Electrical Drive

The asymmetric assembly of electric drive devices with offset parallel longitudinal axes addresses the bulkiness and weight distribution issues, resulting in a more compact and balanced design.

JP7787145B2Active Publication Date: 2025-12-16BRAUN GMBH
View PDF 5 Cites 0 Cited by

Patent Information

Application Number
JP2023500048
Authority / Receiving Office
JP · JP
Patent Type
Patents
Current Assignee / Owner
Filing Date
2020-07-01
Publication Date
2025-12-16
Estimated Expiration
2040-07-01

AI Technical Summary

Technical Problem

Existing electric drive devices, such as shavers and toothbrushes, face issues with bulky design due to centrally located motors and separate battery placement, leading to uneven weight distribution and inefficient use of space.

Method used

An asymmetric assembly design with a chassis that houses the electric motor and battery unit side by side, featuring offset parallel longitudinal axes for the drive shafts, allowing for a more balanced weight distribution and optimized space utilization.

Benefits of technology

The design optimizes space usage and weight distribution, enabling a more compact and balanced electric drive device with improved assembly efficiency and reduced bulkiness.

✦ Generated by Eureka AI based on patent content.

Smart Images

  • Figure 0007787145000001
    Figure 0007787145000001
  • Figure 0007787145000002
    Figure 0007787145000002
  • Figure 0007787145000003
    Figure 0007787145000003
Patent Text Reader

Abstract

The present invention relates to an electrically driven device (300), for example, an electric hair removal device such as a wet or dry shaver, an electric toothbrush, or an electric skin care device. The electrically driven device (300) includes a housing (301, 302, 304, 305) having a chassis (200). The chassis (200) includes an electric motor (100) having a first drive shaft (103), a battery unit (102), and a vibrator (2) having a second drive shaft (3). A first longitudinal axis (I) is defined along the second drive shaft (3), a second longitudinal axis (II) is defined along the first drive shaft (103), and a third longitudinal axis (III) is defined through the center of the body of the battery unit (102). The second longitudinal axis and / or the third longitudinal axis are offset parallel to the first longitudinal axis. To improve the required space required for assembly of the electric drive unit (300) and the overall weight distribution relative to the drive shaft (3) of the vibrating body (2), the second longitudinal axis (II) and / or the third longitudinal axis (III) are offset parallel to the first longitudinal axis (I).
Need to check novelty before this filing date? Find Prior Art

Description

[Technical Field]

[0001] The present invention relates to an asymmetric assembly of an electric drive, for example an electric hair removal device such as a wet or dry shaver, an electric toothbrush or an electric skin beauty device. More precisely, the electric drive comprises an electric motor, a battery unit and a vibrator with a second drive shaft, for example for actuating a cutter unit, with a parallel offset between the electric motor and / or the battery unit and the second drive shaft of the vibrator. [Background technology]

[0002] German Patent Application Publication No. 32 24 223 A1 discloses an electrically driven shaver having a centrally located motor and two batteries arranged alongside the motor. The motor and batteries are accommodated and fixed directly within the outer housing of the shaver. The central location of the motor may have the advantage of keeping the drive mechanism simple. On the other hand, the provision of two batteries arranged adjacent to the motor makes the shaver design bulky.

[0003] Another example of a centrally located motor in an electric shaver is shown in EP 2 024 147 B1, where the battery may be located at the opposite axial end of the motor, i.e., the side facing away from the cutter unit, which increases the length of the shaver housing.

[0004] Furthermore, European Patent No. 2 024 147 (B1) discloses an oscillating bridge for converting rotary motion into oscillatory motion. This known oscillating bridge can be used in an electric drive device such as an electric shaver. The oscillating bridge includes an oscillator with a coupling, a drive shaft, and two oscillating arms. The coupling includes a slot for coupling an eccentrically rotatable drive pin, which is coupled to the drive shaft of an electric motor, to the oscillating bridge. The drive shaft of the oscillator may be coupled to a cutter unit, and the two drive shafts, i.e., the drive shaft of the electric motor and the drive shaft of the oscillator, are arranged in a common plane extending through the slot. The oscillating arms may be coupled to the housing of the electric drive device. Therefore, during use of the electric drive device, the oscillator of the oscillating bridge is free to move only linearly between the two oscillating arms. Thus, the oscillating bridge converts the rotary motion of the drive pin into linear oscillatory motion of the drive shaft.

[0005] Aligning the drive shafts in a common plane can have drawbacks for the assembly of the electric drive because the drive shaft of the electric motor must be aligned with the drive shaft of the swing bridge, which can therefore lead to unused space in the housing as well as uneven weight distribution on the drive shaft when the battery unit is located separately from the electric motor. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] German Patent Application Publication No. 32 24 223(A1) [Patent Document 2] European Patent No. 2 024 147(B1) Summary of the Invention [Means for solving the problem]

[0007] It is an object of the present disclosure to provide an electric drive having a housing with a chassis, the chassis adapted to house an electric motor, a battery unit and a vibrating body, improving the overall weight distribution relative to the drive shaft of the vibrating body as well as the required space required for assembly.

[0008] The electric drive according to claim 1 solves this object. Advantageous further features are set forth in the dependent claims. According to claim 1, an electric drive device having a housing comprises a chassis, the chassis comprising a plastic skeleton for accommodating an electric motor having a first drive shaft, a battery unit, a PCB, and a vibrating body having a second drive shaft, the chassis being provided with an opening or cavity for accommodating the motor and battery unit side by side, and the PCB being provided on a side thereof, side by side with one of the motor and the battery unit.

[0009] Claim 10 According to the patent, the electric drive device includes a housing having a chassis, the chassis including a plastic skeleton including an electric motor having a first drive shaft, a battery unit, and a vibrating body having a second drive shaft, wherein a first longitudinal axis is defined along the second drive shaft, a second longitudinal axis is defined along the first drive shaft, and a third longitudinal axis is defined through a center of the body of the battery unit, and the second longitudinal axis and / or the third longitudinal axis are offset parallel to the first longitudinal axis. DETAILED DESCRIPTION OF THE INVENTION

[0010] Preferably, the electric motor includes a first drive shaft centered relative to the motor and mechanically coupled to the oscillatory body via an eccentric drive pin. The oscillatory body may be part of an oscillating bridge. Hereinafter, the "oscillating bridge" feature may also be referred to as a "oscillating bridge." Thus, upon actuation, i.e., rotation, of the first drive shaft, the oscillatory body, and thus the second drive shaft, vibrates. Each of the two drive shafts extends along a longitudinal axis, i.e., a first and a second longitudinal axis. The oscillatory body may define a plane extending in two directions, i.e., two transverse directions, perpendicular to the longitudinal axis. Preferably, the oscillatory body substantially vibrates in one of the transverse directions, i.e., one direction of the plane, perpendicular to the longitudinal axis. Furthermore, a third longitudinal axis extends through the center of the body of the battery unit. If there are multiple battery units, the third longitudinal axis is preferably given by a point averaged from several centers of the body, or each battery unit has its own longitudinal axis extending through its center of the body, i.e., there are multiple third longitudinal axes. Preferably, the second and / or third longitudinal axes are offset parallel to the first longitudinal axis in at least one of the lateral directions defined by the plane. Furthermore, if an offset is given only in one lateral direction, this direction is preferably the direction of the vibrational motion of the vibrating body. Furthermore, there can also be embodiments in which at least one of the longitudinal axes is not only offset parallel but also inclined.

[0011] In one embodiment, the second longitudinal axis and the first longitudinal axis, and the third longitudinal axis and the first longitudinal axis are offset by different offset distances. This means that the parallel offset between the first longitudinal axis and the second axis is different from the parallel offset between the first longitudinal axis and the third longitudinal axis. It is also possible for the first longitudinal axis and, for example, the second longitudinal axis to be parallel offset in only one lateral direction, while the first longitudinal axis and the third longitudinal axis to be parallel offset in two lateral directions, or vice versa. In this case, offset distances pointing in the same lateral direction must be comparable, i.e., different. However, the first longitudinal axis extending through the second drive shaft of the vibrating body is preferably aligned substantially along an axis extending through the center of the body of the electric drive device. As a result, the second drive shaft preferably vibrates in one lateral direction and therefore substantially vibrates around an axis extending through the center of the body of the electric drive device.

[0012] In a preferred embodiment, the second longitudinal axis and the third longitudinal axis are offset in opposite lateral directions from the first longitudinal axis. Considering that the second drive shaft substantially oscillates around the first longitudinal axis, the second longitudinal axis, i.e., the first drive shaft of the electric motor, is offset in parallel in at least one lateral direction, and the third longitudinal axis is offset in parallel in the opposite lateral direction. When one of the second or third longitudinal axes is offset in parallel in two lateral directions relative to the first longitudinal axis and the other longitudinal axis is offset in parallel in only one lateral direction relative to the first longitudinal axis, the term "opposite lateral directions" means that one of the two lateral directions is opposite to the first lateral direction. The same applies when both the second and third longitudinal axes are offset in parallel in two lateral directions. The second and third longitudinal axes are offset in parallel in opposite lateral directions at different offset distances, but the displacement of the second and third longitudinal axes in the vibration direction of the vibrating body is preferably such that the outermost parts of the electric motor in the vibration direction and the outermost parts of the battery unit in the vibration direction are substantially equidistant from the first longitudinal axis.

[0013] Furthermore, it may be preferred that the housing and / or chassis each comprise at least two components. This means that either the housing and / or the chassis comprises at least two components. Thus, it may be preferred that the chassis comprises one component and the housing comprises multiple components, or vice versa. It is also preferred if the chassis is an integral part of the housing or at least one of the housing components. In contrast, the chassis may be coupled to the housing or at least one of the housing components. Regardless of the number of chassis and / or housing components and regardless of the coupling between the chassis and the housing, the chassis is defined as a component for accommodating at least the electric motor and the battery unit.

[0014] Preferably, at least two components, i.e., at least two components of the housing and / or chassis, comprise different material stiffnesses. Preferably, the chassis comprises one component and the housing comprises multiple components. Screws, hooks, welds, etc. may connect the chassis and the housing. Furthermore, the at least two components may differ in other material properties, such as strength, hardness, etc. It is also preferred if some of the housing components at least partially overlap, and the overlapping components comprise different material properties. The chassis may be made by 2k hard-soft injection molding.

[0015] Furthermore, the housing or at least one of the housing components can be formed integrally with the chassis or with one of the chassis components, so that the only difference between the housing component and the chassis or chassis component can be found in the fact that the chassis houses at least the electric motor and the battery unit, as described above.

[0016] In one embodiment, the chassis has an opening or cavity for accommodating the motor and battery unit side by side, and a PCB is provided on a side of one of the motor and battery unit. The chassis with its framework includes at least an upper wall, a lower wall, a rear wall, and a front wall, and the front or rear wall has an opening or cavity for accommodating the battery unit and the motor, and the PCB is fixed to the side of the chassis. Preferably, the front wall is at least partially open to provide easy access to the interior of the chassis and thus facilitate assembly. Furthermore, a closed or at least partially closed rear wall improves the rigidity of the chassis. Additional design measures, such as crossbars, may also be used to increase the rigidity of the chassis. Note that an at least partially open front or rear wall also includes a completely open front or rear wall, i.e., a chassis without a front or rear wall. Furthermore, the chassis may include an additional element, such as a wall-type element, between the electric motor and the battery unit. This wall-type element can secure the electric motor and / or the battery unit and can also reinforce the chassis.

[0017] Furthermore, the second drive shaft can be adapted to be mechanically coupled to at least one cutter unit. The at least one cutter unit may include at least one slit cutter, which includes at least one outer blade, preferably a foil-type blade, and an inner blade. Preferably, the vibration of the inner blade is caused by vibration of the second drive shaft of the oscillating body. Because the second drive shaft can substantially oscillate around an axis extending through the center of the body of the electric drive device, units such as the cutter unit attached to the drive shaft can be driven substantially centrally.

[0018] In one embodiment, the electric motor comprises a drive pin eccentrically rotatable about the second longitudinal axis, the drive pin adapted to be mechanically coupled to the vibrating body. More precisely, the eccentrically rotatable drive pin is coupled to the first drive shaft or is integrally formed with the first drive shaft. Furthermore, the eccentrically rotatable drive pin may be coupled to a slot or groove or the like in the vibrating body, where the slot may be an elongated hole, and the slot or groove has a smaller width in a transverse direction of the electric drive, preferably a transverse direction equal to the direction of vibration of the vibrating body. As a result, rotation of the eccentrically rotatable drive pin pushes the vibrating body back and forth in a transverse direction.

[0019] Preferably, the housing and / or chassis are provided with mounting means, preferably pressure ribs, for fixing the movement of the vibrating body in at least one direction. Thus, the housing and / or chassis may be provided with mounting means on the side walls of the chassis and / or housing, but also on the wall-type element separating the electric motor and the battery unit. Furthermore, as mentioned above, the vibrating body may be part of an oscillating bridge, further comprising two webs or wings extending at least substantially perpendicular to the plane of the vibrating body. The two webs may have free ends facing away from the vibrating body. Thus, the mounting means can fix these free ends, and the vibrating movement of the vibrating body bends the two webs. To fix the free ends in the pressure ribs, the free ends of the webs may be pressed into the pressure ribs, after which, optionally, heat staking melts the ribs.

[0020] In a preferred embodiment, the housing or at least one of the housing components and / or the chassis or at least one of the chassis components comprise means for fixing the electric motor. The chassis or chassis component preferably forms these means to provide a form fit. Alternatively, the electric motor may be fixed to the chassis or chassis component in a rigidly coupled manner.

[0021] Furthermore, the housing or housing components and / or the chassis or chassis components may be formed by injection molding. Since a type of plastic material is preferably used to form the housing or housing components and the chassis or chassis components, injection molding provides a manufacturing process that is particularly suitable for mass production. Obviously, other manufacturing processes may exist, which may be advantageous depending on the quantity of components, etc., the type of material, and the preferred material properties.

[0022] The electric drive device may further include a cap, which is removably attached to the housing or one of the housing components, and which covers at least a button for activating the electric drive device. The cap may be removed during use of the electric drive device, and may be attached to the electric drive device during storage and / or transportation. Thus, using the cap during storage and / or transportation can prevent undesired operation of the device and / or undesired soiling, such as undesired soiling of the dop kit by clipped hair. Furthermore, the cap can protect the electric drive device from any intrusion, such as dust intrusion, and therefore can extend the durability of the electric drive device.

[0023] Furthermore, the electric motor and battery unit may be sealed against moisture penetration by seals on at least one of the housing or housing components and / or the chassis or chassis components and / or the cap. This is particularly necessary when the electric drive is used in a wet environment, such as a bathroom. Sealing of the electric drive and / or moisture-sensitive components is carried out by conventional means.

[0024] The invention will now be described in detail with reference to particular embodiments illustrated in the drawings. All features described and / or shown in the drawings are subject of the invention, regardless of the grouping of features in the claims and / or references thereto. [Brief explanation of the drawings]

[0025] [Figure 1a] FIG. 2 shows a perspective view of a swing bridge. [Figure 1b] 1c shows a cross-sectional view of the swing bridge of FIG. 1a along line AA. [Figure 1c] 1b shows a plan view of the oscillating unit of FIG. 1a; [Figure 1d] 1b shows a side view of the oscillating unit of FIG. 1a; [Figure 2] 1b shows an exploded view of the components of the swing bridge of FIG. 1a together with the electric motor. [Figure 3] 3 shows a perspective view of the swing bridge and electric motor of FIG. 2 arranged in a chassis. [Figure 4a] 1 shows a perspective view of an assembled electric drive according to an embodiment of the present invention. [Figure 4b] 4b shows a cross-sectional view of the electrical drive of FIG. 4a; [Figure 5] 4b shows an exploded view of the electrical drive of FIG. 4a together with the cap.

[0026] The oscillating bridge 1 shown in Figure 1a comprises an oscillatory body 2 and a second drive shaft 3. The oscillatory body 2 in Figure 1a has an upper first component 4 and a lower second component 5, the first component 4 having a different shape than the second component 5. The oscillatory body 2 and each of the first and second components 4 and 5 are ultrasonically welded to each other and define a plane X.

[0027] The oscillating bridge 1 further comprises two webs 6 that are an integral part of the second component 5 of the oscillating body 2. The two webs 6 each have a free end 7 facing away from the oscillating body 2. To allow bending in the lateral direction of an electric drive (not shown), the webs 6 generally have a material strength or thickness V that is smaller compared to their width W. The width W of the webs 6 shown in FIG. 1a is slightly smaller than the width of the components 4 and 5 of the oscillating body 2. Furthermore, the width W of the webs 6 between the oscillating body 2 and the free ends 7 can be different. Furthermore, the free ends 7 in FIG. 1a have protrusions facing away from the oscillating body 2 to fix the oscillating bridge 1.

[0028] Furthermore, the second component 5 of the swing bridge 1 has a slot 8 (shown in FIG. 2). The second drive shaft 3 is overmolded into a corner portion of the first component 4 and extends along the first longitudinal axis I.

[0029] Figure 1 c The cross section AA of Fig. 1 b 1b. The weld dots 9 in FIG. 1b are used for ultrasonic welding of the two components 4 and 5 of the vibrating body 2. The first component 4 with the second drive shaft 3 protrudes beyond the second component 5 on the side where the second drive shaft 3 is located. Furthermore, the overmold of the second drive shaft 3 is provided with ribs 10 for supporting it on the first component 4.

[0030] FIG. 1c shows a plan view of the oscillating bridge 1. It can be seen that the first component 4 and the second component 5 are ultrasonically welded together by four welding dots 9. The oscillating bridge 1 appears to have only one web 1 on the left side, while the web on the right side is simply covered by the protruding first component 4, as previously mentioned. Furthermore, the second drive shaft 3, located in a corner of the oscillator 2, is offset in two directions in the plane X, with one lateral offset being greater than the other lateral offset in the plane X.

[0031] In Figure 1d a side view of the swaying bridge 1 is shown, in which the above-mentioned different widths W of the webs 6 can be seen. The width W of the webs 6 is greater at the free ends 7 which are provided with protrusions for fixing the swaying bridge 1.

[0032] FIG. 2 shows an exploded view of the oscillating bridge 1 of FIGS. 1a to 1d together with the electric motor 100. The second component 5 represents the slot 8 mentioned above. The slot 8 shown in FIG. 2 is an elongated hole with a smaller extension in the direction of oscillation of the oscillating bridge 1. The electric motor 100 comprises an eccentrically rotatable drive pin 101. When the oscillating bridge 1 and the electric motor 100 are assembled, the drive pin 101 extends into the slot 8 of the oscillating bridge 1. This allows the rotational movement of the drive pin 101 to be converted into an oscillation movement of the oscillating bridge 1. In particular, if the oscillating bridge 1 is fixed by the free end 7 of the web 6, this oscillation movement is a linear oscillation movement in the transverse direction of the electric drive (not shown) (deflection in the direction perpendicular to the plane X is ignored). The drive pin 101 may be coupled to the first drive shaft 103 (shown in FIG. 4b) of the electric motor 100 or may be an integral part of the first drive shaft 103. Furthermore, a second longitudinal axis II is shown extending along this first drive shaft 103 of the electric motor 100. Furthermore, Figure 2 shows a parallel offset between the first longitudinal axis I and the second longitudinal axis II, and therefore an asymmetric assembly. The two longitudinal axes I and II are offset in parallel in two lateral directions of the plane X. Furthermore, it can be seen that the second longitudinal axis II extends through the center of the slot 8.

[0033] The chassis 200, which includes the assembled swing bridge 1 and electric motor 100 together with the battery unit 102, is shown in FIG. 3. The chassis 200 is semi-open, meaning that the front wall 205 of the chassis 200, which includes an upper wall 202, a lower wall 203, and a rear wall 204, has been cut away. Thus, the chassis 200 opens on the front wall 205, providing easy access to the electric motor 101 and the battery unit 102. Furthermore, the at least mostly closed rear wall 204 provides additional rigidity to the chassis 200. Additionally or alternatively, the chassis 200 may be coupled to or be an integral part of the housing. The battery unit 102 is preferably rechargeable, and a third longitudinal axis III extends through the center of the body. Furthermore, the free end 7 of the swing bridge 1 is fixed to the chassis 200. One way to secure the oscillating bridge 1 to the chassis 200 is to press the free ends 7 of the webs 6 into the pressure ribs of the chassis 200 and melt these ribs by heat staking. Once the oscillating bridge 1 is secured, only the movement of the vibrating body 2 is permitted. Furthermore, due to the large width W of the webs 6 compared to the material strength V of the webs 6, the webs 6 are rigid in the lateral direction, which represents a smaller extension of the chassis 200, while being flexible in the lateral direction equal to the vibration direction of the vibrating body 2. Thus, the linear oscillating movement of the oscillating bridge 1 is caused by the rotational movement of the drive pins 101 that extend into the slots 8 of the vibrating body 2.

[0034] 4a shows an electric drive device 300 comprising the assembled chassis 200 (not shown) of FIG. 3. The electric drive device 300, here an electric shaver, comprises an upper housing 301, an outer housing 302, a button 303, and a cutter unit 201. The upper housing 301 includes the button 303. The button 303 is used to operate the electric drive device 300.

[0035] A cross-sectional view of the electric drive 300 is shown in Figure 4b. The electric drive 300 comprises a chassis 200 and a cutter unit 201. The chassis 200 is fixed in a housing and comprises a swing bridge 1, an electric motor 100, and a battery unit 102. As can be seen in Figure 4b, the electric motor 1 is arranged on the left side of the electric drive 300, and the battery unit 102 is arranged on the right side of the chassis 200. The assembly of the electric motor 100 and the battery unit 102 is therefore asymmetric with respect to the second drive shaft 3 of the oscillator 2.

[0036] The electric motor 100 comprises a first drive shaft 103 extending along a second longitudinal axis II and an eccentrically rotatable drive pin 101. The drive pin 101 extends into the slot 8 and mechanically couples the electric motor 100 to the oscillating bridge 1, which is fixed within the outer and inner walls of the chassis 200. As can be seen in FIG. 4b, the drive pin 101 extends through the slot 8 of the second component 5 and protrudes into a recess in the first component 4. Furthermore, the second drive shaft 3 of the oscillator 2 of the oscillating bridge 1, which extends along the first longitudinal axis I, is mechanically coupled to the cutter unit 201. Furthermore, the battery unit 102 comprises a third longitudinal axis III passing through the center of its body. As can be clearly seen, all three longitudinal axes I, II, and III are offset parallel to at least one lateral direction of the electric drive 300.

[0037] FIG. 4b also shows that, together with the parallel offset in the opposite lateral direction of the electric drive device 300 between the first longitudinal axis I and the second longitudinal axis II compared to the parallel offset between the first longitudinal axis I and the third longitudinal axis III, the offset distance between the first longitudinal axis I and the second longitudinal axis II is smaller than the offset distance between the first longitudinal axis I and the third longitudinal axis III.

[0038] The electric drive 300 further comprises multiple housing parts: an upper housing 301, an outer housing 302, a lower housing 304, and an inner housing 305. All housing parts 301, 302, 304, and 305, as well as the chassis 200, are connected by attachment means such as hooks, screws, etc., or some of them may be integrally molded. Here, the upper housing 301 is made of a soft plastic / component that is over-injected onto the inner housing 305, which is made of a hard plastic component. Thus, this housing / chassis part and optionally other housing / chassis parts are made in a 2K injection molding process. The upper housing 301 comprises a softer material than the inner housing 305. To prevent the internal components of the electric drive 300, especially the electric motor 100 and the battery unit 102, from getting wet, the PCB, electrical contacts, and chassis are sealed by a lower seal 306 and an upper seal / O-ring 308. The lower housing 304 is made up of the housing plastic part, the LED components and the charging pins, all co-injected together.

[0039] The additional seal 306 can be seen in the exploded view of the electric drive 300 in Figure 5. Furthermore, Figure 5 shows a cap 307 that can be attached to the electric drive 300 during storage and / or transportation. The dotted lines in Figure 5, excluding the line indicating the longitudinal axis III, show how some of the housing components and the seal 306 are assembled to the chassis 200.

[0040] Thus, the assembled exemplary electric drive 300 comprising the electric motor 100, the battery unit 102, the oscillating bridge 1 with the oscillating mass 2, and the cutter unit 201 is adapted to convert the rotational movement of the first drive shaft 103 of the electric motor 100 into a linear oscillation of the second drive shaft 3, and thus operate the cutter unit 201. The oscillating bridge 1 thus converts the rotational movement of the first drive shaft 103 of the electric motor 100 and each eccentric drive pin 101 into a linear oscillatory movement of the second drive shaft 3 and thus the cutter unit 103.

[0041] When the electric drive 300, i.e., the electric motor 100, is activated by the button 303 and the battery unit 102 supplies power to the electric motor 100, the first drive shaft 103 begins to rotate. The drive pin 101 attached to the first drive shaft 103 converts the rotational motion into an eccentric rotational motion. Because the drive pin 101 extends into the slot 8, i.e., an elongated hole with a smaller extension in the direction of oscillation of the oscillating bridge 1, a full rotation of the drive pin 101 first pushes the oscillating bridge 1 to its right side, bending the web 6 and shifting only the oscillator 2 of the oscillating bridge 1. As the drive pin 101 continues to rotate, it reaches a larger extension of the elongated hole and subsequently pushes the oscillating bridge 1 in the opposite direction, i.e., to the left. During the transition of the oscillating bridge 1 from right to left, the web 6 relaxes before being bent again. As the rotational movement of the drive pin 101 continues, the oscillating bridge 1, and therefore the second drive shaft 3, continues to oscillate in its longitudinal direction, thereby moving the cutter unit 201.

[0042] Since the oscillating bridge 1 allows for an offset between the drive shafts 3 and 103, the electric motor 100 can be assembled in the electric drive 300 at an edge close to the side wall of the chassis and / or housing. Thus, space is created for the battery unit 102 on the opposite side of the electric motor 100, optimizing the use of available installation space. Furthermore, the chassis 200 allows for an asymmetric assembly, where the electric motor 100 and the battery unit 102 are offset parallel to the second drive shaft 3, i.e., a parallel offset between the longitudinal axes I, II, and III, which provides a more balanced overall weight distribution within the electric drive 300 relative to the second drive shaft 3 of the oscillating mass 2.

[0043] As a result, the described assembly of the electric drive device 300 of the present invention is particularly suitable for small electric drives, especially those used for locomotion. The electric drive system includes: A. An electric drive device having a housing (301, 302, 304, 305) with a chassis (200), the chassis (200) comprising a plastic skeleton for accommodating an electric motor (100) having a first drive shaft (103), a battery unit (102), a PCB (104), and a vibrating body (2) having a second drive shaft (3), wherein a first longitudinal axis (I) is defined along the second drive shaft (3), a second longitudinal axis (II) is defined along the first drive shaft (103), and a third longitudinal axis (III) is defined through the center of the body of the battery unit (102); 10. An electric drive device, characterized in that the second longitudinal axis (II) and / or the third longitudinal axis (III) are offset parallel to the first longitudinal axis (I). B. The electric drive device described in A., characterized in that the second longitudinal axis (II) and the first longitudinal axis (I) and the third longitudinal axis (III) and the first longitudinal axis (I) are offset by different offset distances. C. An electric drive device as described in A. or B., characterized in that the second longitudinal axis (II) and the third longitudinal axis (III) are offset in opposite lateral directions from the first longitudinal axis (I). D. An electric drive device according to any one of A. to C., characterized in that the housing (301, 304, 305) and / or the chassis (200) comprises at least two components. E. The electric drive device of A. and D., wherein the at least two components comprise a soft component and a hard component. F. An electric drive device having a housing (301, 302, 304, 305) with a chassis (200), the chassis (200) having a plastic skeleton for accommodating an electric motor (100) having a first drive shaft (103), a battery unit (102), a PCB (104), and a vibrating body (2) having a second drive shaft (3), the chassis (200) having an opening or cavity for accommodating the motor (100) and the battery unit (102) side by side, the PCB (104) being provided on a side (206) of the electric drive device, also side by side with one of the motor and the battery unit. G. An electric drive device as described in any one of A. to F., characterized in that the chassis (200) having its skeleton has at least an upper wall (202), a lower wall (203), a rear wall (204) and a front wall (205), the front wall or the rear wall (204; 205) having an opening or cavity for accommodating the battery unit and the motor, and the PCB (104) is fixed to a side (206) of the chassis. H. An electric drive device as described in any one of A. to G., characterized in that the second drive shaft (3) is adapted to be mechanically coupled to at least one cutter unit (201). I. An electric drive device as described in any one of A. to H., characterized in that the electric motor (100) has a drive pin (101) eccentrically rotatable about the second longitudinal axis (II), and the drive pin (101) is adapted to be mechanically coupled to the vibrating body (2). J. An electric drive device according to any one of A. to I., characterized in that the housing (301, 302, 304, 305) and / or the chassis (200) are provided with mounting means, preferably pressure ribs, for fixing the movement of the vibrating body in at least one direction. K. An electric drive device as described in any of A. to J., characterized in that the housing (301, 302, 304, 305) or at least one of the housing components and / or the chassis (200) or at least one of the chassis components comprises means for fixing the electric motor (100). L. An electric drive device according to any one of A. to K., characterized in that the housing (301, 302, 304, 305) or the housing components and / or the chassis (200) or the chassis components are formed by injection molding. M. The electric drive device described in any one of A. to L., wherein the electric drive device (300) further comprises a cap (307), the cap (307) being removably attached to the housing (301, 302, 304, 305) or one of the housing components, the cap (307) covering at least a button (303) for activating the electric drive device (300). N. An electric drive device as described in any one of A. to N., characterized in that the electric motor (100) and the battery unit (102) are sealed against moisture penetration by a seal (306) of at least one of the housing (301, 302, 304, 305) or the housing components and / or the chassis (200) or the chassis components and / or the cap (307).

[0044] Reference number 1 Swinging Bridge 2 vibrating body 3 Second drive shaft (vibrator) 4. First Component 5. Second component 6. Web 7 Free end 8 slots 9 Welding Dots 10. Ribs 100 electric motor 101 Drive pin 102 Battery Unit 103 First drive shaft (electric motor) 104 Printed Circuit Board PCB 200 chassis 201 Cutter unit 202 Upper Wall 203 Lower Wall 204 Back wall 205 Front wall 206 Side wall 300 Electric Drive 301 Upper housing 302 outer housing 303 Button 304 Lower housing 305 inner housing 306 Seal 307 Cap 308 Seal / O-ring I First Longitudinal Axis II. Second longitudinal axis III Third longitudinal axis V Material strength (web) W Width (web) X plane

Claims

1. An electric drive device having a housing (301, 302, 304, 305) with a chassis (200), The chassis (200) an electric motor (100) having a first drive shaft (103); a battery unit (102), a PCB (104), a vibrating body (2) having a second drive shaft (3); and a plastic skeleton for accommodating the vibrating body (2); the chassis (200) has an opening or cavity in which the motor (100) and the battery unit (102) are housed side by side, the PCB (104) is provided on a side surface (206) of the chassis, side by side with one of the motor and the battery unit, the chassis (200) having its skeleton has at least an upper wall (202), a lower wall (203), a rear wall (204), and a front wall (205), the front wall or the rear wall (204; 205) having an opening or cavity for accommodating the battery unit and the motor, and the PCB (104) is fixed to the side surface (206) of the chassis.

2. 2. An electric drive device according to claim 1, characterized in that the second drive shaft (3) is adapted to be mechanically coupled to at least one cutter unit (201).

3. 3. An electric drive device according to claim 1 or 2, characterized in that the electric motor (100) comprises a drive pin (101) eccentrically rotatable about a second longitudinal axis (II), the drive pin (101) being adapted to be mechanically coupled to the oscillating body (2).

4. 4. An electric drive device according to claim 1, characterized in that the housing (301, 302, 304, 305) and / or the chassis (200) are provided with mounting means for fixing the movement of the vibrating body in at least one direction.

5. 5. An electric drive device according to claim 1, characterized in that the housing (301, 302, 304, 305) or at least one of the components of the housing and / or the chassis (200) or at least one of the components of the chassis comprises means for fixing the electric motor (100).

6. 6. Electric drive device according to any one of claims 1 to 5, characterized in that the housing (301, 302, 304, 305) or components of the housing and / or the chassis (200) or components of the chassis are formed by injection molding.

7. 7. The electric drive device according to claim 1, further comprising a cap (307) removably attached to the housing (301, 302, 304, 305) or one of the components of the housing, the cap (307) covering at least a button (303) for activating the electric drive device.

8. 8. The electric drive device according to claim 7, characterized in that the electric motor (100) and the battery unit (102) are sealed against moisture penetration by a seal (306) of at least one of the housing (301, 302, 304, 305) or a component of the housing and / or the chassis (200) or a component of the chassis and / or the cap (307).

9. a first longitudinal axis (I) is defined along the second drive shaft (3), a second longitudinal axis (II) is defined along the first drive shaft (103), and a third longitudinal axis (III) is defined through the center of the body of the battery unit (102); 2. The electric drive device according to claim 1, characterized in that the second longitudinal axis (II) and / or the third longitudinal axis (III) are offset parallel to the first longitudinal axis (I).

10. 10. The electric drive device according to claim 9, characterized in that the second longitudinal axis (II) and the first longitudinal axis (I) and the third longitudinal axis (III) and the first longitudinal axis (I) are offset by different offset distances.

11. 11. An electric drive device according to claim 9 or 10, characterized in that the second longitudinal axis (II) and the third longitudinal axis (III) are offset in opposite laterally from the first longitudinal axis (I).

12. 12. Electric drive device according to any one of claims 9 to 11, characterized in that the housing (301, 304, 305) and / or the chassis (200) comprises at least two components.

13. 13. The electric drive device of claim 12, wherein the at least two components comprise a soft component and a hard component.

Citation Information

Patent Citations

  • drive mechanism of an electrically operated dry shaver

    DE3224223A1

  • Swing bridge for converting a rotary motion into an oscillating motion and use of same in an electrical device

    EP2024147B1

  • Reciprocal type electric razor

    JP1986005872A

  • Charging type electric razor

    JP1986220687A

  • JP1987050561U