Stator segment with clamp elements

Abstract

A stator for an electric motor, in particular as a drive of a power tool, comprises at least one first toothed arrangement and one second toothed arrangement, each having a web element for receiving a radial arrangement of coil windings. Each toothed arrangement comprises an arcuate ring section and a connecting device having a first connecting element and a second connecting element, the first connecting element and the second connecting element being configured in the shape of a wedge such that, in the connected state, the first connecting element and the second connecting element are connected to each other. A first contact surface of the first connecting element, which extends obliquely with respect to the tooth segment plane, rests on a second contact surface of the second connecting element, which extends obliquely with respect to the tooth segment plane, and wherein the first connecting element comprises a first radially outwardly directed projection and the second connecting element comprises a second radially outwardly directed projection, and wherein the first connecting element comprises a first undercut and the second connecting element comprises a second undercut, the undercuts being configured to receive and retain at least one clip element.

Description

[0001] The present invention relates to a stator for an electric motor, particularly as a drive device for a power tool, the stator comprising at least one first tooth arrangement and a second tooth arrangement, each of the first tooth arrangement and the second tooth arrangement having a web element for receiving a radially arranged coil winding.

[0002] According to existing technology, the stator, as a component for an electric motor, essentially has a ring element and multiple toothed elements. The toothed elements extend from the circumferential inner surface of the ring element to the center point of the ring element. A circular gap for the rotor is maintained at the free end of the toothed element. Each toothed element is used to receive and hold a winding coil composed of conductive coil wires to correspondingly generate a magnetic field.

[0003] Especially with smaller stators, winding individual tooth elements with coil wire typically involves a significant amount of technical effort. The available space between adjacent tooth elements is usually narrow, and therefore, the rapid and, most importantly, neat winding of the coil around the tooth elements involves considerable time, meticulously crafted winding equipment, and high costs.

[0004] Therefore, the purpose of this invention is to solve the above-mentioned problems.

[0005] This objective is achieved through the subject matter of independent claim 1.

[0006] Advantageous embodiments of the subject matter of the invention can be found in the dependent claims.

[0007] This objective is achieved in particular by a stator for an electric motor, especially as a drive unit for a power tool, the stator comprising at least one first tooth arrangement and a second tooth arrangement, each of the first tooth arrangement and the second tooth arrangement having a web element for receiving a radially arranged coil winding.

[0008] According to the present invention, each toothed arrangement includes an arcuate ring segment and a connecting device having a first connecting element and a second connecting element, wherein both the first connecting element and the second connecting element are configured in the shape of a wedge, such that in the connected state, a first contact surface of the first connecting element extending obliquely relative to the plane of the tooth segment rests on a second contact surface of the second connecting element extending obliquely relative to the plane of the tooth segment, and wherein the first connecting element includes a first radially outwardly oriented protrusion, and the second connecting element includes a second radially outwardly oriented protrusion, and wherein the first connecting element includes a first undercut and the second connecting element includes a second undercut, the undercuts being configured to receive and hold at least one clamping element.

[0009] "Cooperation" can also be understood as referring to the precision or accuracy of cooperation.

[0010] According to another advantageous embodiment, the connecting device may include at least one first undercut and a second undercut.

[0011] According to another advantageous embodiment, it is possible to configure the first connecting element and the second connecting element such that the connecting line has both a segment extending obliquely relative to the tooth segment plane and a segment extending radially.

[0012] According to another advantageous embodiment, it is possible that the segment extending obliquely relative to the tooth segment plane can be longer than the radially extending segment.

[0013] According to another advantageous embodiment, it is possible that the distance between the connecting lines between the first connecting element and the second connecting element can be longer than the width of the toothed arrangement.

[0014] The dividing lines at the connection points required for the division of gear elements have a negative impact on the structural cohesion of the magnetic circuit and the stator as a whole. This can adversely affect the power density, stability, and / or noise behavior of the entire electric motor. In particular, the negative impact of dividing lines in the form of punched edges on the electromagnetic characteristics of the stator laminations must be considered.

[0015] To minimize these drawbacks, it has proven advantageous, according to another alternative embodiment, that at least one first connection point of the first and second connecting elements lies substantially in a plane passing through the toothed arrangement. This allows regions with high magnetic flux density through the stator's magnetic circuit to lie within the radial range of the toothed elements, thus optimizing the magnetic flux.

[0016] According to another advantageous embodiment, it is possible that the first and second connecting elements, in the closed state, at least produce a form-fit, press-fit, and / or material bond connection with each other. Therefore, the connecting elements can be connected in a simple manner. In addition to mechanical connections (i.e., form-fit or force-fit connections), a material bond connection in the form of an adhesive can also be provided between adjacent ring segments.

[0017] According to another advantageous embodiment, the connecting device may be configured as a snap-fit ​​connection. This makes it possible to achieve a reliable and releasable connection of the connecting elements in a simple manner.

[0018] According to another advantageous embodiment, the connecting device may be configured for an engaging connection. This allows for a simple releasable connection of the connecting elements, which does not require elastic deformation of the connecting elements or portions thereof. For releasable connection or disconnection, the connecting elements can simply be displaced opposite to or relative to each other on the stator axis.

[0019] According to another advantageous embodiment, it is possible that at least one first dividing line of the engagement connection between the first connecting element and the second connecting element extends parallel to the central axis of the stator, such that the first connecting element and the second connecting element can be displaced opposite to each other and parallel to the central axis of the stator. This makes it possible to achieve a relatively robust and load-bearing connection of the connecting elements in a simple manner.

[0020] According to another advantageous embodiment, it is possible that the distance between the dividing lines of the engagement connection between the first connecting element and the second connecting element is longer than the width of the toothed arrangement. This results in the connecting lines or dividing lines between adjacent connecting elements being as long as possible, thus minimizing the negative impact on the magnetic flux between the mutually adjacent connecting elements.

[0021] Further advantages will become apparent from the following description of the accompanying drawings, which illustrate various exemplary embodiments of the invention.

[0022] The accompanying drawings, description, and claims contain many combinations of features. Those skilled in the art will also be able to consider these features individually and combine them to produce other useful combinations.

[0023] In the attached diagram:

[0024] Figure 1 A schematic side view of a power tool with a drive device according to an exemplary embodiment is shown;

[0025] Figure 2 A perspective side view of the stator and rotor, which are part of the drive unit, is shown;

[0026] Figure 3 A perspective side view of the stator according to an exemplary embodiment is shown;

[0027] Figure 4 A front view of the stator according to the first embodiment is shown;

[0028] Figure 5 A detailed view of a stator according to a first embodiment is shown, the stator having a toothed arrangement and an arcuate first ring segment and a second ring segment;

[0029] Figure 6 A front view of the stator according to the second embodiment is shown; and

[0030] Figure 7 A detailed view of a stator according to a second embodiment is shown, the stator having a toothed arrangement and an arcuate first ring segment and a second ring segment. Detailed Implementation

[0031] Figure 1A power tool 1 in the form of a rechargeable battery-operated screwdriver is shown according to an exemplary embodiment.

[0032] Power tool 1 can also be alternatively designed in the form of a hammer drill, combination hammer, power drill, saw, grinder, etc.

[0033] like Figure 1 As shown, the power tool 1 according to an exemplary embodiment basically includes a housing 2, a tool accessory 3, a handle 4, and a power supply device 5.

[0034] The housing 2 has a top side 2a, a bottom side 2b, a front end 2c, and a rear end 2d.

[0035] Tool accessory 3 for receiving and holding tool 6 is positioned at the front end 2c of housing 2. In the present case, tool 6 is in the form of a screwdriver tip (or simply a tip).

[0036] The handle 4 allows the user (not shown in the attached drawings) to hold and guide the power tool 1. The handle 4 has an upper end 4a, a lower end 4b, a front side 4c, and a rear side 4d. The upper end 4a of the handle 4 is connected to the bottom side 2b of the housing 2 of the power tool 1.

[0037] As in Figure 1 As can be seen, the actuation switch 7 is located on the front side 4c of the handle 4. The actuation switch 7 is used to activate the power tool 1. The control device 8 of the power tool 1 is located inside the handle 4 and is used to control and adjust the function of the power tool 1.

[0038] A base device 8 having a power tool interface 9 is disposed on the bottom side 2b of the housing 2 of the power tool 1. The power tool interface 9 is used to releasably connect the power tool 1 to the power supply device 5.

[0039] In this embodiment, the power supply device 5 is in the form of a rechargeable battery. According to an alternative embodiment (not shown in the drawings), the power supply device 5 may also be configured as a cable for releasably connecting the power tool 1 to an AC power source (also known as an electrical outlet).

[0040] The housing 2 of the power tool 1 also houses a drive unit 10, a transmission device 11, and a drive shaft 12. In this exemplary embodiment, the drive unit 10 is in the form of an electric motor and is used to generate torque. The drive unit 10, transmission device 11, and drive shaft 12, which are in the form of electric motors, are arranged or positioned relative to each other in the housing 2 in such a way that the torque generated by the drive unit 10 can be transmitted via the transmission device 11 and the drive shaft 12 and ultimately transmitted to the tool accessory 3.

[0041] The drive unit 10 further comprises essentially a stator 13 and a rotor 14, the rotor being positioned within the stator 13 and rotatable relative to the stator 13, see [link to previous section]. Figure 2 The rotor 14 rotates around the central axis MA of the stator 13.

[0042] As in Figures 3 to 5 As can be seen, the stator 13 includes six tooth arrangements 20 according to an exemplary embodiment. According to alternative embodiments, the stator 13 may also include more or fewer than six tooth arrangements 20.

[0043] Each individual toothed arrangement 20 is used to receive a coil winding 15 consisting of conductive wires. For example, the conductive wires may be made of copper or a copper alloy.

[0044] Each toothed arrangement 20 includes a web element 16, and an arcuate first annular segment 17 and a second annular segment 18. (As in...) Figure 3 and Figure 4 As can be seen, the individual ring segments 17 and 18 combine to form a closed ring R.

[0045] Web element 16 has a first end 16a and a second end 16b, with coil winding 15 attached between the first end 16a and the second end 16b. The respective first end 16a of web element 16 is positioned on the circumferential inner surface of ring R formed by various ring segments 17, 18. The second end 16b of web element 16 protrudes to the center point M of ring R. The length of web element 16 is chosen such that a circular recess remains inside stator 13. Rotor 14 can be placed within said recess.

[0046] For example, especially in Figures 4 to 7 As can be seen, the first ring segment 17 and the second ring segment 18 each have a first end and a second end 17a, 17b, 18a, 18b. The first end 17a of the first ring segment 17 is located at the first end 16a of the web element 16. The first end 18a of the second ring segment 18 is also located at the first end 16a of the web element 16. The two ring segments 17 and 18 extend in opposite directions around the ring R. The first ring segment 17 has a first arc KB1 that is longer than the second arc KB2 of the second ring segment 18. In other words, the first ring segment 17 has a larger volume than the second ring segment 18. In the exemplary embodiment shown, the volume of the second ring segment 18 is substantially one-third or 30% of the volume of the first ring segment 17. According to an alternative exemplary embodiment (not shown in the figure), the volume of the second ring segment 18 may also be greater than or less than one-third or 30% of the volume of the first ring segment 17.

[0047] Additionally, a connecting device 19 having a first connecting element 19a and a second connecting element 19b is disposed on the first ring section 17 and the second ring section 18. The first connecting element 19a is positioned on the first ring section 17, and the second connecting element 19b is positioned on the second ring section 18.

[0048] Both the first connecting element 19a and the second connecting element 19b are configured in the shape of a wedge. In the connected state of the first connecting element 19a and the second connecting element 19b, the first contact surface 21a of the first connecting element 19a, which extends obliquely relative to the tooth segment plane, rests on the second contact surface 21b of the second connecting element 19b, which extends obliquely relative to the tooth segment plane E.

[0049] As can also be seen in the accompanying drawings, the first connecting element 19a includes a first radially outwardly pointing protrusion 22a, and the second connecting element 19b includes a second radially outwardly pointing protrusion 22b.

[0050] Figure 4 and Figure 5 The stator 13 and the connecting device 19 according to the first embodiment are shown respectively. As particularly in… Figure 5 As can be seen, the first protrusion 22a of the first connecting element 19a is configured to have a semi-circular cross-sectional area and a first substantially straight end face 25a. Similarly, the second protrusion 22b of the second connecting element 19b is configured to have a semi-circular cross-sectional area and a second substantially straight end face 25b. The first protrusion 22a and the second protrusion 22b are configured such that when the first end face 25a and the second end face 25b rest on each other, the two protrusions 22a and 22b are in a connected state (e.g., when...). Figure 5 As shown, there are continuous semi-circular protrusions 26.

[0051] Furthermore, the first connecting element 19a includes a first undercut portion 23a, and the second connecting element 19b includes a second undercut portion 23b. The first undercut portion 23a and the second undercut portion 23b are configured to receive and hold the clamping element 24. The clamping element 24 has a first end 24a and a second end 24b. The clamping element 24 transitions from a substantially straight state to a bent state. In the bent state, the clamping element 24 is connected to the first connecting element 19a and the second connecting element 19b. Then, the first end 24a of the clamping element 24 protrudes into the first undercut portion 23a, and the second end 24b of the clamping element 24 protrudes into the second undercut portion 23b.

[0052] The clamping element 24 is held onto the connecting device 19 by the first undercut portion 23a and the second undercut portion 23b. At the same time, the clamping element 24 is used to hold the first connecting element 19a and the second connecting element 19b together.

[0053] Figure 6 and Figure 7The stator 13 and connecting device 19 according to the second embodiment are shown respectively. The connecting device 19 according to the second embodiment differs from the connecting device 19 according to the first embodiment in that the first protrusion 22a of the first connecting element 19a has a substantially rectangular cross-sectional area, and the second protrusion 22b of the second connecting element 19a also has a substantially rectangular cross-sectional area. When the first connecting element 19a and the second connecting element 19b are connected to each other, the two connecting elements 19a, 19b form a semi-circular recess 27 between them. A material bond connection in the form of welding or adhesive can be received in said recess 27. In the figures, the material bond connection between the first connecting element 19a and the second connecting element 19b is not shown.

[0054] For example, especially in Figures 4 to 7 As can be seen, the connecting line VL or engagement point of the connecting device 19 is located approximately in the plane E of the tooth segment passing through the toothed arrangement 20.

[0055] Figure Labels

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Claims

1. A stator (13) for an electric motor, particularly as a drive unit for a power tool, the stator comprising at least one first tooth arrangement and a second tooth arrangement (20), each of the first tooth arrangement and the second tooth arrangement having a web element for receiving a radially arranged coil winding. Its features are, Each toothed arrangement (20) includes an arcuate ring segment (17, 18) and a connecting device (19) having a first connecting element (19a) and a second connecting element (19b), wherein the first connecting element (19a) and the second connecting element (19b) are both configured in a wedge shape such that, in the connected state, the first contact surface (21a) of the first connecting element (19a) extending obliquely relative to the tooth segment plane (E) rests on the second connecting element (19b) relative to the tooth segment plane. (E) On an inclined extending second contact surface (21b), wherein the first connecting element (19a) includes a first radially outwardly pointing protrusion (22a), and the second connecting element (19b) includes a second radially outwardly pointing protrusion (22b), wherein the first connecting element (19a) includes a first undercut (23a), and the second connecting element (19b) includes a second undercut (23b), the undercuts being configured to receive and hold at least one clamping element (24).

2. The stator (13) as described in claim 1. Its features are, The first connecting element (19a) and the second connecting element (19b) are configured such that the connecting line (VL) has both a section that extends obliquely relative to the tooth segment plane (E) and a section that extends radially.

3. The stator (13) as described in claim 1 or 2. Its features are, The segment extending obliquely relative to the plane (E) of the tooth segment is longer than the segment extending radially.

4. The stator (13) as described in at least one of claims 1 to 5. Its features are, The distance between the connecting line (VL) between the first connecting element (19a) and the second connecting element (19b) is longer than the width (BZ) of the toothed arrangement (20).

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