Winding type linear potentiometer

Abstract

The utility model discloses a winding type linear potentiometer which comprises a shell, a first end cover, a second end cover, a first fixed seat, a second fixed seat, a shaft, a guide rod, a sliding block, an insulating gasket, a first reed and an output winding, one end of the middle of the first fixed seat protrudes outwards to form a positioning pipe, and the inner end of the shaft penetrates through a central through hole of the positioning pipe from outside to inside and is arranged in the shell; the sliding block is sleeved on the shaft through a central through hole of the sliding block, a guide rod parallel to the shaft penetrates through a corresponding through hole in the sliding block, the insulating gasket is installed on the sliding block, the first reed is installed on the insulating gasket, the length direction of the output winding is parallel to the axial direction of the shaft, and the first reed is in conductive contact with the outer wall of an enameled resistance wire of the output winding. On the premise of meeting an electric signal control or acquisition function, the linear potentiometer can meet the requirements of higher precision and smaller resistance temperature coefficient at the same time, and can effectively solve the problem that the traditional linear potentiometer is difficult to meet the application requirements of special occasions.

Description

Technical Field

[0001] This utility model relates to a linear potentiometer for controlling the output of electrical signals through linear motion or for detecting linear displacement by acquiring electrical signals, and more particularly to a winding type linear potentiometer. Background Technology

[0002] Potentiometers (sensors) can be classified into linear potentiometers (or linear displacement potentiometers) and rotary potentiometers (or angular displacement potentiometers) according to their movement. Linear potentiometers are used to control the output electrical signal (resistance or voltage signal, etc.) through linear motion or to detect the linear displacement by acquiring electrical signals (usually voltage signals).

[0003] Traditional linear potentiometers mainly include conductive plastic linear potentiometers, magnetically sensitive linear potentiometers, and LVDTs (linear variable differential transformers). Magnetically sensitive linear potentiometers and LVDTs both transmit or acquire electrical signals through induction signals; the former uses magnetic signals, and the latter uses induced current signals. Both types of linear potentiometers require integrated decoding circuitry, thus occupying considerable internal space and resulting in a longer product length. Furthermore, due to limitations in their output characteristics, their control or detection accuracy is inherently low, requiring calibration to improve accuracy, which introduces considerable uncertainty. Conductive plastic linear potentiometers use conductive plastic resistive elements and brushes to achieve electrical signal control or acquisition. They suffer from a large temperature coefficient (typically ±500 PP.m / ℃), so they are generally used in applications requiring a large temperature coefficient of resistance. If used in applications requiring a small temperature coefficient of resistance, their output resistance is significantly affected by temperature, leading to reduced accuracy.

[0004] However, in some special cases, such as when acquiring changing resistance signals and requiring high accuracy and a small resistance temperature coefficient, the traditional linear potentiometers mentioned above are difficult to meet the application requirements. Utility Model Content

[0005] The purpose of this invention is to provide a winding-type linear potentiometer with high precision and a small temperature coefficient of resistance in order to solve the above problems.

[0006] This utility model achieves the above objectives through the following technical solutions:

[0007] A winding-type linear potentiometer includes a housing, a first end cap, a second end cap, a first fixing seat, a second fixing seat, a shaft, a guide rod, a slider, an insulating gasket, and a first spring. The first end cap and the second end cap are respectively installed at both ends of the housing. The first fixing seat and the second fixing seat are installed inside the housing and are respectively close to the first end cap and the second end cap. One end of the middle portion of the first fixing seat protrudes outward to form a positioning tube, and the suspended end of the positioning tube passes through the corresponding through hole of the first end cap and is placed outside the housing. The inner end of the shaft passes through the central through hole of the positioning tube from the outside to the inside and is placed inside the housing and close to the second end cap. The two ends of the guide rod, which is located inside the housing and parallel to the shaft, are respectively connected to the first fixing seat and the second fixing seat. Next, the slider is fitted onto the shaft near its inner end through its central through hole, and the guide rod passes through the corresponding through hole on the slider. The insulating pad is installed on the slider, and the first spring is installed on the insulating pad. The winding linear potentiometer also includes an output winding formed by tightly spirally winding enameled resistance wire on a strip frame. The length direction of the output winding is parallel to the axial direction of the shaft. The two ends of the output winding are respectively connected to the first fixed seat and the second fixed seat through insulating sleeves and cannot rotate. The first spring is in conductive contact with the outer wall of the enameled resistance wire of the output winding. The enameled layer is removed from the enameled resistance wire of the output winding at the positions that can contact the first spring. The first spring is conductively connected to the signal line.

[0008] Preferably, in order to facilitate the transmission of the electrical signal of the first spring to the outside and reduce the number of internal wires, the winding linear potentiometer further includes a strip-shaped conductor and a second spring. The length direction of the conductor is parallel to the axial direction of the shaft. The two ends of the conductor are respectively connected to the first fixed base and the second fixed base through insulating sleeves and cannot be rotated. The second spring is mounted on the insulating pad and makes conductive contact with the outer wall of the conductor. The second spring is conductively connected to the first spring. One end of the conductor is conductively connected to the signal line.

[0009] Preferably, in order to make the movement trajectories of the first and second reeds as similar as possible to improve accuracy, the conductor is a current collector winding formed by tightly spirally winding bare resistance wires on a strip frame. The second reed is in conductive contact with the outer wall of the bare resistance wires of the current collector winding, and all turns of bare resistance wires in the current collector winding that can contact the second reed are connected by solder.

[0010] Preferably, to achieve reliable guiding and reliable electrical signal acquisition or control functions, and to facilitate connection between the first and second springs and reduce wires and their interference, there are two guide rods located on opposite sides of the shaft. The output winding and the current collecting winding are located on opposite sides of the shaft. The two guide rods, the output winding, and the current collecting winding are evenly distributed around the outer periphery of the shaft. The two first springs connected as one unit are in conductive contact with the outer wall of the enameled resistance wire on both sides of the output winding. The two second springs connected as one unit are in conductive contact with the outer wall of the bare resistance wire on both sides of the current collecting winding. The first and second springs are electrically connected by a connecting wire. The connecting wire passes through the corresponding through hole on the insulating pad and the corresponding through hole on the slider, and the corresponding hole outside the connecting wire is filled with insulating resin.

[0011] Preferably, in order to facilitate the anti-rotation function of the output winding and conductor, the insulating sleeve is connected to the flat end of the corresponding output winding or conductor through its own flat hole, and the insulating sleeve is connected to the flat hole of the corresponding first fixing seat or second fixing seat through its own flat end.

[0012] Preferably, in order to give the slider a certain amount of elastic movement space to improve its axial buffering effect and eliminate return clearance, the outer diameter of the shaft near the inner end is reduced to form a small diameter section. The slider is fitted outside the small diameter section through its own central through hole. A compression spring retainer is installed at the inner end of the shaft and is fixed to the shaft by a retaining ring. The compression spring is fitted outside the small diameter section and is located between the compression spring retainer and the slider. The slider is located between the compression spring and the step at the end of the small diameter section away from the compression spring retainer.

[0013] Preferably, in order to facilitate reliable installation of the compression spring, the slider has a compression spring blind hole at one end near the compression spring, and the corresponding end of the compression spring is placed in the compression spring blind hole.

[0014] Preferably, in order to facilitate the increase and adjustment of the friction between the shaft and the positioning tube to improve the stability of shaft movement, a bushing for increasing the friction between the shaft and the positioning tube is installed between a section of the outer wall of the shaft corresponding to the positioning tube and the central through hole wall of the positioning tube.

[0015] Preferably, in order to facilitate the installation and replacement of the bushing, the outer wall of the end of the positioning tube away from the first end cover is provided with an external thread, and the bushing cover is connected to the external thread through its own internal thread. The inner wall of the positioning tube away from the first end cover is thinned to form a positioning cavity, and the bushing is placed in the positioning cavity and pressed against by the bushing cover.

[0016] The beneficial effects of this utility model are as follows:

[0017] This invention, through the design of an output winding that contacts and engages with a reed, replaces the conductive plastic on the traditional resistive body with a resistance wire. While satisfying the functions of electrical signal control or acquisition, it can simultaneously meet the requirements of high accuracy and a small temperature coefficient of resistance. Moreover, by reducing the diameter of the resistance wire and increasing the number of turns, the drawback of the non-absolutely continuous control or acquisition of electrical signals in the output winding can be compensated. It can effectively solve the problem that "in some special occasions, such as when acquiring changing resistance signals, and when high accuracy and a small temperature coefficient of resistance are required, traditional linear potentiometers are difficult to meet the application requirements." Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the main cross-sectional structure of the winding linear potentiometer described in this utility model;

[0019] Figure 2 yes Figure 1 A schematic diagram of the AA cross-sectional structure in the diagram;

[0020] Figure 3 yes Figure 2 Schematic diagram of the BB cross-sectional structure in the middle;

[0021] Figure 4 This is a three-dimensional structural diagram of the first fixed base, second fixed base, shaft, two guide rods, output winding, current collecting winding, slider, insulating pad, insulating sleeve and shaft sleeve cover of the winding linear potentiometer of this utility model. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings:

[0023] like Figure 1-Figure 4As shown, the winding-type linear potentiometer of this utility model includes a housing 11, a first end cap 13, a second end cap 1, a first fixing seat 14, a second fixing seat 4, a shaft 12, a guide rod 3, a slider 9, an insulating pad 7, a first spring 17, and an output winding 18 formed by enameled resistance wire tightly spirally wound on a strip frame (the output winding 18 in the figure does not show the enameled resistance wire, it is a schematic structure). The first end cap 13 and the second end cap 1 are respectively installed at both ends of the housing 11, and the first fixing seat 14 and the second fixing seat 4 are respectively installed at both ends of the housing 11. Two fixing seats 4 are installed inside the housing 11 and are respectively close to the first end cover 13 and the second end cover 1. One end of the middle part of the first fixing seat 14 protrudes outward to form a positioning tube (not marked separately in the figure), and the suspended end of the positioning tube passes through the corresponding through hole of the first end cover 13 and is placed outside the housing 11. The inner end of the shaft 12 passes through the central through hole of the positioning tube from the outside to the inside and is placed inside the housing 11 and close to the second end cover 1. The two ends of the guide rod 3, which is located inside the housing 11 and parallel to the shaft 12, are respectively connected to the first fixing seat 14 and the second fixing seat 4. More specifically, one end of the guide rod 3 passes through the corresponding through hole of the second fixed seat 4 and the corresponding through hole of the fixing ring 2 and is connected to the second end cover 1. The fixing ring 2 is installed between the second end cover 1 and the second fixed seat 4. One end of the guide rod 3 is a flat end to achieve the anti-rotation function of the guide rod 3. The slider 9 is fitted onto the shaft 12 near its inner end through its own central through hole, and the guide rod 3 passes through the corresponding through hole on the slider 9. The insulating pad 7 is installed on the slider 9 by screws, and the first spring 17 is installed on the insulating pad. 7. The length direction of the output winding 18 is parallel to the axial direction of the shaft 12. The two ends of the output winding 18 are connected to the first fixed seat 14 and the second fixed seat 4 through the insulating sleeve 20 respectively and cannot rotate. The first spring 17 is in conductive contact with the outer wall of the enameled resistance wire of the output winding 18. The enameled layer is removed from the positions in the enameled resistance wire of the output winding 18 that can contact the first spring 17. The first spring 17 is conductively connected to the signal line (not shown in the figure, the signal line is used to transmit electrical signals to the outside of the housing 11).

[0024] like Figure 1-Figure 4 As shown, this utility model also discloses the following more optimized specific structures:

[0025] To facilitate the transmission of electrical signals from the first spring 17 to the outside and reduce internal wiring, the winding linear potentiometer also includes a strip-shaped conductor 19 and a second spring (not separately marked in the figure, but with the same structure and performance as the first spring 17). The length of the conductor 19 is parallel to the axial direction of the shaft 12. Both ends of the conductor 19 are connected to the first fixed base 14 and the second fixed base 4 respectively through insulating sleeves 20 (which are the same components as the aforementioned insulating sleeves 20 but not the same product) and cannot be rotated. The second spring is mounted on the insulating pad 7 and makes conductive contact with the outer wall of the conductor 19. The second spring is conductively connected to the first spring 17, and one end of the conductor 19 is conductively connected to the signal line.

[0026] To improve accuracy by making the movement trajectories of the first reed 17 and the second reed as similar as possible, the conductor 19 is a current collector winding formed by tightly spirally winding bare resistance wires on a strip frame (the marking position is the same as that of the conductor 19, but it is not marked again in the figure; the resistance wires are not shown in the figure, and it is a schematic structure). The second reed is in conductive contact with the outer wall of the bare resistance wires of the current collector winding. All turns of bare resistance wires in the current collector winding that can contact the second reed are connected by solder (not shown in the figure).

[0027] To achieve reliable guiding and reliable electrical signal acquisition or control functions, and to facilitate the connection between the first spring 17 and the second spring and reduce wires and their interference, there are two guide rods 3, located on opposite sides of the shaft 12. The output winding 18 and the current collecting winding are located on opposite sides of the shaft 12. The two guide rods 3, the output winding 18, and the current collecting winding are evenly distributed on the outer periphery of the shaft 12. The two first springs 17 connected as one unit are in conductive contact with the outer wall of the enameled resistance wire on both sides of the output winding 18. The two second springs connected as one unit are in conductive contact with the outer wall of the bare resistance wire on both sides of the current collecting winding. The first spring 18 and the second spring are electrically connected by a connecting wire 10. The connecting wire 10 passes through the corresponding through hole 22 on the insulating pad 7 and the corresponding through hole on the slider 9 (not visible in the figure), and the corresponding hole outside the connecting wire 10 is filled with insulating resin 8.

[0028] To facilitate the anti-rotation function of the output winding 18 and the conductor 19, the insulating sleeve 20 is connected to the flat end of the corresponding output winding 18 or conductor 19 through its own flat hole, and the insulating sleeve 20 is connected to the flat hole 21 of the corresponding first fixing seat 14 or second fixing seat 4 (other flat holes are not marked, but are similar) through its own flat end.

[0029] To allow the slider 9 to have a certain elastic movement space to improve its axial buffering effect and eliminate return clearance, the outer diameter of the shaft 12 near the inner end is reduced to form a small diameter section. The slider 9 is fitted outside the small diameter section through its own central through hole. A compression spring retaining ring 5 is installed at the inner end of the shaft 12 and is fixed to the shaft 12 by a retaining ring. The compression spring 6 is fitted outside the small diameter section and is located between the compression spring retaining ring 5 and the slider 9. The slider 9 is located between the compression spring 6 and the step at the end of the small diameter section away from the compression spring retaining ring 5.

[0030] To facilitate reliable installation of the compression spring 6, a compression spring blind hole is provided at one end of the slider 9 near the compression spring 6, and the corresponding end of the compression spring 6 is placed in the compression spring blind hole.

[0031] In order to facilitate the increase and adjustment of the friction between the shaft 12 and the positioning tube to improve the stability of the shaft 12 movement, a bushing 15 for increasing the friction between the shaft 12 and the positioning tube is installed between a section of the outer wall of the shaft 12 corresponding to the positioning tube and the central through hole wall of the positioning tube.

[0032] To facilitate the installation and replacement of the bushing 15, the outer wall of the end of the positioning tube away from the first end cover 13 is provided with an external thread, and the bushing cover 16 is connected to the external thread through its own internal thread. The inner wall of the positioning tube away from the first end cover 13 is thinned to form a positioning cavity, and the bushing 15 is placed in the positioning cavity and pressed against by the bushing cover 16.

[0033] like Figure 1-Figure 4 As shown, in use, the control component or the moving part of the device to be tested is connected to the outer end of the shaft 12, driving the shaft 12 to move linearly, or the shaft 12 can be directly controlled to move linearly by hand. The shaft 12 drives the slider 9, the insulating pad 7, the first spring 17 and the second spring to move synchronously. The first spring 17 contacts and slides on the outer wall of the resistance wire of the output winding 18. Because the resistance value between the first spring 17 and one end of the output winding 18 changes, a changing electrical signal is generated. This electrical signal is transmitted to the external electrical equipment or processor through the first spring 18, the connecting wire 10, the second spring, the conductor 19 and the signal line in sequence, so as to output different voltages to the electrical equipment, or obtain the linear displacement of the shaft 12 after conventional calculation, so as to achieve the purpose of controlling the output electrical signal or detecting the linear displacement.

[0034] The above embodiments are merely preferred embodiments of this utility model and are not intended to limit the technical solutions of this utility model. Any technical solution that can be implemented based on the above embodiments without creative effort should be considered to fall within the scope of protection of this utility model patent.

Claims

1. A winding-type linear potentiometer, comprising a housing, a first end cap, a second end cap, a first fixing seat, a second fixing seat, a shaft, a guide rod, a slider, an insulating pad, and a first spring, wherein the first end cap and the second end cap are respectively installed at both ends of the housing, the first fixing seat and the second fixing seat are installed inside the housing and respectively close to the first end cap and the second end cap, one end of the middle portion of the first fixing seat protrudes outward to form a positioning tube, and the suspended end of the positioning tube passes through the corresponding through hole of the first end cap and is placed outside the housing, the inner end of the shaft passes through the central through hole of the positioning tube from the outside to the inside and is placed inside the housing and close to the second end cap, the two ends of the guide rod, located inside the housing and parallel to the shaft, are respectively connected to the first fixing seat and the second fixing seat, the slider is fitted onto the shaft near its inner end through its own central through hole, and the guide rod passes through the corresponding through hole on the slider, the insulating pad is installed on the slider, and the first spring is installed on the insulating pad, characterized in that: The winding-type linear potentiometer further includes an output winding formed by tightly spirally winding enameled resistance wire on a strip frame. The length direction of the output winding is parallel to the axial direction of the shaft. The two ends of the output winding are respectively connected to the first fixed base and the second fixed base through insulating sleeves and cannot be rotated. The first spring is in conductive contact with the outer wall of the enameled resistance wire of the output winding. The enameled layer is removed from all positions of the enameled resistance wire of the output winding that can contact the first spring. The first spring is conductively connected to the signal line.

2. The winding-type linear potentiometer according to claim 1, characterized in that: The winding linear potentiometer further includes a strip-shaped conductor and a second spring. The length direction of the conductor is parallel to the axial direction of the shaft. The two ends of the conductor are respectively connected to the first fixed base and the second fixed base through insulating sleeves and cannot be rotated. The second spring is mounted on the insulating pad and makes conductive contact with the outer wall of the conductor. The second spring is conductively connected to the first spring. One end of the conductor is conductively connected to the signal line.

3. The winding-type linear potentiometer according to claim 2, characterized in that: The conductor is a current collector winding formed by tightly spirally winding bare resistance wires on a strip frame. The second spring is in conductive contact with the outer wall of the bare resistance wires of the current collector winding. Each turn of bare resistance wire in the current collector winding that can contact the second spring is connected by solder.

4. The winding-type linear potentiometer according to claim 3, characterized in that: The guide rods are two in number and located on opposite sides of the shaft. The output winding and the current collecting winding are located on opposite sides of the shaft. The two guide rods, the output winding, and the current collecting winding are evenly distributed on the outer periphery of the shaft. The two first springs connected as one piece are in conductive contact with the outer wall of the enameled resistance wire on both sides of the output winding. The two second springs connected as one piece are in conductive contact with the outer wall of the bare resistance wire on both sides of the current collecting winding. The first springs and the second springs are electrically connected by a connecting wire. The connecting wire passes through the corresponding through hole on the insulating pad and the corresponding through hole on the slider, and the corresponding hole outside the connecting wire is filled with insulating resin.

5. The winding-type linear potentiometer according to any one of claims 2-4, characterized in that: The insulating sleeve is connected to the flat end of the corresponding output winding or the conductor through its own flat hole, and the insulating sleeve is connected to the flat hole of the corresponding first fixing seat or the second fixing seat through its own flat end.

6. The winding-type linear potentiometer according to any one of claims 1-4, characterized in that: The outer diameter of the shaft decreases near the inner end to form a small diameter section. The slider is fitted onto the outside of the small diameter section through its own central through hole. A compression spring retainer is installed at the inner end of the shaft and is fixed to the shaft by a retaining ring. The compression spring is fitted onto the outside of the small diameter section and is located between the compression spring retainer and the slider. The slider is located between the compression spring and a step at the end of the small diameter section away from the compression spring retainer.

7. The winding-type linear potentiometer according to claim 6, characterized in that: The slider has a spring blind hole at one end near the spring, and the corresponding end of the spring is placed in the spring blind hole.

8. The winding-type linear potentiometer according to any one of claims 1-4, characterized in that: A bushing is installed between the outer wall of the shaft corresponding to the positioning tube and the central through hole wall of the positioning tube to increase the friction between the shaft and the positioning tube.

9. The winding-type linear potentiometer according to claim 8, characterized in that: The outer wall of the positioning tube away from the first end cap is provided with an external thread, and the bushing cap is connected to the external thread through its own internal thread. The inner wall of the positioning tube away from the first end cap is thinned to form a positioning cavity. The bushing is placed in the positioning cavity and is pressed against by the bushing cap.

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