Crank arm for rice transplanter and dismounting device of crank arm

Abstract

The crank arm comprises a first positioning part, a second positioning part and a balance fan-shaped part, the first positioning part is in key connection with a driving shaft, the second positioning part is connected with a rice transplanting arm assembly, and the driving shaft drives the first positioning part to rotate; the first positioning part is provided with a first inner cavity and a second inner cavity which are perpendicular to each other; the driving shaft penetrates into the first inner cavity, the second inner cavity is matched with the fastener, the first inner cavity and the second inner cavity are provided with through parts, and the fastener is in interference fit with the driving shaft at the through parts. According to the utility model, the crank arm is tightly connected with the driving shaft, so that the crank arm is ensured not to shift in the swinging process; according to the device for disassembling the crank arm, on one hand, the crank arm is limited through the limiting part; on the other hand, the moving part penetrates through the first inner cavity of the crank arm and then abuts against the driving shaft, the moving part continues to move after abutting, the driving shaft is ejected out of the first inner cavity, and separation of the driving shaft and the crank arm is achieved.

Description

Technical Field

[0001] This utility model relates to the field of mechanical design and manufacturing technology, specifically to a crank arm for a rice transplanter and its disassembly device. Background Technology

[0002] The crank arm mounted on the rice transplanter serves as the transmission connector between the drive mechanism and the transplanting arm. The drive mechanism drives the crank arm to swing, which in turn drives the transplanting arm to swing, completing the transplanting action. Therefore, the crank arm and drive shaft of the rice transplanter need to be tightly connected. If the connection is faulty, abnormal friction, collision, and loosening can occur between the crank arm and drive shaft, easily leading to damage and malfunctions. For example, the crank arm may deform or crack, and the bearings of the drive shaft may be damaged. Once a malfunction occurs, the rice transplanter needs to be stopped for repairs, severely impacting work efficiency and causing delays in the work progress. It can also cause slippage and jamming during power transmission, preventing the transplanter's power from being effectively transmitted to the transplanting mechanism, reducing the transplanter's working speed, and increasing the time required to complete the transplanting operation.

[0003] Furthermore, the crank arm needs to be disassembled when maintaining the drive mechanism. The working environment of a rice transplanter is complex, and the crank arm needs to operate in muddy and watery conditions, often resulting in rust. Due to the rice transplanter's structural layout and limited space, disassembly is extremely difficult. The crank arm itself has a unique shape, and the limited assembly space makes it unusable with commercially available disassembly tools.

[0004] Authorization Announcement No.: CN 211457982U, Application Date: 2019.10.25, Utility Model Name: A Rice Transplanter Arm Claw Assembly. This utility model discloses a rice transplanter arm claw assembly, which includes a crank arm connected to the rice transplanter's transplanting box, a rice transplanter arm connected to the crank arm, a rice transplanter pushing mechanism partially disposed within the rice transplanter arm, and a rice transplanter claw mounted on the rice transplanter arm. A rice transplanter arm oil seal is provided between the rice transplanter arm and the crank arm, and the oil seal cover of the rice transplanter arm oil seal is integrated with the crank arm as an integral structure. Because the oil seal cover of the rice transplanter arm oil seal between the rice transplanter arm and the crank arm is integrated with the crank arm as an integral structure, there is no need to set a separate oil seal cover. This reduces the number of parts, making the overall structure of the rice transplanter arm claw assembly simpler, easier to install, with lower processing costs, higher reliability, and easier to manufacture. Moreover, the sealing effect is better than that of a structure where the crank arm and the oil seal cover are separate.

[0005] As can be seen from the attached figures, in the above-mentioned prior art, the crank arm and the drive shaft are connected only through a square hole, and the crank arm is prone to sliding during transmission.

[0006] In addition, crank arms need to work in muddy and wet environments, and they will rust due to the mud and water. Also, because crank arms are small and have limited installation space, they are very difficult to disassemble. Utility Model Content

[0007] In view of the shortcomings of the prior art, such as the easy loosening between the crank arm and the drive shaft and the difficulty in disassembling the crank arm, the purpose of this utility model is to provide a crank arm that can both move synchronously with the drive shaft and achieve an interference fit with the drive shaft, and to provide a device that facilitates the disassembly of the crank arm.

[0008] The technical solution provided by this utility model is as follows:

[0009] A crank arm for a rice transplanter, comprising,

[0010] A first positioning part is used to be keyed to a drive shaft, and the drive shaft is used to drive the first positioning part to rotate.

[0011] The second positioning part is used to connect with the rice transplanter arm assembly, and the second positioning part is fixedly connected to the first positioning part.

[0012] A balancing sector portion, which is fixedly connected to the first positioning portion;

[0013] The second positioning part and the balanced sector part are located on both sides of the first positioning part;

[0014] The first positioning part has a first inner cavity and a second inner cavity that are perpendicular to each other;

[0015] The first inner cavity is used for the drive shaft to pass through;

[0016] The second inner cavity is adapted to the fastener;

[0017] The first inner cavity and the second inner cavity have a through portion;

[0018] The fastener and the drive shaft are interference-fitted in the through section.

[0019] Furthermore, the first inner cavity is relatively close to the balancing sector, and the second inner cavity is relatively far from the balancing sector, and the cross-sections of the first inner cavity and the second inner cavity are approximately circular; along the cross-sectional direction perpendicular to the drive shaft, the distance between the center of the first inner cavity and the center of the second inner cavity is denoted as A, and the sum of the radii of the first inner cavity and the radii of the second inner cavity is denoted as B; where A < B.

[0020] Furthermore, the fastener is provided with an inclined portion, which is opposite to and abuts against the drive shaft;

[0021] The inclined portion begins approximately in the middle of the fastener and ends near the end of the fastener.

[0022] Furthermore, the inclined portion is a smooth plane, and the angle between the inclined portion and the central axis of the fastener is 10° to 25°.

[0023] Furthermore, the drive shaft is provided with a flat key, and the first inner cavity is provided with a flat keyway adapted to the flat key.

[0024] A disassembly device for separating the crank arm and drive shaft, including a limiting part and a movable part adapted to the limiting part;

[0025] The limiting part is used to limit the first positioning part;

[0026] The moving part moves along the drive shaft direction, and the moving part is used to separate the drive shaft and the crank arm.

[0027] Furthermore, the limiting part is generally U-shaped and includes a connecting plate and a pair of side plates symmetrically disposed at both ends of the connecting plate;

[0028] The first positioning part is located between a pair of side plates, and a first through hole is provided on the side plate, which corresponds to the second inner cavity; the pin is inserted into the first through hole and the second inner cavity in sequence.

[0029] Furthermore, the opposite portions of the side plate and the second inner cavity are both smooth planes.

[0030] Furthermore, a second through hole is provided on the connecting plate to cooperate with the moving part. The second through hole is coaxial with the first inner cavity, and the size of the second through hole is smaller than the size of the first inner cavity.

[0031] Furthermore, along the extension direction of the drive shaft, the length of the moving part is greater than the length of the limiting part, and the length of the side plate is greater than the length of the first inner cavity.

[0032] Compared with the prior art, the technical solution provided by this utility model has the following advantages:

[0033] This invention provides a first inner cavity on the crank arm for key connection with the drive shaft, enabling synchronous movement of the drive shaft and the crank arm. A second inner cavity is also provided on the crank arm for use with a fastener, which is interference-fitted with the drive shaft, ensuring a tight connection between the crank arm and the drive shaft and preventing displacement of the crank arm during swinging.

[0034] This utility model relates to a convenient and compact device for disassembling crank arms. On the one hand, the limiting part limits the crank arm to prevent it from moving during disassembly; on the other hand, the moving part passes through the first inner cavity of the crank arm and abuts against the drive shaft. After abutting, it continues to move, pushing the drive shaft out of the first inner cavity, thereby separating the drive shaft from the crank arm. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the overall structure connecting the drive shaft and the crank arm in one embodiment of this application;

[0036] Figure 2 This is a schematic diagram of the overall structure of the crank arm in one embodiment of this application;

[0037] Figure 3 This is a cross-sectional view of the crank arm in one embodiment of this application;

[0038] Figure 4 This is a schematic diagram showing the positional relationship between the fastener and the drive shaft in one embodiment of this application;

[0039] Figure 5 This is a schematic diagram of the overall structure of the disassembly device in one embodiment of this application;

[0040] Figure 6 This is a schematic diagram showing the moving part abutting against the drive shaft in one embodiment of this application;

[0041] Figure 7 This is a schematic diagram of the moving part pushing the drive shaft out of the crank arm in one embodiment of this application;

[0042] Figure 8 This is a schematic diagram showing the positional relationship between the limiting part and the moving part of the disassembly device in one embodiment of this application;

[0043] Figure 9 This is a schematic diagram of the first through hole and the second through hole in one embodiment of this application.

[0044] Explanation of the labels in the diagram:

[0045] First positioning part 1, first inner cavity 11, second inner cavity 12, drive shaft 13, fastener 14, through part 15, flat keyway 111, flat key 131, inclined part 141;

[0046] Second positioning unit 2;

[0047] Balanced sector 3;

[0048] Rice transplanter arm assembly 4;

[0049] Limiting part 5, connecting plate 51, side plate 52, pin 53, first through hole 521, second through hole 511;

[0050] Mobile Section 6. Detailed Implementation

[0051] To further understand the content of this utility model, a detailed description of this utility model will be provided in conjunction with the accompanying drawings and embodiments.

[0052] The structures, proportions, and sizes illustrated in the accompanying drawings are merely for illustrative purposes and to aid those skilled in the art in understanding and reading the invention. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed in this utility model. Furthermore, terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity and not intended to limit the scope of implementation. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0053] The principle of a rice transplanter is as follows: The power of a rice transplanter is usually provided by an engine, which transmits power to the drive shaft through a transmission device. The drive shaft is the power input shaft of the entire transplanting mechanism; its rotational motion is the power source for subsequent actions. The drive shaft is fixedly connected to a crank arm. When the drive shaft rotates, the crank arm moves in a circular motion along with the drive shaft. The other end of the crank arm is connected to the transplanting arm via a hinge or pin. Due to the circular motion of the crank arm, it drives the transplanting arm to oscillate back and forth.

[0054] During the reciprocating swing of the transplanting arm, the seedling separating mechanism on the transplanting arm comes into contact with the seedlings. The seedling separating mechanism usually consists of multiple seedling separating claws or seedling separating needles. When the transplanting arm swings forward, the seedling separating claws insert into the seedling cluster and separate a certain number of seedlings from the seedling cluster.

[0055] After the seedlings are separated, the transplanting arm continues to swing. As the arm swings backward, the separating claws carry the separated seedlings downward, inserting them into the paddy field. The transplanting arm is typically designed with specific trajectory and angle controls to ensure the seedlings are inserted vertically into the paddy field, and that the insertion depth and spacing meet agronomic requirements.

[0056] It is worth noting that the crank arm needs to be tightly connected to the drive shaft. When the rice transplanter is working, the power generated by the engine is transmitted to the drive shaft through the transmission device. The drive shaft needs to accurately transmit this torque to the crank arm, thereby driving the transplanting arm to perform the transplanting operation. If the connection is not tight, problems such as slippage and energy loss will occur during the torque transmission process, resulting in ineffective power transmission and affecting the working efficiency and operation quality of the rice transplanter.

[0057] A tight connection between the drive shaft and the crank arm ensures strict synchronization of their movements. During rice transplanting, the rotational motion of the drive shaft needs to be precisely converted into the reciprocating oscillation of the crank arm, thereby driving the transplanting arm to complete the transplanting action. If the connection is loose, the coordination between their movements will deviate, causing the transplanting arm's movement rhythm to become disordered, making it impossible to transplant rice accurately according to design requirements, and may even lead to problems such as missed transplanting or damaged seedlings.

[0058] However, since rice transplanters typically operate in paddy fields with high humidity, the crank arms are exposed to this damp air for extended periods, causing moisture to condense on their surface and creating favorable conditions for rust formation. During operation, the crank arms inevitably come into contact with water and mud in the paddy fields. The water contains various minerals and impurities, and the mud may contain corrosive substances, all of which accelerate the rusting of the crank arms.

[0059] When the drive shaft needs maintenance, the crank arm must be disassembled. Due to the compact internal structure of the rice transplanter, the crank arm is often surrounded by various other components, such as the drive shaft, transplanting arm, and connecting rod, making the operating space limited and tools difficult to use, thus increasing the difficulty of disassembly. Therefore, disassembling the crank arm is not an easy task.

[0060] The present application discloses a crank arm for a rice transplanter, comprising a first positioning part 1, a second positioning part 2, and a balancing sector part 3. The first positioning part 1 is tightly connected to a drive shaft 13, the second positioning part 2 is connected to a rice transplanter arm assembly 4, and the balancing sector part 3 uses its own counterweight to stop the rice transplanter arm assembly 4 at certain positions.

[0061] The second positioning part 2 and the balancing sector part 3 are both fixedly connected to the first positioning part 1, and the second positioning part 2 and the balancing sector part 3 are disposed on both sides of the first positioning part 1. Preferably, the above three components of the crank arm are integrally formed.

[0062] The first positioning part 1 is a crucial component, as it is connected to the drive shaft 13 by both a key and an interference fit, thus ensuring a tight connection while achieving power transmission. More specifically, the drive shaft 13 is provided with a flat key 131, and the first positioning part 1 has a first inner cavity 11 through which the drive shaft 13 passes. At the corresponding position of the flat key 131, the first inner cavity 11 is provided with a flat keyway 111.

[0063] The first positioning part 1 also has a second inner cavity 12. Since the flat keyway 111 is located at the bottom of the first inner cavity 11, that is, relatively close to the balancing sector 3, the second inner cavity 12 is preferably located above the first inner cavity 11, that is, relatively far away from the balancing sector 3. Furthermore, it should be noted that the second inner cavity 12 is preferably perpendicular to the first inner cavity 11. The second inner cavity 12 is used in conjunction with a fastener 14, which is preferably a bolt assembly.

[0064] The second inner cavity 12 and the first inner cavity 11 have approximately circular cross-sections, and this cross-sectional direction is perpendicular to the drive shaft 13. The second inner cavity 12 and the first inner cavity 11 have a through portion 15, and the fastener 14 and the drive shaft 13 achieve an interference fit in the through portion 15. More specifically, along the cross-sectional direction perpendicular to the drive shaft 13, the distance between the center of the first inner cavity 11 and the center of the second inner cavity 12 is denoted as A, and the sum of the radii of the first inner cavity 11 and the second inner cavity 12 is denoted as B. The relationship between A and B is A < B. Therefore, the first inner cavity 11 and the second inner cavity 12 must have an overlapping portion. By opening up the overlapping portion, the through portion 15 is formed, which allows the fastener 14 and the drive shaft 13 to contact.

[0065] Since the fastener 14 is preferably a bolt assembly, the screw and the drive shaft 13 are tightly abutted together. The screw passes through the second inner cavity 12 and exits through the first positioning part 1, and the nut fixes the screw. This achieves an interference fit between the fastener 14 and the drive shaft 13.

[0066] To further ensure the effect of interference fit, the screw is provided with an inclined part 141. The inclined part 141 is a smooth plane. The inclined part 141 is opposite to the drive shaft 13 and abuts against the drive shaft 13. By increasing the contact area between the inclined part 141 and the drive shaft 13, the interference fit effect between the two is better achieved, thereby making the crank arm and the drive shaft 13 tightly connected.

[0067] The inclined portion 141 begins approximately at the middle of the fastener 14 and ends near the end of the fastener 14. The angle between the inclined portion 141 and the central axis of the fastener 14 ranges from 10° to 25°.

[0068] When it is necessary to disassemble the crank arm, first detach the rice transplanter arm assembly 4, then remove the fasteners 14 on the crank arm, install the disassembly device, and separate the crank arm from the drive shaft 13. Specifically, the disassembly device includes a limiting part 5 and a moving part 6. The moving part 6 is adapted to the limiting part 5 and can move along the drive shaft 13 to push the drive shaft 13 out.

[0069] The limiting part 5 is used to limit the first positioning part 1. The limiting part 5 is generally U-shaped and includes a connecting plate 51 and a pair of side plates 52 symmetrically arranged at both ends of the connecting plate 51. The connecting plate 51 and the side plates 52 are preferably perpendicular to each other, and the two are preferably integrally formed. The side plates 52 have a first through hole 521, the position of which corresponds to the second inner cavity 12, and the first positioning part 1 is located between the pair of side plates 52.

[0070] The pin 53 is inserted into the first through hole 521 and the second inner cavity 12 in sequence to limit the crank arm. The opposite parts of the side plate 52 and the second inner cavity 12 are smooth planes.

[0071] The connecting plate 51 has a second through hole 511, which is coaxial with the first inner cavity 11, and the size of the second through hole 511 is smaller than the size of the first inner cavity 11. The moving part 6 is adapted to the second through hole 511, and the two are preferably connected by threads. The second through hole 511 is provided with internal threads, and the moving part 6 is provided with external threads adapted to it.

[0072] Along the extension direction of the drive shaft 13, the connecting plate 51 has a certain thickness, not less than 2 cm. The purpose of setting a certain thickness in the connecting plate 51 is to guide the moving part 6 and prevent the moving part 6 from deviating in the direction of movement as it approaches the drive shaft 13. The moving part 6 sequentially passes through the second through hole 511 and the first inner cavity 11 to further limit the movement of the crank arm. After the moving part 6 abuts against the drive shaft 13, it continues to move until it pushes the drive shaft 13 out of the first inner cavity 11.

[0073] Along the extension direction of the drive shaft 13, the length of the side plate 52 is greater than the length of the first inner cavity 11, and the length of the moving part 6 is greater than the length of the limiting part 5. That is, the moving part 6 needs to be set to a certain length in order to contact the drive shaft 13 and push it out of the first inner cavity 11.

[0074] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the inventive spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A crank arm for a rice transplanter, comprising, A first positioning part (1) is used to be keyed to a drive shaft (13), which is used to drive the first positioning part (1) to rotate. The second positioning part (2) is used to connect with the rice transplanter arm assembly (4), and the second positioning part (2) is fixedly connected with the first positioning part (1); Balance sector (3), which is fixedly connected to the first positioning part (1); in, The second positioning part (2) and the balancing sector part (3) are located on both sides of the first positioning part (1); The first positioning part (1) is characterized by having a first inner cavity (11) and a second inner cavity (12) that are perpendicular to each other. The first inner cavity (11) is used for the drive shaft (13) to pass through; The second inner cavity (12) is adapted to the fastener (14); The first inner cavity (11) and the second inner cavity (12) have a through portion (15); The fastener (14) and the drive shaft (13) are interference-fitted in the through part (15).

2. The crank arm for a rice transplanter according to claim 1, characterized in that: The first inner cavity (11) is relatively close to the balancing sector (3), and the second inner cavity (12) is relatively far away from the balancing sector (3). The cross-sections of the first inner cavity (11) and the second inner cavity (12) are approximately circular. Along the cross-sectional direction perpendicular to the drive shaft (13), the distance between the center of the first inner cavity (11) and the center of the second inner cavity (12) is denoted as A, and the sum of the radius of the first inner cavity (11) and the radius of the second inner cavity (12) is denoted as B. Wherein, A < B.

3. The crank arm for a rice transplanter according to claim 1, characterized in that: The fastener (14) is provided with an inclined portion (141), which is opposite to and abuts against the drive shaft (13); The inclined portion (141) begins approximately at the middle of the fastener (14) and ends near the end of the fastener (14).

4. The crank arm for a rice transplanter according to claim 3, characterized in that: The inclined portion (141) is a smooth plane, and the angle between the inclined portion (141) and the central axis of the fastener (14) is 10°~25°.

5. A crank arm for a rice transplanter according to claim 1, characterized in that: The drive shaft (13) is provided with a flat key (131), and the first inner cavity (11) is provided with a flat keyway (111) adapted to the flat key.

6. A disassembly device for separating the crank arm and drive shaft (13) according to any one of claims 1 to 5, characterized in that: It includes a limiting part (5) and a moving part (6) adapted to the limiting part (5); The limiting part (5) is used to limit the first positioning part (1); The moving part (6) moves along the direction of the drive shaft (13), and the moving part (6) is used to separate the drive shaft (13) and the crank arm.

7. A disassembly device according to claim 6, characterized in that: The limiting part (5) is generally U-shaped and includes a connecting plate (51) and a pair of side plates (52) symmetrically arranged at both ends of the connecting plate (51). The first positioning part (1) is located between a pair of side plates (52). The side plates (52) have a first through hole (521) and the first through hole (521) corresponds to the second inner cavity (12). The pin (53) is inserted into the first through hole (521) and the second inner cavity (12) in sequence.

8. A disassembly device according to claim 7, characterized in that: The opposite portions of the side plate (52) and the second inner cavity (12) are both smooth planes.

9. A disassembly device according to claim 7, characterized in that: The connecting plate (51) has a second through hole (511) that works in conjunction with the moving part (6). The second through hole (511) is coaxial with the first inner cavity (11), and the size of the second through hole (511) is smaller than the size of the first inner cavity (11).

10. A disassembly device according to claim 7, characterized in that: Along the extension direction of the drive shaft (13), the length of the moving part (6) is greater than the length of the limiting part (5), and the length of the side plate (52) is greater than the length of the first inner cavity (11).

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