Air bag type piston gear shifting power takeoff

Abstract

The utility model belongs to the technical field of power takeoff devices, and relates to an air bag type piston gear shifting power takeoff device. When the power takeoff needs to be in gear operation, air is sucked outwards through the first ventilation nozzle, negative pressure is formed in the rear air chamber, the reset type air bag piston assembly moves towards one side of the rear air chamber, the reset type air bag piston assembly drives the shifting fork shaft and the shifting fork to move, the shifting fork controls connection of a power component, and gear engagement of the power takeoff is completed. When the power takeoff does not need to work, the first ventilation nozzle is disconnected with the air suction device, the air pressure on the two sides of the front air chamber and the air pressure on the two sides of the rear air chamber are equal, the reset type air bag piston assembly drives the shifting fork shaft to return to the original position, the shifting fork returns to the initial position, the shifting fork controls separation of power components, and gear picking is completed. Reciprocating motion of the piston is achieved through external air exhaust and self-resetting air inflation of the air cylinder, dependence on an air storage cylinder of the whole vehicle is not needed, the air cylinder is suitable for light and medium-sized vehicles, gear shifting efficiency and reliability are improved, the structure of the air cylinder and the piston is simplified, and production cost is reduced.

Description

Technical Field

[0001] This utility model belongs to the field of power take-off technology and relates to a pneumatic piston shifting power take-off. Background Technology

[0002] A power take-off (PTO) is a working device that obtains power from a transmission or engine and outputs that power. Special vehicles such as dump trucks, fire trucks, cement mixers, and refrigerated transport vehicles require PTOs to obtain additional power. Based on their installation position on the transmission, PTOs can be categorized into front PTO, rear PTO, bottom PTO, and side PTO. Currently, most PTOs on the market use pneumatic shifting. The shift cylinder of the PTO is connected to the vehicle's air reservoir, and controlling the intake and exhaust of the cylinder controls the PTO's gear engagement and disengagement. Light and medium-duty vehicles without an air reservoir lack the necessary air source for pneumatic PTOs and cannot be equipped with them.

[0003] Meanwhile, the existing pneumatic shift power take-off (PTO) has a complex cylinder and piston structure, and the seals are prone to wear when moving inside the cylinder, resulting in low shifting efficiency, low reliability, and high manufacturing cost. Utility Model Content

[0004] The purpose of this utility model is to provide an air-cushioned piston shift power take-off to solve the technical problems that light and medium-sized vehicles cannot be equipped with air-controlled shift power take-offs and that the cylinder and piston structures are complex and prone to wear.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This utility model discloses a pneumatic piston shift power take-off device, comprising:

[0007] A housing, and a shift fork shaft movably passing through the housing, wherein a shift fork is provided on the shift fork shaft;

[0008] A cylinder body is fixedly connected to the housing and forms a driving air chamber between the cylinder body and the housing. A reset-type airbag piston assembly is provided in the cylinder body, which divides the driving air chamber into a front air chamber and a rear air chamber. A shift fork shaft extends into the front air chamber and is fixedly connected to the reset-type airbag piston assembly. A first vent is provided on the cylinder body, and a second vent is provided on the housing. The first vent connects the rear air chamber to the atmosphere, and the second vent connects the front air chamber to the atmosphere.

[0009] Furthermore, the reset-type airbag piston assembly includes an airbag seat, an airbag, and a return elastic part. The end of the shift fork shaft and the airbag are both fixedly connected to the airbag seat. The airbag seat is connected to the cylinder body through the return elastic part. The outer side of the airbag is sealed to the inner wall of the cylinder body.

[0010] Furthermore, the airbag, the shift fork shaft, and the airbag seat are connected by bolts, the airbag is located between the shift fork shaft and the airbag seat, and an airbag gasket is provided between the airbag and the shift fork shaft.

[0011] Furthermore, the second vent is embedded in the side wall of the housing;

[0012] The first vent is connected to the air intake device.

[0013] Furthermore, a groove is provided on the shift fork shaft, and a pressure switch is provided on the housing;

[0014] When both the first vent and the second vent are in communication with the atmosphere, the resettable airbag piston assembly resets, and the end of the pressure switch is located in the groove.

[0015] After the air inside the rear air chamber is drawn out using the first vent, the reset-type airbag piston assembly drives the shift fork shaft to move axially, and the end of the pressure switch slides out of the groove and abuts against the shift fork shaft.

[0016] Furthermore, it also includes:

[0017] An input shaft is provided on the housing, and an input gear is sleeved on the input shaft;

[0018] An output shaft is provided on the housing, and an output gear is slidably sleeved on the output shaft. The output shaft has a first spline connection portion, and the output gear has a second spline connection portion. When the first spline connection portion and the second spline connection portion are separated, the output gear is loosely sleeved on the output shaft, and the input gear is partially engaged with the output gear. When the first spline connection portion and the second spline connection portion are engaged, the input gear and the output gear are fully engaged.

[0019] The output gear is provided with a shift fork groove, and the end of the shift fork is located in the shift fork groove.

[0020] Furthermore, the shift fork groove is an annular groove, and the annular groove is coaxial with the output gear.

[0021] Furthermore, the output shaft is provided with an output flange, the output shaft and the output flange are connected by a semi-circular key, the output shaft and the output flange are also fixedly connected by a lock nut, and the output flange is located outside the housing;

[0022] The output shaft is provided with a tapered shaft, the output flange is provided with a tapered hole, the tapered shaft is embedded in the tapered hole, the tapered hole is provided with a semi-circular key, and the tapered shaft is provided with a semi-circular keyway that matches the semi-circular key.

[0023] Furthermore, one end of the output shaft is embedded in the housing and a front bearing is provided between the output shaft and the housing, and the other end of the output shaft passes through the housing and a rear bearing is provided between the output shaft and the housing.

[0024] Furthermore, the input gear has a mounting hole, the input shaft passes through the mounting hole, and annular bearing mounting grooves are provided at both ends of the mounting hole. An input gear support bearing is provided in the mounting groove, the input gear support bearing is located between the input shaft and the input gear, and a bearing gasket is provided between the input gear support bearing and the housing.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] This utility model's housing provides a mounting base and protection for other components. When the power take-off (PTO) needs to engage gears, the intake device draws air out through the first vent, creating a negative pressure in the rear chamber. The reset-type airbag piston assembly moves to one side of the rear chamber, driving the shift fork shaft and shift fork to move. The shift fork controls the engagement of the power component, allowing the PTO to engage gears. When the PTO is not needed, the first vent disconnects from the intake device, equalizing the air pressure on both sides of the front and rear chambers. The reset-type airbag piston assembly drives the shift fork shaft back to its original position, the airbag returns to its free state, and the shift fork returns to its initial position. The shift fork controls the disengagement of the power component, disengaging gears and cutting off power output. This utility model's cylinder is a self-resetting airbag exhaust cylinder, achieving piston reciprocating motion through external air intake and self-resetting inflation, eliminating the need for a vehicle-mounted air reservoir and making it suitable for light and medium-sized vehicles. Secondly, it reduces the wear problem of seals found in traditional cylinders, improving shifting efficiency and reliability. Furthermore, it simplifies the cylinder and piston structure, reducing production costs. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the airbag-type piston shift power take-off device in the disengaged state according to an embodiment of the present utility model;

[0028] Figure 2 This is a schematic diagram of the airbag-type piston shift power take-off device in gear engagement state according to an embodiment of the present utility model;

[0029] Figure 3 This is a schematic diagram of the cylinder in the disengaged state according to an embodiment of the present utility model;

[0030] Figure 4 This is a schematic diagram of the cylinder in the disengaged state according to an embodiment of the present invention.

[0031] The components are as follows: 1. Housing; 2. Input shaft; 3. Input gear; 4. Input gear support bearing; 5. Output shaft; 6. Output flange; 7. Locking nut; 8. Semi-circular key; 9. Cylinder body; 90. Drive chamber; 901. Front chamber; 902. Rear chamber; 91. First vent; 10. Return elastic part; 11. Airbag seat; 12. Airbag; 13. Airbag gasket; 14. Second vent; 15. Bolt; 16. Shift fork shaft; 17. Shift fork; 18. Pressure switch; 19. Output gear; 20. Front bearing of output shaft; 21. Rear bearing of output shaft; 22. Groove; 23. Shift fork groove; 24. Reset airbag piston assembly; 25. First spline connection part; 26. Second spline connection part. Detailed Implementation

[0032] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0033] It should be noted that the terms "first," "second," etc., in the specification and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0034] The present invention will now be described in further detail with reference to the accompanying drawings:

[0035] Example 1:

[0036] See Figure 1 and Figure 2 This utility model discloses a pneumatic piston shift power take-off, including: a housing 1, a cylinder body 9 and a shift fork shaft 16 movably passing through the housing 1. The housing 1 serves as the main frame of the power take-off and provides a mounting base and protection for other components, ensuring the structural stability and safety of the power take-off during operation.

[0037] The shift fork shaft 16 is provided with a shift fork 17. When the reset airbag piston assembly 24 moves, the shift fork shaft 16 drives the shift fork 17, and the shift fork 17 controls the engagement and disengagement of the power components.

[0038] The cylinder body 9 is fixedly connected to the housing 1 and forms a driving air chamber 90 between them. The cylinder body 9 is provided with a reset-type airbag piston assembly 24, which divides the driving air chamber 90 into a front air chamber 901 and a rear air chamber 902. The shift fork shaft 16 extends into the front air chamber 901 and is fixedly connected to the reset-type airbag piston assembly 24. The cylinder body 9 is provided with a first vent 91, and the housing 1 is provided with a second vent 14. The first vent 91 connects the rear air chamber 902 to the atmosphere, and the second vent 14 connects the front air chamber 901 to the atmosphere.

[0039] When the power take-off (PTO) needs to engage gears, the air intake device draws air out through the first vent 91, creating a negative pressure in the rear air chamber 902. This causes the reset-type airbag piston assembly 24 to move towards the rear air chamber 902. Figure 4 As shown, the reset-type airbag piston assembly 24 drives the shift fork shaft 16 and shift fork 17 to move, and controls the engagement of the power components through the shift fork 17, so that the power take-off completes the gear engagement.

[0040] When the power take-off (PTO) is not needed, the first vent 91 disconnects from the intake device, the air pressure on both sides of the front air chamber 901 and the rear air chamber 902 is equal, and the reset-type airbag piston assembly 24 drives the shift fork shaft 16 back to its original position. (See below) Figure 3 The airbag returns to its free state, the shift fork 17 returns to its initial position, the shift fork 17 controls the separation of the power unit, completes the disengagement, and cuts off the output power.

[0041] This utility model relates to a self-resetting airbag-type exhaust cylinder. The reciprocating motion of the piston is achieved through external air extraction and self-resetting inflation, eliminating the need for a vehicle-mounted air reservoir. It is suitable for light and medium-duty vehicles. The negative pressure generated by external vacuum suction moves the piston to engage gears, making it compatible with vehicles without an onboard air source, thus broadening its applicability. Secondly, it reduces the wear problem of seals found in traditional cylinders, improving shifting efficiency and reliability. Furthermore, it simplifies the cylinder and piston structure, reducing production costs.

[0042] Preferably, the reset-type airbag piston assembly 24 includes an airbag seat 11, an airbag 12, and a return elastic part 10. The end of the shift fork shaft 16 and the airbag 12 are both fixedly connected to the airbag seat 11. The airbag seat 11 is connected to the cylinder body 9 through the return elastic part 10. The outer side of the airbag 12 is sealed to the inner wall of the cylinder body 9. The reset-type airbag piston assembly 24 of this utility model has a simple structure. During the shifting process, the sealing airbag moves axially with the airbag seat 11 and undergoes elastic deformation. The seal and the cylinder body 9 have a soft contact seal. There is no wear caused by relative sliding during the shifting process, resulting in low energy consumption and high shifting efficiency.

[0043] Preferably, the airbag 12, the shift fork shaft 16 and the airbag seat 11 are connected by bolts 15, the airbag 12 is located between the shift fork shaft 16 and the airbag seat 11, and an airbag gasket 13 is provided between the airbag 12 and the shift fork shaft 16.

[0044] Preferably, the second vent 14 is embedded in the side wall of the housing 1;

[0045] The first vent 91 is connected to the air intake device.

[0046] Preferably, the fork shaft 16 is provided with a groove 22, and the housing 1 is provided with a pressure switch 18;

[0047] When both the first vent 91 and the second vent 14 are in communication with the atmosphere, the reset type airbag piston assembly 24 is reset, and the end of the pressure switch 18 is located in the groove 22;

[0048] After the air inside the rear air chamber 902 is drawn out by the first vent 91, the reset airbag piston assembly 24 drives the shift fork shaft 16 to move axially, and the end of the pressure switch 18 slides out of the groove 22 and abuts against the shift fork shaft 16.

[0049] Preferably, the present invention further includes: an input shaft 2 disposed on the housing 1 and an output shaft 5 disposed on the housing 1;

[0050] An input gear 3 is fitted onto the input shaft 2;

[0051] An output gear 19 is slidably sleeved on the output shaft 5. The output shaft 5 has a first spline connection part 25, and the output gear 19 has a second spline connection part 26. When the first spline connection part 25 and the second spline connection part 26 are separated, the output gear 19 is loosely sleeved on the output shaft 5, and the input gear 3 is partially meshed with the output gear 19. When the first spline connection part 25 and the second spline connection part 26 are meshed, the input gear 3 and the output gear 19 are fully meshed. In the disengaged state, the output gear 19 and the input gear 3 are already in a partially meshed state, resulting in less impact during gear shifting, shorter gear sliding distance, and higher efficiency.

[0052] The output gear 19 is provided with a shift fork groove 23, and the end of the shift fork 17 is located in the shift fork groove 23.

[0053] Preferably, the shift fork groove 23 is an annular groove, and the annular groove is coaxial with the output gear 19.

[0054] In this embodiment of the invention, the shift fork shaft 16 engages with the shift fork groove 23 via the shift fork 17 to achieve axial movement of the output gear 19. The first spline connection part engages with the second spline connection part of the output gear to achieve power engagement and disengagement. When the first spline connection part 25 and the second spline connection part 26 are separated, the output gear 19 is loosely fitted on the output shaft 5, and the input gear 3 is partially engaged with the output gear 19. When the first spline connection part 25 and the second spline connection part 26 are engaged, the output gear 19 is splined to the output shaft 5, and the input gear 3 is fully engaged with the output gear 19 to achieve power output. Specifically, the input shaft 2 transmits power to the output gear 19 via the input gear 3, and the output gear 19 transmits power to external devices via the output shaft 5.

[0055] Preferably, the output shaft 5 is provided with an output flange 6, the output shaft 5 and the output flange 6 are connected by a semi-circular key 8, the output shaft 5 and the output flange 6 are also fixedly connected by a lock nut, and the output flange 6 is located outside the housing 1;

[0056] The output shaft 5 is provided with a tapered shaft, the output flange 6 is provided with a tapered hole, the tapered shaft is embedded in the tapered hole, the tapered hole is provided with a semi-circular key 8, and the tapered shaft is provided with a semi-circular keyway that matches the semi-circular key 8.

[0057] The output shaft 5 and output flange 6 of this utility model adopt a tapered shaft hole fit, and axial positioning is achieved by the fit length between the tapered surfaces. There is no need to set a positioning shoulder or install positioning parts on the output shaft 5 for the output flange 6. The shaft structure is simple and the positioning between the shaft holes is better.

[0058] Preferably, one end of the output shaft 5 is embedded in the housing 1 and a front bearing 20 is provided between the output shaft 5 and the housing 1, while the other end of the output shaft 5 passes through the housing 1 and a rear bearing 21 is provided between the output shaft 5 and the housing 1. The front end of the housing 1 of this invention is a fully enclosed design, eliminating the need for a sealing design for the front ends of the input shaft 2 and the output shaft 5. It also eliminates the need for a front end cover and seals, saving on the number of parts and reducing the risk of leakage at the front end of the housing, resulting in high reliability.

[0059] Preferably, the input gear 3 has a mounting hole, the input shaft 2 passes through the mounting hole, and annular bearing mounting grooves are formed at both ends of the mounting hole. An input gear support bearing 4 is provided in the mounting groove, and the input gear support bearing 4 is located between the input shaft 2 and the input gear 3. A bearing gasket is provided between the input gear support bearing 4 and the housing 1. That is, the input gear 3 is supported on the input shaft 2 by the input gear support bearing 4, and axial positioning is achieved by the input gear support bearing 4, the housing 1 and the bearing gasket.

[0060] Example 2:

[0061] like Figure 1 and Figure 2 As shown, this embodiment discloses a pneumatic piston-type power take-off (PTO), specifically a side or bottom PTO with external vacuum control for shifting, to solve the problem of some vehicles lacking an air source and therefore unable to use pneumatically controlled PTOs. This PTO uses a pneumatic piston; during shifting, the sealed airbag moves axially with the airbag seat 11, generating elastic deformation. The airbag 12 and the cylinder body have a soft contact seal, eliminating relative sliding friction during shifting, resulting in low energy consumption and high efficiency. Furthermore, compared to existing products, this PTO also boasts advantages such as lightweight design, low cost, and high reliability.

[0062] like Figure 1 As shown, a pneumatic piston shift power take-off includes a housing 1 with an internal chamber. The front end of the housing 1 is a fully enclosed design. A second vent 14 connected to the atmosphere is provided in the housing 1. The second vent 14 is a buried pipe. A cylinder body 9 is connected to the rear end of the housing 1.

[0063] The cylinder body 9 is a stamped part, and a bent first vent 91 is provided at the center of the rear end of the cylinder body 9.

[0064] The cylinder body 9 and the end face of the housing 1 form a driving air chamber 90, and the second air vent 14 and the first air vent 91 of the cylinder body are respectively located at both ends of the gear shifting driving air chamber 90.

[0065] The driving air chamber 90 houses a reset-type airbag piston assembly 24, which consists of an airbag gasket 13, an airbag 12, and an airbag seat 11. The airbag gasket 13, airbag 12, and airbag seat 11 are arranged sequentially within the driving air chamber. The airbag 12 is fitted onto the outer wall of the airbag seat 11, and the outer wall of the airbag 12 is in close contact with the inner wall of the cylinder body 9. A return elastic part 10 is located between the airbag seat 11 and the cylinder body 9, and abuts against both the airbag seat and the cylinder body. In this embodiment, the return elastic part 10 is a return spring.

[0066] The airbag 12 divides the driving air chamber 90 into two parts: the front air chamber 901 and the rear air chamber 902. The second vent 14 is connected to the front air chamber 901, and the first vent 91 of the cylinder block is connected to the rear air chamber 902.

[0067] The housing 1 is equipped with an input shaft 2, an output shaft 5, and a shift fork shaft 16. The support holes of the input shaft 2, the output shaft 5, and the shift fork shaft 16 at the front end of the housing 1 are all blind holes.

[0068] The front and rear ends of the input shaft 2 and the shift fork shaft 16 are directly supported in the housing, and the front and rear ends of the output shaft 5 are supported in the housing by the front bearing 20 and the rear bearing 21 of the output shaft, respectively.

[0069] An input gear 3 is fitted onto the input shaft 2. The input gear 3 can be either a double gear or a single gear.

[0070] An output gear 19 and an output flange 6 are fitted onto the output shaft 5. When disengaged, the output gear 19 is partially engaged with the input gear 3 and loosely fitted onto the output shaft 5. Figure 1 As shown. At this time, the output shaft 5 cannot transmit power outward. In the geared state, the output gear 19 engages with the spline on the output shaft 5 through axial sliding, and can transmit power outward, as shown. Figure 2 As shown.

[0071] The output shaft 5 and the output flange 6 are fitted with a tapered shaft and a tapered hole. The output flange 6 is connected to the output shaft 5 by a semi-circular key 8 and is fixed to the output shaft 5 by a lock nut 7.

[0072] The front end of the shift fork shaft 16 is provided with a groove 22 that mates with the pressure switch 18, used to indicate the engagement and disengagement status of the power take-off. A shift fork 17 is fixedly connected to the middle of the shift fork shaft 16, and the shift fork 17 is sleeved in the shift fork groove 23 of the output gear 19.

[0073] The rear end of the shift fork shaft 16 extends into the power take-off drive air chamber 90, and the shift fork shaft in the drive air chamber 90 is connected to the reset airbag piston assembly 24 by bolts 15.

[0074] In the disengaged state, both the front air chamber 901 and the rear air chamber 902 of the drive air chamber 90 are open to the atmosphere, and there is no pressure difference. The reset-type airbag piston assembly 24 is pressed to the front air chamber side under the action of the return spring, and the airbag 12 is in a free state in the cylinder. Figure 3 As shown. The shift fork shaft 16, shift fork 17, and output gear 19 are in their original positions within the power take-off housing, and the push rod of the pressure switch 18 is located in the groove of the shift fork shaft 16, as shown. Figure 1 As shown.

[0075] When the power take-off (PTO) needs to engage gears, air is drawn out through the first vent 91, creating a negative pressure in the rear air chamber 902. This causes the piston assembly to move rearward, compressing the return spring and causing the air bladder 12 to undergo elastic deformation. Figure 4 As shown. The piston assembly drives the shift fork shaft 16, shift fork 17, and output gear 19 to move together towards the output flange 6. The output gear 19 and input gear 3 transition from partial engagement to full engagement. The internal spline on the output gear 19 engages with the external spline on the output shaft 5. The output gear 19 drives the output shaft 5 to rotate synchronously, and the power take-off completes gear engagement. Power is output through the output shaft 5 and output flange 6. The push rod of the pressure switch 18 slides out of the groove 22 of the shift fork shaft 16 and presses against the outer surface of the shift fork shaft 16, illuminating the gear engagement indicator light. Figure 2 As shown.

[0076] When the power take-off is not needed, the first vent 91 is disconnected from the intake device, the air pressure on both sides of the front air chamber 901 and the rear air chamber 902 is equal, the return spring pushes the reset airbag piston assembly 24 and the shift fork shaft 16 back to their original positions, the airbag 12 returns to its free state, the shift fork 17 and the output gear 19 return to their initial positions, the internal spline on the output gear 19 disengages from the external spline on the output shaft 5, completing the disengagement and cutting off the output power.

[0077] In summary, compared with the prior art, the advantages of this utility model of airbag-type piston shift power take-off are as follows:

[0078] This invention uses the negative pressure generated by external vacuum to move the piston and engage gears, which can be matched with vehicles without an air source and is applicable to a wider range of vehicle models.

[0079] The resetting airbag piston assembly 24 of this utility model has a simple structure. During the shifting process, the sealed airbag moves axially with the airbag seat 11 and undergoes elastic deformation. The seal and the cylinder body 9 are in soft contact seal. There is no wear caused by relative sliding during the shifting process, resulting in low energy consumption and high shifting efficiency.

[0080] This utility model adopts an integrated stamped cylinder body 9, and the air bag cooperates with both the cylinder body 9 and the air bag seat 11. One air bag provides sealing for both the piston and the cylinder body 9. The number of parts is small and the cost is low.

[0081] When the power take-off unit of this invention is in the disengaged state, the output gear 19 and the input gear 3 are already in a partially meshed state, resulting in less impact during gear shifting, shorter gear sliding distance, and higher efficiency.

[0082] The front end of the power take-off housing 1 of this utility model is a fully enclosed design, which eliminates the need for sealing design of the front end of the input shaft 2 and output shaft 5, and eliminates the need for front end cover and sealing components. This saves on the number of parts and reduces the risk of leakage at the front end of the housing, resulting in high reliability.

[0083] The output shaft 5 and output flange 6 of this utility model adopt a tapered shaft hole fit, and axial positioning is achieved by the fit length between the tapered surfaces. There is no need to set a positioning shoulder or install positioning parts on the output shaft 5 for the output flange 6. The shaft structure is simple and the positioning between the shaft holes is better.

[0084] The above content is only for illustrating the technical concept of this utility model and should not be construed as limiting the scope of protection of this utility model. Any modifications made to the technical solution based on the technical concept proposed in this utility model shall fall within the scope of protection of this utility model.

Claims

1. A pneumatic piston-type power take-off (PTO), characterized in that, include: Housing (1), a fork shaft (16) movably passing through the housing (1), and a fork (17) provided on the fork shaft (16). A cylinder body (9) is fixedly connected to the housing (1) and forms a drive chamber (90) between the cylinder body (9) and the housing (1). A reset type airbag piston assembly (24) is provided inside the cylinder body (9). The reset type airbag piston assembly (24) divides the drive chamber (90) into a front chamber (901) and a rear chamber (902). The shift fork shaft (16) extends into the front chamber (901) and is fixedly connected to the reset type airbag piston assembly (24). A first vent (91) is provided on the cylinder body (9), and a second vent (14) is provided on the housing (1). The first vent (91) connects the rear chamber (902) to the atmosphere, and the second vent (14) connects the front chamber (901) to the atmosphere.

2. The pneumatic piston shift power take-off according to claim 1, characterized in that, The reset-type airbag piston assembly (24) includes an airbag seat (11), an airbag (12), and a return elastic part (10). The end of the shift fork shaft (16) and the airbag (12) are both fixedly connected to the airbag seat (11). The airbag seat (11) is connected to the cylinder body (9) through the return elastic part (10). The outer side of the airbag (12) is sealed to the inner wall of the cylinder body (9).

3. A pneumatic piston shift power take-off according to claim 2, characterized in that, The airbag (12), the shift fork shaft (16), and the airbag seat (11) are connected by bolts (15). The airbag (12) is located between the shift fork shaft (16) and the airbag seat (11). An airbag gasket (13) is provided between the airbag (12) and the shift fork shaft (16).

4. The pneumatic piston shift power take-off according to claim 1, characterized in that, The second vent (14) is embedded in the side wall of the housing (1); The first vent (91) is connected to the suction device.

5. A pneumatic piston shift power take-off according to claim 1, characterized in that, The fork shaft (16) is provided with a groove (22), and the housing (1) is provided with a pressure switch (18). When both the first vent (91) and the second vent (14) are in communication with the atmosphere, the reset type airbag piston assembly (24) is reset, and the end of the pressure switch (18) is located in the groove (22); After the air inside the rear air chamber (902) is drawn out by the first vent (91), the reset airbag piston assembly (24) drives the shift fork shaft (16) to move axially, and the end of the pressure switch (18) slides out of the groove (22) and abuts against the shift fork shaft (16).

6. A pneumatic piston shift power take-off according to claim 1, characterized in that, Also includes: An input shaft (2) is provided on the housing (1), and an input gear (3) is sleeved on the input shaft (2). An output shaft (5) is provided on the housing (1), and an output gear (19) is slidably sleeved on the output shaft (5). A first spline connection part (25) is provided on the output shaft (5), and a second spline connection part (26) is provided on the output gear (19). When the first spline connection part (25) and the second spline connection part (26) are separated, the output gear (19) is loosely sleeved on the output shaft (5), and the input gear (3) partially meshes with the output gear (19). When the first spline connection part (25) and the second spline connection part (26) are meshed, the input gear (3) and the output gear (19) are fully meshed. The output gear (19) is provided with a shift fork groove (23), and the end of the shift fork (17) is located in the shift fork groove (23).

7. A pneumatic piston shift power take-off according to claim 6, characterized in that, The shift fork groove (23) is an annular groove, and the annular groove is coaxial with the output gear (19).

8. A pneumatic piston shift power take-off according to claim 6, characterized in that, The output shaft (5) is provided with an output flange (6), and the output shaft (5) and the output flange (6) are connected by a semi-circular key (8). The output shaft (5) and the output flange (6) are also fixedly connected by a lock nut. The output flange (6) is located outside the housing (1). The output shaft (5) is provided with a tapered shaft, the output flange (6) is provided with a tapered hole, the tapered shaft is embedded in the tapered hole, the tapered hole is provided with a semi-circular key (8), and the tapered shaft is provided with a semi-circular keyway that matches the semi-circular key (8).

9. A pneumatic piston shift power take-off according to claim 6, characterized in that, One end of the output shaft (5) is embedded in the housing (1) and a front bearing (20) is provided between the output shaft (5) and the housing (1). The other end of the output shaft (5) passes through the housing (1) and a rear bearing (21) is provided between the output shaft (5) and the housing (1).

10. A pneumatic piston shift power take-off according to claim 6, characterized in that, The input gear (3) has an installation hole, the input shaft (2) passes through the installation hole, and the two ends of the installation hole have annular bearing mounting grooves. The installation grooves are provided with input gear support bearings (4). The input gear support bearings (4) are located between the input shaft (2) and the input gear (3). The input gear support bearings (4) and the housing (1) are provided with bearing gaskets.

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