String button device based on planetary gear train

Abstract

The utility model discloses a string button device based on planetary gear train, including mandrel, one end of mandrel is rotatably connected with end cover, rotatable planet carrier is arranged in end cover, at least one planet shaft is rotatably arranged on planet carrier, and two planetary gears of coaxial connection are arranged on each planet shaft, the first sun gear is fixedly connected with one end of mandrel close to end cover, the second sun gear is fixedly connected in end cover, and the two planetary gears of coaxial connection are engaged with the first sun gear and the second sun gear respectively, when end cover is stationary and planet carrier rotates, planet carrier drives mandrel differential rotation through the cooperation of planetary gear and the first sun gear. The shaft sleeve is sleeved on the mandrel, and the shaft sleeve is extruded between the mandrel and the head hole when the mandrel is in interference fit with the head hole. The utility model aims at the problem that wooden string button is difficult to fine tune, and realizes speed reduction adjustment based on planetary gear train.

Description

Technical Field

[0001] This utility model relates to a part of a musical instrument, and more particularly to a tuning peg device based on a planetary gear system. Background Technology

[0002] A tuning peg is a component located on the headstock of a violin, cello, or other violin used for securing the strings and tuning. It is also called a tuning pin, knob, or headstock knob. The violin's tuning peg achieves self-locking by an interference fit with the headstock hole. When the strings need to be tightened or loosened, the tuning peg is turned clockwise or counterclockwise, applying a torque to overcome the frictional torque used for self-locking, thus driving the tuning peg to rotate. When the torque is removed, the tuning peg re-locks due to the interference fit with the headstock hole.

[0003] Under the influence of humidity and temperature, the headstock hole of a violin can deform after repeated adjustments of the tuning pegs, changing from a round hole to an oval or other non-round hole. This disrupts the interference fit between the tuning peg and the headstock hole, preventing self-locking and causing slippage, necessitating repair or scrapping. On the other hand, for violin beginners, adjusting the sound through the tuning pegs requires fine-tuning as the pitch approaches the desired level, which wooden tuning pegs struggle to achieve. Summary of the Invention

[0004] Purpose of the invention: In order to overcome the shortcomings of the existing technology, this utility model provides a knob device based on a planetary gear system, which addresses the problem of the difficulty in fine-tuning wooden knobs by achieving speed reduction adjustment based on a planetary gear system.

[0005] Technical Solution: To achieve the above objectives, this utility model provides a knob device based on a planetary gear train, comprising a spindle, one end of which is rotatably connected to an end cap, a rotatable planetary carrier disposed inside the end cap, at least one planetary shaft rotatably disposed on the planetary carrier, and two planetary gears coaxially connected on each planetary shaft; a first sun gear is fixedly connected to one end of the spindle near the end cap, and a second sun gear is fixedly connected inside the end cap, the two coaxially connected planetary gears meshing with the first sun gear and the second sun gear respectively; when the end cap is stationary and the planetary carrier rotates, the planetary carrier drives the spindle to rotate differentially through the engagement of the planetary gears with the first sun gear.

[0006] Furthermore, a bushing is fitted onto the mandrel, and when the mandrel is interference-fitted with the headstock hole, the bushing is pressed between the mandrel and the headstock hole.

[0007] Furthermore, the headstock hole is a tapered hole, the bushing is a tapered sleeve, and the two ends of the spindle are a small end and a large end, respectively; the bushing and the end cap are both located at the large end of the spindle, and the bushing and the end cap are fixedly connected.

[0008] Furthermore, the small end of the mandrel is provided with a tapered mating surface, and the mandrel can be interference-fitted with the headstock hole through the tapered mating surface; both the tapered mating surface and the outer surface of the bushing are provided with knurled patterns.

[0009] Furthermore, the bushing is an elastic structure; when the bushing is pressed between the spindle and the headstock hole, the bushing undergoes elastic deformation.

[0010] Furthermore, the end cap and the bushing form an adjustment cavity, in which the planet carrier, the first sun gear, and the second sun gear are all located.

[0011] Furthermore, the end cap is provided with a rotating hole; a torsion bar is connected to the planetary carrier, the torsion bar is rotatably engaged with the rotating hole, and one end of the torsion bar passes through the adjusting cavity from the rotating hole. When the torsion bar rotates in the rotating hole, it drives the planetary carrier to rotate.

[0012] Furthermore, a torsion handle is connected to one end of the torsion bar that extends out of the adjustment cavity.

[0013] Furthermore, the rotation axes of the mandrel, the torsion bar, the first sun gear, and the second sun gear are on the same straight line.

[0014] Beneficial effects: The beneficial effects of the button device based on the planetary gear system of this utility model are as follows:

[0015] 1) The planetary carrier is rotated by the torsion bar, and the planetary carrier then drives the spindle to rotate through the cooperation of the planetary gears and the sun gear, which can realize the speed reduction adjustment of the tuning pegs so as to fine-tune the pitch;

[0016] 2) The mandrel is fitted with a bushing, which is elastic and can enhance the self-locking of the knob; in addition, the tapered mating surface of the mandrel and the outside of the bushing are both provided with knurled texture, which further enhances the self-locking of the knob.

[0017] 3) The bushing is fixedly connected to the end cap. Due to the friction between the bushing and the headstock hole, the end cap will remain stationary when the knob is turned, so there is no need to manually keep the end cap stationary, making it more convenient to adjust the knob. Attached Figure Description

[0018] Appendix Figure 1 A three-dimensional diagram of the tuning pegs mounted on the headstock;

[0019] Appendix Figure 2 A cross-sectional view of the tuning pegs mounted on the headstock;

[0020] Appendix Figure 3 This is a schematic diagram of the internal structure of the regulating cavity;

[0021] Appendix Figure 4 This is a schematic diagram of the planetary carrier structure;

[0022] Appendix Figure 5 This is a schematic diagram of the mandrel structure. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings.

[0024] As attached Figures 1 to 5 The aforementioned planetary gear system-based knob device includes a spindle 1, as shown in the attached figure. Figure 1 As shown, when the tuning pegs are installed on the headstock, the spindle 1 passes through two opposing headstock holes 9 of different sizes, and the two headstock holes 9 have the same taper.

[0025] One end of the spindle 1 is rotatably connected to an end cap 2, which is rotatable relative to the spindle 1. A rotatable planetary carrier 3 is housed inside the end cap 2, and at least one planetary shaft 4 is rotatably mounted on the planetary carrier 3. Each planetary shaft 4 has two planetary gears 5 coaxially connected. (See attached diagram) Figure 4 In one embodiment shown, two planetary shafts 4 are mounted on the planet carrier 3. The planetary shafts 4 are clearance-fitted to the planet carrier 3. One end of each planetary shaft 4 is provided with a limiting end, and the other end of each planetary shaft 4 is connected to a nut 14. The planetary shaft 4 is locked to the planet carrier 3 by the cooperation of the nut 14 and the limiting end. A planetary gear 5 is mounted on each side of each planetary shaft 4. The planetary gear 5 is interference-fitted to the planetary shaft 4, and there is no relative rotation between the planetary shaft 4 and the planetary gear 5.

[0026] A first sun gear 6 is fixedly connected to one end of the mandrel 1 near the end cap 2. The first sun gear 6 is concentrically sleeved on the end of the mandrel 1, and is interference-fitted with the mandrel 1, with no relative rotation between the mandrel 1 and the first sun gear 6. A second sun gear 7 is fixedly connected inside the end cap 2. A connecting post is provided inside the end cap 2, and the second sun gear 7 is sleeved on the connecting post, with an interference-fitted connection between the second sun gear 7 and the connecting post, with no relative rotation between the end cap 2 and the second sun gear 7.

[0027] Two planetary gears 5, coaxially connected, mesh with the first sun gear 6 and the second sun gear 7, respectively. When the end cap 2 is stationary, the second sun gear 7 also remains stationary. If the planet carrier 3 rotates at this time, because the second sun gear 7 meshes with the planetary gears 5, the planetary gears 5 will rotate on their own axis while revolving around the sun. The planetary gears 5, which are revolving around the sun and rotating on their own axis, will drive the first sun gear 6 to rotate. Therefore, the planet carrier 3 drives the spindle 1 to rotate at a differential speed through the cooperation of the planetary gears 5 and the first sun gear 6. Moreover, the angular velocity of the spindle 1 when it rotates is less than that of the planet carrier 3, so it is possible to achieve deceleration adjustment of the tuning pegs for fine-tuning of the pitch.

[0028] If the end cap 2 does not remain stationary, the result of rotating the planetary carrier 3 may be that the end cap 2 rotates instead of the spindle 1, making it impossible to adjust the rotation of the tuning pegs and thus impossible to adjust the pitch.

[0029] A bushing 8 is fitted onto the mandrel 1. The bushing 8 is an elastic structure, and its material can be low-density, highly elastic, and high-strength, such as wood or carbon fiber. (See attached image) Figure 2 As shown, when the spindle 1 and the headstock hole 9 are interference-fitted, the bushing 8 is pressed between the spindle 1 and the headstock hole 9, and the bushing 8 undergoes elastic deformation, thereby enhancing the self-locking of the tuning peg.

[0030] The headstock has two tapered holes 9 of different sizes. The bushing 8 is also tapered. The spindle 1 has a small end and a large end; the small end corresponds to the smaller headstock hole 9, and the large end corresponds to the larger headstock hole 9. Both the bushing 8 and the end cap 2 are located at the large end of the spindle 1, and the bushing 8 is fixedly connected to the end cap 2. As mentioned earlier, for the rotation of the planetary carrier 3 to produce the rotation of the spindle 1, the end cap 2 needs to remain stationary. If the operator were to hold the end cap 2 by hand to keep it stationary, the operation would be cumbersome. Therefore, the end cap 2 is connected to the bushing 8, and the friction between the end cap 2 and the headstock hole 9 is used to keep the end cap 2 stationary.

[0031] There is a moderately viscous resin glue between the bushing 8 and the spindle 1. When the pitch needs to be adjusted, the torsion bar 12 is rotated to overcome the viscous friction torque between the bushing 8 and the spindle 1, causing the spindle 1 to rotate relative to the bushing 8. When the adjustment is completed, the viscous friction torque between the bushing 8 and the spindle 1 can prevent the spindle 1 from rotating relative to the bushing 8, that is, it remains locked. During the entire adjustment process, the bushing 8 remains stationary due to the friction torque between itself and the headstock hole.

[0032] As attached Figure 5 As shown, a tapered mating surface 10 is provided at the small end of the spindle 1, allowing the spindle 1 to be interference-fitted with the headstock hole 9 via the tapered mating surface 10. Both the tapered mating surface 10 and the bushing 8 are provided with knurled patterns to further improve the self-locking capability of the tuning pegs.

[0033] As attached Figure 3 As shown, the end cap 2 and the bushing 8 are fixedly connected by adhesive bonding, and the end cap 2 and the bushing 8 form an adjustment cavity 11. The planet carrier 3, the first sun gear 6 and the second sun gear 7 are all located in the adjustment cavity 11. The end cap 2 and the bushing 8 serve as a shell to protect the planet carrier 3, the planet gear 5 and the sun gear located in the adjustment cavity 11.

[0034] A rotating hole is provided on the end cap 2. A torsion bar 12 is connected to the planet carrier 3. In one embodiment, the planet carrier 3 is assembled and connected to the torsion bar 12 through a shaped hole, and there is no relative rotation between the planet carrier 3 and the torsion bar 12. The torsion bar 12 is rotatably engaged with the rotating hole, and one end of the torsion bar 12 passes through the adjusting cavity 11 from the rotating hole. When the torsion bar 12 rotates in the rotating hole, it drives the planet carrier 3 to rotate. A torsion handle 13 is connected to the end of the torsion bar 12 that passes through the adjusting cavity 11, so that the torsion bar 12 can be rotated easily through the torsion handle 13. The rotation axes of the spindle 1, the torsion bar 12, the first sun gear 6, and the second sun gear 7 are on the same straight line, so rotating the torsion bar 12 can drive the spindle 1 to rotate.

[0035] In practical applications, when it is necessary to tighten or loosen the strings, the planetary carrier 3 is rotated by the torsion handle 13 and the torsion bar 12. The planetary carrier 3 drives the first sun gear 6 to rotate through the planetary gear 5, thereby driving the spindle 1 to rotate to tighten or loosen the strings.

[0036] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A knob device based on a planetary gear train, characterized in that: The device includes a spindle (1), one end of which is rotatably connected to an end cap (2). A rotatable planetary carrier (3) is provided inside the end cap (2). At least one planetary shaft (4) is rotatably provided on the planetary carrier (3). Each planetary shaft (4) has two planetary gears (5) coaxially connected. A first sun gear (6) is fixedly connected to one end of the spindle (1) near the end cap (2). A second sun gear (7) is fixedly connected inside the end cap (2). The two coaxially connected planetary gears (5) mesh with the first sun gear (6) and the second sun gear (7) respectively. When the end cap (2) is stationary and the planetary carrier (3) is rotating, the planetary carrier (3) drives the spindle (1) to rotate at a differential speed through the cooperation of the planetary gears (5) and the first sun gear (6).

2. The knob device based on a planetary gear train according to claim 1, characterized in that: A bushing (8) is fitted on the spindle (1). When the spindle (1) and the headstock hole (9) are interference-fitted, the bushing (8) is pressed between the spindle (1) and the headstock hole (9).

3. A knob device based on a planetary gear train according to claim 2, characterized in that: The headstock hole (9) is a tapered hole, the bushing (8) is a tapered sleeve, and the two ends of the spindle (1) are the small end and the large end, respectively; the bushing (8) and the end cap (2) are both located at the large end of the spindle (1), and the bushing (8) and the end cap (2) are fixedly connected.

4. A knob device based on a planetary gear train according to claim 3, characterized in that: The small end of the mandrel (1) is provided with a tapered mating surface (10), and the mandrel (1) can be press-fitted with the headstock hole (9) through the tapered mating surface (10); the tapered mating surface (10) and the bushing (8) are both provided with knurled patterns.

5. A knob device based on a planetary gear train according to claim 3, characterized in that: The bushing (8) is an elastic structure; when the bushing (8) is pressed between the spindle (1) and the headstock hole (9), the bushing (8) undergoes elastic deformation.

6. A knob device based on a planetary gear train according to claim 3, characterized in that: The end cap (2) and the bushing (8) form an adjustment cavity (11), and the planet carrier (3), the first sun gear (6) and the second sun gear (7) are all located in the adjustment cavity (11).

7. A knob device based on a planetary gear train according to claim 6, characterized in that: The end cap (2) has a rotating hole; a torsion bar (12) is connected to the planet carrier (3), the torsion bar (12) rotates with the rotating hole, and one end of the torsion bar (12) passes through the adjustment cavity (11) through the rotating hole. When the torsion bar (12) rotates in the rotating hole, it drives the planet carrier (3) to rotate.

8. A knob device based on a planetary gear train according to claim 7, characterized in that: A torsion handle (13) is connected to one end of the torsion bar (12) that extends out of the adjustment cavity (11).

9. A knob device based on a planetary gear train according to claim 7, characterized in that: The rotation axes of the spindle (1), the torsion bar (12), the first sun gear (6), and the second sun gear (7) are on the same straight line.

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