Self-ventilated rotating electrical machine

Abstract

The present invention relates to a self-ventilated rotary motor (1) having a housing (6) that at least partially surrounds the rotary motor (1) axially, wherein the rotary motor (1) has a drive side and a ventilation side, wherein at least one ventilator (2) is torsionally connected to a shaft (9) on the ventilation side and generates a main airflow (7) when the shaft (9) rotates about an axis (10), wherein the ventilator (2) is equipped with an outer cover (3) that deflects the cooling main airflow (7) generated by the ventilator (2) onto the housing (6), wherein the outer cover (3) is provided with at least means for improving the cooling of the housing.

Description

Technical Field

[0001] This invention relates to a self-ventilated rotary motor. Background Technology

[0002] The ventilation design of such machines, such as electric motors, typically consists of a ventilator fixed to the shaft to resist torsion and a ventilation shroud that guides the generated airflow. Cooling air is drawn in axially through the shroud's grille and ejected outwards through the axial ventilator. This creates pressure on the inner wall of the shroud. This causes the cooling air to deflect and accelerate axially in the direction of the machine housing. The cooling air flows out of the shroud and, ideally, flows along the housing from the ventilation side to the drive side within or between the housing ribs.

[0003] However, this theoretical ventilation concept does not correspond to reality. The cooling air dissipates radially from the ribbed area of ​​the housing after flowing out of the outer casing, thus losing its cooling function. Here, the loss of cooling air increases axially along the ribs to the drive side, resulting in a very small portion of cooling air still providing cooling on the drive side.

[0004] Insufficient cooling causes the machine or motor to overheat. Furthermore, the temperature on the AS (drive side) is higher than on the BS (ventilation side). This axial thermal gradient within the machine prevents it from operating at full load. Consequently, the drive side is also subjected to increased thermal stress first.

[0005] Therefore, more power is required to achieve the desired performance or efficiency of the rotating electric motor. External cooling is employed in some cases. Summary of the Invention

[0006] Therefore, the object of the present invention is to provide a rotary electric motor with a self-cooling system, which has an improved application of cooling air and thus enables a more compact structure.

[0007] The solution to this objective is achieved by a self-ventilated rotary motor having a housing that at least partially surrounds the rotary motor axially, wherein the rotary motor has a drive side and a ventilation side, wherein at least one ventilator is torsionally connected to the shaft on the ventilation side and generates a main airflow when the shaft rotates about the axis, wherein the ventilator is equipped with an outer cover that deflects the cooling main airflow generated by the ventilator onto the housing, wherein the outer cover is provided with at least means for improving the cooling of the housing.

[0008] According to the present invention, a device for guiding cooling airflow along the housing is now provided on the outer casing. Here, on the one hand, the cooling airflow is guided to flow over the housing for as long as possible, and on the other hand, additional cooling airflow is provided.

[0009] The outer casing has at least one air guide element that provides additional cooling airflow. The air guide element is located at the outer casing outlet, directing the additional cooling airflow inward toward the machine axis. The air guide element has openings constructed between axially extending tabs, and air guide surfaces are constructed between the tabs. Here, as a supplement to the main cooling airflow, fresh air is drawn in from the outside or additional cooling airflow is generated during ventilator and motor operation according to the ejector principle. Preferably, cooler air from the outside is delivered at an angle to the surface of the casing, particularly the cooling fin base (in finned casings). This results in a significant improvement in cooling performance, which extends all the way to the drive side (AS), thereby reducing the axial temperature gradient within the machine.

[0010] Here, the air guide element is designed to cause it to mix with the cold air exiting from the outer casing. Therefore, the cooling effect is improved in terms of the machine's axial length.

[0011] The cooling function can be significantly improved by the structure of the outer casing according to the invention, in which a longer residence time of cooling air is achieved on the surface of the casing or between the casing fins.

[0012] The overall temperature of the motor decreases. The temperature difference between AB and BS decreases. The temperature of the windings and bearings decreases, thereby increasing their lifespan. The motor's efficiency increases.

[0013] The air guide surface extends at an angle relative to the axis. This improves the injector principle and the cooling of the additional airflow. Preferably, the air guide surface is equipped with the same angle relative to the axis; however, different angles can also be assigned to the air guide surface during the manufacture of the air guide element.

[0014] Furthermore, the curvature of the air-guiding surface of the shell profile, that is, the corresponding air-guiding surface, has a radius related to the diameter of the shell when viewed in the circumferential direction.

[0015] The outer casing can be constructed as a single piece with a preset number of air guiding elements. Here, the air guiding elements are understood as circumferentially closed or segmented components. Similarly, these components can also be arranged sequentially along the axial direction.

[0016] The one-piece construction simplifies manufacturing because only one component needs to be "processed". Thus, this one component has an outer cover, one or more air guiding elements, wherein each air guiding element has a tab, an air guiding surface, and an opening.

[0017] Alternatively, the air guide element is constructed in segments in the circumferential direction and is removably fixed to the housing. The housing and one or more air guide elements are separate components, and the air guide element can be additionally installed to the housing according to the thermal requirements of the motor.

[0018] In order to optimally cover the thermal requirements of the motor, the sections of the air guide element have different axial extensions and / or different numbers of openings and / or different inclinations of the air guide surface.

[0019] Depending on thermal requirements, multiple segmented air guide elements can also be arranged axially along the housing. For example, four or six segments of air guide elements can be arranged circumferentially on the outer casing. Thus, it applies to the entire circumferential direction. In machines with shorter axial lengths, the junction box is an obstacle to further axial extension where possible, so additional air guide elements can only be arranged axially in the remaining circumferential direction.

[0020] The mechanical connections between the outer cover and the air guiding elements, and especially between the air guiding elements, are achieved through removable clamping or snap-fit ​​connections.

[0021] Alternatively or additionally, a device for reducing the inner radius is provided at the axial end of the outer casing (towards the AS side). Now, according to the invention, there, the cold air is not guided parallel to the axis to the surface of the housing or to the rib area, but is deflected at an angle toward the machine axis, i.e., inward toward the machine axis, to the surface or to the cooling rib base.

[0022] This is achieved through a corresponding profile at the axial end of the outer casing. Before exiting the outer casing, the cooling air is deflected inward toward the cooling fin base, for example by means of tilting or a continuous decrease in the inner radius. This significantly extends the residence time of the cooling air in the cooling fins and enhances the cooling effect along the casing.

[0023] This can also be achieved using a separate reduction element positioned at the end of the outer casing. This reduction element has a wedge-shaped cross-section.

[0024] The reduction element is present at least locally in the circumferential direction, especially in the sections of the outer casing that require priority cooling.

[0025] The outer casing is basically constructed in a canister shape, which simplifies the installation and placement of the air guiding elements and / or reduction elements.

[0026] When the inner radius of the outer cover is greater than the outer radius of the shell, the outer cover can tilt on the ribs of the shell.

[0027] As long as the housing is equipped with fins at least in some areas, it improves cooling and contributes to the mechanical stability of the air-guiding elements on the housing and outer casing.

[0028] According to the present invention, the cooling air is not guided into the rib area parallel to the axis, but is deflected into the cooling rib base at an angle toward the machine axis, that is, toward the machine axis inward.

[0029] By tilting at the end of the outer casing, the residence time of cooling air in the cooling fins is significantly extended and the cooling function is improved along the casing.

[0030] The cooling effect is further enhanced when at least one air guide element, which also deflects inward in the direction of the machine axis, is provided at the outer casing outlet. Here, fresh air is additionally drawn in from the outside or an additional cooling airflow is generated according to the ejector principle during the operation of the ventilator and the motor. Preferably, the cooler air from the outside is delivered to the cooling fin substrate at an inclined angle, resulting in a significant improvement in cooling function, which extends all the way to the drive side (AS), thereby reducing the axial temperature gradient within the machine.

[0031] Here, the air guide element is designed to preferably cause mixing with the cold air exiting from the outer casing. Therefore, the cooling effect is improved in terms of the machine's axial length.

[0032] The cooling function can be significantly improved by means of the outer casing and / or air guiding elements according to the invention, wherein a longer residence time of cooling air in the housing fins is achieved.

[0033] The overall motor temperature decreases. The temperature difference between AB and BS decreases. The winding and bearing temperatures decrease, thereby increasing lifespan. The motor efficiency increases.

[0034] The air guiding element can also be formed from metal or synthetic materials, just like the outer casing. Similarly, the outer casing and / or air guiding element can be made by spray casting or 3D printing.

[0035] Additional support for the air guide elements at the housing or housing ribs improves mechanical stability, especially when multiple air guide elements are arranged sequentially along the axial direction. Attached Figure Description

[0036] The invention and its other advantageous designs are explained in detail with reference to embodiments illustrated in principle; shown herein:

[0037] Figure 1 The longitudinal section of the motor is shown.

[0038] Figure 2 Showing detailed images,

[0039] Figures 3 to 7 A partial 3D view is shown.

[0040] Figure 8 A partial longitudinal section of the motor is shown.

[0041] Figure 9 A partial cross-section of the motor is shown.

[0042] Figure 10 A 3D view of the motor is shown.

[0043] Figure 11 A partial top view of the motor is shown. Detailed Implementation

[0044] Figure 1 A schematic longitudinal sectional view of a rotating electric motor 1, particularly an asynchronous motor with a squirrel-cage armature, is shown. The motor 1 has a stator 14, which is implemented as laminations and has winding heads of a winding system 15 on its end sides. The stator 14 is mounted in a housing 6, particularly configured to facilitate heat transfer from the stator 14 to the housing 6. The housing 6 has substantially radially spaced fins 13 distributed on its outer periphery for cooling the motor 1.

[0045] Electromagnetic interaction, via the energized winding system 15 of the stator 14, influences the rotor 16 through the air gap 17, thereby causing the shaft 9 to rotate about the axis 10. The shaft 9 is fixed to the housing 6 via bearings 11 and their bearing supports 12. A ventilator 2 is torsionally connected to the shaft 9. The ventilator 2 has essentially radially extending fan blades 4. The ventilator 2 draws in airflow axially through perforations 5 in the outer casing 3, which then passes through the fan blades 4 and is deflected by the outer casing 3, thereby essentially axially adjusting the cooling main airflow 7 along the ribs 13.

[0046] However, after exiting the outer casing 3, the cooling air gradually dissipates radially from the rib area of ​​the housing 6 and thus loses its cooling function. Here, the loss of cooling air increases sharply along the axial extension of the rib 13 to the drive side, resulting in a very small amount of cooling air still performing a cooling function on the drive side.

[0047] Now according to Figure 2 The cooling airflow is separated from the housing surface in advance by the reduction of the inner radius of the outer casing at its axial end and / or by the air guide element 18, thereby significantly improving cooling.

[0048] The reduction of the inner radius at the axial end of the outer cover 3 can also be achieved by an additional reduction element, which is fixed in or on the outer cover 3. In cross-section, the reduction element is implemented as a wedge shape.

[0049] By means of the air guiding element 18 that is already present in one piece on the outer casing 3 or can be attached, a cooling additional airflow 8 is generated when the ventilator 2 is running, which flows through the opening 21 to the surface of the casing and / or between the ribs 13.

[0050] In the one-piece outer cover 3, the air guiding element 8 can occupy only a certain angular range around the outer cover 3. That is, there is an outer cover 3 that occupies only a preset angular range, and there is also an air guiding element 18 that occupies the entire circumference of the outer cover 3.

[0051] In the case of separate air guide elements 18 segmented in the circumferential direction, the air guide elements can be fixed on the outer cover 3 and / or on the housing 6.

[0052] The air guide element 18 has an axially extending tab 23 on which air guide surfaces 26 are arranged. In the axial direction, there are openings 21 between the air guide surfaces 26, which enable additional cooling airflow 8 during the operation of the rotary motor 1. The air guide surfaces 26 substantially follow the contour of the housing 6; in other words, the curvature of the corresponding air guide surfaces 26 has a radius related to the diameter of the housing 6 when viewed in the circumferential direction.

[0053] Figure 3 Multiple separate air guiding elements 18 are shown, arranged on the outer casing 3. Here, they occupy the entire angular range in the circumferential direction.

[0054] Figure 4 Another detailed view of the outer cover 3 is shown, which has segmented air guiding elements 18, which are fastened to the outer cover 3 in the opening of the outer cover 3 by means of, for example, removable clamping connections.

[0055] Here, the splice 23 protrudes axially toward the ventilation side due to mechanical and / or fluid technology reasons, as is particularly true in Figure 5 As given in the document.

[0056] Figure 6 The diagram shows a section of the air guiding element 18 having two rows of three air guiding surfaces 26 arranged sequentially along the axial direction on the outer cover 3, with an opening 21 between the axial end of the outer cover and the first air guiding surface 26 or between the air guiding surfaces 26.

[0057] Figure 7 The tilt angle of the air guide surface 26 relative to the axis 10 is shown in particular. This results in the injection angle, thereby generating an additional cooling airflow 8 in addition to the main cooling airflow 7, which is used to cool the motor 1.

[0058] Preferably, when the outer cover 3 and the air guiding element 18 are implemented as a single piece, for example by spray casting or 3D printing, the angular orientation of the air guiding surface 26 is taken into account when manufacturing the outer cover 3.

[0059] When manufacturing the air guide element 18, which should be clamped onto the outer casing 3, separately, the angular orientation can be taken into account during manufacturing. The separate air guide element 18 can also be replaced to obtain an axially longer air guide element 18 and / or other angular orientations of the air guide surface 26.

[0060] Figure 8The diagram illustrates how the segmented air guide element 18 can be secured to the outer casing 3, for example, by engaging a hook into a gap at the axial end of the outer casing 3. The air guide surface 26 is located on or slightly spaced from the outer casing 3. A tab 23 is present on the outer casing 3.

[0061] Also from Figure 9 It can be seen that the air guide surface 6 is located on the rib.

[0062] Figure 10 An outer casing 3 with an air guide element 18 is shown, wherein an angled section of the outer casing 3 is not occupied by the air guide element 18.

[0063] Figure 11 A top view of the air guide element 18 on the outer casing 3 and a section of the motor 1 with the housing 6 or ribs 13 to be cooled are shown.

Claims

1. A self-ventilated rotary electric machine (1) having a housing (6) which at least partially surrounds the rotary electric machine (1) in an axial direction, wherein The rotary motor (1) has a drive side and a ventilation side, wherein at least one ventilator (2) is torsionally connected to the shaft (9) on the ventilation side and generates a main airflow when the shaft (9) rotates about the axis (10), wherein the ventilator (2) is equipped with an outer cover (3) that deflects the cooling main airflow (7) generated by the ventilator (2) onto the housing (6), wherein the outer cover (3) is provided with at least one means for improving the cooling of the housing, wherein the outer cover (3) has at least one air guide element (18), the guide element... The air element provides additional cooling airflow (8), characterized in that the air guide element (18) is segmented in the circumferential direction and the air guide element is removably fixed to the outer cover (3), wherein the outer cover and one or more of the air guide elements are separate components, the air guide element can be additionally installed to the outer cover according to the thermal requirements of the motor, the air guide element (18) has a tab (23), the tab has an air guide surface (26) located between the tabs, wherein an opening (21) is provided between the air guide surfaces (26).

2. The self-ventilated rotary electric machine (1) according to claim 1, characterized in that, The air guide surface (26) extends obliquely relative to the axis (10).

3. The self-ventilated rotary motor (1) according to claim 1, characterized in that, The air guide element (18) has sections with different axial extensions and / or different numbers of openings (21).

4. The self-ventilated rotary motor (1) according to claim 1 or 3, characterized in that, The air guide element (18) can be arranged in multiple segments along the housing (6) in the axial direction.

5. The self-ventilated rotary motor (1) according to any one of claims 1 to 3, characterized in that, A device for reducing the inner radius is provided at the inner radius of the axial end of the outer cover (3).

6. The self-ventilated rotary motor (1) according to claim 5, characterized in that, At the axial end of the outer cover (3), a reduction element is provided at least partially in the circumferential direction, or the end of the outer cover (3) is inclined radially toward the axis (10).

7. The self-ventilated rotary motor (1) according to any one of claims 1 to 3, characterized in that, The outer cover (3) is constructed in the shape of a can.

8. The self-ventilated rotary motor (1) according to any one of claims 1 to 3, characterized in that, The inner radius of the outer cover (3) is greater than the outer radius of the shell (6).

9. The self-ventilated rotary motor (1) according to any one of claims 1 to 3, characterized in that, The housing (6) is equipped with ribs (13) at least in some areas.

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