MACHINE TOOL WITH AIR COOLING AND METHOD FOR COOLING COMPONENTS OF A MACHINE TOOL

Description

[0001] The present invention relates to a machine tool with air cooling. Within the context of the invention, a special airflow system is proposed with which the components of the machine tool, such as the motor, gearbox, or electronics, can be cooled particularly efficiently by a flow of cooling air. The cooling is intended to be independent of any components of the machine tool housing, since the airflow is advantageously achieved by internal control processes, which preferably occur independently of any components of the machine tool housing.The housing-independent air cooling of the machine tool components is achieved in particular by providing a fan on a rotor of the machine tool's motor, which is configured to generate a cooling airflow by means of a negative pressure and to guide it through the machine tool in a suitable manner. In a second aspect, the invention relates to a method for cooling machine tool components.

[0002] From DE 10 2016 106559 A1 a machine tool according to the preamble of claim 1 is known. Background of the invention:

[0003] In the field of machine tools, angle grinders or cut-off grinders are well-known, used to make cuts in a substrate or to machine the surface of a substrate. Such angle grinders or cut-off grinders typically have a disc-shaped tool called a cutting or grinding wheel.

[0004] Due to the increasing availability of rechargeable batteries, battery-powered cut-off saws with cutting discs and blade diameters greater than 230 mm are being introduced to the market, particularly for applications where gasoline-powered cut-off saws were previously used. For the purposes of this invention, such devices are preferably referred to as "battery-powered cut-off saws" or "angle grinders." These power tools are usually cooled by an airflow.

[0005] Depending on the machine tool type, components such as the motor, electronics, gearbox, or tooling are cooled by airflow. Components of the housing are typically used for air distribution. In existing machines, air distribution and cooling are therefore often integrated into housing parts. However, these housing parts also serve other purposes, such as robustness, appearance, ergonomics, and protection for the user and the machine's internal components. Often, compromises are made between function, construction, and design in the design of these housing parts, resulting in machine tools being offered with suboptimal air distribution and cooling.

[0006] It is therefore an objective of the present invention to overcome the aforementioned shortcomings and disadvantages of the prior art and to provide a machine tool and a cooling method for components within a machine tool, in which optimized air cooling is provided. Furthermore, the air cooling system should be particularly simple in design and contribute to a robust and compact design of the machine tool.

[0007] When working with a machine tool, for example during cutting with a cordless angle grinder, dust, sludge, and / or metal shavings can be generated, or small stones can be thrown up. Particles can undesirably penetrate the machine tool via the air cooling system and reduce the service life of components. Therefore, a further objective of the present invention is to provide a machine tool and a cooling method for components within a machine tool that effectively prevents the ingress of particles into the machine tool via the air cooling system. In other words, the internal components of the machine tool, such as electronics, connectors, or the motor, should be protected as effectively as possible from dust, sludge, and other particles.

[0008] The problem is solved by the subject matter of the independent claims. Advantageous embodiments relating to the subject matter of the independent claims are found in the dependent claims. Description of the invention:

[0009] According to the invention, a machine tool with air cooling is provided. The machine tool is characterized in particular by the fact that it includes a fan for cooling components of the machine tool, wherein the machine tool a) a carrier unit with electronics, b) a motor connector, c) a motor with a stator and a rotor and d) a motor housing as components, wherein the fan is arranged on the rotor of the motor and is designed to create a negative pressure such that an airflow generated by the negative pressure cools the components of the machine tool.

[0010] In one embodiment, the invention relates in particular to an air-cooled battery-powered cut-off grinder with a brushless motor. A fundamental concept underlying the invention is that a special airflow system is provided within the machine tool, enabling particularly effective and efficient cooling of the machine tool's components. The airflow is generated, in particular, by a fan, which is preferably driven by a rotor shaft of the machine tool's motor.

[0011] The invention proposes a special airflow system within a machine tool, enabling the machine tool components, such as the motor, gearbox, or electronics, to be cooled with a particularly efficient flow of cooling air. This cooling is designed to be independent of any components of the machine tool housing, as the airflow is advantageously controlled by internal steering processes. These internal steering processes preferably operate independently of any components of the machine tool housing. This housing-independent air cooling of the machine tool components is achieved, in particular, by providing a fan on a rotor of the machine tool motor. This fan is configured to generate a cooling airflow using a vacuum and to guide it appropriately through the machine tool.It is preferred according to the invention that the air cooling of the machine tool is designed independently of any components of the machine tool housing. This allows for a particularly simple and robust design of the main body of the machine tool.

[0012] According to the invention, the airflow generated by the fan cools the components of the machine tool in the order a) to d) of their appearance above. In other words, the invention relates to a machine tool with an air cooling device, wherein the machine tool comprises a fan for cooling components of the machine tool, wherein the machine tool comprises a carrier unit for electronics and for the battery interfaces, a motor connector, a motor with a stator and a rotor, and a motor housing as components, wherein the fan is arranged on the rotor of the motor and is configured to generate a negative pressure such that an airflow generated by the negative pressure cools the components of the machine tool in the order they are listed.In the context of the invention, this preferably means that the fan is configured to generate an airflow such that the components of the machine tool are cooled in the sequence a) to d). In the context of the invention, this preferably means that first the electronics in the carrier unit are cooled, then the motor connector, then the motor, in particular the stator of the motor, and finally the motor housing, which preferably comprises a cutting arm and a gearbox of the machine tool.

[0013] Cooling the components in this sequence is advantageous because the airflow first cools the component with the greatest cooling requirement, namely the electronics. The airflow then cools the motor and, when expelled, passes by the gearbox housing. For the function and service life of the machine tool, it is beneficial if any particles can first be deposited on the preferably passively designed cooling elements of the electronics before they reach the rotating rotor and cause bearing damage, rotor seizure, or similar issues.

[0014] According to the invention, the motor of the machine tool is a brushless motor. A brushless motor is advantageously used because of its high efficiency and its long service life, which brushless motors exhibit due to contactless commutation.

[0015] It is preferred, in accordance with the invention, that the motor connector causes a deflection of the airflow by approximately 90 degrees. The phrase "approximately 90 degrees" is not an unclear term for those skilled in the art, because they know that the phrase "approximately 90 degrees" or "essentially 90 degrees" refers to a substantially right angle, which—for example, due to manufacturing processes—may deviate from exact mathematical perpendicularity by 1 to 5 degrees.

[0016] The motor connector is designed to connect the electronics of the machine tool to the stator of the motor via contact points and wires. It is preferred, according to the invention, that the electronics control the motor during operation. For this purpose, a defined current flow to the stator is preferably used. The electronics are configured to control the commutation of the motor and, in particular, the drive of the rotor.

[0017] In a preferred embodiment of the invention, the housing of the motor connector serves internally as an air guide, deflecting the cooling airflow by approximately 90 degrees, and externally as a cable guide for the lines connecting the motor to the electronics. These are preferably also referred to as "motor lines" within the meaning of the invention. The motor lines are preferably configured to transmit data and / or control commands from the electronics to the motor.

[0018] Tests have shown that the ingress of particles into the proposed machine tool via air cooling can be effectively prevented. In particular, the internal components of the machine tool, such as electronics, connectors, or motor, can be especially effectively protected from dust, mud, and other particles. It is preferred, according to the invention, that the machine tool has two accumulators as a power source. These accumulators ("batteries") can each be arranged in a receiving compartment in a rear, lower section of the main body of the machine tool. The machine tool can include a rear section, which is formed, for example, by a main body and a protective frame. The main body of the machine tool can be enclosed in a housing and include a control unit, a drive or drive train, and / or a motor.The protective frame can comprise a front, circumferential handle and a second, upper handle. The front part of the machine tool is formed by its tool, which, particularly in the case that the machine tool is designed as an angle grinder, is a disc-shaped tool. It can be specifically referred to as a cutting disc. According to the invention, it is preferred that the spatial directions "front" and "back" are defined by the front area of ​​the machine tool formed by the tool and by the rear area of ​​the machine tool, formed, among other things, by the main body. The spatial areas "top" and "bottom," or the "top" and "bottom," of the machine tool are preferably defined by the upper handle ("top"), which, according to the invention, is also preferably referred to as the second handle, and by the protective frame, the underside of which preferably runs along the underside of the machine tool.

[0019] It is preferred, according to the invention, that the machine tool comprises a first, circumferential handle, a second, upper handle, and a protective frame to protect the main body of the machine tool. Details of these components of the machine tool can be seen in the figures. The first, circumferential handle preferably extends in the area of ​​the transition between the front and rear sections of the machine tool and is typically gripped by the left hand of a right-handed person. In this respect, the first, circumferential handle can also be used to transport the machine tool. Due to its circumferential design, the first handle provides effective impact protection on the sides of the machine tool, particularly if the machine tool were to land on its right or left side in the event of a fall.The circumferential design of the first handle protects, in particular, the components of the machine tool located in the main body, such as the motor, drive, or gearbox, but also the accumulators. It is preferred, according to the invention, that the plane in which the first handle predominantly runs is essentially orthogonal to a longitudinal axis of the machine tool. This longitudinal axis, which can be conceptually placed through the machine tool, runs, in particular, centrally through the device and extends from the front region of the machine tool towards its rear region. It is preferred, according to the invention, that the plane in which the first handle predominantly runs is essentially perpendicular to the longitudinal axis of the machine tool.

[0020] The second, upper handle preferably runs substantially parallel to the virtual longitudinal axis of the machine tool and is typically gripped by the right hand of a right-handed person. According to the invention, it is preferred that the upper handle projects beyond the main body of the machine tool in a rearward direction, so that the main body and its internal components are well protected against the machine tool being dropped and landing on its rear side. For the purposes of the invention, the term "projection" preferably describes the distance between a substantially vertical rear wall of the main body of the machine tool and the furthest point on the rear of the upper handle. This distance or projection is, for example, in the range of 1 to 12 cm, preferably 3 to 9 cm, and particularly preferably approximately 6 cm.

[0021] It is preferred according to the invention that the second handle is arranged above the electronics of the machine tool and includes operating switches for the machine tool on its upper and / or lower surface. Since the second handle of the machine tool is typically gripped by the user's right hand, the machine tool can be operated particularly well thanks to the provision of operating switches on the upper and / or lower surface of the second handle. The preferred spatial proximity between the electronics of the machine tool and the at least one operating switch in the second handle significantly shortens the transmission paths for control commands and simplifies the wiring and connection within the device.

[0022] It is preferred, according to the invention, that a carrier unit of the machine tool has at least one interface for a battery. It is preferred, according to the invention, that the batteries include contacts with which they can be plugged into the machine tool. For this purpose, the machine tool includes a corresponding connection arrangement with which the contacts of the batteries can interact. Preferably, the machine tool includes an interface with which the power supply to the device or the energy output of the batteries can be controlled. It may be preferred, according to the invention, that the machine tool includes one interface that controls the energy output of both batteries. However, it may also be preferred that the machine tool includes two interfaces, i.e., one interface for each battery.It is particularly preferred, according to the invention, that the accumulators can be connected to the electronics of the machine tool via an interface and contacts. In other words, it may be preferred, according to the invention, that the accumulators can be connected to the electronics of the machine tool via an interface and contacts.

[0023] Furthermore, the carrier unit can include electronics for the machine tool. The machine tool's electronics can include a control unit for controlling the machine tool's operation. It is preferred, according to the invention, that the machine tool's electronics incorporate heat sinks.

[0024] It is preferred, according to the invention, that the electronics can be installed suspended within the machine tool. In other words, the electronics are suspended within the machine tool or its main body. This preferably suspended installation of the electronics within the machine tool advantageously prevents the formation of deposits of protective particles, dust particles, or sludge. The installation of the electronics in the carrier unit is designed so that only the heat sink comes into contact with the airflow. This ensures optimal cooling of the electronics and prevents deposits from forming on contacts such as connectors or similar components. Experience shows that particles from the airflow tend to settle on the front of the heat sink, thus only minimally affecting the cooling of the electronics.Preferably, the electronics are installed inside the machine tool rotated by 180°, with the electronics cup pointing upwards.

[0025] It is preferred in accordance with the invention that the machine tool has air inlets for drawing in air, wherein the air inlets are arranged on a rear side of a main body of the machine tool. The position of the air inlets is particularly advantageous in Fig. 1 The air inlets can be considered components of the carrier unit, with air being drawn into the carrier unit above the accumulators. This drawing-in is primarily caused by the negative pressure generated by the fan, which is located in the area of ​​the rotor of the machine tool's motor.

[0026] The term "air" is not unclear to those skilled in the art, as it refers to the gaseous oxygen-nitrogen mixture that essentially constitutes the Earth's atmosphere. For the purposes of the invention, it is preferred that a stream of such air is drawn in from the vicinity of the machine tool through the air inlets and used to cool the components inside the machine tool or its main body.

[0027] It is preferred according to the invention that the machine tool comprises a first air inlet arranged above a first accumulator, and a second air inlet arranged above a second accumulator. Preferably, the air inlets are located on opposite sides of the second handle of the machine tool. In other words, the air inlets can be located on a right and a left side of the second handle of the machine tool. This preferred bilateral arrangement of the at least two air inlets with respect to the second handle on the rear of the machine tool is also in Fig. 1 depicted.

[0028] It is preferred in accordance with the invention that domes are provided in the area of ​​the air inlet to protect the air inlets from the ingress of larger dust particles. The provision of the domes allows the internal components of the machine tool to be particularly well protected against such particles that enter the interior of the machine tool or its main body with the incoming airflow through the air inlet. The domes are preferably designed to block the passage of larger particles through the air inlets, thus preventing them from entering the interior of the machine tool or its main body in the first place.

[0029] It is preferred, according to the invention, that the air inlets are located as far away as possible from the working area of ​​the machine tool. Tests have shown that it is a significant advantage of the invention that the air inlets are arranged as far away as possible from the location where the machining or cutting process of the machine tool takes place. For the purposes of the invention, the location where the machining or cutting process of the machine tool takes place is preferably also referred to as the working area of ​​the machine tool.

[0030] It is preferred according to the invention that the machine tool has an air outlet located in the area of ​​a gearbox of the machine tool. By providing the air outlet in close proximity to the gearbox of the machine tool, cooling of the gearbox can also be advantageously provided. In particular, cooling of the gearbox by the outgoing air, which has previously cooled the components of the machine tool, is made possible.

[0031] It is preferred, according to the invention, that the at least one air outlet is designed as a lateral air outlet and is located on a right or left side of the machine tool. Preferably, the at least one air outlet is located on the side of the machine tool where the cutting arm of the machine tool is located. The cutting arm is preferably part of the motor housing, from which it extends in the direction of the preferably disc-shaped tool of the machine tool. Furthermore, the air outlet is preferably not located on the side of the machine tool where the user stands when using the machine tool. This ensures that the airflow from the machine tool is not directed at the user, thus preventing unpleasant drafts.Furthermore, due to its lateral arrangement on the side of the machine tool facing away from the user, the airflow exiting the machine tool is not directed towards the machine tool's working area. This prevents dust from being stirred up during operation of the machine tool, which could then enter the user's respiratory tract. It is preferred, in accordance with the invention, that the outgoing air can also cool the machine tool's gearbox. In particular, the arrangement of the at least one air outlet prevents the outgoing air from being blown into the machine tool's working area. This effectively prevents additional dust turbulence.

[0032] It is preferred according to the invention that the motor rotor has an encapsulation for dust protection. The encapsulation provides particularly good protection against dust for the rotor and thus for the moving part of the motor, thereby significantly extending its service life, as tests have shown. In particular, the encapsulation of the rotor allows for a preferably hermetic separation of the rotor, so that dust ingress towards the rotating components of the rotor is particularly effectively prevented.

[0033] It is preferred according to the invention that a central support, preferably also referred to as a support unit, is arranged within the main body of the machine tool. This support unit is preferably made of plastic or comprises one or more plastics. This allows the support unit to be very stable on the one hand and particularly lightweight on the other, so that it contributes only negligibly to the overall weight of the machine tool. It is preferred according to the invention that the support unit is rigidly connected to the motor housing and is configured to accommodate the electronics, interfaces, contacts, batteries, and / or damping elements. It is preferred according to the invention that the support provides an internal structure for the main body of the machine tool, wherein the machine tool components located within the main body can be attached to the support unit.It is preferred according to the invention that the protective frame and the upper handle can also be attached to the support unit. The housing of the machine tool can preferably consist of two housing shells, which can also be mounted on the support unit.

[0034] It is preferred, according to the invention, that the support, together with the motor housing, forms a central component for the cooling airflow. It is preferred, according to the invention, that the electronics of the machine tool are suspended within or on the support unit to effectively prevent the accumulation of dust and / or water. The support unit can include a heat sink for cooling the electronics, and an airflow can be directed through the support for this purpose. It is preferred, according to the invention, that the support unit is inclined backwards at an angle of inclination greater than 3 degrees, preferably greater than 5 degrees.It is preferred, according to the invention, that the angle of inclination is preferably formed between an imaginary ground plane on which the machine tool can be placed and a plane that runs centrally through the support unit of the machine tool. Despite the inclined design of the support unit, it is preferred, according to the invention, that the interfaces and contacts for connecting the machine tool to the accumulators are essentially horizontal. Preferably, the accumulators within the machine tool are also oriented essentially horizontally. The term "essentially horizontal" preferably means, according to the invention, that the aforementioned components are not inclined within the machine tool, i.e., that any straight line or plane passing through them forms an angle of essentially 0 degrees with an imaginary ground plane.In other words, an imaginary straight line or plane through the interfaces, contact surfaces and / or accumulators runs essentially parallel to an imaginary subsurface plane.

[0035] It is preferred, according to the invention, that the accumulators include contacts with which they can be plugged into the machine tool. For this purpose, the machine tool includes a corresponding connection arrangement with which the contacts of the accumulators can interact. Preferably, the machine tool includes an interface with which the power supply to the device or the energy output of the accumulators can be controlled. It may be preferred, according to the invention, that the machine tool includes one interface that controls the energy output of both accumulators. However, it may also be preferred that the machine tool includes two interfaces, i.e., one interface for each accumulator. It is particularly preferred, according to the invention, that the accumulators can be connected to the electronics of the machine tool via an interface and contacts.

[0036] In a second aspect, the invention relates to a method for cooling components of a proposed machine tool. The definitions, technical advantages, and effects described for the machine tool preferably apply analogously to the cooling method. The cooling method is characterized in particular by the following process steps. a) Providing the machine tool with a fan, wherein the machine tool comprises i) a carrier unit, ii) a motor connector, iii) a motor with a stator and a rotor and iv) a motor housing as components, wherein the fan of the machine tool is arranged on the rotor of the motor, b) generating a vacuum with the fan, thereby causing an airflow within the machine tool, c) cooling the components of the machine tool by the airflow generated in process step b).

[0037] In the context of the proposed method, a machine tool is provided with a fan and the aforementioned components, namely at least one carrier unit, a motor connector, a motor, and a motor housing. The motor of the machine tool is preferably a brushless electric motor comprising a rotor as a moving part and a stator as a stationary part. The fan of the machine tool is arranged upstream of the motor's rotor and is configured to generate a negative pressure, which preferably causes an airflow within the machine tool. This airflow generated by the fan is used in the context of the invention to cool the components of the machine tool, in particular by directing it past the components of the machine tool.

[0038] It is preferred, according to the invention, that the cooling of the machine tool components is carried out in the sequence i) to iv), i.e., preferably in the sequence specified in the description of the method. It is particularly preferred, according to the invention, that the machine tool components are cooled in the sequence i) to iv), preferably by a cooling airflow that can be generated by a negative pressure. This negative pressure is preferably generated by a fan arranged on the rotor of the machine tool motor. The cooling airflow enables device cooling that is advantageously independent of parts of the machine tool housing. In particular, the airflow within the machine tool is not guided by housing parts of the machine tool, but rather by the carrier unit containing the electronics, the motor connector, the motor, and the motor housing with an integrated gearbox.

[0039] In one embodiment of the invention, the proposed solution provides a machine tool wherein the machine tool has a fan that is fixed to the rotor. The fan creates a negative pressure, thus generating an airflow for cooling the components of the machine tool. The airflow is optimized to such an extent that the following assemblies can be cooled in this order by the airflow generated by the fan: 1. Carrier unit, wherein the carrier unit may have electronics and / or a battery interface, 2. Motor connector, at which a deflection of the airflow by approximately 90 degrees is caused, 3. Motor with a stator and a rotor, 4. Motor housing with a cutting arm and a gearbox.

[0040] The airflow and / or device cooling is advantageously independent of the housing components. The machine tool, its air cooling device, or the support unit can have air inlets configured to draw in air, the drawn-in air forming an airflow for cooling the machine tool components. Preferably, the air inlets are arranged on the rear side of a main body of the machine tool. It is preferred, according to the invention, that the machine tool comprises a first air inlet arranged above a first accumulator and a second air inlet arranged above a second accumulator. It is particularly preferred, according to the invention, that the air inlets are located on the right and left sides of the second handle of the machine tool.Furthermore, the air inlets on the carrier unit can have domes to protect them from the ingress of protective and / or dust particles. The machine tool can also have an air outlet located in the area of ​​a gearbox. The electronics, which are preferably mounted on the carrier unit, can have heat sinks and are preferably suspended. This helps to prevent the accumulation of particles or sludge.

[0041] Further advantages arise from the following character description. The characters, the description, and the requirements contain numerous features in combination.

[0042] In the figures, identical and similar components are numbered with the same reference symbols. They show: Fig. 1 Side and rear view of a preferred embodiment of the proposed machine tool. Fig. 2 Side view of a preferred embodiment of the proposed machine tool without accumulators. Fig. 3 View of a preferred embodiment of an internal functional unit of components of the proposed machine tool with an indicated airflow for component cooling. Fig. 4 View of a preferred embodiment of an internal functional unit of components of the proposed machine tool with an indicated airflow for component cooling. Fig. 5 Sectional view through a preferred embodiment of the gearbox and motor of the proposed machine tool with an indicated airflow for component cooling. Fig. 6 View of a bottom surface of a preferred embodiment of the proposed machine tool. Examples of implementation and description of figures:

[0043] Figure 1Figure 1 shows in an upper area a side view of a preferred embodiment of the proposed machine tool 1 and in a lower area a rear view of a preferred embodiment of the proposed machine tool 1. In particular, Figure 1 shows Fig 1A machine tool 1, designed as an angle grinder, has a cutting disc 25 as a disc-shaped tool. The rear section of the machine tool 1 is formed by a main body 4, which is surrounded by a first, circumferential handle 12, a second handle 13 for carrying the machine tool 1, and a protective frame 14. The protective frame 14 may have two lateral L-shaped structures 16, which are connected to each other via connecting webs (not shown). Actuating switches 21 and locking mechanisms 30 may be provided on the upper handle 13. It is preferred according to the invention that the second handle 13 forms a projection 17, i.e., has a section that extends beyond the rear 9 of the main body 4 of the machine tool 1. The main body 4 of the machine tool 1 may be enclosed by a housing 6. The machine tool has a motor 5, which is enclosed by a separate motor housing 22.

[0044] Air inlets 29 are provided on the rear side 9 of the main body 4 of the machine tool 1. These are openings through which air can be drawn into the interior of the machine tool 1. The drawn-in air, or the airflow 35 generated by the intake, is used to cool various components of the machine tool 1, in particular to cool a carrier unit 32, which contains or is designed to house electronics 20 of the machine tool 1. Furthermore, the airflow 35 cools a motor connector 34, the motor 5, and the motor housing 22 of the machine tool 1. The motor 5 is preferably a brushless electric motor comprising a rotor 37 and a stator 38. A fan 40 is located in the area of ​​the rotor 37 of the motor 5, which draws in air through the air inlets 29a and 29b, thus generating the airflow 35.The machine tool 1 preferably has two accumulators 2, 3 as its energy source, above which the air inlets 29a, 29b are arranged. The accumulators 2, 3 are located in a first receiving compartment 7 and a second receiving compartment 8 within the main body 4 of the machine tool 1. The accumulators 2, 3 are connected to the machine tool 1 and the electronics 20 of the machine tool 1, respectively, via contacts 19 and interfaces 18. A possible arrangement of the contacts 19 and interfaces 18 is shown in [reference]. Fig. 2 shown. In addition, it shows Fig. 1 a charge level indicator 31, which is located on the back 9 of the machine tool 1 and with which a charge level of the accumulators 2, 3 can be displayed.

[0045] Fig. 2Figure 1 shows a side view of a preferred embodiment of the proposed machine tool 1 without accumulators 2, 3. The electronics 20 of the machine tool 1 are arranged above the interface 18 and above the contacts 19 for the accumulators 2, 3. Furthermore, the electronics 20 are located in close proximity to the accumulators 2, 3 to minimize transmission and communication paths. In addition, Figure 1 shows... Fig. 2The motor 5 of the machine tool 1 is shown, which is arranged in a front region of the main body 4 of the machine tool 1. The motor 5 has an axis that is essentially orthogonal to a longitudinal axis of the machine tool 1 running centrally within the machine tool 1. In other words, the axis of the motor 5 of the machine tool 1 is preferably perpendicular to the longitudinal axis of the machine tool 1. This arrangement is described within the meaning of the invention by stating that the motor 5 of the machine tool 1 is oriented transversely to the accumulators 2, 3 of the machine tool 1. The motor axis projects into Fig. 2 practically out of the image plane and the position of the motor axis is also in Fig. 6 depicted.

[0046] The electronics 20 of the machine tool 1 are preferably housed in a carrier unit 32, which has an inclination angle of 3 to 5 degrees. The accumulators 2, 3 are arranged at an angle within the machine tool 1. The carrier unit 32 can preferably also include the contacts 19 and interfaces 18, thus establishing the connection between the accumulators 2, 3 and the machine tool 1. Furthermore, the carrier unit 32 has cooling elements 36, over which the airflow 35 passes to cool the machine tool components. These cooling elements 36 of the carrier unit 32 are particularly well integrated into Fig. 4 depicted.

[0047] In a lower area it shows Fig. 2 the other side of a preferred embodiment of the proposed machine tool 1. In particular, the lower area of Fig. 2The air outlet 33 allows the used air, which is used for cooling the components of the machine tool 1, to be expelled. The air outlet 33 is formed, in particular, by ventilation slots, which may be located in the area of ​​a gearbox 23 of the machine tool 1. The arrangement of the air outlet 33 prevents unwanted dust from being stirred up, as the air outlet 33 is positioned away from a working area of ​​the machine tool 1.

[0048] Fig. 3 Figure 1 shows a view of a preferred embodiment of an internal functional unit of components of the proposed machine tool 1 with an indicated airflow 35 for cooling the components of the machine tool 1. In particular, Figure 2 shows Fig. 3 the cutting arm 24 of the machine tool 1, as well as a preferably independently functioning unit consisting of motor 5, electronics 20, gearbox 23, interfaces 18 and contacts 19. This can be clearly seen in Fig. 3The electronics 20 of the machine tool 1 are mounted in a suspended position. The motor connector 34 is located in the area of ​​the motor 5 of the machine tool 1, with wires connecting the motor connector 34 to the electronics 20. The accumulators 2 and 3 are in Fig. 3 The inner functional unit is not shown for better illustration. The hand-drawn arrow indicates the position of the inner functional unit in the two sub-figures. Fig. 3 a possible path of the cooling airflow 35 through the machine tool 1. It is preferred, according to the invention, that the airflow 35 first flows through and cools the carrier unit 32 with the electronics 20, then the motor connector 34, then the motor 5 and subsequently the motor housing 22.

[0049] The drawn-in air, forming the airflow 35, is drawn in through the air inlets 29a and 29b and discharged back into the environment of the machine tool 1 through the air outlet 33. The airflow 35, which is used to cool the machine tool components, is generated by a negative pressure, which in turn is created by a fan 40. The fan 40 is located in the area of ​​the rotor 37 of the motor 5 of the machine tool 1, as shown in particular in Fig. 5 It is shown. In accordance with the invention, it is preferred that the motor 5 is surrounded by a separate motor housing 22, so that the proposed machine tool 1 essentially comprises two housings, namely the housing 22 of the motor 5, and the housing 6 of the main body 4 of the machine tool 1.

[0050] The lower part of Fig. 3This allows a view of the underside of the carrier unit 32, which includes the contacts 19 and interfaces 18 for connecting the machine tool 1 to the accumulators 2, 3. The accumulators 2, 3 are each arranged in a receiving space 7, 8, with each accumulator 2, 3 or each receiving space 7, 8 being assigned a contact area 19 and an interface area 18 for connecting one accumulator 2, 3 to the machine tool 1.

[0051] Fig. 4 Figure 1 shows a further view of a preferred embodiment of the internal functional unit of the components of the proposed machine tool 1. In particular, in the lower area of Fig. 4The airflow 35 for component cooling, or rather its path through the machine tool 1, is shown. The airflow 35 is drawn into the machine tool 1 through the air inlets 29a and 29b. The air inlets 29a and 29b are located, in particular, between the support unit 32 and the electronics 20 of the machine tool 1. This is clearly visible in Fig. 4 the inclination of the support unit 32. In the right area of ​​the upper half of Fig. 4 The cutting arm 24 of the machine tool 1 and the drive means 26, which transmits the movement of the motor 5 of the machine tool 1 to the tool 25, are shown. The gearbox 23 and the drive means 26 – here a belt – are preferably arranged in the preferably separate motor housing 22 of the machine tool 1.

[0052] In the lower area of Fig. 4Figure 1 shows a section through the carrier unit 32 and a section through the heat sinks 36 of the electronics 20. Air is drawn in through the air inlets 29a, 29b and forms a cooling airflow 35, which flows through the heat sinks 36 of the electronics 20 of the machine tool 1 and thus cools the electronics 20. The airflow 35 is guided by internal processes from the carrier 32 and the heat sinks 36 to the area of ​​the motor connector 34 and further into the motor 5 to cool it.

[0053] Fig. 5 Figure 1 shows a sectional view through a preferred embodiment of gearbox 23 and motor 5 of the proposed machine tool 1. In particular, the following is shown in Figure 2: Fig. 5The cooling airflow 35, which cools the components of the machine tool 1, is also shown. According to the invention, it is preferred that the airflow 35 is directed outside the stator 38 to the fan 40. From there, it is guided past the motor housing 22 and the gearbox 23 towards the air outlet 33, where the used air is blown out of the machine tool 1. The airflow 35 enters the Fig. 5 The unit shown, consisting of motor 5 and gearbox 23, is connected via the motor connector 34. The motor 5 has, in a manner known per se, a rotor 37 and a stator 38, which are arranged as shown in Fig. 5 They can be arranged as shown. In the lower area of ​​the Fig 5An encapsulation 39 of the rotor 37 of the motor 5 of the machine tool is shown. The encapsulation 39 can be formed by or include a seal. The encapsulation 39 protects the rotor 37, in particular from dust and moisture. Specifically, the encapsulation 39 also seals the rotor 37 against the airflow 35. This advantageously increases the service life of the bearings of the rotor 37. The airflow 35 flows past the outside of the stator 38 and thus cools the stator 38. The airflow 35 is then expelled at the motor housing 22 next to the gearbox 23 of the machine tool 1.

[0054] Fig. 6Figure 1 shows a view of the underside of a preferred embodiment of the proposed machine tool 1. The motor 5 is arranged in a front region of the main body 4 of the machine tool 1. It is surrounded by a motor housing 22. The movement generated by the motor 5 of the machine tool 1 is transmitted to the tool 25 of the machine tool 1 via drive means 26. A gearbox 23 of the machine tool is arranged between the drive means 26 and the motor 5, preferably also arranged within the motor housing 22. The drive means 26 can comprise or be formed by a belt. The cutting disc 25 of the cut-off grinder 1 is connected to the main body 4 of the cut-off grinder 1 via a cutting arm 24, with the belt for transmitting the movement of the motor 5 of the cut-off grinder running at least partially parallel to the cutting arm 24. The accumulators 2, 3 are in Fig. 6not shown. By omitting them, the battery interface 18 and the connection contacts 19, which electrically and electronically connect the batteries 2 and 3 to the machine tool, can be seen. Reference symbol list

[0055] 1 Machine tool 2 First battery 3 Second battery 4 Main body 5 Motor 6 Housing 7 First loading chamber 8 Second loading chamber 9 Rear of main body 10 Top of housing 11 Dome at air inlet 12 First wraparound handle 13 Second upper handle 14 Protective frame 16 L-shaped structure 17 Overhang 18 Interface between batteries and machine tool 19 Contacts between batteries and machine tool 20 Electronics of the machine tool 21 Operating switch 22 Motor housing 23 Gearbox 24 Cutting arm 25 Tool or cutting disc 26 Drive element or belt 27 Front of the housing 28 Protective plate 29 Air outlet 30 Switch-on lock 31 Charge level indicator 32 Carrier unit 33 Air outlet 34 Motor connector 35 Airflow 36 Heat sink 37 Rotor 38 Stator 39 Seal or encapsulation 40 Fan

Claims

1. Power tool (1) having an air cooling system for cooling components (32, 20, 34, 5, 38, 22) of the power tool (1) having a fan (40) for cooling components (32, 20, 34, 5, 38, 22) of the power tool (1), wherein the power tool (1) comprises a) a carrier unit (32) with electronics (20) for commutation of a brushless motor (5); b) a motor connector (34), c) the brushless motor (5) having a stator (38) and a rotor (37), and d) a motor housing (22) as components, wherein the fan (40) is arranged on the rotor (37) of the motor (5) and is designed to produce a reduced pressure in such a way that an air flow (35) produced by the reduced pressure cools the components (32, 20, 34, 5, 38, 22) of the power tool (1), characterized in that the air flow (35) cools the components (32, 20, 34, 5, 38, 22) of the power tool (1) in the sequence a) to d).

2. Power tool (1) according to Claim 1, characterized in that the carrier unit (32) has electronics (20) and at least one interface (18) for a rechargeable battery (2, 3).

3. Power tool (1) according to Claim 2, characterized in that the electronics (20) have at least one heat sink (36).

4. Power tool (1) according to Claim 3, characterized in that the electronics (20) can be installed in a suspended manner within the power tool (1).

5. Power tool (1) according to any of the preceding claims, characterized in that the power tool (1) has two rechargeable batteries (2, 3) as energy sources.

6. Power tool (1) according to any of the preceding claims, characterized in that the power tool (1) has a first, circumferential handle (12), and a second, upper handle (13) and a protection frame (14) for protecting the main body (4) of the power tool (1).

7. Power tool (1) according to any of the preceding claims, characterized in that the power tool (1) has air inlets (29) for sucking in air, wherein the air inlets (29) are arranged on a rear side (9) of a main body (4) of the power tool (1).

8. Power tool (1) according to any of the preceding claims, characterized in that the power tool (1) comprises a first air inlet (29a), which is arranged above a first rechargeable battery (2), and a second air inlet (29b), which is arranged above a second rechargeable battery (3).

9. Power tool (1) according to either of Claims 7 and 8, both if dependent on Claim 6, characterized in that the air inlets (29, 29a, 29b) are on opposite sides of the second handle (13) of the power tool (1).

10. Power tool (1) according to any of Claims 7 to 9, characterized in that the air inlets (29, 29a, 29b) have domes (11) to protect the air inlets (29a, 29b) from penetration of dirt and / or dust particles.

11. Power tool (1) according to any of the preceding claims, characterized in that the power tool (1) has an air outlet (33), which is arranged in the region of a transmission (23) of the power tool (1).

12. Power tool (1) according to any of the preceding claims, characterized in that the rotor (37) of the motor (5) has an enclosure (39) for protection from dust.

13. Method for cooling components (32, 20, 34, 5, 38, 22) of a power tool (1) according to any of the preceding claims, characterized by the following method steps: a) providing the power tool (1) having a fan (40), wherein the power tool (1) comprises i) a carrier unit (32), ii) a motor connector (34), iii) a motor (5) having a stator (38) and a rotor (37), and iv) a motor housing (22) as components (32, 20, 34, 5, 38, 22), wherein the fan (40) of the power tool (1) is arranged on the rotor (37) of the motor (5), b) producing a reduced pressure by means of the fan (40), thereby causing an air flow (35) within the power tool (1), c) cooling the components (32, 20, 34, 5, 38, 22) of the power tool (1) by means of the air flow (35) produced in method step b), wherein the cooling of the components (32, 20, 34, 5, 38, 22) of the power tool (1) takes place in the sequence i) to iv).