing arm can be provided with a fastening element, by means of which it can be attached to the shaft 40, preferably detachably.

By rotating the shaft, the mixing tools 60 are guided radially around the shaft 40 in the housing 50 .

figure 2 shows an exploded view of a mixing arm with blade 30 according to the invention and an exemplary view of the protective part segments 23, 23a, 23b, 24, 25a and 25b according to the invention, from which the protective part can be formed.

Mixing arm 20 may include a first elongated portion 21a connecting shaft 40 to paddle 30 . Furthermore, in the area of the connection between the shaft 40 and the mixing arm 20, a fastening element 22a, 22b provided, by means of which the mixing arm 20 can be fastened to the shaft 40, preferably detachably.

For this purpose, a screw connection 29 with corresponding recesses can be provided in order to fix the fastening element 22a, 22b on the shaft 40, for example as a clamping connection in a non-positive and/or positive manner.

According to the embodiment in FIG figure 2 the fastening element 22a, 22b is formed in two parts, the two parts enclosing an opening 22c in which the shaft 40 is provided in the operating state. The shaft can have a shape along its outer contour, at least in the area of the fastening element, which corresponds approximately to the inner contour of the opening 22c. The screw connection 29 preferably has a depression, at least on the first part of the fastening element 22a, i.e. on that part of the fastening element 22a, 22b, on which the screw head can be provided and can be secured against twisting, in which the screws for the screw connection 29 can be lowered relative to an outer circumference of the fastening element 22a. Preferably, the outer circumference of the fastening element 22a, 22b can be approximately circular or cylindrical.

At an upper end of the mixing arm 20, a blade 30 can be arranged, as for example from the DE 10 2016 108 310 or the PCT/EP2017/078089 emerges. The content of these publications, which relates to a paddle and/or the connection of the paddle to a mixing arm, is therefore intended to form part of this application by reference.

This blade 30, which is particularly preferably detachable from the mixing arm 20, can be connected to the mixing arm 20 via a groove, bayonet or snap-in connection, for example. For a change of blade 30 on the mixing arm 20 can be one in one Housing part 32 can be countersunk screw 31, which can be protected from abrasion or dirt, for example, by a protective cap 33.

The protective part according to the invention for protecting the shaft 40 and/or the individual mixing arms 20 can preferably be constructed in segments. Exemplary are segments 23a, 23b, 24, 25a and 25b in figure 2 shown for such a protective party.

According to the invention, it is particularly preferred that the arrangement and/or the removal of the individual protective part segments from shaft 40 or mixing arm 20 can be carried out as far as possible without tools (or with simple tools). On the one hand, this should offer faster replacement compared to other protection concepts and, on the other hand, make the protective section less susceptible to defects.

In the present case, the mixing arm is provided with the elongated part 21a, which forms the transition between the fastening element 22a, 22b and the blade 30. In principle, the elongate part 21a can have any shape or extent and can also comprise shovel-like segments or shapes, for example. According to the present embodiment, a sleeve-like protective part segment 23a is provided for the elongate part 21a, the inner circumference of which corresponds approximately to the outer circumference of the elongate part 21a. This protective part segment 23a can in particular protect the elongate part 21a from wear and tear due to the abrasive effect of mixed material and preferably completely surrounds the elongate part 21a in the longitudinal direction, ie from the end of the fastening element facing the mixing arm to the shovel.

In principle, the protective part segment 23a and/or the further protective part segments 23b, 24, 25a and 25b can each have additional elements on their outer circumference have, which supports a thorough mixing of material to be mixed in the mixer in the operating state. For this purpose, for example, further wing-like, shovel-like and/or other mixing tools or shapes deviating from a round shape can be provided.

According to figure 2 a mixing surface 23' is provided on the protective part segment 23a, which can also be provided with an armored coating, whereby the protective part segment 23a is particularly resistant to wear. The mixing surface 23' can provide an additional mixing surface and thus positively influence the mixing effect of the mixer. In the direction of the shaft, the elongated part 21a is followed by a fastening element 22a, 22b, by means of which the mixing arm 20 can be fixed on the shaft 40. 21a and 22a can also be in one piece.

The fastening element 22a, 22b preferably has a detachable connection to the shaft. The fastening device can preferably be designed in two parts. Conveniently, the fastener 22a, 22b may be provided with an enlarged diameter relative to the elongate portion 21a. In particular, this may provide an increased contact area between shaft 40 and fastener 22a, 22b than when fastener 22a, 22b has the same diameter as elongate portion 21a. The fastening element can have an approximately cylindrical outer contour, which is preferably aligned coaxially to the longitudinal axis of the shaft 40 at least in regions.

Following the protective part segment 23a, an extension 23b can be provided, which at least partially covers the fastening element 22a, 22b and thus protects it from abrasion. The extension 23b can basically be formed in one piece with the protective part segment 23a. However, it is advantageous that in the region of the fastening element 22a, 22b at least one protective part segment 23b can be provided which can be provided separately but which can preferably be positively connected to the protective part segment 23a.

The protective part segment 23b can also be referred to as an extension of the protective part segment 23a for the mixing arm 20. Expansion in this sense can refer both to the composition of the mixing section segment from at least two parts (first part for the mixing arm, second part for the fastening element 22a) and to a larger spatial extent than the protective section segment for the mixing arm, in particular in terms of width - So a one-piece structure of 23a and 23b.

In the event that the fastening element 22a, 22b and mixing arm 20 have approximately the same external dimensions, a protective part segment can also be provided for the fastening element 22a and the mixing arm 21a together, which segment has an approximately uniform outer contour with no or only a slight expansion.

In principle, the protective part segment can also be constructed in several parts in this case. Advantageously, the protective part segments for all components of the mixer 10 according to the invention form a self-contained protective part surface as armor that is flush to the outside.

Both the guard segment 23b for the part of the fastening element 22a which faces the mixing arm 20 and the guard segment 23a can be provided in a fixed position/locked on the mixing arm 21a by the attachment of the blade 30.

However, the blade 30 can at least prevent said guard segments from accidentally falling out. This circumstance can also apply if the protective part segment 23a for the mixing arm 21a and the fastening element 23b, in particular for the part of the fastening element 22a which faces the mixing arm 21a, is designed in one piece. Due to the fact that the shovel 30 causes the protective part segment(s) 23a/23b to be fixed to the mixing arm 21a, further fastening means for the protective part segments on the mixing arm can be dispensed with. The guard segments can thus be trapped between blade 30 and attachment means.

If the fastening element 22a, 22b for the mixing arm 20 has an area which is provided on a side of the shaft opposite the mixing arm, a protective part segment 24 can be provided which surrounds this area of the fastening element 22b.

Like all protective part segments, this can also correspond on its inner circumference to the outer circumference in terms of shape, dimensions and/or size of the element to be protected.

To fix the protective part segment 24 for the part of the fastening element that is provided on a side of the shaft opposite the mixing arm, the shaft can have at least one fastening means 28, by means of which the protective part segment 24 can be fixed to a part of the fastening element 22a/b.

This can in particular be a detachable catch or snap connection which engages in a corresponding recess or undercut on the fastening element 22a/b. The fastening means 28 can be arranged in particular on an inner circumference of the protective part segment 24, whereby it is at least partially protected from abrasion when the mixer 10 is in operation. Should a region of the fastening means 28 protrude beyond an edge of the protective part segment 24, this can be covered by the protective part segment 23b or by the protective part segment which extends between blade 30 and fastening element 22a. This can also prevent an unintentional detachment of the armor 24, since this opposing protective part segment spatially opposes a loosening movement of the fastening means.

The guard segment 24 preferably has at least one fastening means 28 on opposite sides.

If all of the protective-part segments (23a, 23b and 24) described so far are provided on the mixing arm, this is preferably completely encased by the protective-part segments, ie as seen from the blade 30, ie a total of one protective part.

The only areas which are preferably not taken into account here are both an opening 22c, which is also delimited by a radially inwardly projecting collar of the protective part segments 23b and 24 and through which the shaft 40 is guided, as well as the area on the mixing arm 20, on which the blade 30 is preferably releasably attached. This area is occupied by the wave and covered by the wave protection segments. The radial collar (26, 27) can also be present at a radial distance from the opening 22c.

Like in particular figure 2 shows, the protective part segments of the fastening device can have a receptacle 26, 27 in the region of the shaft, which extends approximately parallel to the longitudinal axis of the shaft 40. This longitudinal axis 41 is in figure 3 shown. The provided recording 26, 27 can be provided on an outside of the protective part segments for the mixing arm 20 and/or fastening element 22a, 22b such that its inner circumference corresponds approximately to an outer circumference of a protective part segment 25a, 25b for the shaft 40. The protective part segment for the shaft 40/the shaft segment can in particular extend between two mixing arms or two fastening elements or two protective part segments of two adjacent fastening devices. The receptacles 26, 27 can be provided on both adjacent mixing arms or two fastening elements or two protective part segments of two adjacent fastening devices, between which the protective part segment for the shaft 40 is fixed between the receptacles of the two adjacent mixing arms 20.

In contrast to figure 2 the receptacle 26, 27 can in principle also be a depression in the protective part segments of the mixing arm 20 or, for example, a tongue groove connection with the same. According to the invention, the definition of the protective part segment for the shaft 40 should not be limited to specific design details. Rather, it should preferably be important that the protective part segment for shaft 40 can be fixed between two mixing arms 20 or its protective part segments or two fastening elements or two protective part segments of two adjacent fastening devices, i.e. it should preferably only be possible to loosen the protective part segment for shaft 40 , if at least one of the protective part segments for the mixing arm 20, with its fastening element 22a, 22b, is detached from the mixing arm or the protective part segments of the corresponding fastening devices are detached.

The protective part segment for the shaft 40 particularly preferably has a casing which is formed from at least two shell parts 25a, 25b. An inner contour the casing can correspond approximately to an outer contour of the shaft, but can also be provided at a distance from the shaft in the operating state, that is to say with a larger inner diameter than the outer diameter of the shaft. The shaft and its casing can in principle have a shape that deviates from the round shape or can also be provided with a polygon, preferably a polygonal cross-section (see reference number 40 in figure 5 ).

In an outer area, the protective part segment 25a, 25b for the shaft 40 or the casing can have a smooth or rounded surface in order to prevent unnecessary friction with mixed material in the operating state.

In principle, however, the protective part segment for the shaft 40 can also have mixing tools on its outer circumference.

The casing for a shaft section between two mixing arms 20 particularly preferably has two half-shells 25a and 25b, which each extend along a longitudinal axis of the shaft 40 and are each assigned to one of the receptacles 26 and/or 27 of the two adjacent mixing arms. If, for example, the fastening element 22a and 22b is covered by two separate protective part segments 23b and 24, each of the two protective part segments can have a receptacle 26, 27, the shape of which corresponds approximately to the outer contour of the shell halves 25a and 25b. In the assembled state, the two receptacles 26, 27 form approximately a circular shape, which can be interrupted or uninterrupted, with the two casing parts being held one on top of the other on the respective mixing arm 20 by the receptacles 26, 27, or on top of one another are pressed, whereby these can be fixed both radially and axially on the shaft between the two mixing arms.

According to the invention, a mount in the manner described above or a protective part segment of the shaft 40 is provided at least when the mount is provided in an area of the protective part segment for the mixing arm 20 or its fastening element 22a, 22b and defines a protective part segment for the shaft 40 in the operating state in such a way that that falling out or slipping out in a shell-like structure, for example with half-shells which extend in the longitudinal direction of the shaft 40, is prevented.

figure 3 shows a section of a shaft 40 with two mixing arms arranged thereon (preferably completely encased with protective elements, preferably without encasing the blade) 21a, blades 30 attached thereto and the protective part segments provided for these elements to form a protective part. Both mixing arms 20 have a protective part segment 23a, which is approximately shovel-shaped on its outer contour. The protective part segment 23a merges into the protective part segment 23b, with which it can be designed in one piece or in several pieces. The guard segment 25a and 25b for the shaft 40 is provided between two adjacent mixing arms 20. As shown in FIG. And fixed in position along the shaft 40 by the receptacles 26, 27 on the mixing arms 20.

Also on the sides of the two mixing arms 20 facing away from the protective part segment 25a, 25b for the shaft 40, the receptacle 26, 27 is provided in each case in order to accommodate a protective part segment 25a and 25b for the shaft 40 between respectively further adjacent mixing arms 20 to the right or left can.

A protective part segment 24 is arranged in a lower area on both mixing arms 20, which protects a part of the fastening element 22b, which is arranged opposite the mixing arm 20 on the shaft 40 in the axial direction, from abrasion. The fastening means 28, as an element protected by the protective part segment 24 or 23b, is indicated on the right mixing arm.

the inside figure 3 The gap shown, in order to represent the fastening means 28, can be closed in the operating state, as a result of which a continuous armouring of the individual mixing arms, including their fastening elements, is provided. The gap between the two casing segments 25a and 25b of the protective part segment for the shaft 40 can also be closed in the operating state.

figure 4 shows a perspective view of the in figure 3 embodiment described, wherein the shaft 40 is not shown in the opening 22c. In contrast to figure 3 is in figure 4 the protective segment 23a is not provided with a blade shape but rather with an elongate shape, with an armor element 23' being provided in an operating direction, which is indicated in particular by the orientation of the blade 30, which can additionally protect the protective part segment 23a from abrasion.

Out of figure 4 shows particularly clearly how the protective part segment for the shaft 40 is fixed between two mixing arms due to the receptacle 26, 27 on the mixing arm. The relative alignment of the individual mixing arms with one another is irrelevant for the provision of the protective part segments for the shaft.

The protective part segment for the shaft 40 can be fixed both axially and (and/or) radially opposite the protective part segments of the mixing arm on the receptacles 26, 27, which prevents the in figure 4 shown half shells from the connection between the recordings of two adjacent mixing arms 20 is prevented.

In principle, the armouring, ie protective part segments for mixing arms which only have a further mixing arm neighbor on one side, can also have receptacles 26, 27 for fixing a protective part segment for the shaft 40 only on this side.

In principle, the shaft 40 can be provided continuously, with all mixing arms 20 being provided on the same shaft 40 . On the other hand, several shafts can also be provided approximately parallel or at a defined angle to one another, each of which can carry part of the mixing arms 20 and can each have a protective section.

The shaft is protected by a combination of protective part segments for the shaft and protective part segments for the respective mixing arm or for the respective connecting element of the mixing arm, so that the shaft is completely surrounded by the individual protective part segments, at least along the area of the mixing arms 20. The armouring of the shaft is preferably provided alternately by protective part segments for the shaft, in particular the casing 25a, 25b and the protective part segments for the respective mixing arm or for the respective fastening element 24, 23b.

How out figure 5 shows, a scraper 70 can be provided on the shaft 40, preferably in the area of a fastening element, which scraper moves with the shaft rotation and can scrape mixed material from an inside of a seal between shaft and mixer housing (not shown). The wiper 70 preferably interacts with a collar on a protective part segment of a fastening element, which is not through a protective part segment for a shaft section is occupied. It is held in place by the guard segment of a fastener, preventing it from falling out/falling off the shaft. The wiper can be designed as part of a circle or part of a polygon shape on its inner contour

A seal 80, in particular a metal seal or elastic seal or fabric seal, can be provided between the individual protective part segments, in particular between that of the mixing arm and the fastening device, which can seal the individual segments against the ingress of mixed material.

Claims (8)

1. Mixer with a container (50 ) with at least one driven shaft (40 ), to which mixing arms (20 ) carrying blades (30 ) are fastened at intervals, with a protective section which surrounds at least the individual mixing arms (20), the fastening devices (22a, 22b) for the individual mixing arms on a shaft (40) and the shaft (40) in each case at least in regions, wherein the protective section is constructed in the manner of segments and whereby the segments have a multi-part structure consisting of shell parts (23a, 23b, 24, 25a, 25b),
   characterized in

   that the shell parts (23a, 23b, 24, 25a, 25b) of the respective segment jointly surround at least one region of the mixer, namely the fastening devices (22a, 22b) and/or the shaft (40) and/or the mixing arms (20 ) and

   that the shell parts of a region are held by the protective part, namely a protective part segment of an adjacent region .
2. Mixer according to claim 1,
   characterized in
   that the protective section segments are each assigned to a mixing arm, a fastening device or a section of the shaft between two fastening devices.
3. Mixer according to one of claims 1 or 2,
   characterized in
   that the protective section segments for the mixing arm is provided at least between the blade and the shaft.
4. Mixer according to any one of claims 1 to 3,
   characterized in
   that a protective section segments (23b) is provided on the fastening element, which surrounds at least a part of the fastening element, preferably the part which is arranged on a side of the shaft facing the mixing arm.
5. Mixer according to any one of claims 1 to 4,
   characterized in
   that the fastening element has, on a side of the shaft opposite the mixing arm, a further protective section segments (24) which surrounds the fastening element at least on the side facing away from the mixing arm.
6. Mixer according to one of claims 1 to 5,
   characterized in that at least one of the protective section segments (23b, 24) of the fastening element has a receptacle in which the protective section segments (25a, 25b) of the shaft can be fixed.
7. Mixer according to any one of claims 1 to 6,
   characterized in
   that the protective section segments (25a, 25b) of the shaft, which is provided regionally between each two adjacent mixing arms, is fixed between the protective party segments of the adjacent mixing arms or the protective section segments (23b, 24) of the fastening elements.
8. Mixer according to one of claims 1 to 7,
   characterized in
   that the protective section or the individual protective section segments protectively surround at least connecting means and/or connecting sections of shaft with mixing arm and/or mixing arm with blade.

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