ACTUATING DRIVE COMPRISING A GUIDING ELEMENT

Abstract

The invention relates to an actuating drive and to a guiding element for use in an actuating drive. The actuating drive according to the invention includes an electric motor, comprising a rotor rotatably supported on a rotor axle and an output gear mechanically coupled to the rotor. The actuating drive further includes a guiding element comprising a guide configured to radially guide the output gear relative to an output axis. The guiding element also includes a first axle receiver configured to receive a distal end of the rotor axle. The guiding element also includes a second axle receiver configured to receive a central portion of the transmission axle.

Claims

1.-6. (canceled)

7. An actuating drive, comprising an electric motor, comprising a rotor rotatably supported on a rotor axle; an output gear mechanically coupled to the rotor; a transmission comprising a plurality of compound gears configured to mechanically couple the output gear to the rotor, wherein one of the compound gears is rotatably supported on the rotor axle, wherein two of the compound gears are rotatably supported on a transmission axle arranged offset with respect to the rotor axle, and wherein the transmission axle is of greater length than the rotor axle; and a guiding element comprising a guide configured to radially guide the output gear relative to an output axis, wherein the guiding element includes a first axle receiver configured to receive a distal end of the rotor axle, and a second axle receiver configured to receive a central portion of the transmission axle.

8. The actuating drive according to claim 7, wherein the second axle receiver includes a through opening configured to be slid onto the transmission axle up to a central portion of the transmission axle.

9. The actuating drive according to claim 7, wherein the second axle receiver is arranged between the two compound gears rotatably supported on the transmission axle.

10. A guiding element for use in an actuating drive, the guiding element comprising: a plate-like main body through which an opening extends having a circular cross-section having an inner contact surface at its inner circumference, configured to come into contact with a rotatably supported element of the actuating drive and to radially guide the rotatably supported element relative to a rotation axis; a first axle receiver configured to receive a distal end of a rotor axle of the actuating drive; and a second axle receiver configured to receive a central portion of a transmission axle of the actuating drive.

11. The guiding element according to claim 10, wherein the guiding element includes a plurality of positioning and/or fixing elements configured to engage corresponding counterparts in the housing of the actuating drive to position and/or fix the guiding element within the housing.

12. The guiding element according to claim 10, wherein the plate-like main body of the guiding element includes a receiving region having a circular cross-section configured to receive a compound gear of a transmission of an actuating drive rotatably supported on the transmission axle of the actuating drive.

Description

DRAWING

[0039] Further advantages can be derived from the following description of the drawing. In the drawing, an exemplary embodiment of the invention is shown. The drawing, the description and the claims comprise numerous features in combination. The person skilled in the art will also suitably consider the features in isolation and will combine them to further suitable configurations.

[0040] In the drawing:

[0041] FIG. 1 shows an explosive view of an actuating drive in accordance with an example;

[0042] FIG. 2 shows a cross-sectional view of the actuating drive of FIG. 1 without a housing;

[0043] FIG. 3 shows a cross-sectional view of the actuating drive of FIG. 1 with the housing;

[0044] FIG. 4 shows a perspective view of the actuating drive of FIG. 1 without a housing;

[0045] FIG. 5 shows a bottom view of the electric motor of the actuating drive of FIG. 1;

[0046] FIG. 6a shows an oblique perspective top view of a guiding element for use in an actuating drive according to an example;

[0047] FIG. 6b shows an oblique perspective bottom view of the guiding element of FIG. 6a.

DESCRIPTION OF THE EXEMPLARY EMBODIMENT

[0048] FIGS. 1 to 5 show an actuating drive 100 according to an example. FIG. 1 shows an explosive view of the actuating drive 100, FIG. 2 shows a cross-sectional view without the housing 122, 124, FIG. 3 shows a cross-sectional view of the housing 122, 124, and FIG. 4 shows a perspective view without the housing 122, 124. FIG. 5 shows a bottom view of the electric motor 102 of the actuating drive 100.

[0049] The actuating drive 100 includes an electric motor 102 comprising a rotatably supported rotor 104 and a stator 106 surrounding the rotor 104. In the example of FIGS. 1 to 5, the electric motor 102 is formed as a brushless DC motor, wherein the stator 106 includes a plurality of phase windings 106A arranged about the rotor 104. The rotor 104 is rotatably supported on a rotor axle 108, wherein the rotor axle 108 is formed as a cylindrical rod, and a proximal or bottom end of the rotor axle 108 is arranged in a corresponding receiver in a bottom plate of the housing 122 in a manner resistant to rotation.

[0050] The actuating drive 100 further includes an output gear 110 integrally formed with an output shaft 110A formed as a hollow shaft. The output shaft 110A includes an engagement profile on its inner circumference, via which the output gear 110 can be connected to an actuated component (not shown). The output gear 110 is mechanically coupled to the rotor 104 via a transmission 112, so that a rotary motion of the rotor 104 about the rotor axle 108 is converted to a rotary motion of the output gear 110.

[0051] The actuating drive 100 also includes a guiding element 114 comprising a guide 116 adapted to radially guide the output gear 110 relative to an output axis 118. For this purpose, the guide 116 includes, as discussed in more detail below with reference to FIGS. 6a and 6b, a circular opening 138 in the guiding element 114 adapted to receive a shaft 110B. The shaft 110B is connected to the output gear 110, for example is integrally formed with the output gear 110, and is arranged on the side of the output gear 110 opposite the output shaft 110A. In the example of FIGS. 1 to 5, the output axis 118 extends in parallel to the rotor axle 108 and thus to the rotation axis of the rotor 104. The guiding element 114 can be formed, for example, of metal and/or a plastic material, in particular a thermoplastic material, wherein the plastic material can be glass-fiber reinforced to increase the mechanical stability of the guiding element 114, as needed.

[0052] The guiding element 114 includes a first axle receiver 120 adapted to receive a distal or top end of the rotor axle 108. For this purpose, the first axle receiver 120 includes, as described in more detail below with reference to FIGS. 6a to 6b, a recess 120B which can be fitted on the rotor axle 108, for example in such a manner that the rotor axle 108 is pressed into the recess 120B in a manner resistant to rotation and/or is hot caulked or ultrasonically welded thereto.

[0053] The above-mentioned components of the actuating drive 100 are arranged in a housing 122 having a lid 124, wherein the lid 124 includes an opening through which the engagement profile of the output shaft 110A is accessible from the outside. The guiding element 114 is arranged between the rotor 104 and the output gear 110 in the direction of the output axis 118, wherein the shaft 110B extends from the bottom end face of the output gear 110 through the guiding element 114 towards the rotor 104.

[0054] The actuating drive 100 further includes a printed circuit board 126 arranged between the guiding element 114 and the rotor 104. A magnetic field sensor 128 is arranged on the printed circuit board 126, wherein the magnetic field sensor 128 can be, for example, a two-dimensional or three-dimensional Hall sensor. The magnetic field sensor 128 is adapted to measure the strength and/or direction of a magnetic field which is produced by a magnet 130 fixed in a manner resistant to rotation in an end side recess in the shaft 110B connected to the output gear 110 by means of a retainer. Both the magnetic field sensor 128 and the magnet 130 are arranged in such a manner that the output axis 118 extends through the magnetic field sensor 128 and the magnet 130. In an analogous fashion, in other embodiments, an arrangement comprising a capacitive or inductive sensor can be provided, wherein an electrically conductive element is arranged on the end face of the output gear, for example in the end face recess of the output gear.

[0055] The transmission 112 of the actuating drive 100 includes a plurality of compound gears. In the example of FIGS. 1 to 5, the transmission consists of three compound gears 112-I, 112-II, 112-III, each including a gear facing the rotor 104 and a pinion facing away from the rotor 104, wherein the gear and the pinion are connected to each other in a manner resistant to rotation and can be integrally formed, for example.

[0056] A first compound gear 112-I is rotatably supported on a transmission axle 132, wherein the transmission axle 132 extends in parallel to the rotor axle 108 from a bottom receiver in the bottom plate of the housing 122 through an opening in the printed circuit board 126 to a top receiver in the lid 122. The first compound gear 112-I is arranged above the printed circuit board 126 and meshes with an input gear 104A arranged on the rotor axle 108. The input gear 104A is connected in a manner resistant to rotation to the rotor 104 arranged below the printed circuit board 126 via a shaft arranged in a further opening in the printed circuit board 126.

[0057] The pinion of the first compound gear 112-I meshes with the gear of a second compound gear 112-II, which is rotatably supported on the rotor axle 108 above the input gear 104A. The pinion of the second compound gear 112-II includes a recess at its top end face, in which a cylindrical protrusion 120A of the first axle receiver 120 is arranged, which is described in more detail below with reference to FIGS. 6a to 6b. This enables axial guiding of the second compound gear 112-II and of the rotor 104 with the input gear 104A along the rotor axle 108.

[0058] The pinion of the second compound gear 112-II meshes with the gear of a third compound gear 112-III which is rotatably supported on the transmission axle 132 above the first compound gear 112-I. The pinion of the third compound gear 112-III, in turn, meshes with the output gear 112 and is in contact with a protrusion on the lid 122 at its end face, which thus provides a top axial guide for the first compound gear 112-I and the third compound gear 112-III along the transmission axle 132. At the same time, the stator 106, at its top side, has a contact surface 106C in contact with an end-side working surface of a shaft, which is connected to the first compound gear 112-I and extends along the transmission axle 132 through the corresponding opening in the printed circuit board 126. The contact surface 106C of the stator 106 thus forms a bottom axial guide for the first compound gear 112-I and the third compound gear 112-III along the transmission axle 132.

[0059] The rotor axle 108 is arranged in such a manner that it is within an outer circumference of the output gear 110 in the direction radial to the output axis 118, that is that the rotor axle 108 is closer to the output axis 118 than the outer circumference of the output gear 110. The first axle receiver 120 of the guiding element 114 arranged below the end face of the output gear 110 forms a top retaining point for the rotor axle 108 so that the rotor axle 108 can be firmly held within the housing 122 even without contact to the lid 122.

[0060] The transmission axle 132 is arranged within an outer circumference of the stator 106 and extends, as can be seen in FIGS. 3 and 5, from the printed circuit board 126 through a space between two neighboring phase windings 106A of the stator 106 to the bottom plate of the housing 122. Correspondingly, the transmission axle 132 is arranged within a magnetic back iron element 106b surrounding the phase windings 106A in the circumferential direction. Due to this arrangement of the transmission axle 132, a maximum diameter of the transmission axle 132 is limited to the magnetic back iron element 106b surrounding the phase windings 106A in the circumferential direction, in which the transmission axle 132 is arranged. This limited diameter of the transmission axle 132, in combination with the length of the transmission axle 132, which is greater than the length of the rotor axle 108, leads to the necessity of preventing bending of the transmission axle 132 during operation of the actuating drive 100.

[0061] To prevent bending of the transmission axle 132 during operation of the actuating drive 100, the guiding element 114, in addition to the first axle receiver 120, further includes a second axle receiver 148 adapted to receive a central portion of the transmission axle 132. The second axle receiver 148 includes a through opening 150 in the guiding element 114 through which the transmission axle 132 can pass. Preferably, the second axle receiver 148 is adapted to receive the central portion of the transmission axle 132 disposed between the distal end and the proximal end of the transmission axle 132. The transmission axle 132 is introduced into the second axle receiver 148, or the second axle receiver 148 is slid onto the transmission axle 132 up to a point so that the central portion of the transmission axle 132 is directly arranged in the second axle receiver 148. The second axle receiver 148, in the assembled state, is arranged, in the axial direction, between the first compound gear 112-I and the third compound gear 112-III. Such placement of the rotor axle 108 and the transmission axle 132, in combination with the alternating arrangement of the compound gears 112-I to 112-III on the rotor axle 108 and the transmission axle 132, enables space-saving arrangement of the components of the actuating drive 100 only occupying a small base area perpendicular to the output axis 118. All the compound gears 112-I to 112-III are arranged on the side of the printed circuit board 126 facing away from the rotor 104, on which the output gear 110 is also situated.

[0062] The actuating drive 100 further includes a connection or connector 134 via which the printed circuit board 126 can be electrically contacted from the outside. To further reduce the base area occupied by the actuating drive 100, the connector 134 can extend in parallel to a sidewall of the housing 122 which, in turn, can be parallel to the rotor axle 108 and the output axis 118. The connector 134 can extend, as shown in FIG. 3, upwards from the level of the printed circuit board 126 to enable contacting of the actuating drive 100 from above. Alternatively, the connector 134 can also extend downwards from the level of the printed circuit board 126, for example, in parallel to the sidewall of the housing 122 surrounding the stator 106.

[0063] FIGS. 6a and 6b show a guiding element 114 for use with an actuating drive according to one example. In FIG. 6b, the guiding element 114 is shown in a perspective view obliquely from above, and in FIG. 6b, in a perspective view obliquely from below. The guiding element 114 can be used, for example, in the actuating drive 100 described above with reference to FIGS. 1 to 5, as a guiding element for the output gear 110, a receiver for the rotor axle 108 and a receiver for the transmission axle 132. Such use will be described in the following for exemplary illustration of the guiding element 114. Alternatively, the guiding element 114 can also be used in a different actuating drive, as a guiding element for a different rotatably supported element of an actuating drive and/or for receiving any other axle of an actuating drive.

[0064] The guiding element 114 includes a plate-like main body 114A, through which an opening 138 having a circular cross-section extends, adapted to receive a shaft 110B connected to the output gear 110. The opening 138 has a cylindrical contact surface 144 on its inner circumference adapted to come into contact with the outside of the shaft 110B and to rotatably support the shaft 110B and thus the output gear 110 about a rotary axis or output axis 118. The opening 138 in the guiding element 114 thus forms a guide 116 adapted to radially guide the shaft 110B and the output gear 110 relative to the output axis 118. The main body 114A, on its top side shown in FIG. 6a, includes an end-side contact surface 146 annularly extending about the output axis 118. The contact surface 146, as shown in FIG. 2, is adapted to come into contact with an end face of the output gear 110 connected to the shaft 110B and so to axially guide the output gear 110 relative to the rotary axis 118. The guiding element 114 thus forms both a radial and an axial guide for the output gear 110.

[0065] A first axle receiver 120 is arranged on the main body 114A adapted to receive the rotor axle 108 of the actuating drive 100 in a manner resistant to rotation. The first axle receiver 120 includes a cylindrical protrusion 120A arranged on a bottom side of the main body 114A extending downwards in parallel to the output axis 118. A recess 120B is arranged on a bottom end face of the cylindrical protrusion 120A into which a distal end of the rotor axle 108 can be pressed in a manner resistant to rotation. The cylindrical protrusion 120A is adapted as described above with reference for the actuating drive 100 to be arranged in a recess on an end face of a gear rotatably supported on the rotor axle 108, such as for example the second compound gear 112-II. The bottom end face of the cylindrical protrusion 120A can come into contact with a bottom surface of a recess on the end face of the second compound gear 112-II and thus axially guide the second compound gear 112-II along the rotor axle 108.

[0066] The plate-like main body 114A of the guiding element 114 further includes a receiving region 152 adapted to receive the third compound gear 112-III rotatably supported on the transmission axle 132. The receiving region 152 has a circular cross-section and extends starting from a top side of the main body 114A towards a bottom side of the main body 114A. The receiving region 152 is open at the top of the main body 114A so that the third compound gear 112-III can be introduced into the receiving region 152 from above. To allow meshing of the third compound gear 112-III with the pinion of the second compound gear 112-II, a bottom and also a circumferential wall of the receiving region 152 are formed to be discontinuous. At the bottom of the receiving region 152, a second axle receiver 148 is arranged. As shown in FIG. 3, the transmission axle 132 extends starting from a receiver in a bottom of the housing 122, through the first compound gear 112-I, through the second axle receiver 148 and through the third compound gear 112-III towards a receiver in the lid 124.

[0067] The guiding element 114 further includes a plurality of positioning and/or fixing elements 140 adapted to engage corresponding counterparts 142 in the housing 122 of the actuating drive to position and/or fix the guiding element 114 within the housing 122. The positioning and/or fixing elements 140 are each arranged on a peripheral region of the plate-like main body 114A. The guiding element 114 includes, by way of example, four positioning and/or fixing elements 140 which are arranged in a distributed manner over an outer circumference of the plate-like main body 114A of the guiding element 114. The positioning and/or fixing elements 140 are formed as noses facing towards a bottom of the housing 122 in an assembled state of the guiding element 114 adapted to engage, for example introduced or pressed into, counterparts 142 on the housing 122 of the actuating drive 100 formed as grooves extending in the axial direction.

LIST OF REFERENCE NUMERALS

[0068] 100 actuating drive [0069] 102 electric motor [0070] 104 rotor [0071] 104A input gear [0072] 106 stator [0073] 106A phase winding [0074] 106B back iron element [0075] 106C contact surface of stator 106 [0076] 108 rotor axle [0077] 110 output gear [0078] 110A output shaft [0079] 110B shaft of output gear 110 [0080] 112 transmission [0081] 112-I first compound gear [0082] 112-II second compound gear [0083] 112-III third compound gear [0084] 114 guiding element [0085] 114A main body [0086] 116 guide [0087] 118 output axis/rotation axis [0088] 120 first axle receiver [0089] 120A cylindrical protrusion [0090] 120B recess [0091] 122 housing [0092] 124 lid [0093] 126 printed circuit board [0094] 128 magnetic field sensor [0095] 130 magnet [0096] 132 transmission axle [0097] 134 connector [0098] 138 opening in guiding element [0099] 140 positioning/fixing element [0100] 142 counterpart [0101] 144 inner contact surface [0102] 146 end-side contact surface [0103] 148 second axle receiver [0104] 150 through opening [0105] 152 receiving region