Patent Application
20230001561
There has already been proposed a power tool comprising at least one housing unit, comprising at least one drive unit arranged within the housing unit, and comprising at least one separating unit, the separating unit being designed to divide at least one fluid stream conducted through the housing unit into at least two sub-streams, one sub-stream of the sub-streams having a higher foreign body density in comparison with another sub-stream of the sub-streams.
The invention is based a power tool, in particular a hand-held power tool, comprising at least one housing unit, comprising at least one drive unit arranged within the housing unit, and comprising at least one separating unit that is designed to divide at least one fluid stream conducted through the housing unit into at least two sub-streams, in particular in dependence on a foreign body density, wherein one sub-stream of the sub-streams has a higher foreign body density in comparison with another sub-stream of the sub-streams.
It is proposed that the power tool comprise at least one fluid cooling unit that is designed to cool the drive unit by means of the at least two sub-streams, in particular the sub-stream and the other sub-stream.
“Designed” is to be understood to mean, in particular, specially programmed, specially configured and/or specially equipped. That an object, in particular the fluid cooling unit, is designed for a particular function, in particular to cool the drive unit by means of the at least two sub-streams, is to be understood to mean, in particular, that the object fulfils and/or executes this particular function in at least one application state and/or operating state. Preferably, the fluid stream comprises a multiplicity of foreign bodies, in particular a number, a volume and/or a mass of foreign bodies per unit of volume, for example per cm3, in the fluid stream indicating the foreign body density. In particular, the foreign bodies in the fluid stream and/or the sub-streams are in the form of dust particles, residues from a machined workpiece, in particular metal chips, impurities in the fluid stream or the like. In particular, the fluid stream and/or the sub-streams are/is composed at least partially, in particular at least largely, of air. Preferably, the fluid cooling unit comprises at least one intake opening, which in particular is delimited by the housing unit. In particular, the intake opening is arranged on a side of the housing unit that faces away from a working region of the power tool. Preferably, the fluid cooling unit comprises at least one outlet opening, which is at least partially delimited by the housing unit and preferably arranged at a distance from the intake opening. In particular, the sub-stream and/or the other sub-stream comprise/comprises a non-zero value for the foreign body density. Preferably, the fluid cooling unit is realized in such a manner that when the drive unit is cooled by means of the sub-streams, in particular the sub-stream and the further sub-stream, thermal energy is transferred from the drive unit to the sub-streams, in particular the sub-stream and/or the further sub-stream.
Preferably, the fluid cooling unit is designed to conduct the heat transferred to the sub-streams, in particular the sub-stream and/or the other sub-stream, out of the power tool, in particular the housing unit, via the sub-streams, in particular the sub-stream and/or the further sub-stream.
Preferably, the separating unit is realized in such a manner that a value of the foreign body density of the sub-stream is greater than a value of the foreign body density of the other sub-stream, in particular by at least 50%, preferably at least 70%, more preferably at least 80% and particularly preferably at least 90%, in particular the foreign bodies having a size, in particular a mean diameter, of at least 500 μm, preferably at least 100 μm and particularly preferably at least 20 μm. Preferably, the separating unit is designed to divide the fluid stream into the sub-stream and the other sub-stream by a geometric configuration of a guide section of the, in particular aspirated, fluid stream, in particular the sub-stream having a higher foreign body density in comparison with the other sub-stream. Preferably, the separating unit is designed to conduct the sub-stream and the other sub-stream, in particular from the guide section to the various guide sub-sections.
Preferably, the fluid cooling unit is designed to conduct the fluid stream via the intake opening, through at least one channel element, to the separating unit. In particular, the channel element is arranged at least substantially entirely within the housing unit.
“Substantially entirely” is to be understood to mean, in particular, an indication of a proportion of a component, in particular of the channel element, that has a particular property, in particular of being enclosed by the housing unit, in particular at least 90%, preferably at least 95% and particularly preferably at least 98% of a total volume and/or of a total mass of the component having the property. Preferably, the separating unit and the fluid cooling unit are realized as a single piece, in particular a channel element of the fluid cooling unit being designed to delimit the fluid stream on the guide section and/or the guide sub-sections. In particular, at least one separating element of the separating unit is realized as a channel element of the fluid cooling unit and delimits, in particular, at least one fluid channel for conducting the fluid. “As a single piece” is to be understood to mean, in particular, connected in a materially bonded manner such as, for example, by a welding process and/or an adhesive process and, particularly advantageously, formed-on, as by being produced from a casting and/or by being produced in a single or multi-component injection process. Preferably, the fluid cooling unit is designed to conduct the sub-streams, after flowing through the separating unit, at least partially in the direction of the drive unit, for the purpose of cooling the drive unit.
Preferably, the power tool is realized as a hand-held power tool. For example, the power tool is realized as an angle grinder, a drill, a vacuum cleaner, a screwdriver or the like. In particular, the drive unit is realized as a motor, in particular an electric motor. Preferably, the drive unit, the separating unit and/or the fluid cooling unit, in particular with the exception of the intake opening and/or the outlet opening, are/is arranged at least substantially entirely within the housing unit.
The design of the power tool according to the invention makes it possible to achieve advantageously effective cooling of the drive unit, in particular without fouling the drive unit, in particular because the sub-stream and the other sub-stream can be used to cool the drive unit.
An advantageously high energy efficiency can be achieved in cooling of the drive unit, in particular because an aspirated fluid stream can be used fully for cooling the drive unit.
It is furthermore proposed that the separating unit comprise at least one separating element, realized as a channel element, which is arranged in a proximity region of the drive unit and designed to divide the fluid stream. An advantageously effective cooling of the drive unit can be achieved by means of the sub-streams. An advantageously compact design becomes possible, as the sub-streams can be divided just before flowing past the drive unit. In particular, the separating element is designed to conduct the fluid stream on the guide section and to divide it into the sub-stream and the other sub-stream. Preferably, the separating element is realized as a passive element, in particular the separating element being designed to divide the fluid stream by a shape of the separating element, in particular as the fluid stream flows through it. In particular, the separating element is static, or immobile. Preferably, the separating element realizes at least one fluid inlet for conducting the fluid stream, and at least two fluid outlets for conducting the sub-stream and the other sub-stream, respectively. Preferably, the separating element has an at least partially curved basic shape in a sectional plane that comprises the guide section and/or at least one of the guide sub-sections. Preferably, the separating element is realized in such a manner that the guide section, in a region of the fluid inlet, has an angle of in particular at least 30°, preferably at least 60° and particularly preferably at least 80° to the guide sub-section of the other sub-stream in a region of one of the fluid outlets. Preferably, the separating element has at least one basic shape realized in such a manner that foreign bodies are conducted onto a path that deviates from a guide path of the fluid stream, in particular of the other sub-stream. In particular, the separating element is realized in such a manner that the sub-stream is guided at least partially separately from the other sub-stream. Preferably, the separating element is arranged on the fluid cooling unit, or is realized as part of the fluid cooling unit. Preferably, the separating element is arranged on the fluid cooling unit, or is realized as part of the fluid cooling unit.
Preferably, the separating unit, in particular the separating element, is realized fluidically between the intake opening and the drive unit. That “the separating element is arranged in a proximity region of the drive unit” is to be understood to mean, in particular, that the separating unit is arranged, in particular entirely, within a region around the drive unit that extends within a minimal distance of at most 150 mm, preferably at most 100 mm, and particularly preferably at most 50 mm around the drive unit. Preferably, the separating element arranged in the proximity region of the drive unit is arranged, in particular fastened, directly on the drive unit, in particular on a housing of the drive unit. It is conceivable for the separating element arranged in the proximity region of the drive unit to constitute a single piece with the drive unit, in particular the housing of the drive unit.
It is also proposed that the fluid cooling unit comprise at least one channel element, in particular the aforementioned, which is designed to guide the sub-stream, in particular separately from the other sub-stream, at least partially past an outer wall of the drive unit. Fouling of the drive unit with foreign bodies in the sub-stream can be advantageously prevented when the sub-streams are used to the drive unit. Unwanted abrasive damage to the drive unit, in particular to bearings and/or windings of the drive unit, can be advantageously prevented. An advantageously long service life becomes possible. In particular, the separating unit and/or the fluid cooling unit are/is realized in such a manner that the sub-stream, in particular in a region along the drive unit, is conducted, at least largely separately from the other sub-stream, through the housing unit. Preferably, the fluid cooling unit is designed to conduct the other sub-stream into, or through, the drive unit for the purpose of cooling the drive unit. In particular, the channel element is arranged outside of the drive unit, on the outer wall. Particularly preferably, the channel element is arranged directly on the drive unit, in particular on the outer wall. In particular, the channel element bears flatly against the outer wall. Particularly preferably, the channel element is designed to transfer heat from the drive unit, in particular the outer wall, to the sub-stream, in particular cooling of the drive unit being effected by the sub-stream.
Preferably, the channel element extends along an entire length of the drive unit, on the outer wall. Preferably, the channel element is made, at least partially, in particular at least largely, of a thermally conductive material that, in particular, has a thermal conductivity of, in particular, at least 10 W/(m.K), preferably at least 40 W/(m.K), more preferably at least 100 W/(mK) and particularly preferably at least 200 W/(mK). Preferably, the channel element is at least substantially rectilinear, in particular along an entire length of the outer wall. In particular, the channel element is at least substantially parallel to the outer wall, in particular an outer surface of the outer wall, that faces toward the channel element, or that bears at least partially against the channel element. “Substantially parallel” is to be understood here to mean, in particular, an alignment of a direction, in particular a direction of main extent of the channel element, relative to a reference direction, in particular a direction of main extent of the outer wall and/or of the outer surface of the outer wall, the direction deviating from the reference direction, in particular as viewed in at least one plane of projection, by in particular less than 8°, advantageously less than 5°, and particularly advantageously less than 2°. A “direction of main extent” of an object, in particular of the outer wall and/or of the outer surface of the outer wall, is in this case to be understood to mean, in particular, a direction that is parallel to a longest edge of a smallest geometric cuboid that only just completely encloses the object.
It is further proposed that the separating unit comprise at least one conveying unit, which is arranged within the fluid cooling unit and is designed to convey at least the sub-stream out of or through the housing unit. Advantageously effective cooling can be achieved, in particular because high flow rates of the fluid streams, in particular of the sub-streams, become possible by means the conveyor unit. Distribution of foreign bodies from the sub-stream within the housing unit, the separator unit and/or the fluid cooling unit, in particular into the other sub-stream, can be advantageously prevented. In particular, the conveying unit is realized as a flow pump. Preferably, the conveying unit is designed to draw in the sub-stream via the fluid cooling unit, in particular through the intake opening. Preferably, the conveying unit is designed to convey the fluid stream, in particular along the guide section, through the separating unit and to divide it, in particular by means of a conveying speed and the separating element, into the sub-streams, in particular the sub-stream and the other sub-stream. Preferably, the conveying unit is designed to convey the sub-streams, in particular the sub-stream and the other sub-stream, in particular after cooling of the drive unit, through the outlet openings out of the power tool, in particular out of the housing unit. Preferably, the conveying unit comprises at least one conveying element that is realized, for example as a fan impeller, as a blade, as a piston or the like. Preferably, the conveying element is arranged at least partially, in particular at least largely, within the fluid cooling unit, in particular within a channel element of the fluid cooling unit. Preferably, the conveying element is arranged behind the drive unit, as viewed from the intake opening. In particular, the conveying element constitutes a single piece with a fan of the drive unit. Alternatively or additionally, it is conceivable for the conveying element to be arranged between the separating unit and the drive unit or, as viewed from the intake opening, in front of the separating unit. Particularly preferably, the conveying unit, in particular the conveying element, is designed to convey the sub-stream and the other sub-stream through the fluid cooling unit, through the separating unit and/or out of the power tool, or the housing unit.
It is also proposed that the conveying unit comprise at least one conveying element, which is realized as an axial fan. An advantageously simple and inexpensive design of the conveying unit can be achieved. Advantageously, a fan impeller of the drive unit can be used as a conveying element for the sub-streams. It is conceivable for the conveying element realized as an axial fan to be realized as part of the drive unit. Preferably, the conveying element constitutes a single piece with a fan impeller of the drive unit. Preferably, the conveying element is arranged fluidically behind the drive unit, as viewed from the intake opening.
Alternatively, it is conceivable for the conveying element to be arranged in a channel element of the fluid cooling unit that is designed to conduct the sub-stream. In the alternative design, the conveying element is preferably arranged fluidically behind the separating unit, as viewed from the intake opening. In particular, the conveying element is arranged within the guide sub-section of the sub-stream.
It is further proposed that the conveying unit be designed to convey the sub-stream and the other sub-stream separately from each other through the housing unit and/or the fluid cooling unit. Fouling of the drive unit with foreign bodies in the sub-stream can be advantageously prevented when the sub-streams are used to the drive unit. Advantageously effective separation of the sub-streams becomes possible. Preferably, the conveying unit, in particular together with the fluid cooling unit, is designed to convey the sub-streams each in different directions. Preferably, the conveying element of the conveying unit is realized, in at least one region of the conveying element, as a radial fan. Preferably, the conveying element is realized, in at least one further region of the conveying element, as an axial fan. Preferably, the region of the conveying element, as viewed along a drive axis of the conveying element, is surrounded by the further region. Preferably, the region of the conveying element is at a lesser minimum radial distance from the drive axis of the conveying element than the further region of the conveying element. For example, the conveying element is realized as a fan impeller, in particular a two-part fan impeller. Particularly preferably, the conveying element is arranged, in particular fluidically, behind the drive unit, preferably as viewed from the intake opening. In particular, the conveying element is realized as part of the drive unit. Preferably, the conveying element is designed to convey the sub-stream, in particular in a proximity region around the conveying element, in a direction oriented at least substantially parallel to the drive axis of the conveying element. Preferably, the conveying element is designed to convey the other sub-stream, in particular in a proximity region of the conveying element, in a direction oriented at least substantially perpendicularly to the drive axis of the conveying element. “Substantially perpendicularly” is to be understood to mean, in particular, an orientation of a direction, in particular a direction of conveyance of the other sub-stream, relative to a reference direction, in particular a direction along the drive axis of the conveying element, the direction and the reference direction, in particular as viewed in a plane of projection, enclosing an angle of 90°, and the angle having a maximum deviation of in particular less than 8°, advantageously less than 5° and particularly advantageously less than 2°. Preferably, the conveying unit is designed to convey the sub-stream and the other sub-stream out of the power tool, or the housing unit, each through differently realized and/or spaced outlet openings of the fluid cooling unit.
It is furthermore proposed that the separating unit comprise at least one separating element, in particular a further separating element, that is arranged within a channel element, in particular a further channel element, in particular a main channel element, of the fluid cooling unit, and that is designed to conduct the fluid stream onto a circular path, for the purpose of dividing the sub-streams, as viewed along the channel element, in particular the further channel element. An advantageously compact design of the separating unit becomes possible, in particular since the further separating element can be arranged in the further channel element. It becomes possible to achieve advantageously little settling of foreign bodies, in particular because the further channel element can be realized with a flat inner wall. Preferably, the further separating element is arranged at least substantially entirely within the further channel element, in particular the main channel element. Preferably, the further channel element, in particular the main channel element, is realized in the form of a tube and/or hollow cylinder, and in particular has at least one central axis. In particular, the central axis of the further channel element, in particular of the main channel element, is at least substantially parallel to, in particular coaxial with, the drive axis, a longitudinal axis of the power tool, an axis of main extent of the fluid cooling unit and/or of the power tool and/or a direction of propagation of the fluid stream within the fluid cooling unit. In particular, the further channel element, in particular of the main channel element, is arranged, in particular fluidically, between the intake opening and the drive unit. Particularly preferably, the conveying unit, in particular the conveying element, is designed to convey the fluid stream from the intake opening through the further channel element, in particular the main channel element, the fluid stream being conducted by means of the further separating element, as viewed along the further channel element and/or the central axis of the further channel element, onto the circular path. In particular, the fluid stream, as it flows through the further channel element and the further separating element, in particular on the circular path, is divided into the sub-stream and the other sub-stream, in particular the sub-stream being conducted through the further channel element onto a path that, in particular due to inertia, has a larger radius with respect to the central axis than a path of the other sub-stream through the further channel element. Preferably, foreign bodies in the sub-stream have a path that, with respect a central axis of the further channel element, have a larger radius than a path of the other sub-stream. Preferably, the separating element realized as a channel element is realized at least partially in the shape of a funnel and/or trumpet. In particular, the separating element realized as a channel element is arranged behind the further separating, as viewed from the intake opening. Preferably, the separating element is at least partially cone-shaped. Preferably, the separating element delimits at least one passage, around the central axis of the separating element, that is designed in particular to conduct the other sub-stream. Preferably, the separating element is designed to separate the sub-stream conducted by means of the further separating element onto the circular path from the other sub-stream, in particular the sub-stream being conducted, along an outer wall of the separating element, into the channel element, and in particular the other sub-stream being conducted, through the passage of the separating element, onto and/or into the drive unit.
It is furthermore proposed that the separating element, in particular the aforementioned, be realized as a helical and/or spiral shaped part. Advantageously simple and inexpensive separation of the fluid stream into the sub-streams can be achieved. An advantageously compact design of the power tool, in particular of the fluid cooling unit and the separating unit, becomes possible, in particular since the fluid stream can be divided within a straight fluid channel. It can be achieved that there is advantageously little wear on the fluid cooling unit and the separator unit, in particular on the inner walls, in particular because foreign bodies have a shallower angle to the inner walls of the fluid channels when the fluid stream is divided. It is thus also possible to achieve advantageously low levels of residues due to foreign bodies within the fluid cooling unit. Preferably, the further separating element delimits, in particular within and/or together with the main channel element, in particular the main channel element, a fluid guiding channel that extends, from the intake opening in the direction of the drive unit, along a curve that runs with a constant gradient around a lateral surface of an imaginary cylinder. Preferably, the further separating element is realized as a single-thread screw. Alternatively, it is conceivable for the further separating element to be realized as a two-thread, three-thread or multi-thread screw. Particularly preferably, the further separating element has a central axis around which in particular the fluid guiding channel is wound. Particularly preferably, the central axis of the further separating element is oriented coaxially with a central axis of the further channel element, in particular of the main channel element, and/or with the central axis of the separating element, around which in particular the passage of the separating element is realized. It is conceivable for the conveying unit to comprise at least one, in particular a further, conveying element, which is arranged, in particular fluidically, between the intake opening of the fluid cooling unit and the drive unit. Preferably, the conveying element is arranged at least partially, in particular at least largely, within the fluid cooling unit, in particular within a channel element of the fluid cooling unit. It is conceivable for the conveying element arranged between the intake opening and the drive unit to be arranged between the separating unit and the drive unit, or between the intake opening and the separating unit. In particular, the conveying element arranged between the intake opening and the drive unit is designed to convey the sub-stream and/or the other sub-stream through the fluid cooling unit, through the separating unit and/or out of the power tool, or the housing unit. Alternatively or additionally, it is conceivable for the conveying unit to comprise at least one, in particular the aforementioned or a further, conveying element, which is realized as a spiral wheel. Preferably, the conveying element realized as a spiral wheel is realized as part of the separation unit. In particular, the conveying element realized as a spiral wheel is designed to divide the fluid stream into the sub-streams, in particular the sub-stream being at a greater radial distance from the drive axis than the other sub-stream. Preferably, a separating element of the separating unit and/or the fluid cooling unit are/is realized in such a manner that the sub-stream and the other sub-stream are conducted separately from one another after exiting the conveying element realized as a spiral wheel, or a conveying region of the conveying element realized as a spiral wheel. For example, the separating element is realized as a funnel, in particular the other sub-stream being conducted along a central axis of the funnel that in particular is coaxial with the drive axis of the conveying element, and the sub-stream being guided along an outer wall of the separating element.
It is also proposed that the separating unit and/or the fluid cooling unit comprise at least one filter element that is designed to alter, in particular to reduce, the foreign body density of the fluid stream. It becomes possible to achieve an advantageously low foreign body density of the fluid stream, in particular even before it is divided into the sub-streams. It becomes possible to achieve an advantageously low foreign body density of the sub-stream used to cool the drive unit. It becomes possible to achieve an advantageously low degree of fouling, or deposition of foreign bodies, within the housing unit, the separating unit and/or the fluid cooling unit. In particular, the filter element is arranged, in particular directly, at the intake opening of the fluid cooling unit. Preferably, the filter element, in particular a filter surface of the filter element, is arranged at least partially transversely or at least substantially perpendicularly to a direction of flow of the fluid stream. Preferably, the filter surface spans, with the direction of flow of the fluid stream, in a region of the filter element, or of the intake opening, an angle having a value from a value range of, in particular, 8° to 82°, preferably 10° to 50° and particularly preferably 15° to 30°. In a preferred design, the filter element is at least partially, in particular at least largely, cone-shaped.
It is further proposed that the fluid cooling unit comprise at least one main channel element, in particular the aforementioned, for conducting the fluid stream, which is arranged in front of the drive unit as viewed along a direction of main extent of the fluid cooling unit, wherein the conveying element is arranged within the main channel element and/or within a region of the fluid cooling unit delimited by the main channel element. An advantageously simple and inexpensive design becomes possible, in particular since the conveying unit in the main channel element can be used centrally for conveying the entire fluid stream, and/or since all components influencing the fluid stream, such as, for example, the filter element and/or the separator unit, can be advantageously realized as a single piece. It becomes possible to achieve advantageously effective cooling of the drive unit and/or of the other components of the power tool that are arranged in front of the drive unit, on the main channel element, as viewed along the direction of main extent of the fluid cooling unit. In particular, the fluid cooling unit comprises, along the direction of main extent of the fluid cooling unit, in a region of the main channel element, only exactly one guide section that is arranged in particular within the main channel element. Preferably, the direction of main extent of the fluid cooling unit is oriented at least substantially parallel to a direction of main extent of the drive unit and/or of the housing unit and to the drive axis of the conveying element. Particularly preferably, the main channel element extends from the intake opening, in particular along the direction of main extent of the fluid cooling unit, to the separating unit.
Also proposed is a process for cooling at least one drive unit of a power tool according to the invention.
The design of the process according to the invention makes it possible to achieve advantageously effective cooling of the drive unit, in particular without fouling the drive unit, in particular because the sub-stream and the other sub-stream can be used to cool the drive unit. An advantageously high energy efficiency can be achieved in cooling of the drive unit, in particular because an aspirated fluid stream can be used fully for cooling the drive unit. An advantageously long service life becomes possible.
The power tool according to the invention and/or the process according to the invention are/is not intended in this case to be limited to the application and embodiment described above. In particular, the power tool according to the invention and/or the process according to the invention may have a number of individual elements, components and units that differs from a number stated herein, in order to fulfill an operating principle described herein. Moreover, in the case of the value ranges specified in this disclosure, values lying within the stated limits are also to be deemed as disclosed and applicable in any manner.
Further advantages are given by the following description of the drawings. Six exemplary embodiments of the invention are represented in the drawings. The drawings, the description and the claims contain numerous features in combination. Persons skilled in the art will also expediently consider the features individually and combine them to create appropriate further combinations.
In the drawings:
However, other designs of the drive unit 16a are also conceivable, for example as a universal motor. The power tool 10a comprises an electronic device 17a. The power tool 10a has an electronic unit 18a, which is designed at least to control and supply electricity to the drive unit 16a, and in particular is realized as part of the electronic device 17a. It is also conceivable for the electronic unit 18a to be designed to control and/or supply other components of the power tool 10a such as, for example, display elements, interfaces or the like.
The electronic unit 18a is designed to commutate the drive unit 16a. The electronic unit 18a comprises a printed circuit board 20a, arranged on which in particular are a processor unit and a memory unit that in particular are not shown in
The fluid cooling unit 30a comprises an intake opening 34a for drawing in the fluid, or fluid stream 24a. The intake opening 34a is delimited by the housing unit 14a and arranged on a side of the power tool 10a, in particular of the housing unit 14a, that faces away from a working region 38a of the power tool 10a. The intake opening 34a is realized along the longitudinal axis 12a of the power tool 10a, in particular at an end region 40a of the power tool 10a that is realized along the longitudinal axis 12a of the power tool 10a and that at least partially faces away from the working region 38a.
The fluid cooling unit 30a comprises a multiplicity of outlet openings 42a, 44a, 46a for draining the fluid, or the fluid stream 24a, from the power tool 10a. The outlet openings 42a, 44a, 46a are arranged in an end region 48a of the power tool 10a that faces away from the intake opening 34a. The outlet openings 42a, 44a, 46a are arranged in a region around a tool holder 50a of the power tool 10a. One outlet opening 42a of the multiplicity of outlet openings 42a, 44a, 46a is arranged on a side of the power tool 10a, in particular of the housing unit 14a, that faces away from the working region 38a. Two outlet openings 44a, 46a of the multiplicity of outlet openings 42a, 44a, 46a are arranged on a side of the power tool 10a, in particular of the housing unit 14a, that faces toward the working region 38a. One outlet opening 44a of the two outlet openings 44a, 46a is designed to divert the sub-stream 26a. Another outlet opening 46a of the two outlet openings 44a, 46a is designed to divert the other sub-stream 28a.
The drive unit 16a has a drive axis 52a, about which a rotor of the drive unit 16a is driven. The drive axis 52a of the drive unit 16a is oriented at least substantially parallel to the longitudinal axis 12a of the power tool 10a. The drive axis 52a of the drive unit 16a is oriented coaxially with a direction of main extent 54a of the fluid cooling unit 30a. The fluid cooling unit 30a comprises a channel element, in particular a fluid cooling element 66a, the fluid flow path 32a, in particular in a region in which the electronic unit 18a is arranged, running at least largely through the channel element. The fluid flow path 32a extends from the intake opening 34a of the fluid cooling unit 30a to the outlet openings 42a, 44a, 46a of the fluid cooling unit 30a. The fluid cooling unit 30a has a guide section 58a along which the fluid flow path 32a is realized. In particular, the guide section 58a is realized along a direction of main extent 54a of the fluid flow path 32a. The electronic unit 18a is arranged at least largely, in particular entirely, outside of a flow recess 60a, enclosed by the fluid cooling unit 30a, for conducting the fluid, or fluid stream 24a. The fluid cooling unit 30a is realized and/or the electronic unit 18a is arranged in such a manner that the electronic unit 18a, in particular via a channel element, in particular the fluid cooling element 66a, of the fluid cooling unit 30a, is arranged at a distance from the fluid flow path 32a and/or the flow recess 60a enclosed by the fluid cooling unit 30a. The fluid cooling unit 30a is designed to conduct the fluid stream 24a via the intake opening 34a, through the channel element, in particular the fluid cooling element 66a, past the electronic unit 18a and the drive unit 16a to the outlet openings 42a, 44a, 46a. The channel element, in particular the fluid cooling element 66a, is arranged at least substantially entirely within the housing unit 14a. The drive unit 16a, the electronic unit 18a and the fluid cooling unit 30a, in particular with the exception of the intake opening 34a and/or the outlet openings 42a, 44a, 46a, are arranged at least substantially entirely within the housing unit 14a.
The fluid, or fluid stream 24a, aspirated via the intake opening 34a contains a large number of foreign bodies. In particular, the foreign bodies in the fluid stream 24a and/or the sub-streams 26a, 28a are dust particles, residues from a machined workpiece, such as, for example metal chips, impurities in the fluid stream 24a or the like. The fluid, or fluid stream 24a, is at least partially, in particular at least largely, composed of air. The fluid cooling unit 30a is realized in such a manner that when the drive unit 16a is cooled by means of the sub-streams 26a, 28a, in particular the sub-stream 26a and the further sub-stream 28a, thermal energy is transferred from the drive unit 16a to the sub-streams 26a, 28a. The fluid cooling unit 30a is designed to conduct the heat transferred to the sub-streams 26a, 28a, in particular the sub-stream 26a and the other sub-stream 28a, respectively, out of the power tool 10a, in particular the housing unit 14a, via the sub-streams 26a, 28a. The fluid cooling unit 30a is designed to conduct the fluid stream 24a via the intake opening 34a through at least one channel element, in particular the fluid cooling element 66a, of the fluid cooling unit to the separating unit 22a. The separating unit 22a and the fluid cooling unit 30a constitute a single piece, in particular the channel element, in particular the fluid cooling element 66a, of the fluid cooling unit 30a being designed to delimit the fluid stream 24a on the guide section 58a and/or on guide sub-sections 62a, 64a of the sub-stream 28a and of the other sub-stream 28a, respectively. The fluid cooling unit 30a is designed to conduct the sub-streams 26a, 28a, after flowing through the separating unit 22a, at least partially in the direction of the drive unit 16a, for the purpose of cooling the drive unit 16a.
The fluid cooling unit 30a comprises the fluid cooling element 66a, against which the electronic unit 18a bears, at least partially. The electronic unit 18a comprises a heat diffusion element 68a for dissipating heat. The heat diffusion element 68a is realized as a copper block and is designed to collect heat generated in particular during operation of the electronic unit 18a and/or to transfer it to the fluid cooling element 66a. The electronic unit 18a, in particular the heat diffusion element 68a, has at least one support surface 70a (see
The fluid flow path 32a extends in a proximity region 76a of the electronic unit 18a at least substantially entirely within the fluid cooling element 66a. The fluid cooling element 66a is designed, in particular in the proximity region 76a of the electronic unit 18a, to conduct an entire fluid stream 24a that in particular flows via the intake opening 34a into the fluid cooling unit 30a. The fluid flow path 32a runs, in particular in the proximity region 76a of the electronic unit 18a, at least substantially entirely through the fluid cooling element 66a, in particular the fluid channel 72a. Alternatively, it is conceivable for the fluid cooling element 66a to delimit at least, in particular exactly, two fluid channels 72a, the fluid flow path 32a, in particular in the proximity region 76a of the electronic unit 18a, running at least substantially entirely through the fluid cooling element 66a, in particular the fluid channels 72a. The proximity region 76a of the electronic unit 18a extends along the direction of main extent 54a of the fluid cooling unit 30a, in particular the of fluid cooling element 66a, at least over an entire length 78a of the electronic unit 18a. The drive unit 16a is arranged, in particular fluidically, behind the electronic unit 18a and the fluid cooling element 66a, as viewed from the intake opening 34a. The separating unit 22a is arranged, in particular fluidically, behind the electronic unit 18a and the fluid cooling element 66a and in front of the drive unit 16a, as viewed from the intake opening 34a.
The separating unit 22a comprises a separating element 80a, realized as a channel element, arranged in a proximity region 82a of the drive unit 16a and designed to divide the fluid stream 24a. The separating element 80a is designed to conduct the fluid stream 24a on the guide section 58a and to divide it into the sub-stream 26a and the other sub-stream 28a. The separating element 80a is realized as a passive element, in particular the separating element 80a being designed to divide the fluid stream 24a by a shape of the separating element 80a, in particular as the fluid stream 24a flows through it. In particular, the separating element 80a is static, or immobile. In particular, the separating element 80a is described in detail in the description of
A channel element 56a of the fluid cooling unit 30a is designed to guide the sub-stream 26a, in particular separately from the other sub-stream 28a, at least partially past an outer wall 84a of the drive unit 16a. It is also conceivable for the fluid cooling unit 30a to comprise a multiplicity of channel elements 56a designed to conduct the sub-stream 26a, in particular the channel elements 56a being arranged, in a distributed manner around the longitudinal axis 12a, around the drive unit 16a. The separating unit 22a and the fluid cooling unit 30a are realized in such a manner that the sub-stream 26a, in particular in a region along the drive unit 16a, is conducted, at least largely separately from the other sub-stream 28a, through the housing unit 14a. The fluid cooling unit 30a is designed to conduct the other sub-stream 28a into, or through, the drive unit 16a for the purpose of cooling the drive unit 16a. The channel element 56a is arranged outside of the drive unit 16a, on the outer wall 84a of the drive unit 16a. The channel element 56a is arranged directly on the drive unit 16a, in particular on the outer wall 84a of the drive unit 16a. The channel element 56a bears flatly against the outer wall 84a of the drive unit 16a. The channel element 56a is designed to transfer heat from the drive unit 16a, in particular the outer wall 84a of the drive unit 16a, to the sub-stream 26a, in particular the drive unit 16a being cooled by the sub-stream 26a. The channel element 56a extends along an entire length 86a of the drive unit 16a, on the outer wall 84a of the drive unit 16a. The channel 56a element is made at least largely of a thermally conductive material that, in particular, has a thermal conductivity of, in particular, at least 10 W/(m.K), preferably at least 40 W/(m.K), more preferably at least 100 W/(m.K), and particularly preferably at least 200 W/(mK). The channel element 56a is at least substantially rectilinear, in particular along an entire length 88a of the outer wall 74a of the drive unit 16a. In particular, the channel element 56a is, at least largely, at least substantially parallel to the outer wall 84a of the drive unit 16a, in particular an outer surface of the outer wall 84a of the drive unit 16a, that faces toward the channel element 56a, or that bears at least partially against the channel element 56a.
The separating unit 22a comprises a conveying unit 90a, which is at least partially arranged within the fluid cooling unit 30a and is designed to convey at least the sub-stream 26a out of or through the housing unit 14a. The conveying unit 90a is realized as a flow pump. The conveying unit 90a is designed to aspirate the sub-stream 26a via the fluid cooling unit 30a, in particular through the intake opening 34a. The conveying unit 90a is designed to convey the fluid stream 24a, in particular along the guide section 58a, through the separating unit 22a and to divide it, in particular by means of a conveying speed and the separating element 80a, into the sub-streams 26a, 28a, in particular the sub-stream 26a and the other sub-stream 28a. The conveying unit 90a is designed to convey the sub-streams 26a, 28a, in particular the sub-stream 26a and the other sub-stream 28a, in particular after cooling of the drive unit 16a, through the outlet openings 42a, 44a, 46a out of the power tool 10a, in particular out of the housing unit 14a. The conveying unit 90a comprises a conveying element 92a, which is realized, at least partially, as an axial fan. The conveying element 92a constitutes a single piece with a fan impeller 94a of the drive unit 16a. The conveying element 92a is arranged fluidically behind the drive unit 16a, as viewed from the intake opening 34a. The conveying unit 90a is designed to convey the sub-stream 26a and the other sub-stream 28a separately from each other through the housing unit 14a and/or the fluid cooling unit 30a.
The conveying unit 90a, in particular together with the fluid cooling unit 30a, is designed to convey the sub-streams 26a, 28a, in particular after the drive unit 16a, each in different directions that in particular are directed radially outward from a drive axis 96a of the conveying element 92a. The conveying element 92a is arranged, in particular fluidically, behind the drive unit 16a, as viewed from the intake opening 34a. The conveying element 92a is designed to convey the sub-stream 26a, in particular in a proximity region of the conveying element 92a, in a direction oriented at least substantially parallel to the drive axis 96a of the conveying element 92a. The conveying element 92a is designed to convey the other sub-stream 28a, in particular in a proximity region of the conveying element 92a, in a direction oriented at least substantially perpendicularly to the drive axis 96a of the conveying element 92a. The conveying unit 90a is designed to convey the sub-stream 26a and the other sub-stream 28a out of the power tool 10a, or the housing unit 14a, each through differently realized and/or spaced outlet openings 42a, 44a, 46a of the fluid cooling unit 30a. The conveying unit 90a is designed to convey the sub-stream 26a through the outlet openings 42a, 44a, 46a. The conveying unit 90a is designed to convey the other sub-stream 28a through the outlet openings 42a, 44a, 46a.
The fluid cooling unit 30a comprises a main channel element 98a, for conducting the fluid stream 24a, which is arranged in front of the drive unit 16a, as viewed from the intake opening 34a, in particular as viewed along the direction of main extent 54a of the fluid cooling unit 30a. The fluid cooling unit 30a comprises, along the direction of main extent 54a of the fluid cooling unit 30a, in a region of the main channel element 98a, only exactly one guide section 58a that is arranged in particular within the main channel element 98a. The guide section 58a extends from the intake opening 34a through the fluid cooling unit 30a to the outlet openings 42a, 44a, 46a. The direction of main extent 54a of the fluid cooling unit 30a is oriented at least substantially parallel to a direction of main extent 102a of the drive unit 16a and/or of the housing unit 14a and to the drive axis 96a of the conveying element 92a. The main channel element 98a extends from the intake opening 34a, in particular along the direction of main extent of the fluid cooling unit 30a, to the separating unit 22a. The main channel element 98a is connected to the fluid cooling element 66a so as to constitute a single piece. The main channel element 98a, the fluid cooling element 66a and the channel element 56a of the fluid cooling unit 30a each have at least substantially smooth inner walls 104a, which in particular delimit the fluid channels 72a guiding the fluid stream 24a. Preferably, the main channel element 98a, the fluid cooling element 66a and the channel element 56a of the fluid cooling unit 30a, in particular the inner walls 104a of the main channel element 98a, of the fluid cooling element 66a and of the channel element 56a of the fluid cooling unit 30a, are realized without edges, in particular the inner walls 104a of the main channel element 98a, of the fluid cooling element 66a and of the channel element 56a of the fluid cooling unit 30a merging continuously into one another along a guide direction 106a of the fluid stream 24a.
In addition, it is conceivable for the power tool 10a to comprise a sensor unit 108a, which is merely indicated in the figures. The sensor unit 108a comprises at least one sensor element 110a for sensing a temperature of the drive unit 16a. Preferably, the electronic unit 18a is designed to control by open-loop and/or closed-loop control, preferably to limit, a performance characteristic, for example a maximum rotational speed, of the drive unit 16a in dependence on the sensed temperature in order to avoid overheating of the drive unit 16a, or a failure of the power tool 10a. It is also conceivable for the electronic unit 18a to be designed to issue a warning to a user, for example via an optical, acoustic and/or haptic signal, in dependence on the sensed temperature, in particular if a limit value of the temperature is exceeded.
The separating element 80a realizes a fluid inlet 112a for conducting the fluid stream 24a, and two fluid outlets 114a, 116a for conducting the sub-stream 26a and the other sub-stream 28a, respectively. The separating element 80a has an at least partially curved basic shape in a sectional plane that comprises the guide section 58a and/or at least one of the guide sub-sections 62a, 64a and that corresponds in particular to an image plane of
Foreign bodies within the fluid stream 24a, when flowing through the separating element 80a in a flow direction along the guide section 58a, are moved by their inertia on a path that depends on a mass of the foreign bodies. Preferably, foreign bodies that have a larger mass fly on a less curved path than foreign bodies that have a smaller mass. As they flow through the separating element 80a, foreign bodies that have a large mass are conducted to a fluid outlet 116a of the fluid outlets 114a, 116a that is designed to conduct the sub-stream 26a. Another fluid outlet 114a of the fluid outlets 112a, 114a is designed to conduct the other sub-stream 28a. Preferably, the guide section 58a in the region of the fluid inlet 112a has a smaller angle to the guide sub-section 62a of the sub-stream 26a in the region of the fluid outlet 116a than to the guide sub-section 64a of the other sub-stream 28a in the region of the other fluid outlet 114a. Preferably, the separating element 80a is realized in such a manner that a turbulence of the fluid, or fluid stream, is realized on an inner wall 122a of the separating element 80a that delimits the guide sub-section 62a of the sub-stream 26a.
The electronic device 17a comprises a sealing unit 140a, which is designed to close the electronic unit 18a, together with the fluid cooling unit 30a, at least partially, in particular with respect to the fluid flow path 32a, in an at least substantially airtight and/or watertight manner. The sealing unit 140a has a sealing element 142a, which is made of a thermally insulating material, in particular rubber. The sealing element 142a bears at least partially against the heat diffusion element 68a. It is also conceivable for the sealing element 142a to entirely enclose the heat diffusion element 68a, together with the fluid cooling element 66a. Alternatively, it is conceivable for the sealing element 142a to be made of a thermally conductive material that, in particular, has a thermal conductivity of at least 10 W/(m.K), preferably at least 50 W/(m.K), more preferably at least 100 W/(m.K), particularly preferably at least 200 W/(m.K), and most particularly preferably at least 400 W/(mK). The sealing element 142a encloses the electronic component 136a of the electronic unit 18a, together with the fluid cooling element 66a and the heat diffusion element 68a, at least substantially entirely. It is conceivable for a volume enclosed between the sealing element 142a and the electronic unit 18a, or the fluid cooling element 66a and/or the heat diffusion element 68a, to be filled with or evacuated by a thermally insulating gas. In particular, the evacuated volume has a maximum pressure of in particular less than 1000 mbar, preferably less than 300 mbar, more preferably less than 1 mbar, and particularly preferably less than 10−2 mbar.
In a further process step 204a of the process 200a, the fluid stream 24a flowing through the main channel element 98a is used to cool the electronic unit 18a via the fluid cooling element 66a. When flowing through the main channel element 98a, the fluid stream 24a flows through the fluid cooling element 66a, with heat being dissipated from the electronic unit 18a, via the fluid cooling element 66a, to the fluid stream 24a for the purpose of cooling the electronic unit 18a. In a further process step 206a of the process 200a, the separating unit 22a, in particular the separating element 80a, divides the fluid stream 24a into the sub-stream 26a, in particular the one loaded with foreign bodies, and the other sub-stream 28a, in particular the one containing few foreign bodies. The sub-stream 26a is guided by means of the separating unit 22a and the fluid cooling unit 30a, through the channel element 56a, along the outer wall 84a of the drive unit 16a, the drive unit 16a being cooled via the sub-stream 26a, in particular heat being transferred from the outer wall 84a of the drive unit 16a to the sub-stream 26a. The other sub-stream 28a is conducted into, or through, the drive unit 16a by means of the separating unit 22a and the fluid cooling unit 30a, the drive unit 16a, in particular windings of the drive unit 16a, being cooled by means of the other sub-stream 28a, in particular heat being transferred from the drive unit 16a to the other sub-stream 28a. In a further process step 208a of the process 200a, the other sub-stream 28a is conveyed via the region 124a of the conveying element 92a in a direction toward the working region 38a, or the outlet opening 46a, and is conveyed out of the power tool 10a, in particular out of the housing unit 14a and/or the fluid cooling unit 30a, through the outlet opening 46a. In a process step of the process 200a, in particular the process step 208a, the sub-stream 26a is conveyed via the further region 126a of the conveying element 92a in directions oriented at least substantially parallel to the drive axis 96a of the conveying element 92a, and is conducted via the fluid cooling unit 30a to the outlet openings 42a, 44a, or out of the power tool 10a, in particular out of the housing unit 14a and/or the fluid cooling unit 30a.
The further conveying element 144b is designed to convey the sub-stream 26b and/or the other sub-stream 28b through the fluid cooling unit 30b, through the separating unit 22b and/or out of the power tool 10b, or out of the housing unit 14b. After flowing through, or past, the drive unit 16b, the sub-stream 26b and the other sub-stream 28b are guided together out of the power tool 10b through a plurality of outlet openings 42b, 44b, 46b. In particular, after flowing through, or past, the drive unit 16b, the sub-stream 26b and the other sub-stream 28b within the power tool 10b, in particular the housing unit 14b, are brought together in a channel element of the fluid cooling unit 30b. It is also conceivable, however, for the fluid cooling unit 30b to be realized in such a manner that the sub-stream 26b and the other sub-stream 28b are guided separately out of the power tool 10b.
The power tool 10c represented in
The separating unit 22c and the fluid cooling unit 30c respectively comprise a filter element 154c that is designed to alter, in particular to reduce, the foreign body density of the fluid stream 24c. The filter element 154c is arranged, in particular directly, at the intake opening 34c of the fluid cooling unit 30c. The filter element 154c, in particular a filter surface 156c of the filter element 154c, is arranged at least partially transversely to a direction of main extent 54c of the fluid cooling unit 30c. The filter surface 156c spans, with the direction of main extent 54c of the fluid cooling unit 30c, in a region of the filter element 154c, or of the intake opening 34c, an angle 158c having a value from a value range of, in particular, 8° to 82°, preferably 10° to 50° and particularly preferably 15° to 30°. The angle 158c spanned by the filter surface 156c and the direction of main extent 54c of the fluid cooling unit 30c is preferably at least substantially 18°. The filter element 154c is at least largely cone-shaped. Preferably, a low flow resistance of the filter element 154c in the fluid stream 24c can be achieved by the design of the filter element 154c. After flowing past the drive unit 16c, the fluid stream 24c is conveyed out of the power tool 10c, via a plurality of outlet openings 42c, 44c, 46c by means of the conveying element 92c. Alternatively, it is conceivable for the filter element 154c to be arranged on the separating element 80c and to be designed to filter, in particular to reduce, a foreign body density of the other sub-stream 28c before entry into the drive unit 16c. In particular, the sub-stream 26c and the other sub-stream 28c, after flowing through, or past, the drive unit 16c, are brought together within the power tool 10c, in particular the housing unit 14c, in a further channel element 160c of the fluid cooling unit 30c. It is also conceivable, however, for the fluid cooling unit 30c to be realized in such a manner that the sub-stream 26c and the other sub-stream 28c are conducted separately out of the power tool 10c.
It is conceivable for the conveying unit 90c to have a further conveying element, realized as a spiral wheel that in particular is not shown in
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2019 220 623.9 | Dec 2019 | DE | national |
| 10 2020 214 817.1 | Nov 2020 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2020/083457 | 11/26/2020 | WO |
