Speed control switch for working machine and working machine comprising speed control switch

Abstract

The utility model relates to a speed control switch for an operation machine and the operation machine comprising the speed control switch. The speed regulation switch comprises a first shell and a second shell which are fixed together to jointly define a cavity; the transmission part, the fixing plate and the potentiometer are arranged in the cavity and are encapsulated by the first shell and the second shell. The fixed plate is fixed on the first shell, the potentiometer is limited by the fixed plate and is fixed relative to the first shell, and the transmission piece is provided with a transmission shaft extending out of the second shell and is fixed relative to the second shell in the axial direction but can rotate around the axial direction; the transmission member is operatively connected to the potentiometer such that rotation of the transmission shaft caused by operating the speed regulation switch actuates the potentiometer to generate an electrical signal corresponding to an operation amount of the speed regulation switch. The speed control switch has good oil-proof, water-proof and anti-corrosion performance, is simple, stable and reliable to install, and has improved operation hand feeling, operation precision and use durability.

Description

Technical Field

[0001] This utility model relates to the field of speed control switch technology, and in particular to a speed control switch for example, used to regulate the engine speed in working machinery. Background Technology

[0002] For operational / construction machinery equipped with electronic fuel injection engines (such as excavators and loaders), engine speed is typically controlled using a speed control switch (also known as a throttle potentiometer or throttle knob). This speed control switch is operated by the driver, outputting a proportional voltage or current control signal to the engine controller (ECM). The ECM then outputs a corresponding fuel quantity signal to the fuel injection pump and injectors based on the received proportional signal, thereby controlling the engine speed.

[0003] This type of speed control switch is easy to operate and offers high speed control precision. It relies on the engine's built-in controller to control the speed, resulting in minimal additional cost. However, it has been found that existing speed control switches are poor in terms of oil, water, and corrosion resistance, are inconvenient to install, and lack reliability and durability, making them unsuitable for the often harsh working environments of machinery. Furthermore, existing speed control switches suffer from low rotational force during operation, leading to poor feel and difficulty in precise operation. Utility Model Content

[0004] The purpose of this invention is to solve at least one of the above-mentioned problems and / or other defects in the prior art.

[0005] To achieve the above objectives, one aspect of this utility model provides a speed control switch for working machinery, the speed control switch comprising: a first housing and a second housing fixed together to jointly define a cavity; and a transmission member, a fixing plate, and a potentiometer disposed within the cavity and enclosed by the first housing and the second housing. The fixing plate is fixed to the first housing, the potentiometer is limited by the fixing plate and fixed relative to the first housing, the transmission member has a transmission shaft extending beyond the second housing and is mounted to be axially fixed relative to the second housing but rotatable about the axial direction, the transmission member being operatively connected to the potentiometer such that rotation of the transmission shaft caused by operation of the speed control switch actuates the potentiometer to generate an electrical signal corresponding to the operation amount of the speed control switch.

[0006] According to one embodiment of the present invention, the second housing is provided with a sleeve portion extending outward along the axial direction and surrounding the transmission shaft. The transmission shaft extends axially through the sleeve portion and the portion exposed from the sleeve portion is provided with a circumferential groove. The transmission member is fixed axially relative to the second housing via a retaining ring snapped into the circumferential groove.

[0007] According to one embodiment of the present invention, the transmission component includes a first disc-shaped component having the transmission shaft and a second disc-shaped component that is detachably fixed to the first disc-shaped component.

[0008] According to one embodiment of the present invention, the transmission member further includes a plug plate disposed between the first disc-shaped component and the second disc-shaped component and connected to them to rotate with them; the potentiometer includes a rotating shaft coaxial with the transmission shaft; the rotating shaft extends through the fixed plate to the plug plate; and the plug plate is operatively connected to the rotating shaft through a rod portion that extends laterally through the rotating shaft.

[0009] According to one embodiment of the present invention, the speed control switch further includes a gear assembly, the gear assembly including at least one spring groove disposed on the second disc-shaped component, a spring disposed in the spring groove, a plurality of gear holes spaced apart circumferentially along the fixed plate, and a ball bearing that can abut against any one of the gear holes under the biasing force of the spring and can overcome the biasing force of the spring and move out of the gear hole when the transmission shaft drives the second disc-shaped component to rotate.

[0010] According to one embodiment of the present invention, the sleeve portion passes through the control panel of the working machine so that the first housing and the second housing are located on one side of the control panel. The speed control switch further includes a nut that is screwed onto the sleeve portion having external threads on the other side of the control panel to install the speed control switch on the control panel.

[0011] According to one embodiment of the present invention, the sleeve portion has a D-shaped cross-section and passes through a matching D-shaped hole in the operating panel to prevent the second housing from rotating relative to the operating panel.

[0012] According to one embodiment of the present invention, both the first shell and the second shell are cylindrical with a bottom that is open at one end and closed at the other end. The open end of the first shell and the open end of the second shell are fixed together by fitting together.

[0013] According to one embodiment of the present invention, the closed end of the first housing is formed by a bottom cover that is detachably connected to the main body of the first housing.

[0014] Another aspect of this utility model provides a working machine that includes an engine and a speed control switch for the engine, according to any of the above configurations.

[0015] The speed control switch of this utility model forms a relatively closed cavity through the connection of a first housing and a second housing, which encloses and protects the transmission component, the fixing plate, and the potentiometer within the cavity. Only the operable transmission shaft of the transmission component extends out of the second housing, thereby improving the overall oil-proof, water-proof, and corrosion-proof performance of the speed control switch. The overall structural design of the speed control switch, including the first and second housings and the transmission component, enables simple, stable, and reliable installation of the transmission component, potentiometer, and other components within the cavity, as well as the entire speed control switch on a simple panel. The position assembly involving the fixing plate, ball bearing, and spring configured within the speed control switch also increases the rotational resistance when operating the speed control switch, improving the operating feel, operating accuracy, and durability. Attached Figure Description

[0016] The features and advantages of this utility model will become clear from the following detailed description provided with reference to the accompanying drawings. It should be understood that the following drawings are merely schematic and not necessarily drawn to scale, and therefore should not be considered as limitations on this utility model, wherein:

[0017] Figure 1 This is a perspective view of a speed control switch installed on the control panel of a work machine according to an embodiment of the present invention.

[0018] Figure 2 yes Figure 1 The diagram shown is an exploded view of the speed control switch installed on the control panel.

[0019] Figure 3 yes Figure 1 The speed control switch shown is a cross-sectional view taken along the central axis of the two bolts used to fix the first and second disc-shaped components of the transmission.

[0020] Figure 4 yes Figure 1 An exploded view of the transmission component, consisting of the first and second disc-shaped parts, in the speed control switch shown.

[0021] Figure 5 yes Figure 1 A perspective view of the connector plate of the transmission component in the speed control switch shown.

[0022] Figure 6 yes Figure 1 The schematic diagram shows the first disc-shaped component, the second disc-shaped component, and the potentiometer assembled together in the speed control switch, especially showing the gear assembly including the spring groove, the spring, the gear hole, and the ball.

[0023] Figure 7 yes Figure 1 An exploded view of the potentiometer, mounting plate, and second housing in the speed control switch shown.

[0024] Explanation of reference numerals in the attached figures:

[0025] 100. Speed ​​control switch; 200. Knob; 300. Control panel; 301. Recess; 400. Wiring harness connector; 10. Housing assembly; 11. First housing; 111. Housing body; 112. Bottom cover; 113. Protrusion; 12. Second housing; 121. Sleeve portion; 122. Raised portion; 20. Fixing plate; 21. Limiting hole; 30. Transmission component; 31. First disc-shaped component; 311. Drive shaft; 312, circumferential groove; 32, second disc-shaped component; 40, bolt; 50, retaining ring; 60, potentiometer; 61, shaft hole; 62, limiting protrusion; 70, plug plate; 71, main body; 72, rod; 73, notch; 80, gear assembly; 81, spring groove; 82, spring; 83, gear hole; 84, ball bearing; 91, bolt; 92, bolt; 93, washer; 94, nut. Detailed Implementation

[0026] Embodiments of the present invention are described below with reference to the accompanying drawings. In the following description, numerous specific details are set forth to enable those skilled in the art to more fully understand and implement the present invention. However, it will be apparent to those skilled in the art that implementations of the present invention may not include some of these specific details. Furthermore, it should be understood that the present invention is not limited to the specific embodiments described. Rather, the present invention can be conceived to be implemented with any combination of the features and elements described below, regardless of whether they relate to different embodiments. Therefore, the following aspects, features, embodiments, and advantages are for illustrative purposes only and should not be construed as elements or limitations of the claims unless expressly set forth in the claims.

[0027] The terms "first" and "second" are used below to describe the elements of this application. These terms are used only to distinguish the individual elements and not to limit the nature, order, or number of these elements. The terms "comprising" and "having" are used to indicate an open-ended inclusion and mean that there may be additional elements / components besides those listed.

[0028] Figure 1-3A schematic diagram of the installation of a speed control switch 100 according to an embodiment of the present invention is shown. The speed control switch 100 mainly includes a housing assembly 10, a transmission member 30 with a transmission shaft 311, a fixing plate 20, and a potentiometer 60. A knob 200 for manual operation may be fixed to the top of the speed control switch 100, for example. When the speed control switch 100 is installed, for example, on an operating panel (hereinafter also referred to as "panel") 300 in a work machine, the transmission shaft 311 can pass through a mounting hole (not shown) in the panel from below and then be fixed to the knob 200. The transmission member 30 is operatively connected to the potentiometer 60 so that the rotation of the transmission shaft 311 caused by operating the knob 200 of the speed control switch 100 actuates the potentiometer 60 to generate an electrical signal corresponding to the operating amount of the speed control switch. The lower end of the speed control switch 100 is provided with a wiring harness connector 400 that is electrically connected to the potentiometer 60. A signal connection can be established with the controller of the working machinery, for example, via the wiring harness connector 400. The speed control switch 100 and the corresponding controller can be configured, for example, for the engine of the working machinery. Thus, the speed control switch 100 can be actuated by rotating the knob 200, thereby regulating the engine speed.

[0029] Housing assembly 10 may include a first housing 11 and a second housing 12 fixed to the first housing 11. The first housing 11 is oriented to one side ( Figure 2 and Figure 3 The lower side of the protrusion forms a semi-cavity and may include, for example, Figure 7 The diagram shows a shell body 111, a bottom cover 112, and a plurality of protrusions 113 with threaded holes. The shell body 111 is generally a cylindrical structure open at both ends. The plurality of protrusions 113 are arranged, for example, at equal intervals on the inner peripheral wall of the shell body 111 and extend axially along the shell body 111. The bottom cover 112 is provided with through holes corresponding one-to-one with the threaded holes in the plurality of protrusions 113, thereby allowing the bottom cover 112 to be detachably connected to one open end of the shell body 111 by, for example, a plurality of bolts 92 passing through the corresponding through holes and threaded holes. Figure 7 The lower end of the first housing 111, which is the end of the housing body 111 facing away from the second housing 12, is closed, thus making the entire first housing 11 cylindrical with a bottom. The bottom cover 112 has a downwardly protruding recess in the middle for receiving the potentiometer 60, and on one side of this recess are multiple holes for the multiple wires of the wire harness connector 400 to pass through. The other open end of the housing body 111 ( Figure 7 The upper end of the housing is provided with an outer peripheral surface that can be fitted with the second housing 12. For example, a plurality of circumferentially extending grooves and axially extending grooves may be provided on the outer peripheral surface.

[0030] Return to reference Figure 2 and Figure 3 As shown, the second housing 12 faces the other side ( Figure 2 and Figure 3 The upper side of the second housing 12 protrudes to form a semi-cavity, and the second housing 12 also has one end ( Figure 2 , 3 The lower end of the middle is open, and the other end is open. Figure 2 , 3 The first housing 11 is a closed, bottomed cylindrical structure (with its upper end closed). The inner circumferential surface of the open end of the second housing 12 can, for example, be fitted onto the outer circumferential surface of the open end of the first housing 11, and a plurality of circumferential and axial protrusions corresponding to the aforementioned circumferential and axial grooves on the outer circumferential surface can be provided on the inner circumferential surface. Through the engagement of the circumferential protrusions with the circumferential grooves and the axial protrusions with the axial grooves, the second housing 12 can be fixed to the first housing 11 and their relative positions in the axial and axial directions can be defined. Thus, the first and second housings together define a relatively closed cavity within which the various components of the speed control switch 100, which will be detailed below, can be encapsulated and protected. The connection and fixing method of the first and second housings fitting together at their open ends allows for quick assembly and disassembly relative to each other, while providing good sealing performance at the connection. It is conceivable that the positions of the aforementioned circumferential / axial grooves and circumferential / axial protrusions can be interchanged between the first housing 11 and the second housing 12.

[0031] like Figure 2 , 3 As shown, the closed end of the second housing 12 may be provided with a sleeve portion 121 extending outward along the axial direction. The outer peripheral surface of the sleeve portion 121 may be provided with external threads, and the speed control switch may also include a nut 94. The nut 94 and the second housing 12 with the sleeve portion 121 may be located on opposite sides of the panel 300. The sleeve portion 121 may pass through the panel 300 from below and be threadedly connected to the nut 94, thereby allowing the entire speed control switch encapsulated by the first and second housings to be easily and reliably fixed to the panel 300 without the aid of other components through the helical engagement of the nut 94 and the sleeve portion 121. A washer 93 may also be provided between the nut 94 and the panel 300 to improve the fastening effect. The cross-section of the sleeve portion 121 may be, for example, D-shaped, and a D-shaped hole matching the cross-sectional shape of the sleeve portion may also be provided in the panel 300 for the sleeve portion to pass through, thereby preventing the sleeve portion 121, the second housing 12, or even the entire housing assembly 10 from rotating relative to the panel 300. Figure 3 As shown, an outwardly extending protrusion 122 can be provided at the closed end of the second housing 12, and a recess 301 adapted to the protrusion 122 can be provided on the corresponding opposing surface of the panel 300, thereby enabling the second housing and the panel 300 to be positioned more accurately in the circumferential direction.

[0032] The first housing 11 and the second housing 12 can be formed from any suitable material that meets the strength and durability requirements. For example, the first housing 11 can be made of aluminum alloy, while the second housing 12 can be made of plastic.

[0033] In the illustrated embodiment, the speed control switch 100 may further include, for example: Figure 2-3 The potentiometer 60 shown in Figures 6-7. According to an exemplary configuration, the potentiometer 60 includes a body and a rotating shaft extending from the top surface of the body. A variable resistor with two fixed terminals is disposed within the body. Rotation of the rotating shaft changes the position of a moving contact on the variable resistor, thereby changing the resistance value between the moving contact and either fixed terminal, and thus adjusting the output voltage or current of the potentiometer. The top of the rotating shaft of the potentiometer 60 has a rotating shaft hole 61 extending radially through the shaft (described in detail below). The potentiometer 60 typically has three leads, which can be connected one-to-one with the portions of the wiring harness connector 400 extending into the first housing 11. It should be noted that in this invention, the term "potentiometer" is not limited to the exemplary configuration described above, but can refer to or encompass all devices or mechanisms capable of synchronously changing the resistance value and the corresponding voltage / current value when a speed control switch is actuated.

[0034] refer to Figure 2-3 As shown in Figures 6-7, the fixing plate 20 of this embodiment can be fixed to the first housing 11, thereby limiting the potentiometer 60. For this purpose, the fixing plate 20 can be provided with mounting holes at intervals in its circumferential direction, corresponding in position and number to the protrusions 113 on the inner circumferential surface of the first housing. These mounting holes are threaded to the corresponding protrusions 113 by means of, for example, bolts 91 passing through them, thus allowing the protrusions 113 at the same circumferential position to be simultaneously fixed to both the fixing plate 20 and the bottom cover 112. The fixing plate 20 is provided with a central through hole and a limiting hole 21 offset from the through hole. The shaft of the potentiometer 60 can pass through the through hole until the top surface of the potentiometer body abuts against the fixing plate 20. Simultaneously, a limiting protrusion 62 provided on the potentiometer body can extend into the limiting hole 21, thereby limiting the potentiometer 60 in various directions by the fixing plate 20. The fixing plate 20 is also provided with a plurality of stop holes 83 and an arc-shaped limiting groove (described further below) arranged along its circumference, wherein the arc-shaped limiting groove and the plurality of stop holes 83 are located on different circumferences.

[0035] refer to Figure 2-5 As shown, the transmission member 30 of this embodiment has a transmission shaft 311 extending beyond the second housing 12 and is mounted to be axially fixed relative to the second housing 12 but rotatable about the axial direction. In the illustrated embodiment, the transmission member 30 may include a generally disc-shaped first disc member 31 and a second disc member 32, which are detachably fixed to each other.

[0036] The main body of the first disc-shaped component 31 is generally disc-shaped, with an upwardly extending drive shaft 311 (the direction of the drive shaft extension is axial) disposed in the center. The length of the drive shaft 311 is set such that it can pass through the sleeve portion 121 of the second housing 12 and can also protrude at least partially from the sleeve portion 121 for fixed connection with the knob 200. The portion of the drive shaft 311 protruding from the sleeve portion 121 has a circumferential groove 312 at a position adjacent to the end of the sleeve portion 121. Thus, after the drive shaft 311 passes through the sleeve portion 121, a retaining ring 50 can be engaged in the circumferential groove 312, and one side surface of the retaining ring 50 can abut against the end of the sleeve portion 121, thereby defining the position of the first disc-shaped component 31 and the transmission member 30 relative to the second housing 12 in the axial direction. The first disc-shaped component 31 has a groove-shaped structure formed on the side opposite to the drive shaft 311, and a through hole is provided near the outer periphery.

[0037] Correspondingly, the main body of the second disc-shaped component 32 is also generally disc-shaped and has an upwardly protruding protrusion that can be engaged with the groove structure of the first disc-shaped component 31. Threaded holes that match the through holes of the first disc-shaped component 31 are provided on both sides of the protrusion. Thus, bolts 40 can be passed through the through holes of the first disc-shaped component 31 and threadedly connected to the threaded holes on the second disc-shaped component 32 in sequence, so as to fix the first disc-shaped component 31 and the second disc-shaped component 32 in a detachable manner.

[0038] In order to operatively connect the transmission element 30 to the potentiometer 60 so as to transmit the rotation of the transmission element 30 to the potentiometer 60, continue to refer to Figure 2-3 As shown in Figures 5-6, the speed control switch 100 may further include a plug plate 70 disposed between and connected to the first disc-shaped component 31 and the second disc-shaped component 32, and rotatable with them. See especially... Figure 6 As shown, the rotating shaft of potentiometer 60 extends coaxially upward through the fixed plate 20 and the second disc-shaped component 32, along with the drive shaft 311 of the transmission component 30, until the rotating shaft hole 61 on the rotating shaft reaches the mounting height of the plug plate 70. Figure 5 As shown, the connector plate 70 includes a generally disc-shaped main body 71. A notch 73 extending radially inward from the outer periphery of the main body 71 is provided for receiving the shaft of the potentiometer 60. A rod 72 extends from the bottom edge of the notch 73. The rod 72 laterally passes through a shaft hole 61 on the potentiometer shaft, thereby operatively connecting the connector plate 70 to the shaft of the potentiometer 60. This allows the transmission member 30 to drive the shaft of the potentiometer 60 to rotate via the connector plate 70, thereby actuating the potentiometer 60 to generate a corresponding electrical signal.

[0039] In the illustrated embodiment, the speed control switch 100 may further include a gear selection component 80, such as... Figure 6-7As shown. The gear shift assembly may include at least one spring groove 81, a spring (such as a coil spring) 82, a ball bearing 84, and a plurality of gear shift holes 83. The spring groove 81 is disposed on the surface of the second disc-shaped member 32 facing the fixing plate 20 and is used to accommodate the corresponding spring 82. The plurality of gear shift holes 83 are equally spaced along the circumference of the fixing plate 20 and coincide with the position of the spring groove 81 in the radial direction. The upper end of the spring 82 abuts against the bottom wall of the spring groove 81, and the lower end abuts against the ball bearing 84, and is designed to always apply a biasing force toward the fixing plate 20 to the ball bearing 84. When the potentiometer 60, the fixing plate 20, and the second disc-shaped member 32 are axially fixed by the plug plate 70, the biasing force of the spring 82 can abut the ball bearing 84 against the fixing plate 20, and generate a gear shift feel when the ball bearing 84 is transferred from the surface abutting against the fixing plate 20 to abutting into the gear shift hole 83. Furthermore, the spring 82 is designed to overcome the biasing force of the spring 82 when the drive shaft 311 drives the second disc-shaped component 32 to rotate, causing the ball bearing 84 in a certain gear position hole 83 to extend out of the gear position hole onto the surface of the fixed plate 20. Optionally, the gear position assembly 80 can be provided with two radially opposite sets in the circumferential direction of the speed control switch, so that the transmission component 30 can remain balanced when rotating.

[0040] The number of gear holes 83 in each adjacent group in the circumferential direction can be appropriately set to determine the number of speed settings of the speed control switch. Combined with... Figure 7 As shown, the arc-shaped limiting groove on the fixed plate 20 extends in a long strip along the circumference of the fixed plate 20. Correspondingly, a limiting rod that can be inserted into the arc-shaped limiting groove is provided on the second disc-shaped component 32, so that the cooperation between the arc-shaped limiting groove and the limiting rod can limit the total stroke of the speed control switch 100 from the lowest gear to the highest gear.

[0041] Industrial applicability

[0042] The speed control switch according to this invention is particularly suitable for use in machinery equipped with an engine for regulating engine speed. However, it should be understood that the speed control switch according to this invention can also be applied to any other application where speed can be adjusted via a potentiometer.

[0043] Taking the speed control switch 100 in the illustrated embodiment as an example, when it is assembled and in operation, the housing assembly 10, which is composed of the first housing 11 and the second housing 12, and the main body of the potentiometer 60 and the fixing plate 20 contained therein, are directly or indirectly fixed relative to the panel 300. When the driver operates the knob 200 to rotate, the knob 200 drives the transmission component 30 to rotate via the transmission shaft 311, which in turn drives the shaft of the potentiometer 60, which is operatively connected to the transmission component 30, to rotate. This causes the potentiometer 60 to output a proportional voltage or current control signal to the engine controller via the wiring harness connector 400. The engine controller then controls the amount of fuel injected into the engine according to the proportional signal, thereby adjusting the engine speed.

[0044] The speed control switch of this invention forms a relatively enclosed cavity through the connection of a first housing and a second housing, enclosing and protecting the transmission component, fixing plate, and potentiometer within this cavity. Only the operable drive shaft of the transmission component extends out of the second housing, thereby improving the overall oil, water, and corrosion resistance of the speed control switch. The overall structural design of the speed control switch, including the first and second housings and the transmission component, enables simple, stable, and reliable installation of the transmission component, potentiometer, and other components within the cavity, as well as the entire speed control switch on a simple panel. The position assembly involving the fixing plate, contact ball, and spring within the speed control switch further increases the rotational resistance during operation, improving the operating feel, operating accuracy, and durability.

[0045] Various modifications and variations can be made to the embodiments disclosed above without departing from the scope or spirit of this invention. Other embodiments of this invention will be apparent to those skilled in the art based on the practice of this invention disclosed in this specification. This specification and the examples disclosed herein should be considered illustrative only, and the true scope of this invention is defined by the appended claims and their equivalents.

Claims

1. A speed control switch for operating machinery, characterized in that, The speed control switch includes: The first housing (11) and the second housing (12) are fixed together to jointly define the cavity; and The transmission component (30), the fixing plate (20), and the potentiometer (60) are disposed within the cavity and enclosed by the first and second housings. The fixing plate (20) is fixed to the first housing (11), the potentiometer (60) is limited by the fixing plate and fixed relative to the first housing, the transmission member (30) has a transmission shaft (311) extending beyond the second housing (12) and is mounted so as to be axially fixed relative to the second housing but rotatable about the axial direction, the transmission member (30) is operatively connected to the potentiometer (60) such that the rotation of the transmission shaft (311) caused by the operation of the speed control switch actuates the potentiometer to generate an electrical signal corresponding to the operation amount of the speed control switch.

2. The speed control switch according to claim 1, characterized in that, The second housing (12) is provided with a sleeve portion (121) extending outward along the axial direction and surrounding the drive shaft (311). The drive shaft extends outward along the axial direction through the sleeve portion and the portion exposed from the sleeve portion is provided with a circumferential groove (312). The transmission member is fixed in the axial direction relative to the second housing (12) via a retaining ring (50) snapped into the circumferential groove.

3. The speed control switch according to claim 1, characterized in that, The transmission component (30) includes a first disc-shaped component (31) having the transmission shaft (311) and a second disc-shaped component (32) detachably fixed to the first disc-shaped component.

4. The speed control switch according to claim 3, characterized in that, The transmission component (30) further includes a plug plate (70) disposed between and connected to the first disc-shaped component and the second disc-shaped component to rotate with them. The potentiometer (60) includes a rotating shaft coaxial with the transmission shaft, the rotating shaft extending through the fixed plate (20) to the plug plate, and the plug plate being operatively connected to the rotating shaft by a rod (72) extending laterally through the rotating shaft.

5. The speed control switch according to claim 3, characterized in that, The speed control switch also includes a gear assembly (80), which includes at least one spring groove (81) disposed on the second disc-shaped component (32), a spring (82) disposed in the spring groove, a plurality of gear holes (83) spaced circumferentially along the fixed plate (20), and a ball (84) that can abut against any gear hole under the biasing force of the spring and can overcome the biasing force of the spring and move out of the gear hole when the drive shaft drives the second disc-shaped component to rotate.

6. The speed control switch according to claim 2, characterized in that, The sleeve portion (121) passes through the control panel (300) in the working machine so that the first housing and the second housing are located on one side of the control panel. The speed control switch also includes a nut (94) screwed onto the sleeve portion having external threads on the other side of the control panel to mount the speed control switch on the control panel.

7. The speed control switch according to claim 6, characterized in that, The sleeve portion (121) has a D-shaped cross-section and passes through a matching D-shaped hole in the control panel (300) to prevent the second housing from rotating relative to the control panel.

8. The speed control switch according to any one of claims 1 to 5, characterized in that, The first shell (11) and the second shell (12) are both cylindrical with one end open and the other end closed. The open end of the first shell and the open end of the second shell are fixed together by interlocking.

9. The speed control switch according to claim 8, characterized in that, The closed end of the first housing (11) is formed by a bottom cover (112) that is detachably connected to the body of the first housing.

10. A type of operating machinery, characterized in that... Includes an engine and a speed control switch for said engine, as described in any one of claims 1 to 9.

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