Machine tool with improved cooling for the electronics

Abstract

The present invention relates to a machine tool having electronics and an electric motor, wherein the electric motor comprises a rotor and a stator, wherein the electronics are arranged in an electronics compartment of the machine tool. The electronics compartment is fluidically connected to a machine tool motor compartment that surrounds the electric motor, and the electric motor has structural elements for mixing the air in the electronics compartment and / or motor compartment of the machine tool. This mixing of the air in the electronics compartment and / or motor compartment of the machine tool enables effective cooling of the electronics of the machine tool and the components thereof. The cooling of the electronics and the components thereof is able to be further improved when the electronics compartment has an inlet opening and an outlet opening for an exchange of air, with an air flow being able to form between the inlet opening and the outlet opening so as to provide additional cooling for the electronics and the components thereof of the machine tool.

Description

[0001] MACHINE TOOL WITH IMPROVED COOLING FOR ELECTRONICS

[0002] The present invention relates to a machine tool with electronics and an electric motor, wherein the electric motor comprises a rotor and a stator, wherein the electronics are arranged in an electronics compartment of the machine tool. The electronics compartment is fluidly connected to a motor compartment of the machine tool surrounding the electric motor, and the electric motor has structural elements for mixing the air in the electronics compartment and / or motor compartment of the machine tool. This mixing of the air in the electronics compartment and / or motor compartment of the machine tool enables effective cooling of the electronics of the machine tool and its components.The cooling of the electronics and their components can be further improved if the electronics compartment has an inlet and an outlet opening for air exchange, whereby an air flow can form between the inlet opening and the outlet opening for additional cooling of the electronics and their components of the machine tool.

[0003] Background of the invention:

[0004] Machine tools typically comprise a motor and a tool, with the rotary motion of the motor being transmitted from the motor to the tool via a transmission device. The machine tool can be used to perform tasks such as drilling, chiseling, grinding, cutting, or the like. To control the machine tool and its components, most machine tools incorporate electronics which heat up during operation. Particularly in non-ventilated machine tools, significant temperature differences can occur within the machine tool's electronics. These significant temperature differences can be detrimental to electronic components subject to high thermal stress. Electronic components subject to high thermal stress heat up faster and more severely than other electronic components subject to less thermal stress.In particular, if the machine tool is non-ventilated, these temperature differences can be further aggravated by stagnant air within the machine tool.

[0005] The object underlying the present invention is to overcome the above-described deficiencies and disadvantages of the prior art and to provide a machine tool in which improved cooling of the electronics and their components can be enabled.

[0006] The problem is solved by the subject matter of the independent claim. Advantageous embodiments of the subject matter of the independent claim can be found in the dependent claims.

[0007] Description of the invention:

[0008] According to the invention, a machine tool is provided with electronics and an electric motor, wherein the electric motor comprises a rotor and a stator, wherein the electronics are arranged in an electronics compartment of the machine tool. The electronics compartment is fluidically connected to a motor compartment surrounding the electric motor, and the electric motor has structural elements for mixing the air in the electronics compartment and / or motor compartment of the machine tool. The fluidic connection between the electric motor or its surroundings and the electronics compartment of the machine tool can achieve strong turbulence and mixing of the air in the electronics compartment of the machine tool. Due to this mixing, the electronics of the machine tool, in particular its components subject to high thermal stress, can be cooled particularly effectively, and any existing temperature differences within the electronics compartment or its air can be reduced particularly effectively.Advantageously, the improved temperature distribution within the electronics compartment can effectively reduce the maximum temperatures of the electronics and their components. This allows for improved cooling of the electronics and their components, preferably without increasing manufacturing costs and without requiring additional components. Due to the improved cooling of the electronics and their components, the service life of these machine tool components can be significantly extended.

[0009] The term “fluidic connection” in the sense of the invention preferably means that an exchange of air can take place between the electric motor or its immediate surroundings and the electronics compartment of the machine tool. The immediate surroundings of the electric motor can preferably also be referred to as the motor compartment of the machine tool, wherein this motor compartment can preferably be surrounded by a motor housing. In other words, air can flow from the electric motor or from the motor compartment of the machine tool towards the electronics compartment and vice versa. The provision of the fluidic connection between the surroundings of the electric motor or between the motor compartment and the electronics compartment advantageously enables the air in the electronics compartment of the machine tool to be mixed, so that the electronics of the machine tool can be effectively cooled in this way. Consequently, the invention can enable the air in the electronics compartment orin the engine compartment of the machine tool, so that an improved temperature distribution within the electronics and its components can be achieved. The mixing of the air in the electronics compartment or in the engine compartment of the machine tool can advantageously be achieved by providing structural elements in the area of ​​the electric motor.

[0010] According to the invention, it is preferred that the electric motor is arranged entirely or partially in the electronics compartment of the machine tool. The electric motor is preferably arranged below the electronics, or the electronics of the machine tool are provided above the electric motor. Both the electronics of the machine tool and the electric motor of the machine tool are surrounded by air, wherein the common space in which the air surrounding the electronics and the electric motor of the machine tool is present is preferably referred to as the “electronics compartment of the machine tool” according to the invention. According to the invention, it is preferred that the electronics compartment is designed to accommodate the electric motor, the electronics, and the air surrounding these two components of the machine tool.The property that the air surrounding the electric motor of the machine tool and the air surrounding the electronics of the machine tool are not separate from one another, but rather that they form a common space, preferably the electronics space of the machine tool, is preferably referred to in the context of the invention as a fluidic connection between the electric motor and the electronics space. In the context of the invention, it is preferred to refer to the direct air environment of the electric motor as the motor space of the machine tool, wherein this motor space can preferably be surrounded by a motor housing. Due to the fluidic connection between the electronics space and the motor space, the motor space can be at least partially contained in the electronics space of the machine tool.

[0011] The electronics of the machine tool are preferably designed to control the machine tool and its components. The electronics can therefore comprise or form a control device of the machine tool. The electronics of the machine tool can in particular comprise a printed circuit board, wherein electronic components can be provided on the printed circuit board. The electronic components can preferably be arranged on a front side and / or on a back side of the printed circuit board. The printed circuit board can preferably also be referred to as a printed circuit board (PCB) within the meaning of the invention. A significant advantage of the invention is that the provision of the structural elements on the electric motor and / or the provision of the opening for generating a cooling air flow in the electronics compartment of the machine tool enables particularly effective cooling of the electronics and their electronic components.

[0012] A significant advantage of the invention is that it enables improved air circulation within the machine tool or within its electronics and / or motor compartment, effectively reducing any temperature differences in the area of ​​the electronic components subject to high thermal stress. The electronic components subject to high thermal stress can include, but are not limited to, rectifiers, chokes, or insulated-gate bipolar transistors. An insulated-gate bipolar transistor (IGBT) is a semiconductor component used in power electronics to achieve good conduction behavior, a high reverse voltage, and robustness, as well as virtually power-free control.

[0013] According to the invention, it is preferred that the electric motor comprises rotor cores, wherein the structural elements are arranged on the rotor cores of the electric motor. The structural elements advantageously bring about particularly effective air circulation within the machine tool or its electronics and / or motor compartment, wherein this air circulation can surprisingly enable particularly good and effective cooling of the electronics and their electronic components. According to the invention, it is preferred that the structural elements are arranged in a gap between the outside of the rotor and the inside of the stator. In this gap, the structural elements have a ventilation effect, i.e. the structural elements are designed to mix the air in the gap between the stator and rotor or in the motor compartment.Due to the fluidic connection between the electronics and engine compartments, the air in the electronics compartment is also mixed and swirled, resulting in air circulation in the electronics compartment and cooling of the electronics and their components.

[0014] It is very particularly preferred within the meaning of the invention that the electric motor comprises exactly three rotor cores, wherein each of the rotor cores has a structural element. Of course, the electric motor can also comprise only one rotor core or two, four, five or more rotor cores. In a very particularly preferred embodiment of the invention, the electric motor can have one structural element per rotor core. If the electric motor has exactly one structural element per rotor core, it is preferred in the context of the invention to speak of the electric motor having a set of structural elements. If the electric motor has three rotor cores, such a set of structural elements can, for example, comprise three structural elements. It can also be preferred within the meaning of the invention for the electric motor to comprise more than one set of structural elements.In this embodiment of the invention, for example, more than one structural element can be provided per rotor core. If more than one structural element is provided per rotor core, these multiple structural elements per rotor core can, for example, be distributed substantially evenly around a circumference of the rotor core. In a sectional view, a rotor core preferably has a substantially circular shape, wherein, for example, two structural elements can be arranged at an angular distance of 180 degrees, i.e. on opposite sides of the rotor core. If, for example, three structural elements are provided per rotor core, these three structural elements can, for example, be arranged at an angular distance of 120 degrees. If, for example, n structural elements are provided per rotor core, these n structural elements can, for example, be arranged at an angular distance of (360 / n) degrees.

[0015] According to the invention, it is preferred that the rotor packs are arranged in relation to one another and form the electric motor in such a way that the structural elements are offset from one another by an angle of rotation alpha. As a particular advantage of the invention, the outer skin of the rotor packs with their structural elements acts like a fan blade and swirls and mixes the air in the electronics compartment of the machine tool. In other words, the structural elements on the outside of the electric motor are designed to swirl or mix the air in the electronics compartment of the machine tool, so that the electronics and their components can be cooled surprisingly well. In still other words, the structural elements arranged on the electric motor of the machine tool are designed to mix or swirl the air in the electronics compartment of the machine tool.to swirl, so that any temperature differences within the electronics compartment are particularly effectively reduced. The outer skin of the rotor cores can preferably be formed from a sheet metal material, wherein the structural elements can be arranged on the outer skin of the rotor cores. For the purposes of the invention, it is preferred that the outer skin of the rotor cores with the structural elements be referred to as the "sheet metal geometry."

[0016] The structural elements can be concave and / or convex structures on the outer skin of the electric motor or its rotor cores. Concave structural elements can be formed, for example, by indentations, valleys, notches, depressions, or the like in the outer skin of the rotor cores, while convex structural elements can be formed, for example, by elevations, bulges, hills, or the like on the outer skin of the rotor cores.

[0017] According to the invention, it is preferred that the rotor cores are arranged relative to one another and form the electric motor such that the structural elements are offset from one another by a rotation angle alpha. It has been shown that particularly good air mixing in the electronics compartment of the machine tool can be achieved precisely by offsetting the rotor cores by a rotation angle alpha. Due to the offset arrangement of the rotor cores of the electric motor, the structural elements are also offset from one another, so that they act like blades and circulate the air within the machine tool.

[0018] According to the invention, the angle of rotation is preferably in a range of 1 to 15 degrees, preferably in a range of 3 to 10 degrees, particularly preferably in a range of 4 to 6 degrees, and most preferably 5 degrees. It has been shown that a rotation angle of, for example, approximately 5 degrees has a particularly good fan effect and can ensure particularly good air mixing in the electronics compartment of the machine tool.

[0019] According to the invention, it is preferred that the machine tool has a first opening for sucking in air and a second opening for the outlet of air. According to the invention, the first opening is preferably referred to as the inlet opening and the second opening is preferably referred to as the outlet opening. Preferably, in particular, the engine compartment can have the first opening for sucking in air and the second opening for the outlet of air. According to the invention, it is preferred that the first opening is designed to suck air into the machine tool. The negative pressure with which the sucking in is effected is preferably created by the rotational movement of the rotor of the electric motor. The air is sucked into the engine compartment and kept in motion, in particular by the rotation of the rotor of the electric motor.In other words, the electric motor can be configured to draw air into the motor compartment and keep it moving, creating an air flow. The air flow can be swirled by the structural elements on the rotor cores, causing the air to mix in the electronics and motor compartments of the machine tool. This mixing of the air can advantageously lead to particularly good cooling of the machine tool's electronics in the electronics compartment of the machine tool. According to the invention, it is preferred that the second opening is configured to allow the cooling air flow to leave the machine tool. According to the invention, it is especially preferred that the outlet opening is arranged in the region of the bearing plate on the drive side of the electric motor.

[0020] According to the invention, it is preferred that an air flow for cooling the electronics of the machine tool be formed between the first opening and the second opening. Thus, the invention can generate a cooling air flow between the inlet opening and the outlet opening of the motor compartment, enabling improved temperature distribution within the machine tool or its electronics compartment and, in addition, cooling of the electronics.

[0021] It has been shown that particularly good mixing of the air in the electronics compartment of the machine tool can be achieved, in particular, through a suitable geometry of the outer skin of the rotor of the electric motor or its rotor stacks and through the provision of the first and second openings. In addition, a cooling air flow can develop in the electronics compartment, whereby the mixing of the air in the electronics compartment and the formation of the cooling air flow can enable particularly strong and effective cooling of the electronics of the machine tool and its components. It has been shown that the mixing of the air in the electronics compartment and the cooling effect of the air flow do not simply overlap, as might have been expected. Instead, it has been shown that the combination of the mixing of the air in the electronics compartment and the cooling air flow can achieve surprisingly effective cooling of the electronics and their components.In particular, the temperatures of the electronics and their components, as well as any existing temperature differences in the electronics compartment, can be significantly and sustainably reduced with the combined cooling system of air mixing and cooling air flow. For the purposes of the invention, the combined cooling system of air mixing and cooling air flow is also preferably referred to as "improved air circulation within the machine tool."

[0022] According to the invention, it is preferred that the electric motor comprises a housing, wherein the first opening is arranged in the housing of the electric motor. According to the invention, it is preferred that the electric motor comprises a bearing plate, wherein the second opening is arranged in the bearing plate of the electric motor. In other words, the housing of the electric motor can have an inlet opening and the bearing plate can have an outlet opening for the cooling air flow. The bearing plate and the housing of the electric motor, together with other components of the machine tool, form boundaries of the electronics compartment of the machine tool, so that the inlet opening and the outlet opening thereby represent inlet openings and the outlet openings of the electronics compartment of the machine tool.

[0023] Further advantages emerge from the following description of the figures. The figures, the description, and the claims contain numerous features in combination. Those skilled in the art will expediently consider the features individually and combine them into further meaningful combinations. In the figures, identical and similar components are numbered with the same reference numerals.

[0024] They show:

[0025] Fig. 1 View of a preferred embodiment of the machine tool

[0026] Fig. 2 View of a preferred embodiment of the electric motor

[0027] Fig. 3 View of a preferred embodiment of the electronics compartment

[0028] Implementation examples and figure descriptions:

[0029] Figure 1 shows a preferred embodiment of the machine tool 10. Figure 1 particularly illustrates a possible position of the electric motor 14 within the machine tool 10. The machine tool 10 may have a tool holder 36 to which a tool (without reference symbol) of the machine tool 10 can be attached. The machine tool 10 may, for example, be designed as a core drilling machine, wherein the tool of the machine tool 10 may be formed by a core bit. A core drilling machine without a core bit is shown as an example in Figure 1.

[0030] Figure 2 shows a preferred embodiment of the electric motor 14 of the machine tool 10. The electric motor 14 has a rotor 16 and a stator 18, wherein the rotor 16 can move within the stator 18. In the exemplary embodiment of the invention depicted in Figure 2, the rotor 16 comprises three rotor cores 24, each of which comprises a structural element 22. The structural elements 22 depicted as examples in Figure 2 are convex structural elements 22 that protrude from an outer skin of the rotor cores 24. The structural elements 22 advantageously have a fan effect, so that the air in an electronics compartment 22 (see Figure 3) of the machine tool 10 can be thoroughly mixed. This allows the electronics 12 (see also Figure 3) of the machine tool 10 to be particularly well cooled.In the exemplary embodiment of the electric motor 14 of the machine tool 10 shown in Figure 2, the electric motor 14 has three rotor cores 24, each rotor core 24 having a structural element 22. Of course, the electric motor 14 of the machine tool 10 can also have more or fewer than three rotor cores 24. Within the meaning of the invention, it can be preferred for the rotor cores 24 to each have more than one structural element 22 or for the number of structural elements 22 per rotor core 24 to vary. For example, two, three, four or more structural elements 22 can be provided per rotor core 24, which structural elements can preferably be distributed substantially uniformly on the electric motor 14 or on its housing 30.

[0031] The rotor cores 24 forming the electric motor 14 of the machine tool 10 are preferably arranged relative to one another such that the rotor cores 24 and / or the structural elements 22 are offset from one another by a rotation angle alpha. It has been shown that particularly good mixing of the air in the electronics compartment 20 of the machine tool 10 can be achieved precisely by offsetting the rotor cores 24 from one another by a rotation angle alpha. Due to the offset arrangement of the rotor cores 24 of the electric motor 14 relative to one another, the structural elements 22 are also offset from one another, so that they act like blades and circulate the air within the machine tool 10.

[0032] Figure 3 shows a preferred embodiment of the electronics compartment 20 of the machine tool 10. It shows the electric motor 14, which is in fluid communication with the electronics compartment 20 of the machine tool 10. The rotor 16 has structural elements 22 on its outer skin, which are designed to circulate the air in the electronics compartment 20. Figure 3 also shows the motor compartment 40 of the machine tool 10, wherein the motor compartment 40 is formed by the immediate surroundings of the electric motor 14 of the machine tool 10. The motor compartment 40 can preferably be surrounded by a housing 30 of the electric motor 14.

[0033] A first opening 26 (not shown) and a second opening 28 (not shown) are provided in the machine tool 10, serving as an inlet opening 26 and an outlet opening 28 for a cooling air flow 34. The cooling air flow 34 flows through the electronics compartment 20 of the machine tool 10 and is designed to cool the electronics 12 and its electronic components. The first opening 26 is provided in a housing 30 of the motor 14, while the second opening 28 is provided in a bearing plate 32 of the electric motor 14. The cooling air flow 34, which is caused by the provision of the openings 26, 28, and the mixing of the air in the electronics compartment 20 of the machine tool 10, advantageously ensure combined cooling of the electronics 12 of the machine tool 10, as well as improved air circulation within the machine tool 10.

[0034] List of reference symbols

[0035] 10 Machine tool

[0036] 12 Electronics

[0037] 14 Electric motor

[0038] 16 Rotor

[0039] 18 Stator

[0040] 20 Electronics room

[0041] 22 structural elements

[0042] 24 rotor packs

[0043] 26 first opening, entrance opening

[0044] 28 second opening, exit opening

[0045] 30 Electric motor housing

[0046] 32 bearing plate

[0047] 34 Cooling air flow

[0048] 36 tool holder

[0049] 40 Engine compartment

Claims

Patent claims 1. Machine tool (10) with electronics (12) and an electric motor (14), wherein the electric motor (14) comprises a rotor (16) and a stator (18), wherein the electronics (12) is arranged in an electronics compartment (20) of the machine tool (10), characterized in that the electronics compartment (20) is fluidically connected to a motor compartment (40) surrounding the electric motor (14) and the electric motor (14) has structural elements (22) for mixing air in the electronics compartment (20) and / or the motor compartment (40) of the machine tool (10).

2. Machine tool (10) according to claim 1, characterized in that the electric motor (14) comprises rotor packs (24), wherein the structural elements (22) are arranged on the rotor packs (24) of the electric motor (14).

3. Machine tool (10) according to claim 2, characterized in that the electric motor (14) has a structural element (22) per rotor package (24).

4. Machine tool (10) according to claim 2 or 3, characterized in that the rotor packages (24) are arranged relative to one another and form the electric motor (14) in such a way that the structural elements (22) are offset relative to one another by an angle of rotation alpha.

5. Machine tool (10) according to claim 4, characterized in that the angle of rotation is in a range of 1 to 15 degrees, preferably in a range of 3 to 10 degrees, particularly preferably in a range of 4 to 6 degrees and most preferably 5 degrees.

6. Machine tool (10) according to one of the preceding claims, characterized in that the machine tool (10) has a first opening (26) for sucking in air and a second opening (28) for discharging air.

7. Machine tool (10) according to claim 6, characterized in that the electric motor (14) comprises a housing (30), wherein the first opening (26) is arranged in the housing (30) of the electric motor (14).

8. Machine tool (10) according to claim 6 or 7, characterized in that the electric motor (14) comprises a bearing plate (32), wherein the second opening (28) is arranged in the bearing plate (32) of the electric motor (14).

9. Machine tool (10) according to one of claims 6 to 8, characterized in that an air flow (34) for cooling the electronics (12) of the machine tool (10) is formed between the first opening (26) and the second opening (28).

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