A hand mechanical control device for a power take-off

Abstract

The utility model discloses a kind of manual mechanical control devices of power take-off, it is related to power take-off technical field, solve the problem that existing power take-off relies on gas source and power supply, cannot switch state when failure.The power take-off includes shell, piston, sliding sleeve, input shaft, output shaft and piston cavity, core improvement is in that shell and piston are equipped with multiple concentric and different diameter thread holes, by matching the thread pair mechanism of different thread holes-long bolt that is screwed into large thread hole promotes piston to advance, or bolt that is screwed into small thread hole cooperates nut to pull piston to retreat, realize the combination or separation of power take-off when gas source or power supply failure.The utility model under the premise of not changing original gas control function, newly adds manual mechanical control mode, applicable to emergency scene and energy-saving scene, structure is simple, and high reliability.

Description

Technical Field

[0001] This application relates to the field of power take-off (PTO) technology, specifically to a manual mechanical control device for a PTO. Background Technology

[0002] Power take-offs (PTOs), as core intermediate components for power transmission and switching in mechanical equipment, are widely used in automobiles, construction machinery, agricultural machinery, and other fields. Among them, pneumatically controlled jaw-type PTOs have become the mainstream choice for equipment relying on pneumatic power systems due to their fast response speed and convenient control. These PTOs are typically installed on the rear cover of the drive motor. A solenoid valve controls the flow of high-pressure gas from the vehicle's air supply to or from the internal air chamber, driving a piston to move transmission components (such as sliding sleeves). This achieves engagement (PTO engagement, power transmission) or disengagement (PTO disengagement, power cut-off) between the input and output shafts, thereby precisely controlling the power output state of the equipment.

[0003] In existing technologies, the state switching of pneumatically controlled dog clutch power take-offs relies entirely on a dual guarantee of "air source + power supply": on the one hand, the vehicle's pneumatic system needs to provide stable high-pressure gas (typically 0.6-0.8 MPa) as a power source to drive the piston; on the other hand, a solenoid valve is needed to control the air circuit's on / off state. Both are indispensable. However, this single control mode has significant drawbacks in actual operating conditions, making it difficult to meet the reliability and energy-saving requirements of the equipment. Specific problems are as follows:

[0004] First, the lack of emergency adaptability leads to a high risk of failure. During long-term operation, the gas supply system is prone to failure due to pipeline leaks, insufficient gas pressure, or pump malfunctions. The power supply system may also be interrupted due to line faults, power outages, or damaged solenoid valves. Once any of these failures occur, the power take-off (PTO) will completely lose its ability to switch states. If the PTO is engaged when the failure occurs, the equipment will be unable to disconnect power, potentially causing safety accidents such as overload and difficulty in shutdown. If it is disengaged, power engagement will be impossible, directly causing equipment shutdown. This can lead to serious economic losses or safety hazards, especially in critical scenarios such as logistics transportation and emergency rescue.

[0005] Secondly, it consumes a lot of energy, which does not meet the requirements for energy conservation. Under certain specific operating conditions (such as equipment idling for a long time or continuous operation of a fixed load), the power take-off (PTO) needs to remain engaged or disengaged for several hours or even longer. In the existing solution, in order to maintain this state, it is necessary to continuously supply air to the air chamber (to keep it engaged) or rely on the energization of the solenoid valve to keep the air circuit cut off (to keep it disengaged). This causes the air supply system and the power supply system to be in working state for a long time, resulting in a lot of unnecessary energy consumption, which is contrary to the current development trend of "energy conservation and consumption reduction" in industrial equipment.

[0006] Third, it has poor structural compatibility and is difficult to modify. At present, there is no simple manual control solution in the industry that can be adapted to the existing pneumatic jaw-type power take-off. If an independent hydraulic or electric control module is added to realize the emergency function, it will not only greatly increase the size of the equipment and manufacturing cost, but also require a large-scale modification of the original structure of the power take-off, destroying its original pneumatic control logic and appearance dimensions, resulting in incompatibility with mass-produced mechanical equipment and extremely low practicality.

[0007] In summary, existing pneumatically controlled dog clutch power take-offs suffer from problems such as inability to switch to a backup system in case of failure, high energy consumption during long-term operation, and poor compatibility with retrofitting due to their over-reliance on pneumatic and electronic control systems. There is an urgent need for a technical solution that can achieve manual mechanical control through a simple structure without changing the original pneumatic control function, so as to break through the existing technical bottlenecks and improve the reliability and energy efficiency of the power take-off. Utility Model Content

[0008] In view of the above problems, this application provides a manual mechanical control device for a power take-off (PTO) to solve the technical problem of being unable to switch states when the PTO malfunctions.

[0009] To achieve the above objectives, this application provides a manual mechanical control device for a power take-off (PTO), comprising a PTO body, the PTO body including a housing, a piston, a sliding sleeve, an input shaft, an output shaft, and a piston cavity, the piston cavity being provided with multiple air holes or hydraulic oil holes to allow compressed gas or hydraulic oil to be introduced to drive the piston to move within the piston cavity; the sliding sleeve is connected to the piston and is driven by the piston to engage or disengage with the input shaft, thereby switching the PTO between an engaged state and a disengaged state;

[0010] The manual mechanical control device of the power take-off (PTO) also includes multiple threaded joint mechanisms. The housing and piston are respectively provided with concentric threaded holes of different diameters. By screwing in a long bolt adapted to the large-diameter threaded hole in the threaded joint mechanism and applying a thrust, the long bolt drives the piston to move forward mechanically, so that the sliding sleeve engages with both the input shaft and the output shaft to achieve PTO engagement. By cooperating with a nut and a small bolt adapted to the small-diameter threaded hole in the threaded joint mechanism and applying a pull force, the small bolt drives the piston to move backward mechanically, so that the sliding sleeve engages only with the output shaft to achieve PTO disengagement, thereby completing the state switching of the PTO in the event of a gas or power failure.

[0011] Furthermore, the threaded hole includes a large threaded hole and a small threaded hole disposed on the housing, the large threaded hole and the small threaded hole being arranged concentrically, and the diameter of the large threaded hole being larger than the diameter of the small threaded hole.

[0012] Furthermore, at least two sets of threaded holes are symmetrically arranged in the circumferential direction of the housing and the piston, and each set of threaded holes is concentric and has a matching diameter, so as to evenly transmit the force driving the piston to move.

[0013] Furthermore, the diameter of the long bolt is smaller than the diameter of the large threaded hole but larger than the diameter of the small threaded hole. When screwed into the large threaded hole, it can directly abut against the piston end face and push it forward, avoiding structural interference caused by passing through the small threaded hole.

[0014] Furthermore, when the power take-off is in normal pneumatic control, the large threaded hole is sealed by a sealing bolt to ensure the airtightness of the piston cavity. At this time, the power take-off can automatically engage or disengage by introducing or disconnecting high-pressure gas through the piston cavity.

[0015] Furthermore, the diameter of the bolt adapted to the small threaded hole is smaller than the diameter of the large threaded hole, and the outer diameter of the nut is larger than the diameter of the large threaded hole; after the bolt is screwed into the small threaded hole, the nut can be fitted onto the bolt and fit against the end face of the housing, and the piston is pulled back by the abutment force generated by fixing the bolt and rotating the nut.

[0016] Furthermore, after the bolt is screwed into the small threaded hole to a preset depth, the nut is tightened along the bolt axis toward the housing until it fits tightly against the end face of the housing; the fixing bolt does not rotate, and the nut is rotated clockwise. The contact force between the nut and the housing can be converted into a pulling force that moves the piston toward the return spring side, thereby separating the power take-off.

[0017] Furthermore, the sliding sleeve is a splined sliding sleeve, the input shaft is an input splined shaft, and the output shaft is an output splined shaft; when the piston moves forward, the splined sliding sleeve engages with both the input splined shaft and the output splined shaft simultaneously through the spline structure; when the piston moves backward, the splined sliding sleeve engages with the output splined shaft only through the spline structure.

[0018] Furthermore, the power take-off is installed on the rear end cover of the drive motor, and the drive paths of the manual mechanical control mode and the original pneumatic control mode do not interfere with each other.

[0019] Unlike existing technologies, the manual mechanical control device of the power take-off (PTO) in the above-mentioned technical solution adds multiple threaded joint mechanisms to the main structure of the PTO. The housing and piston have concentric threaded holes of different diameters. A long bolt is screwed into the large threaded hole to push the piston forward, engaging the input and output shafts (PTO engagement). Alternatively, a bolt and nut are screwed into the small threaded hole to pull the piston backward, engaging only the output shaft (PTO disengagement). This allows for manual switching in case of air / electricity failure. Technical advantages: Breaks the dependence on air and electricity; reliable emergency switching; simple structure without affecting the original air control function; strong adaptability; manual mode can be maintained for extended periods; energy-saving and low-cost.

[0020] The above description of the utility model is merely an overview of the technical solution of this application. In order to enable those skilled in the art to better understand the technical solution of this application and to implement it based on the description and drawings, and to make the above-mentioned objectives and other objectives, features and advantages of this application easier to understand, the following description is provided in conjunction with the specific embodiments and drawings of this application. Attached Figure Description

[0021] The accompanying drawings are only used to illustrate the principles, implementation methods, applications, features, and effects of specific embodiments of this utility model and other related contents, and should not be considered as limitations on this application.

[0022] In the accompanying drawings of the instruction manual:

[0023] Figure 1 This is a schematic diagram of the manual mechanical control device of the power take-off unit described in a specific embodiment;

[0024] Figure 2 This is a schematic diagram of the pneumatically controlled dental clutch power take-off device in manual engagement according to a specific embodiment;

[0025] Figure 3 This is a schematic diagram of the pneumatically controlled dental clutch power take-off device during manual disengagement, as described in a specific embodiment.

[0026] The reference numerals used in the above figures are explained as follows:

[0027] 1. Bolt; 2. Large threaded hole; 3. Small threaded hole; 4. Piston; 5. Housing; 6. Long bolt; 7. Small bolt; 8. Nut; 9. Sliding sleeve; 10. Output shaft; 11. Input shaft; 12. Piston chamber; 13. Return spring; Detailed Implementation

[0028] To illustrate the possible application scenarios, technical principles, implementable specific solutions, and achievable objectives and effects of this application in detail, the following description, in conjunction with the listed specific embodiments and accompanying drawings, provides a detailed explanation. The embodiments described herein are merely illustrative of the technical solutions of this application and are therefore intended to limit the scope of protection of this application.

[0029] In this document, the term "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The term "embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment, nor does it specifically limit its independence or connection with other embodiments. In principle, in this application, as long as there are no technical contradictions or conflicts, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0030] Unless otherwise defined, the technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the use of related terms herein is merely for the purpose of describing particular embodiments and is not intended to limit this application.

[0031] In the description of this application, the term "and / or" is used to describe the logical relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A exists, B exists, and A and B exist simultaneously. Additionally, the character " / " in this document generally indicates that the preceding and following objects have an "or" logical relationship.

[0032] In this application, terms such as “first” and “second” are used only to distinguish one entity or operation from another, and do not necessarily require or imply any actual quantity, hierarchy or order relationship between these entities or operations.

[0033] Without further limitations, the use of terms such as “comprising,” “including,” “having,” or other similar open-ended expressions in this application is intended to cover non-exclusive inclusion, which does not exclude the presence of additional elements in a process, method, or product that includes the stated elements, such that a process, method, or product that includes a list of elements may include not only those defined elements but also other elements not expressly listed, or elements inherent to such a process, method, or product.

[0034] As understood in the Examination Guidelines, in this application, expressions such as "greater than," "less than," and "exceeding" are understood to exclude the stated number; expressions such as "above," "below," and "within" are understood to include the stated number. Furthermore, in the description of the embodiments in this application, "multiple" means two or more (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups" and "multiple times," unless otherwise explicitly specified.

[0035] In the description of the embodiments of this application, the space-related expressions used, such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "vertical," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," indicate the orientation or positional relationship based on the orientation or positional relationship shown in the specific embodiments or drawings. They are only for the purpose of describing the specific embodiments of this application or for the reader's understanding, and do not indicate or imply that the device or component referred to must have a specific position, a specific orientation, or be constructed or operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0036] Unless otherwise expressly specified or limited, the terms "installation," "connection," "linking," "fixing," and "setting," as used in the description of the embodiments of this application, should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral setting; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two components or the interaction between two components. For those skilled in the art to which this application pertains, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0037] Please see Figures 1 to 3 This embodiment provides a manual mechanical control device for a power take-off (PTO). This device can be applied to common small and medium-sized mechanical equipment (compatible with 100-200kW drive motors), enabling manual switching in case of air / hydraulic / power supply failures. It effectively solves the technical problem of the PTO's inability to switch states due to air / power supply failures. The PTO can be either a pneumatic or hydraulic PTO. In a pneumatic PTO, the piston reciprocates within the piston cavity driven by compressed gas, thereby driving the sliding sleeve to move and engaging or disengaging the PTO. Similarly, in a hydraulic PTO, hydraulic oil flows into the piston cavity, driving the piston to reciprocate within the cavity, thereby driving the sliding sleeve to move and engaging or disengaging the PTO.

[0038] like Figure 1As shown, this embodiment uses a pneumatic power take-off (PTO) as an example. The manual mechanical control device of the PTO includes a housing 5, a piston 4, a sliding sleeve 9, an input shaft 11, an output shaft 10, a piston cavity 12, and a return spring 13. The housing 5 can be made of cast iron or aluminum alloy to ensure structural strength and airtightness. The sliding sleeve 9 is cylindrical and is mounted on the front end of the piston 4 via bearings. The sliding sleeve 9 can move synchronously with the piston 4. The piston 4 can be made of aluminum alloy, and its outer wall has a sealing structure to ensure air cavity sealing. The input shaft 11 and output shaft 10 can be made of steel to ensure stable power transmission. The piston 4 is movably disposed within the piston cavity 12. The piston cavity 12 has multiple air holes connected to solenoid valves. By controlling the solenoid valves (specifically, solenoid directional valves), the direction of compressed gas entering and exiting the piston cavity 12 can be controlled, thereby controlling the direction of movement of the piston 4. The input shaft 11 and output shaft 10 are coaxially arranged. The sliding sleeve 9 is slidably mounted on the output shaft 10 via a spline and moves synchronously with the piston 4, allowing the sliding sleeve 9 to engage or disengage from the input shaft 11. When the sliding sleeve 9 is engaged with the input shaft 11, the power take-off (PTO) is in the engaged state; when the sliding sleeve 9 is disengaged from the input shaft 11, the PTO is in the disengaged state. In another embodiment, the PTO is a hydraulic PTO. The piston cavity 12 is provided with multiple hydraulic oil holes, which are connected to solenoid valves. By controlling the solenoid valves (specifically, solenoid directional valves), the direction of hydraulic oil entering and exiting the piston cavity 12 can be controlled, thereby controlling the direction of movement of the piston 4.

[0039] In this embodiment, the sliding sleeve 9 is a splined sliding sleeve 9, the input shaft 11 is an input splined shaft, and the output shaft 10 is an output splined shaft. When the piston 4 moves forward, the splined sliding sleeve 9 engages with both the input splined shaft and the output splined shaft simultaneously through the spline structure, and the power take-off is in an engaged state. When the piston 4 moves backward, the splined sliding sleeve 9 engages with the output splined shaft only through the spline structure, and the power take-off is in a disengaged state.

[0040] The housing 5 and piston 4 are machined with two sets of circumferentially symmetrical concentric threaded holes. One set of concentric threaded holes is a large threaded hole 2 with a larger diameter, and the other set is a small threaded hole 3 with a smaller diameter. The threaded holes in each set are concentric and have matching diameters to evenly transmit the force that drives the piston 4 to move.

[0041] like Figure 2 and Figure 3As shown, the matching threaded pair mechanism includes a long bolt 6 adapted to the large threaded hole 2, a small bolt 7 adapted to the small threaded hole 3, and a nut 8 matching the small bolt 7. When the pneumatic control or hydraulic circuit (i.e., hydraulic system) of the power take-off is normal, the large threaded hole 2 is sealed with a sealing bolt 1 with a sealing ring to ensure the airtightness of the piston cavity 12. The diameter of the long bolt 6 is smaller than the diameter of the large threaded hole 2 but larger than the diameter of the small threaded hole 3. When screwed into the large threaded hole 2, it can directly abut against the end face of the piston 4 and push it forward, avoiding structural interference caused by passing through the small threaded hole 3. Furthermore, the outer diameter of the nut 8 is larger than the diameter of the large threaded hole 2. After the bolt 1 is screwed into the small threaded hole 3, the nut 8 can be fitted onto the bolt 1 and fit against the end face of the housing 5. The abutment force generated by fixing the bolt 1 and rotating the nut 8 pulls the piston 4 backward. After the bolt 1 is screwed into the small threaded hole 3 to the preset depth, the nut 8 is tightened along the axis of the bolt 1 toward the housing 5 until it is tightly fitted with the end face of the housing 5; the bolt 1 is fixed and does not rotate, and the nut 8 is rotated clockwise. The contact force between the nut 8 and the housing 5 can be converted into a pulling force that moves the piston 4 toward the return spring 13, thereby realizing the separation of the power take-off.

[0042] The power take-off (PTO) has a manual mechanical control device that includes a pneumatic control mode and a manual operation mode. Under normal operating conditions, when the power supply, pneumatic supply system, or hydraulic oil system is functioning correctly, the PTO automatically switches between pneumatic and hydraulic modes via a solenoid valve.

[0043] Separated state: The solenoid valve is not energized, and high-pressure gas or hydraulic oil is not introduced into the piston chamber 12. The piston 4 is pushed to the side closer to the return spring 13 under the elastic force of the return spring 13. At this time, the piston 4 drives the sliding sleeve 9 to move synchronously. The sliding sleeve 9 only keeps in contact with the output shaft 10 and is separated from the input shaft 11. The motor power cannot be transmitted to the output shaft 10 through the input shaft 11, and the power take-off does not output power to the outside.

[0044] Engagement state: When the equipment requires power take-off, the solenoid valve is energized, and high-pressure gas or hydraulic oil (normal working pressure 0.6-0.8MPa) is introduced into the piston chamber 12; the gas pressure overcomes the elastic force of the return spring 13, pushing the piston 4 to move away from the return spring 13; the piston 4 drives the sliding sleeve 9 to move closer to the input shaft 11 until the sliding sleeve 9 simultaneously engages with the input shaft 11 and the output shaft 10, and the motor power is transmitted to the output shaft 10 through the input shaft 11 and the sliding sleeve 9, and the power take-off enters the working state, providing power to the working device.

[0045] In case of pneumatic or hydraulic system failure, the manual mode is activated. The manual mode includes a manual engagement process and a manual disengagement process. The manual engagement process is as follows:

[0046] When the equipment's air supply system experiences pipeline leaks, air pump / oil pump malfunctions, or power outages or solenoid valve damage, causing the pneumatic or hydraulic oil system to fail to drive piston 4 to move, and the power take-off needs to be engaged urgently to maintain operation, such as... Figure 2 As shown, this is achieved through manual operation: The operator first removes the sealing bolt 1 of the large threaded hole 2, and screws the long bolt 6, which is adapted to the large threaded hole 2, into the large threaded hole 2; rotates the long bolt 6 clockwise, and the end of the long bolt 6 gradually abuts against the end face of the piston 4 and applies a continuous thrust, pushing the piston 4 to move towards the input shaft 11 against the elastic force of the return spring 13; as the piston 4 moves, the sliding sleeve 9 moves closer to the input shaft 11 in sync, until the sliding sleeve 9 forms a stable fit with both the input shaft 11 and the output shaft 10, and then stops rotating the long bolt 6; at this time, the power take-off remains engaged, and the motor power can be transmitted normally without relying on an air source or power source, and the equipment can continue to complete the operation, avoiding shutdown due to air control failure.

[0047] The manual separation process is as follows:

[0048] When the pneumatic or hydraulic control fails and the power take-off is engaged, and power needs to be cut off (e.g., for equipment maintenance or emergency shutdown), disengagement can be achieved manually: e.g. Figure 3 As shown, first, the matching nut 8 is fitted onto the small bolt 7 that fits the small threaded hole 3. Then, the small bolt 7 is screwed into the small threaded hole 3 on the piston 4 until the end face of the nut 8 is tightly fitted against the outer wall of the housing 5. Use a tool to fix the small bolt 7 so that it cannot rotate during subsequent operations. Then, use another tool to rotate the nut 8 clockwise. Since the outer diameter of the nut 8 is larger than the diameter of the large threaded hole 2, the nut 8 cannot pass through the large threaded hole 2. During the rotation, a contact force is formed between the nut 8 and the housing 5. This force is converted into a pulling force that moves the small bolt 7 away from the piston 4, thereby driving the piston 4 to move towards the return spring 13. The piston 4 drives the sliding sleeve 9 to gradually disengage from the input shaft 11, retaining only the engagement with the output shaft 10, and stops rotating the nut 8. At this time, the power take-off is in a disengaged state, the power transmission is cut off, and this state can be stably maintained without additional energy.

[0049] The manual mechanical control device of the aforementioned power take-off also includes a manual holding state process:

[0050] When the equipment needs to be idle for a long time (e.g., more than 4 hours), in order to avoid energy waste caused by continuously supplying power to maintain the state of the solenoid valve or supplying air to maintain the position of piston 4 in pneumatic control mode or hydraulic oil drive mode, the separation state can be maintained by manual operation: follow the operation steps of "pneumatic control failure condition: manual separation process" above, so that the sliding sleeve 9 is disengaged from the input shaft 11 and only engages with the output shaft 10, and then turn off the air supply and power supply of the equipment; since the engagement of the small bolt 7 and nut 8 can stably restrict the position of piston 4, the sliding sleeve 9 will not change its state due to external force or vibration, and the power take-off will continue to maintain the separation state; no electrical energy or air pressure is consumed during standby, which greatly reduces energy consumption compared with the traditional pneumatic control standby mode; when the equipment needs to be restarted, if the pneumatic control system has been restored, the small bolt 7 and nut 8 can be rotated in the opposite direction to reset piston 4 under the action of return spring 13, and the large threaded hole 2 can be sealed with sealing bolt 1, and the power take-off can be restored to the pneumatic control automatic working mode.

[0051] In this embodiment, the power take-off is installed on the rear end cover of the drive motor, and the drive paths of the manual mechanical control mode and the original pneumatic control mode do not interfere with each other.

[0052] Finally, it should be noted that although the above embodiments have been described in the text and drawings of this application, this should not limit the scope of patent protection of this application. Any technical solutions that are based on the essential concept of this application and utilize the content described in the text and drawings of this application, resulting in equivalent structural or procedural substitutions or modifications, as well as the direct or indirect application of the technical solutions of the above embodiments to other related technical fields, are all included within the scope of patent protection of this application.

Claims

1. A manual mechanical control device for a power take-off (PTO), characterized in that, The device includes a power take-off (PTO) body, which comprises a housing, a piston, a sliding sleeve, an input shaft, an output shaft, and a piston cavity. The piston cavity is provided with multiple air holes or hydraulic oil holes to allow compressed gas or hydraulic oil to be introduced to drive the piston to move within the piston cavity. The sliding sleeve is connected to the piston and is driven by the piston to engage or disengage with the input shaft, thereby switching the PTO between an engaged state and a disengaged state. The manual mechanical control device of the power take-off (PTO) also includes multiple threaded joint mechanisms. The housing and piston are respectively provided with concentric threaded holes of different diameters. By screwing in a long bolt adapted to the large-diameter threaded hole in the threaded joint mechanism and applying a thrust, the long bolt drives the piston to move forward mechanically, so that the sliding sleeve engages with both the input shaft and the output shaft to achieve PTO engagement. By cooperating with a nut and a small bolt adapted to the small-diameter threaded hole in the threaded joint mechanism and applying a pull force, the small bolt drives the piston to move backward mechanically, so that the sliding sleeve engages only with the output shaft to achieve PTO disengagement, thereby completing the state switching of the PTO in the event of a gas or power failure.

2. The manual mechanical control device according to claim 1, characterized in that, The threaded hole includes a large threaded hole and a small threaded hole disposed on the housing. The large threaded hole and the small threaded hole are arranged concentrically, and the diameter of the large threaded hole is larger than the diameter of the small threaded hole.

3. The manual mechanical control device according to claim 2, characterized in that, At least two sets of threaded holes are symmetrically arranged in the circumferential direction of the housing and the piston. Each set of threaded holes is concentric and has a matching diameter to evenly transmit the force that drives the piston to move.

4. The manual mechanical control device according to claim 2, characterized in that, The diameter of the long bolt is smaller than the diameter of the large threaded hole but larger than the diameter of the small threaded hole. When screwed into the large threaded hole, it can directly abut against the piston end face and push it forward, avoiding structural interference caused by passing through the small threaded hole.

5. The manual mechanical control device according to claim 4, characterized in that, When the power take-off is in normal pneumatic control, the large threaded hole is sealed by the sealing bolt to ensure the airtightness of the piston cavity. At this time, the power take-off introduces or disconnects high-pressure gas through the piston cavity to achieve automatic engagement or disengagement.

6. The manual mechanical control device according to claim 2, characterized in that, The diameter of the bolt adapted to the small threaded hole is smaller than the diameter of the large threaded hole, and the outer diameter of the nut is larger than the diameter of the large threaded hole. After the bolt is screwed into the small threaded hole, the nut can be fitted onto the bolt and fit against the end face of the housing. The piston is pulled back by the abutment force generated by fixing the bolt and rotating the nut.

7. The manual mechanical control device according to claim 6, characterized in that, After the bolt is screwed into the small threaded hole to the preset depth, the nut is tightened along the bolt axis toward the housing until it fits tightly against the end face of the housing. The fixing bolt does not rotate, and the nut is rotated clockwise. The contact force between the nut and the housing can be converted into a pulling force that moves the piston toward the return spring, thus separating the power take-off.

8. The manual mechanical control device according to claim 1, characterized in that, The sliding sleeve is a splined sliding sleeve, the input shaft is an input splined shaft, and the output shaft is an output splined shaft. When the piston moves forward, the splined sliding sleeve engages with both the input splined shaft and the output splined shaft simultaneously through the spline structure. When the piston moves backward, the splined sliding sleeve engages with the output splined shaft only through the spline structure.

9. The manual mechanical control device according to claim 1, characterized in that, The power take-off unit is installed on the rear end cover of the drive motor, and the drive paths of the manual mechanical control mode and the original pneumatic control mode do not interfere with each other.

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