Assembly for a motor feedback system and motor feedback system

Abstract

Assembly (1) for a motor feedback system (2) comprising at least one plastic connecting part (3), a first printed circuit board (4) and a second printed circuit board (5), wherein the plastic connecting part (3) is arranged between the first circuit board (4) and the second circuit board (5), characterized by the fact that the plastic connecting part (3) has at least two elongated channels (6), wherein a conductive compression spring (7) is arranged in each channel, wherein the conductive compression springs (7) are each in contact surfaces (8) of the first circuit board (4) and the second circuit board (5) at their ends, thereby creating an electrical connection between the first circuit board (4) and the second circuit board (5).

Description

[0001] The present invention relates to an assembly for a motor feedback system according to the preamble of claim 1 and a motor feedback system according to the preamble of claim 6.

[0002] In a wide variety of industrial applications, optoelectronic detection devices, such as optoelectronic sensors or rotary encoders, are used to determine the angle of rotation of a shaft rotating around an axis. For this purpose, the detection device is designed as a separate, standalone rotary encoder or as a module or component of a motor feedback system. Whether as a standalone rotary encoder or as a module of the motor feedback system, the detection device has at least one light source that illuminates a code disk attached to the shaft and rotating with it. The light passes through the code disk, and the encoded light, along with a code, reaches light receivers. The light receivers process the received light and the code into signals and make them available to an evaluation unit.

[0003] The evaluation unit, for example in the form of a microcontroller, evaluates the signals and determines the angle of rotation of the rotating shaft.

[0004] This design of an optoelectronic detection device has the advantage that determining the shaft's angle of rotation is straightforward thanks to the coding on the code disk. However, such detection devices are expensive to manufacture because very precise assembly is required to ensure high detection accuracy against mechanical disturbances, such as inaccurate mounting of the code disk to the shaft or imprecise alignment of the optical components (light source, light receiver, and code disk) relative to each other.

[0005] As part of a motor feedback system, the well-known optoelectronic detection device requires a lot of installation space, due, for example, to the code disk and bearings for the optical components that must be provided on the motor.

[0006] DE102017117179B4 relates to a device arrangement comprising a first device part in which a first printed circuit board is arranged, and a second device part in which a second printed circuit board is arranged, wherein the first and second device parts are designed for planar arrangement on top of each other, and wherein the first and second printed circuit boards form two spaced-apart layers when the first and second device parts are planar arranged on top of each other. At least one wall of a device housing of one of the two device parts is located between the first and second layers.

[0007] A contact element is arranged between the circuit boards. In one embodiment, the contact element can be designed as a spirally wound compression spring. This compression spring is fixed in position at the contact area of ​​the second circuit board and, when the first and second device parts are positioned against each other, exerts spring pressure on the first contact element of the first circuit board. When the first device part is placed onto the second device part, the compression spring is compressed by the first device part, thus achieving a fast, secure, and reliable electrically conductive contact between the two opposing circuit boards via the compression spring.

[0008] One object of the invention is to provide an improved assembly for a motor feedback system and an improved motor feedback system.

[0009] The problem is solved according to claim 1 by an assembly for a motor feedback system comprising at least one plastic connecting part, a first printed circuit board and a second printed circuit board, wherein the plastic connecting part is arranged between the first printed circuit board and the second printed circuit board, wherein the plastic connecting part has at least two elongated channels, wherein a conductive compression spring is arranged in each channel, wherein the conductive compression springs at their ends each bear against contact surfaces of the first printed circuit board and the second printed circuit board, thereby establishing an electrical connection between the first printed circuit board and the second printed circuit board.

[0010] The problem is further solved according to claim 6 by a motor feedback system with an assembly comprising at least one plastic connecting part, a first printed circuit board and a second printed circuit board, wherein the plastic connecting part is arranged between the first printed circuit board and the second printed circuit board, wherein the plastic connecting part has at least two elongated channels, wherein a conductive compression spring is arranged in each channel, wherein the conductive compression springs at their ends each bear against contact surfaces of the first printed circuit board and the second printed circuit board, thereby establishing an electrical connection between the first printed circuit board and the second printed circuit board.

[0011] The plastic connector acts as the mechanical stop for the first and second circuit boards. Specifically, the walls of the elongated channels form the mechanical stops for both the first and second circuit boards. However, additional mechanical stops may also be provided on the plastic connector for the first and second circuit boards.

[0012] The plastic connector is primarily manufactured as a single piece, for example using an injection molding process. This makes the plastic connector inexpensive to produce.

[0013] Contacting the printed circuit boards (PCBs) using conductive compression springs compensates for axial and radial misalignments between the boards. This also simplifies assembly and reduces costs. Adjacent components, such as optics, are not damaged. Only one side of each PCB is used for contacting the boards, freeing up space on the other side for positioning electronic components. This also reduces manufacturing costs for the contacting process.

[0014] One requirement for the contacting is flexibility in the radial and axial directions, since the distances between the printed circuit boards (PCBs) can vary, and these distances are flexibly compensated for according to the invention. By using conductive compression springs and contact surfaces on the PCB, the positions of the PCBs can vary in the radial and axial directions, for example, within a range of + / - 0.1 mm to + / - 0.2 mm. An advantage of this contacting method is that the electrical connection between the PCBs is not rigid and can compensate for the different offsets in the radial and axial directions.

[0015] Simultaneously, the conductive compression springs provide a conductive electrical connection between the first and second circuit boards. This conductive connection is maintained even if the position between the first and second circuit boards changes. The spring compensates for positional variations between the compression spring and the contact surface. The compression spring rests against the contact surface, allowing it to slide transversely to its longitudinal axis. This allows the spring to slide parallel to the contact surface, compensating for radial positional changes. Axial positional changes are also compensated for by the compression spring itself. The conductive compression spring can be made of metal, such as spring steel, or other conductive materials, such as conductive plastic.

[0016] The assembly is first installed in a flange, for example. Then, the compression springs are inserted into the elongated channels or feedthroughs in the plastic connector. The first circuit board has simple pads or contact surfaces that are made contact with the compression spring when it is inserted. Afterward, the second circuit board or main board is mounted to the plastic connector. The second circuit board also has pads or contact surfaces for making contact with the compression spring.

[0017] The contact pads on the circuit boards can be manufactured using the standard SMD process to reduce costs. The compression springs are also preferably standard components, resulting in very low manufacturing costs. Assembly is achieved by simply inserting the compression springs into the plastic connector. The gap between the two circuit boards tensions the compression springs accordingly, ensuring reliable electrical contact between the contact pads.

[0018] In a further development of the invention, the plastic connecting part has plastic pins, wherein the first circuit board and / or the second circuit board are crimped to the plastic connecting part by means of the plastic pins, so that the first circuit board and / or the second circuit board is fixed to the plastic connecting part.

[0019] The riveting process can be, for example, hot riveting. In this process, the plastic pin is pressed against the circuit board using a heated die, creating a positive-locking connection, specifically a hot rivet connection, between the circuit board and the plastic connector. The plastic used for hot riveting is typically a thermoplastic. The plastic pins are, for example, integrally bonded to the plastic connector.

[0020] In a further development of the invention, the plastic connecting part has positioning pins, wherein the first printed circuit board and / or the second printed circuit board are positioned on the plastic connecting part by means of the positioning pins. For this purpose, the first printed circuit board and / or the second printed circuit board have positioning openings or holes into which the positioning pins engage. The positioning openings or holes are precisely adapted to the positioning pins, so that accurate and precise positioning between the plastic connecting part and the first printed circuit board and / or the second printed circuit board is achieved.

[0021] In a further development of the invention, at least one light-emitting diode (LED) is arranged on the first circuit board. In particular, the first circuit board has only the one LED. For example, the conductive compression springs are provided, in particular, for the electronic connection of the LED. The LED serves, in particular, to illuminate a code disc.

[0022] In a further development of the invention, at least one optoelectronic receiving element and at least one control and evaluation unit are arranged on the second circuit board.

[0023] A code disk encodes the light, and the encoded light is received by the optoelectronic receiver on the second circuit board. The optoelectronic receiver processes the received light and its encoding into signals and makes them available to a control and evaluation unit. This unit is designed to evaluate the received encoded signals and generate position signals. The code disk is positioned between the first and second circuit boards.

[0024] The invention is further explained below with regard to its advantages and features, with reference to the accompanying drawing and by means of exemplary embodiments. The figures in the drawing show: Fig. 1 a module for a motor feedback system and a motor feedback system; Fig. 2, Fig. 2a and Fig. 4 each a plastic connecting part; Fig. 3 and Fig. 3a each an assembly with a plastic connecting part; Fig. 5 a first circuit board; Fig. 6 and Fig. 6a each a subassembly with a plastic connecting part.

[0025] In the following figures, identical parts are labelled with identical reference symbols.

[0026] Fig. Figure 1 shows an assembly 1 for a motor feedback system 2 with at least one plastic connecting part 3, a first printed circuit board 4 and a second printed circuit board 5, wherein the plastic connecting part 3 is arranged between the first printed circuit board 4 and the second printed circuit board 5, wherein the plastic connecting part 3 has at least two elongated channels 6, wherein a conductive compression spring 7 is arranged in each channel 6, wherein the conductive compression springs 7 each bear against contact surfaces 8 of the first printed circuit board 4 and the second printed circuit board 5 at their ends, thereby establishing an electrical connection between the first printed circuit board 4 and the second printed circuit board 5.

[0027] The plastic connecting part 3 forms the mechanical stops for the first circuit board 4 and the second circuit board 5. In particular, the walls of the elongated channels 6 each form the mechanical stops for the first circuit board 4 and the second circuit board 5. However, additional mechanical stops can also be provided on the plastic connecting part 3 for the first circuit board 4 and the second circuit board 5.

[0028] The conductive compression springs 7 used to connect the printed circuit boards 4 and 5 compensate for axial and radial misalignments between them. Only one side of each printed circuit board 4 or 5 is used for contact, thus freeing up space on the other side for positioning electronic components. By using the conductive compression springs 7 and the contact surfaces 8 on the printed circuit board 4 or 5, the positions of the printed circuit boards 4 or 5 can vary in the radial and axial direction, for example, within a range of ±0.1 mm to ±0.2 mm.

[0029] Simultaneously, the conductive compression springs 7 provide a conductive electrical connection between the first circuit board 4 and the second circuit board 5. This conductive connection is maintained even if the position between the first circuit board 4 and the second circuit board 5 changes. The position between the compression spring 7 and the contact surface 8 is compensated for. The compression spring 7 rests against the contact surface 8 transversely to a longitudinal axis of the compression spring 7, allowing it to slide. This enables the compression spring 7 to slide parallel to the contact surface 8. This allows radial position changes to be compensated for. Axial position changes are compensated for by the compression spring 7 itself.

[0030] The assembly 1 is, for example, first installed in a flange. Then, for example, the compression springs 7 are inserted into the elongated channels 6 or feedthroughs in the plastic connecting part 3. The first circuit board 4 has simple pads or contact surfaces 8, which are contacted by the compression spring 7 when it is inserted. Afterwards, for example, the second circuit board 5 or main board is mounted to the plastic connecting part 3. The second circuit board 5 also has pads or contact surfaces 8 for contacting the compression spring 7.

[0031] Assembly is achieved by simply inserting the compression springs 7 into the plastic connecting part 3. The distance between the two circuit boards 4 and 5 tensions the compression springs 7 accordingly. This ensures reliable electrical contact between the contact surfaces 8 via the compression springs 7.

[0032] Fig. Figure 2 shows a detailed example of a plastic connecting part. Figure 3. According to Fig. 2 has the plastic connecting part 3 plastic pins 9, wherein the first circuit board 4 and / or the second circuit board 5 according to Fig. 6 are crimped to the plastic connecting part 3 by means of the plastic pins 9, so that the first circuit board 4 and / or the second circuit board 5 is fixed to the plastic connecting part 3.

[0033] The riveting process is, for example, hot riveting. In this process, the plastic pin 9 is pressed against the circuit board 4 or 5 using a heated die, thereby creating a positive connection, in particular a hot rivet connection, between the circuit board 4 or 5 and the plastic connecting part 3. The plastic pins 9 are, for example, integrally connected to the plastic connecting part 3.

[0034] Furthermore, the plastic connecting part 3 has positioning pins 10, wherein the first circuit board and / or the second circuit board are positioned on the plastic connecting part 3 by means of the positioning pins 10. The first circuit board and / or the second circuit board have positioning openings or holes into which the positioning pins engage.

[0035] Fig. 2a shows the plastic connecting part 3 according to Fig. 2 in a sectional view. According to Fig. 2a shows the elongated channels 6.

[0036] Fig. Figure 3a shows a cross-sectional view of the plastic connecting part 3. Fig. 3 with the first circuit board 4.

[0037] Fig. Figure 4 shows the plastic connecting part 3 with an integrated lens. For example, the plastic connecting part 3 is made of transparent plastic. The lens is, for example, integrally bonded to the plastic connecting part 3 and manufactured in a single injection molding process.

[0038] Fig. Figure 5 shows the first circuit board 4 with the contact surfaces 8.

[0039] For example, at least one light-emitting diode (LED) is arranged on the first circuit board 4. In particular, the first circuit board 4 has only this one LED. For example, the conductive compression springs 7 are provided, in particular, for the electronic connection of the LED. The LED serves, in particular, to illuminate a code disc.

[0040] Fig. Figure 6 shows a cross-sectional view of the plastic connecting part 3 with the first printed circuit board 4 and the second printed circuit board 5 as assembly 1. Fig.Figure 6a shows another cross-sectional view of the plastic connecting part 3 with the first circuit board 4 and the second circuit board 5 as assembly 1 with the compression springs 7 in cross-sectional view.

[0041] For example, at least one optoelectronic receiving element and at least one control and evaluation unit are arranged on the second circuit board 5.

[0042] A code disk encodes the light, and the encoded light is received by the optoelectronic receiver or light receiver on the second circuit board 5. The optoelectronic receiver processes the received light with the encoding into signals and makes them available to a control and evaluation unit. The control and evaluation unit is configured to evaluate the received encoded signals and generate position signals. The code disk is, for example, arranged between the first circuit board 4 and the second circuit board 5. Reference symbol: 1 assembly 2 Motor feedback system 3 plastic connecting part 4 first circuit board 5 second circuit board 6 elongated channels 7 conductive compression springs 8 contact surfaces 9 plastic pens 10 positioning pins QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 102017117179B4

[0006]

Claims

[1] Assembly (1) for a motor feedback system (2) comprising at least one plastic connecting part (3), a first printed circuit board (4) and a second printed circuit board (5), wherein the plastic connecting part (3) is arranged between the first circuit board (4) and the second circuit board (5), characterized by , that the plastic connecting part (3) has at least two elongated channels (6), wherein a conductive compression spring (7) is arranged in each channel, wherein the conductive compression springs (7) are each in contact surfaces (8) of the first circuit board (4) and the second circuit board (5) at their ends, thereby creating an electrical connection between the first circuit board (4) and the second circuit board (5). [2] Assembly (1) according to claim 1, characterized by, that the plastic connecting part (3) has plastic pins (9), wherein the first circuit board (4) and / or the second circuit board (5) are crimped to the plastic connecting part (3) by means of the plastic pins (9), so that the first circuit board (4) and / or the second circuit board (5) is fixed to the plastic connecting part (3). [3] Assembly (1) according to claim 1, characterized by , that the plastic connecting part (3) has positioning pins (10), wherein the first circuit board (4) and / or the second circuit board (5) are positioned on the plastic connecting part (3) by means of the positioning pins (10). [4] Assembly (1) according to any one of the preceding claims, characterized by , that at least one light-emitting diode is arranged on the first circuit board (4). [5] Assembly (1) according to any one of the preceding claims, characterized by, that at least one optoelectronic receiving element is arranged on the second circuit board (5) and at least one control and evaluation unit is arranged. [6] Motor feedback system (2) comprising an assembly (1) with at least one plastic connecting part (3), a first printed circuit board (4) and a second printed circuit board (5), wherein the plastic connecting part (3) is arranged between the first circuit board (4) and the second circuit board (5), characterized by , that the plastic connecting part (3) has at least two elongated channels (6), wherein a conductive compression spring (7) is arranged in each channel (6), wherein the conductive compression springs (7) are each in contact surfaces (8) of the first circuit board (4) and the second circuit board (5) at their ends, thereby creating an electrical connection between the first circuit board (4) and the second circuit board (5).

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