Two-gear power gear shifting transmission

Abstract

The utility model discloses a two-gear power gear shifting transmission, and belongs to the technical field of new energy engineering machinery. Which comprises a planetary gear mechanism, a clutch (13) and a gear shifting mechanism, and is characterized in that a planet carrier (12) and an outer gear ring (11) of the planetary gear mechanism are connected through the clutch (13), the gear shifting mechanism comprises a high-speed gear set and a low-speed gear set, an output shaft (6) is led out of the output ends of the high-speed gear set and the low-speed gear set, and a switching assembly is further arranged in the gear shifting mechanism. The driving system drives the switching assembly to move in a reciprocating mode, and the switching assembly is connected with the power output end of the planetary gear mechanism and the high-speed gear set or connected with the power output end of the planetary gear mechanism and the low-speed gear set. According to the two-gear power gear shifting transmission, gear shifting is achieved through the switching assembly which is driven by the driving system to move in a reciprocating mode, the driving system only works in the gear shifting process, no extra energy is consumed after gear shifting is finished, and power consumption is reduced.

Description

Technical Field

[0001] The invention relates to a two-speed power shift transmission, belonging to the technical field of new energy engineering machinery. Background Art

[0002] In the existing technology, the drive of construction machinery and agricultural machinery cannot get rid of the limitations of the gearbox. The existing gearboxes used in construction machinery and agricultural machinery are developed and designed based on the working characteristics of the engine. Direct application to construction machinery and agricultural machinery will lead to problems such as low input speed, poor gear precision, low mechanical efficiency, and high noise.

[0003] With the continuous development of technology, some speed-shifting solutions for construction machinery and agricultural machinery have also appeared on the market. For example, the technical solution disclosed in Chinese invention patent application number 201410538136.8, filed on October 13, 2014, and entitled "Electric drive system based on two-speed transmission and coordinated shift control method thereof" connects the clutch and brake. However, its disadvantage is that the hydraulic system is always in operation during operation, resulting in high energy consumption. The technical solution disclosed in Chinese invention patent application number 202311420633.3, filed on October 30, 2023, and entitled "Gearbox for electric construction machinery and electric construction machinery" achieves gear shifting by connecting the sun gear or the inner ring gear in the planetary transmission mechanism to the driven gear. The technical solution disclosed in the Chinese invention patent with application number 202010884577.9 and application date August 28, 2020, and the patent name is "An electronically controlled automatic transmission and method for engineering machinery", in which a two-speed clutch is provided. When the first-speed clutch is engaged, the planetary gear train drives the transfer gear and outputs the first gear through the output shaft assembly; when the second-speed clutch is engaged, the output shaft assembly is driven by the transfer gear for output, which is the second-speed output.

[0004] The applicant of this application hopes to design a technical solution with a completely new structure to meet the needs of gearboxes for engineering machinery and agricultural machinery. Utility Model Content

[0005] The technical problem to be solved by the utility model is: to overcome the shortcomings of the existing technology and provide a two-speed power shift transmission that realizes gear shifting by providing a switching component that moves back and forth driven by a drive system, wherein the drive system only works during the gear shifting process and does not consume additional energy after the gear shifting is completed, thereby reducing power consumption.

[0006] The technical solution adopted by the utility model to solve its technical problems is: the two-speed power shift transmission includes a planetary gear mechanism, a clutch and a shift mechanism, which is characterized in that the planetary carrier and the outer ring gear of the planetary gear mechanism are connected by a clutch, the shift mechanism includes a high-speed gear set and a low-speed gear set, the output ends of the high-speed gear set and the low-speed gear set lead out output shafts, and a switching component is also provided in the shift mechanism. The drive system drives the switching component to move back and forth, and the switching component connects the power output end of the planetary gear mechanism and the high-speed gear set, or connects the power output end of the planetary gear mechanism and the low-speed gear set.

[0007] Preferably, the switching assembly includes a coupling sleeve, the drive system drives the coupling sleeve to move back and forth, the planetary carrier is the power output end of the planetary gear mechanism, and the coupling sleeve connects the driving gear set and the planetary carrier in the high-speed gear set, or connects the driving gear set and the planetary carrier in the low-speed gear set.

[0008] Preferably, the switching assembly includes a power intermediate gear, the driving gear set in the high-speed gear set includes a high-speed driving gear, the driving gear set in the low-speed gear set includes a low-speed driving gear, and the power intermediate gear is located between the high-speed driving gear and the low-speed driving gear and is rigidly connected to the planet carrier.

[0009] Preferably, the power intermediate gear, the high-speed driving gear and the low-speed driving gear are coaxially arranged and have the same number of teeth. The combining sleeve is sleeved on the outer rings of the power intermediate gear, the high-speed driving gear and the low-speed driving gear. The driving system drives the combining sleeve to move back and forth, and the combining sleeve connects the power intermediate gear and the high-speed driving gear, or connects the power intermediate gear and the low-speed driving gear.

[0010] Preferably, the driving gear set in the high-speed gear set also includes a high-speed intermediate gear fixed coaxially with the high-speed driving gear, the driving gear set in the low-speed gear set also includes a low-speed intermediate gear fixed coaxially with the low-speed driving gear, the high-speed driven gear is meshed with the high-speed intermediate gear, the low-speed driven gear is meshed with the low-speed intermediate gear, and the output shaft is coaxially fixed with both the high-speed driven gear and the low-speed intermediate gear.

[0011] Preferably, the drive system includes a shift cylinder, one end of the drive shaft is connected to the coupling sleeve, and the other end is connected to the piston in the shift cylinder, the two sides of the piston inside the shift cylinder are respectively a high-speed chamber and a low-speed chamber, the high-speed shift pipeline is connected to the high-speed chamber, and the low-speed shift pipeline is connected to the low-speed chamber.

[0012] Preferably, the inlet of the hydraulic pump is connected to the oil tank, the outlet of the hydraulic pump is connected to the inlet of the shift valve, the two outlets of the shift valve that are connected in time are respectively connected to the high-speed shift pipeline and the low-speed shift pipeline, the high-speed shift pipeline is also connected to the high-speed clutch drive pipeline, and the low-speed shift pipeline is also connected to the low-speed clutch drive pipeline, the high-speed clutch drive pipeline and the low-speed clutch drive pipeline are respectively connected to the clutch through the clutch release valve.

[0013] Preferably, a high-speed driving overflow valve is further connected to the high-speed shift pipeline, and a low-speed driving overflow valve is further connected to the low-speed shift pipeline.

[0014] Preferably, a high-speed return relief valve and a low-speed return relief valve are also provided, the oil inlet of the high-speed return relief valve pilot valve body is connected to the high-speed shift pipeline, the oil inlet of the high-speed return relief valve main valve body is connected to the oil outlet of the low-speed drive relief valve, the oil inlet of the low-speed return relief valve pilot valve body is connected to the low-speed shift pipeline, the oil inlet of the low-speed return relief valve main valve body is connected to the oil outlet of the high-speed drive relief valve, the oil inlet of the low-speed return relief valve main valve body is connected to the connecting pipeline between the low-speed drive relief valve and the shift cylinder, and the oil outlets of the high-speed return relief valve and the low-speed return relief valve main valve body are connected to the oil tank.

[0015] Preferably, an overflow port is further provided on the surface of the shift oil cylinder, the overflow port is connected to the oil tank through an overflow pipe, and the overflow port is connected to the high-speed cavity or the low-speed cavity as the piston moves.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] In this two-speed power shift transmission, gear shifting is achieved by a switching assembly that is driven by a drive system to move back and forth. The drive system only works during the gear shifting process and does not consume additional energy after the gear shifting is completed, thereby reducing power consumption.

[0018] The first stage reduction of this two-speed power shift transmission adopts a planetary gear system scheme, which has a large reduction ratio and a compact structure.

[0019] This two-speed powershift transmission is primarily developed for new energy engineering and agricultural machinery, filling the gap in transmissions for motor-driven machinery in these sectors. It addresses the inability of single-motor-driven vehicles to simultaneously meet the requirements of both "high traction at low speeds" and "high speeds during field operations."

[0020] This two-speed power shift transmission can output torque in reverse, simplifying the transmission structure while significantly reducing the cost of the motor and its controller, giving full play to the advantages of electric motors in the fields of construction machinery and agricultural machinery, and maximizing energy conservation and emission reduction.

[0021] This two-speed powershift transmission features a multi-plate wet clutch that utilizes the physical properties of a planetary gear train to achieve power disengagement. Shifting can be performed under any operating condition. Shifting shock is minimal, significantly improving transmission reliability and service life. Hydraulic powershifting, combined with a sophisticated hydraulic system design, eliminates hydraulic energy consumption during transmission output. Combined with the transmission controller's algorithm, it enables automatic shifting and integrated manual and automatic control. Replacing the shift valve with a manual mechanism allows for pure mechanical control. This flexible control scheme facilitates cost control. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the power transmission principle of Example 1 of a two-speed power shift transmission.

[0023] Figure 2 This is a schematic diagram of the shift oil circuit for a two-speed power shift transmission.

[0024] Figure 3 This is a schematic diagram of the power transmission principle of Example 2 of a two-speed power shift transmission.

[0025] Among them: 1. Input shaft 2. High-speed driven gear 3. High-speed driving gear 4. Low-speed driven gear 5. Low-speed driving gear 6. Output shaft 7. Low-speed intermediate gear 8. Power intermediate gear 9. Coupling sleeve 10. High-speed intermediate gear 11. Outer ring gear 12. Planetary carrier 13. Clutch 14. Clutch release valve 15. Low-speed return line 16. Overflow pipe 17. Shift cylinder 18. High-speed drive overflow valve 19. Drive shaft 20. Low-speed drive overflow valve 21. High-speed shift line 22. High-speed return line 23. Low-speed shift line 24. High-speed return overflow valve 25. Low-speed return overflow valve 26. Low-speed clutch drive line 27. Shift valve 28. Hydraulic pump 29. Fuel tank 30. Main line overflow valve 31. High-speed clutch drive line 32. Shift controller 33. Low-speed intermediate shaft gear 34. Intermediate shaft 35. High-speed intermediate shaft gear 36. Driving gear. DETAILED DESCRIPTION

[0026] Figures 1 and 2 This is the best embodiment of the present invention, Figures 1-3 The utility model is further described.

[0027] Example 1:

[0028] like Figure 1As shown, a two-speed power shift transmission includes a planetary reducer mechanism. An input shaft 1 extends from the axle of the sun gear of the planetary reducer mechanism and is connected to the output shaft of an electric motor or engine via input shaft 1. A clutch 13 is provided on the exterior of the planetary reducer mechanism to connect the outer ring gear 11 and the planetary carrier 12 of the planetary reducer mechanism. When clutch 13 is disengaged, the outer ring gear 11 is released and placed in a free state, preventing the planetary reducer from transmitting power. When clutch 13 is engaged, the outer ring gear 11 is locked, allowing power to be output through the planetary carrier 12 of the planetary reducer mechanism.

[0029] A shifting mechanism is also provided, which includes a high-speed driving gear 3 and a low-speed driving gear 5. A power intermediate gear 8 is also provided between the high-speed driving gear 3 and the low-speed driving gear 5. The gear shaft of the power intermediate gear 8 passes through the center of the wheel axle of the high-speed driving gear 3 and is rigidly connected to the planet carrier 12. The high-speed driving gear 3, the low-speed driving gear 5 and the power intermediate gear 8 have the same number of teeth, and the high-speed driving gear 3, the low-speed driving gear 5 and the power intermediate gear 8 are coaxially arranged.

[0030] A coupling sleeve 9 is sleeved on the outside of the power intermediate gear 8, and the coupling sleeve 9 moves back and forth in the axial direction. At one end of the axial reciprocating movement, the high-speed driving gear 3 and the power intermediate gear 8 are simultaneously sleeved therein, and the coupling sleeve 9 is simultaneously engaged with the high-speed driving gear 3 and the power intermediate gear 8; at the other end of the axial reciprocating movement, the low-speed driving gear 5 and the power intermediate gear 8 are simultaneously sleeved therein, and the coupling sleeve 9 is simultaneously engaged with the low-speed driving gear 5 and the power intermediate gear 8.

[0031] A high-speed intermediate gear 10 is provided, which is coaxially connected to the high-speed driving gear 3 and meshes with the high-speed driven gear 2. A low-speed intermediate gear 7 is provided, which is coaxially connected to the low-speed driving gear 5 and meshes with the low-speed driven gear 4. The high-speed driven gear 2 and the low-speed driven gear 4 are coaxially connected via an output shaft 6. The gear ratio of the high-speed intermediate gear 10 to the high-speed driven gear 2 is greater than the gear ratio of the low-speed intermediate gear 7 to the low-speed driven gear 4.

[0032] When the high-speed driving gear 3 and the power intermediate gear 8 are connected through the coupling sleeve 9, the automatic power intermediate gear 8 is transmitted to the high-speed driving gear 3 through the coupling sleeve 9, and is further transmitted to the high-speed driven gear 2 through the high-speed intermediate gear 10 by the high-speed driving gear 3, and drives the output shaft 6 to rotate. At this time, the output shaft 6 is in the high-speed gear position; similarly, when the low-speed driving gear 5 and the power intermediate gear 8 are connected through the coupling sleeve 9, the automatic power intermediate gear 8 is transmitted to the low-speed driving gear 5 through the coupling sleeve 9, and is further transmitted to the low-speed driven gear 4 through the low-speed intermediate gear 7 by the low-speed driving gear 5, and drives the output shaft 6 to rotate. At this time, the output shaft 6 is in the low-speed gear position.

[0033] Combine Figure 2 The coupling sleeve 9 is axially moved by the shift cylinder 17. The drive shaft 19 drawn out from the shift cylinder 17 is connected to the piston in the shift cylinder 17. The drive shaft 19 is connected to the coupling sleeve 9, and the coupling sleeve 9 is driven to move axially through the drive shaft 19. When the piston in the shift cylinder 17 is output, the drive shaft 19 is output from the shift cylinder 17, driving the coupling sleeve 9 to move toward the side of the high-speed driving gear 3 to achieve upshifting; when the piston in the shift cylinder 17 is reset, the drive shaft 19 is reset, driving the coupling sleeve 9 to move toward the side of the low-speed driving gear 5 to achieve downshifting.

[0034] The shift cylinder 17 is driven by a hydraulic system, which includes a hydraulic pump 28. The inlet of the hydraulic pump 28 is connected to the oil tank 29, and the outlet of the hydraulic pump 28 is connected to the shift valve 27 through a pipeline. A main line relief valve 30 is installed on the connecting pipeline between the hydraulic pump 28 and the shift valve 27. The main line relief valve 30 is implemented as a direct-acting relief valve. The oil inlet of the main line relief valve 30 is connected to the connecting pipeline between the hydraulic pump 28 and the shift valve 27, and the oil outlet of the main line relief valve 30 returns to the oil tank 29 through a pipeline.

[0035] The shift valve 27 is implemented as a two-position, three-way solenoid valve with one inlet and two outlets. The control coil of the shift valve 27 is connected to a shift controller 32. When the shift controller 32 outputs a voltage signal to the control coil of the shift valve 27, the valve core of the shift valve 27 actuates. The outlet of the hydraulic pump 28 is connected to the oil inlet of the shift valve 27 via a pipeline. The high-speed shift line 21 and the high-speed clutch drive line 31 are respectively led from one of the oil outlets of the shift valve 27. The low-speed shift line 23 and the low-speed clutch drive line 26 are respectively led from the other oil outlet of the shift valve 27.

[0036] A clutch release valve 14 is provided, which is implemented by a two-position two-way solenoid valve. The other ends of the high-speed clutch drive pipeline 31 and the low-speed clutch drive pipeline 26 are respectively connected to the oil inlet of the clutch release valve 14, and the oil outlet of the clutch release valve 14 is connected to the oil cylinder of the clutch 13.

[0037] The high-speed shift pipeline 21 is led out from the shift valve 27 and connected to the oil inlet of the high-speed drive relief valve 18. The high-speed drive relief valve 18 is realized by a direct-acting relief valve, and the oil outlet of the high-speed drive relief valve 18 is connected to the cylinder body of the shift cylinder 17 through a pipeline; the low-speed shift pipeline 23 is led out from the shift valve 27 and connected to the oil inlet of the low-speed drive relief valve 20. The low-speed drive relief valve 20 is realized by a direct-acting relief valve, and the oil outlet of the low-speed drive relief valve 20 is also connected to the cylinder body of the shift cylinder 17 through a pipeline. The oil outlets of the high-speed drive overflow valve 18 and the low-speed drive overflow valve 20 and the connection points with the cylinder body of the shift cylinder 17 are respectively located on both sides of the piston in the shift cylinder 17. For the convenience of description, the cavity where the high-speed drive overflow valve 18 and the cylinder body of the shift cylinder 17 are located is called the high-speed cavity of the shift cylinder 17, and the cavity where the low-speed drive overflow valve 20 and the cylinder body of the shift cylinder 17 are located is called the low-speed cavity of the shift cylinder 17. The cylinder body of the self-shift cylinder 17 is also provided with a cylinder overflow port, and an overflow pipe 16 is connected to the cylinder overflow port, and the other side of the overflow pipe 16 returns to the oil tank 29.

[0038] A high-speed return relief valve 24 and a low-speed return relief valve 25 are also provided. Both the high-speed return relief valve 24 and the low-speed return relief valve 25 are implemented as pilot-operated relief valves. The oil inlet of the pilot valve body of the high-speed return relief valve 24 is connected to the high-speed shift pipeline 21. The oil inlet of the main valve body of the high-speed return relief valve 24 is connected to the connection pipeline between the low-speed drive relief valve 20 and the shift cylinder 17 through the high-speed return pipeline 22. The oil outlet of the main valve body of the high-speed return relief valve 24 is returned to the oil tank 29 through a pipeline. The oil inlet of the pilot valve body of the low-speed return relief valve 25 is connected to the low-speed shift pipeline 23. The oil inlet of the main valve body of the low-speed return relief valve 25 is connected to the connection pipeline between the low-speed drive relief valve 20 and the shift cylinder 17 through the low-speed return pipeline 15. The oil outlet of the main valve body of the low-speed return relief valve 25 is returned to the oil tank 29 through a pipeline.

[0039] The conduction pressures of high-speed return relief valve 24 and low-speed return relief valve 25 are both lower than the conduction pressures of high-speed drive relief valve 18 and low-speed drive relief valve 20. In this two-speed powershift transmission, the conduction pressures of high-speed return relief valve 24 and low-speed return relief valve 25 are set at 2 MPa, while the conduction pressures of high-speed drive relief valve 18 and low-speed drive relief valve 20 are set at 3 MPa. The pressure within clutch 13 that drives it to disengage is 2 MPa.

[0040] The specific working process and working principle are as follows:

[0041] The vehicle controller can automatically control upshifts and downshifts based on pre-set logic (e.g., based on vehicle speed). The driver can also manually upshift or downshift according to actual circumstances using a shift button connected to the shift controller 32 or the vehicle controller. Whether in manual or automatic mode, when an upshift is required, the shift controller 32 outputs a control signal (represented as the input drive voltage) to the shift valve 27. This activates the valve body within the shift valve 27, connecting the hydraulic pump 28 to the high-speed clutch drive line 31 (and the high-speed shift line 21). The hydraulic pump 28 then delivers hydraulic oil to both the high-speed clutch drive line 31 and the high-speed shift line 21. The shift controller 32 also controls the operation of the clutch release valve 14. The hydraulic oil then flows through the clutch release valve 14 into the cylinder of the clutch 13. Simultaneously, the hydraulic oil is delivered to the oil inlet of the high-speed drive relief valve 18 and the oil inlet of the pilot valve body of the high-speed return relief valve 24.

[0042] Since the conduction pressure of the high-speed drive relief valve 18 is greater than the separation pressure of the clutch 13 and the conduction pressure of the pilot valve body of the high-speed return relief valve 24, the clutch 13 and the high-speed return relief valve 24 are both actuated before the high-speed drive relief valve 18. At this time, when the clutch 13 is disengaged, the outer ring gear 11 is released and is in a free state. At this time, the planetary reducer cannot transmit power, and at the same time, the low-speed cavity in the shift cylinder 17 is connected to the oil tank 29 through the high-speed return relief valve 24.

[0043] When the oil pressure output by the hydraulic pump 28 is greater than the conduction pressure of the high-speed drive relief valve 18, the high-speed drive relief valve 18 is opened, and the hydraulic oil enters the high-speed chamber of the shift cylinder 17 through the high-speed drive relief valve 18, driving the piston of the shift cylinder 17 to move. During the movement of the piston in the shift cylinder 17, the hydraulic oil and air in the low-speed chamber of the shift cylinder 17 are discharged into the oil tank 29. As the piston in the shift cylinder 17 moves, the drive shaft 19 is output from the shift cylinder 17. After the drive shaft 19 is in place, it drives the coupling sleeve 9 to move toward the side of the high-speed driving gear 3. At this time, the high-speed driving gear 3 and the power intermediate gear 8 are connected through the coupling sleeve 9.

[0044] After the piston of the shift cylinder 17 moves into position, the high-speed cavity in the shift cylinder 17 is connected to the overflow port, and the hydraulic oil output from the hydraulic pump 28 is instantly discharged into the oil tank 29 through the overflow pipe 16. At the same time, the hydraulic oil in the clutch 13 is withdrawn and discharged into the oil tank 29 through the overflow pipe 16. At this time, the clutch 13 locks the outer ring gear 11 of the planetary reduction mechanism under the action of its internal spring, and the planetary reduction mechanism can output power.

[0045] At this time, the outer ring gear 11 transmits power to the planetary carrier 12 through the clutch 13, and the planetary carrier 12 transmits power to the power intermediate gear 8. At this time, the power intermediate gear 8 and the high-speed driving gear 3 are connected by the coupling sleeve 9. The power intermediate gear 8 transmits power to the high-speed driving gear 3 through the coupling sleeve 9, and the high-speed driving gear 3 further transmits power to the high-speed driven gear 2 through the high-speed intermediate gear 10, thereby driving the output shaft 6 to rotate. At this time, the output shaft 6 is in the high-speed gear position, completing the upshift.

[0046] When a downshift is required, the shift controller 32 outputs a control signal (recorded as the input drive voltage) to the shift valve 27. This activates the internal valve of the shift valve 27, connecting the hydraulic pump 28 to the low-speed shift line 23 (and the low-speed clutch drive line 26). Hydraulic pump 28 delivers hydraulic oil to both the low-speed shift line 23 and the low-speed clutch drive line 26. The shift controller 32 also activates the clutch release valve 14, causing the hydraulic oil to flow through it into the cylinder of the clutch 13. Simultaneously, the hydraulic oil is delivered to the oil inlet of the low-speed drive relief valve 20 and the oil inlet of the pilot valve body of the low-speed return relief valve 25.

[0047] Since the conduction pressure of the low-speed drive relief valve 20 is greater than the separation pressure of the clutch 13 and the conduction pressure of the pilot valve body of the low-speed return relief valve 25, the clutch 13 and the low-speed drive relief valve 20 both act before the low-speed drive relief valve 20. At this time, when the clutch 13 is disengaged, the outer ring gear 11 is released and the outer ring gear 11 is in a free state. At this time, the planetary reducer cannot transmit power, and at the same time, the high-speed cavity in the shift cylinder 17 is connected to the oil tank 29 through the low-speed return relief valve 25.

[0048] When the oil pressure output by the hydraulic pump 28 is greater than the conduction pressure of the low-speed drive relief valve 20, the low-speed drive relief valve 20 is opened, and the hydraulic oil enters the low-speed chamber of the shift cylinder 17 through the low-speed drive relief valve 20, driving the piston of the shift cylinder 17 to move. During the movement of the piston in the shift cylinder 17, the hydraulic oil and air in the high-speed chamber of the shift cylinder 17 are discharged into the oil tank 29 through the low-speed return relief valve 25. As the piston in the shift cylinder 17 moves, the drive shaft 19 is reset. After the drive shaft 19 is reset, it drives the coupling sleeve 9 to move toward the side of the low-speed driving gear 5. At this time, the low-speed driving gear 5 and the power intermediate gear 8 are connected through the coupling sleeve 9.

[0049] After the piston of the shift cylinder 17 moves into position, the low-speed chamber in the shift cylinder 17 is connected to the overflow port, and the hydraulic oil output from the hydraulic pump 28 is instantly discharged into the oil tank 29 through the overflow pipe 16. At the same time, the hydraulic oil in the clutch 13 is withdrawn and discharged into the oil tank 29 through the overflow pipe 16. At this time, the clutch 13 locks the outer ring gear 11 of the planetary reduction mechanism under the action of its internal spring, and the planetary reduction mechanism can output power.

[0050] At this time, the outer ring gear 11 transmits power to the planetary carrier 12 through the clutch 13, and the planetary carrier 12 transmits power to the power intermediate gear 8. At this time, the power intermediate gear 8 and the low-speed driving gear 5 are connected by the coupling sleeve 9. The power intermediate gear 8 transmits power to the low-speed driving gear 5 through the coupling sleeve 9, and the low-speed driving gear 5 further transmits power to the low-speed driven gear 4 through the low-speed intermediate gear 7, thereby driving the output shaft 6 to rotate. At this time, the output shaft 6 is in the low-speed gear position, completing the downshift.

[0051] Example 2:

[0052] like Figure 3 As shown, the difference between this embodiment and embodiment 1 is that the high-speed driving gear 3, the power intermediate gear 8 and the low-speed driving gear 5 are arranged on the output shaft 6, wherein the power intermediate gear 8 is coaxially fixed to the output shaft 6, the high-speed driving gear 3 and the high-speed intermediate gear 10 coaxially fixed thereto are sleeved on the outer ring of the output shaft 6, and the low-speed driving gear 5 and the low-speed intermediate gear 7 coaxially fixed thereto are also sleeved on the outer ring of the output shaft 6.

[0053] An intermediate shaft 34 is also provided, to which a high-speed intermediate shaft gear 35 and a low-speed intermediate shaft gear 33 are coaxially fixed. The high-speed intermediate shaft gear 35 meshes with the high-speed intermediate gear 10, and the low-speed intermediate shaft gear 33 meshes with the low-speed intermediate gear 7. The planetary carrier 12 transmits power to the driving gear 36, which meshes with the high-speed intermediate shaft gear 35.

[0054] The clutching action and shifting logic of this embodiment are the same as those of the first embodiment. The difference lies in the transmission mode. When the gear is switched to the high-speed gear, the coupling sleeve 9 connects the high-speed driving gear 3 and the power intermediate gear 8. The planetary carrier 12 drives the driving gear 36 to rotate. The driving gear 36 transmits power to the high-speed intermediate gear 10 through the high-speed intermediate shaft gear 35. The high-speed intermediate gear 10 further transmits power to the power intermediate gear 8 through the high-speed driving gear 3 and the coupling sleeve 9. The power intermediate gear 8 drives the output shaft 6 to rotate. At this time, the low-speed driving gear 5 and the low-speed intermediate gear 7 fixed coaxially therewith rotate idly on the outer ring of the output shaft 6.

[0055] When switching to the low-speed gear, the coupling sleeve 9 connects the low-speed driving gear 5 and the power intermediate gear 8, the planetary carrier 12 drives the driving gear 36 to rotate, the driving gear 36 transmits power to the high-speed intermediate gear 10 through the high-speed intermediate shaft gear 35, the high-speed intermediate gear 10 further transmits power to the low-speed intermediate shaft gear 33 through the intermediate shaft 34, the low-speed intermediate shaft gear 33 transmits power to the low-speed intermediate gear 7, the power is further transmitted to the power intermediate gear 8 through the low-speed driving gear 5 and the coupling sleeve 9, and the output shaft 6 is driven to rotate by the power intermediate gear 8. At this time, the high-speed driving gear 3 and the high-speed intermediate gear 10 fixed coaxially therewith rotate idly on the outer ring of the output shaft 6.

[0056] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation thereto. Any person skilled in the art may utilize the above disclosure to modify or remodel the present invention into equivalent embodiments. However, any simple modification, equivalent variation, or modification of the above embodiment that does not depart from the technical content of the present invention and is based on the technical essence of the present invention shall still fall within the scope of protection of the present invention.

Claims

1. A two-speed power shift transmission comprising a planetary gear mechanism, a clutch (13) and a shift mechanism, characterized in that: The planetary carrier (12) and the outer ring gear (11) of the planetary gear mechanism are connected via a clutch (13). The shift mechanism includes a high-speed gear set and a low-speed gear set. The output ends of the high-speed gear set and the low-speed gear set lead out an output shaft (6). A switching component is also provided in the shift mechanism. The driving system drives the switching component to move back and forth. The switching component connects the power output end of the planetary gear mechanism with the high-speed gear set, or connects the power output end of the planetary gear mechanism with the low-speed gear set.

2. The two-speed power shift transmission according to claim 1, characterized in that: The switching assembly includes a coupling sleeve (9), a driving system drives the coupling sleeve (9) to move back and forth, a planetary carrier (12) is a power output end of the planetary gear mechanism, and the coupling sleeve (9) connects the driving gear set in the high-speed gear set and the planetary carrier (12), or connects the driving gear set in the low-speed gear set and the planetary carrier (12).

3. The two-speed power shift transmission according to claim 1 or 2, characterized in that: The switching assembly includes a power intermediate gear (8), a driving gear set in the high-speed gear set includes a high-speed driving gear (3), and a driving gear set in the low-speed gear set includes a low-speed driving gear (5). The power intermediate gear (8) is located between the high-speed driving gear (3) and the low-speed driving gear (5) and is rigidly connected to the planet carrier (12).

4. The two-speed power shift transmission according to claim 3, characterized in that: The power intermediate gear (8), the high-speed driving gear (3) and the low-speed driving gear (5) are coaxially arranged and have the same number of teeth. The coupling sleeve (9) is sleeved on the outer rings of the power intermediate gear (8), the high-speed driving gear (3) and the low-speed driving gear (5). The driving system drives the coupling sleeve (9) to move back and forth. The coupling sleeve (9) connects the power intermediate gear (8) and the high-speed driving gear (3), or connects the power intermediate gear (8) and the low-speed driving gear (5).

5. The two-speed power shift transmission according to claim 3, characterized in that: The driving gear set in the high-speed gear set further includes a high-speed intermediate gear (10) fixed coaxially with the high-speed driving gear (3), and the driving gear set in the low-speed gear set further includes a low-speed intermediate gear (7) fixed coaxially with the low-speed driving gear (5). The high-speed driven gear (2) is meshed with the high-speed intermediate gear (10), and the low-speed driven gear (4) is meshed with the low-speed intermediate gear (7). The output shaft (6) is fixed coaxially with both the high-speed driven gear (2) and the low-speed intermediate gear (7).

6. The two-speed power shift transmission according to claim 4, characterized in that: The drive system includes a shift oil cylinder (17), one end of a drive shaft (19) is connected to a coupling sleeve (9), and the other end is connected to a piston in the shift oil cylinder (17), two sides of the piston inside the shift oil cylinder (17) are respectively a high-speed cavity and a low-speed cavity, a high-speed shift pipeline (21) is connected to the high-speed cavity, and a low-speed shift pipeline (23) is connected to the low-speed cavity.

7. The two-speed power shift transmission according to claim 6, characterized in that: The inlet of the hydraulic pump (28) is connected to the oil tank (29), the outlet of the hydraulic pump (28) is connected to the inlet of the shift valve (27), and the two outlets of the shift valve (27) are connected to the high-speed shift pipeline (21) and the low-speed shift pipeline (23) respectively. The high-speed shift pipeline (21) is also connected to the high-speed clutch drive pipeline (31), and the low-speed shift pipeline (23) is also connected to the low-speed clutch drive pipeline (26). The high-speed clutch drive pipeline (31) and the low-speed clutch drive pipeline (26) are respectively connected to the clutch (13) through the clutch release valve (14).

8. The two-speed power shift transmission according to claim 6, characterized in that: A high-speed drive relief valve (18) is also connected to the high-speed shift pipeline (21), and a low-speed drive relief valve (20) is also connected to the low-speed shift pipeline (23).

9. The two-speed power shift transmission according to claim 8, characterized in that: A high-speed reflux relief valve (24) and a low-speed reflux relief valve (25) are also provided. The oil inlet of the pilot valve body of the high-speed reflux relief valve (24) is communicated with the high-speed shift pipeline (21). The oil inlet of the main valve body of the high-speed reflux relief valve (24) is connected to the oil outlet of the low-speed drive relief valve (20). The oil inlet of the pilot valve body of the low-speed reflux relief valve (25) is communicated with the low-speed shift pipeline (23). The oil inlet of the main valve body of the low-speed reflux relief valve (25) is connected to the oil outlet of the high-speed drive relief valve (18). The oil inlet of the main valve body of the low-speed reflux relief valve (25) is connected to the connecting pipeline between the low-speed drive relief valve (20) and the shift oil cylinder (17). The oil outlets of the main valve bodies of the high-speed reflux relief valve (24) and the low-speed reflux relief valve (25) are connected to the oil tank (29).

10. The two-speed power shift transmission according to claim 6, characterized in that: An overflow port is also provided on the surface of the shift oil cylinder (17), and the overflow port is connected to the oil tank (29) through an overflow pipe (16). The overflow port is connected to the high-speed cavity or the low-speed cavity as the piston moves.

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