Hydraulic and pneumatic gear shifting mechanism of transfer case

Abstract

The utility model discloses a hydraulic and pneumatic gear shifting mechanism of a transfer case, which comprises a shell of the transfer case and a shifting fork shaft which is positioned in an inner cavity of the shell and is used for gear shifting, the cylinder sleeve is arranged in an inner cavity of the shell close to the periphery of the tail end of the shifting fork shaft; the piston is positioned in the cylinder sleeve and is fixed on the periphery of the shifting fork shaft; the reset spring is arranged in an inner cavity of the cylinder sleeve behind the piston and is used for applying forward pressure to the piston; the hydraulic air pressure cavity is formed in an inner cavity of the cylinder sleeve in front of the piston; and the hydraulic air flow channel is communicated with the hydraulic air pressure cavity and a hydraulic air supply device outside the shell. The gear shifting device has the advantages that the shifting fork shaft can slide back and forth to execute gear shifting operation without additionally arranging a propelling mechanism outside the shell of the transfer case, and for large mechanical equipment with a plurality of transfer cases, a large amount of installation space can be saved, and a large amount of manufacturing cost can also be saved.

Description

Technical Field

[0001] This utility model relates to a transfer case hydraulic-pneumatic shifting mechanism, belonging to the field of power distribution technology. Background Technology

[0002] Multi-axis mechanical equipment is equipped with a transfer case to provide power to specific actuators. This transfer case needs a shifting mechanism to adapt to speed changes. Currently, with the emergence of a new type of large-scale construction machinery, its functions are becoming increasingly diverse, resulting in a greater number of actuators and transfer cases. Consequently, this machinery requires more installation space, which is extremely valuable for mobile large-scale construction machinery.

[0003] The hydraulic-pneumatic actuation mechanism of existing transfer cases typically involves installing a hydraulic-pneumatic cylinder or pneumatic cylinder outside the transfer case, which is then connected to the shift fork lever inside the transfer case housing via a connector to achieve the forward and backward movement of the shift fork lever. This external placement of the hydraulic-pneumatic cylinder or pneumatic cylinder requires additional space, thus affecting the setup of other mechanisms, and also increases manufacturing costs accordingly.

[0004] Existing transfer cases use sensors installed on the pneumatic or hydropneumatic lines that drive the shift fork lever. When there is a change in pneumatic or hydropneumatic pressure, an indicator light illuminates. However, this often results in false alarms because when the hydropneumatic or pneumatic device is activated to shift gears, the indicator light may have already illuminated before the shift fork lever has been fully engaged or even engaged. This can mislead the driver or operator into continuing with subsequent invalid operations. Utility Model Content

[0005] The technical problem this utility model aims to solve is: how to avoid the transfer case shifting mechanism occupying too much space, so as to make the transfer case more compact.

[0006] To address the above problems, the technical solution proposed by this utility model is as follows:

[0007] A transfer case hydraulic shifting mechanism includes a transfer case housing and a shift fork shaft located in the inner cavity of the housing. It also includes a cylinder liner disposed in the inner cavity of the housing near the outer periphery of the tail end of the shift fork shaft, a piston fixed to the outer periphery of the shift fork shaft and located in the cylinder liner, a return spring disposed in the inner cavity of the cylinder liner behind the piston to apply forward pressure to the piston, a hydraulic-pneumatic chamber formed in the inner cavity of the cylinder liner in front of the piston, and a hydraulic flow passage connecting the hydraulic-pneumatic chamber to a hydraulic-pneumatic supply device outside the housing.

[0008] An annular baffle is provided on the housing in front of the hydraulic-gas pressure chamber. The shift fork shaft passes through the annular hole formed by the annular baffle. A sealing ring is provided on the wall of the annular hole, which is pressed between the shift fork shaft and the wall of the annular hole.

[0009] The cylinder liner is sealed to the inner wall of the housing.

[0010] The cylinder liner is provided with a seat plate that is fixed to the inner wall of the housing. The seat plate has a through hole in the center for the shift fork shaft to pass through. The rear end of the return spring is mounted on the seat plate.

[0011] It also includes a shift indicator switch triggered by the shift fork shaft. The shift indicator switch has a telescopic trigger rod and a mounting cavity is provided at the tail end of the housing cavity. A mounting position for mounting the shift indicator switch is provided on the side wall of the mounting cavity. The shift indicator switch is mounted in the mounting position, and the trigger rod of the shift indicator switch extends into the mounting cavity and can touch the tail end of the shift fork shaft.

[0012] The trigger rod is perpendicular to the shift fork shaft, and a guide slope is provided at the tail end of the shift fork shaft. When the shift fork shaft retracts after shifting gears, the guide slope contacts the lower end of the trigger rod and causes the trigger rod to slide on the guide slope, forcing the trigger rod to retract and triggering the shift indicator light switch to turn on. Beneficial effects

[0013] 1. The shift fork shaft can slide back and forth to perform shifting operations without the need for a separate propulsion mechanism outside the transfer case. For large mechanical equipment with multiple transfer cases, this can save a lot of installation space and manufacturing costs.

[0014] 2. The indicator light will only illuminate after the shift fork shaft has been pushed into place and the shifting is truly successful. Compared with existing technologies that rely on pneumatic or hydropneumatic pressure sensors to illuminate the indicator light before the shifting is successful or ultimately unsuccessful, thus creating a false alarm, this technology can prevent the operator from continuing to make invalid operations when the shifting is unsuccessful. Attached Figure Description

[0015] Figure 1 This is a cross-sectional schematic diagram of the transfer case hydraulic-pneumatic shifting mechanism described in Embodiment 1;

[0016] Figure 2 This is a cross-sectional schematic diagram of the transfer case hydraulic-pneumatic shifting mechanism described in Embodiment 2.

[0017] In the diagram: 1. Housing; 2. Shift fork shaft; 21. Guide slope; 3. Cylinder liner; 4. Piston; 41. Piston ring; 5. Return spring; 6. Hydraulic-pneumatic pressure chamber; 7. Hydraulic-gas passage; 8. Annular partition; 9. Sealing ring; 10. Seat plate; 11. Shift indicator switch; 111. Trigger rod; 12. Mounting cavity; 121. Mounting position. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings:

[0019] First, it should be noted that "liquid-gas" in this article refers to either "liquid" or "gas". For example, "hydraulic-pneumatic shifting mechanism" refers to either "hydraulic shifting mechanism" or "pneumatic shifting mechanism". Example 1

[0020] like Figure 1 As shown, a transfer case hydraulic shifting mechanism includes a transfer case housing 1 and a shift fork shaft 2 located within the housing 1. It also includes a cylinder liner 3 located within the housing 1 near the outer periphery of the shift fork shaft 2, a piston 4 fixed to the outer periphery of the shift fork shaft 2 within the cylinder liner 3, a return spring 5 located within the cylinder liner 3 behind the piston 4 to apply forward pressure to the piston 4, a hydraulic-pneumatic pressure chamber 6 formed within the cylinder liner 3 in front of the piston 4, and a hydraulic-pneumatic flow channel 7 connecting the hydraulic-pneumatic pressure chamber 6 to a hydraulic-pneumatic supply device outside the housing. In application, liquid or gas with a set pressure is input into the hydraulic-pneumatic pressure chamber 6 through the hydraulic-pneumatic flow channel 7, causing the piston 4 to overcome the resistance of the return spring 5 and push the shift fork shaft 2 backward to perform the shifting operation. When the pressure of the liquid or gas in the hydraulic-pneumatic flow channel 7 is released, the return spring 5 pushes the piston 4 and the shift fork shaft 2 forward to reset. In this way, the shift fork shaft 2 can slide back and forth to perform shifting operations without the need for a separate propulsion mechanism outside the housing 1 of the transfer case. For large mechanical equipment with multiple transfer cases, this can save a lot of installation space and manufacturing costs.

[0021] An annular baffle 8 is provided on the housing 1 in front of the hydraulic-pneumatic chamber 6. The shift fork shaft 2 passes through the annular hole formed by the annular baffle 8. A sealing ring 9 is provided on the hole wall of the annular hole, which is pressed between the shift fork shaft 2 and the hole wall of the annular hole, so that the liquid or gas entering the hydraulic-pneumatic chamber 6 cannot enter the transfer case.

[0022] The cylinder liner 3 and the inner wall of the housing 1 are sealed together, so that the piston 4 and the shift fork shaft are sealed together. The piston 4 slides in a sealed manner between the piston ring 41 and the cylinder wall of the cylinder liner 3 (a mature existing technology), so that the liquid or gas entering the hydraulic-gas pressure chamber 6 cannot enter the space behind the piston 4.

[0023] The cylinder liner 3 is provided with a seat plate 10 fixed to the inner wall of the housing 1. The seat plate 10 has a through hole in the center for the shift fork shaft 2 to pass through. The rear end of the return spring 5 is mounted on the seat plate 10. Example 2

[0024] like Figure 2As shown, the difference between this and Embodiment 1 is that the transfer case hydraulic-pneumatic shifting mechanism also includes a shift indicator switch 11 triggered by the shift fork shaft 2. The shift indicator switch 11 has a retractable trigger rod 111. A mounting cavity 12 is provided at the rear of the inner cavity of the housing 1, and a mounting position 121 for mounting the shift indicator switch 11 is provided on the side wall of the mounting cavity 12. The shift indicator switch 11 is mounted on the mounting position 121, and the trigger rod 111 of the shift indicator switch 11 extends into the mounting cavity 12 and can touch the rear end of the shift fork shaft 2. In this way, when the indicator light is on, it means that the shift fork rod 1 has been pushed into place and the hydraulic or pneumatic shifting mechanism has successfully shifted gears, thus avoiding the false alarm phenomenon that occurs when a sensor is installed on the hydraulic or pneumatic pipeline, causing the indicator light to illuminate when the shifting is unsuccessful.

[0025] Furthermore, the trigger rod 111 is perpendicular to the shift fork shaft 2. A guide slope 21 is provided at the tail end of the shift fork shaft 2. When the shift fork shaft 2 shifts gears backward, the guide slope 21 contacts the lower end of the trigger rod 111 and causes the trigger rod 111 to slide on the guide slope, forcing the trigger rod 111 to retract and trigger the shift indicator light switch 11 to open. The circuit is connected, and the indicator light is lit. When the shift fork shaft 2 moves forward, the trigger rod 111 can slide backward along the guide slope 21 and extend. The shift indicator light switch 11 is automatically turned off, and the indicator light is turned off.

[0026] The above embodiments are only used to describe the present invention more clearly, and should not be regarded as limiting the scope of protection covered by the present invention. Any equivalent modifications should be regarded as falling within the scope of protection covered by the present invention.

Claims

1. A hydro-pneumatic gear shift mechanism for a transfer, comprising a housing (1) of the transfer and a shift fork shaft (2) located in the inner cavity of the housing (1), characterized in that: It also includes a cylinder liner (3) installed in the inner cavity of the housing (1) near the outer periphery of the tail end of the shift fork shaft (2), a piston (4) fixed to the outer periphery of the shift fork shaft (2) inside the cylinder liner (3), a return spring (5) installed in the inner cavity of the cylinder liner (3) behind the piston (4) to apply forward pressure to the piston (4), a hydraulic-gas pressure chamber (6) formed in the inner cavity of the cylinder liner (3) in front of the piston (4), and a hydraulic-gas flow passage (7) connecting the hydraulic-gas pressure chamber (6) with the hydraulic-gas supply device outside the housing.

2. The hydrokinetic torque-sensing transfer case of claim 1, wherein: An annular baffle (8) is provided on the housing (1) in front of the liquid-gas pressure chamber (6). The shift fork shaft (2) passes through the annular hole formed by the annular baffle (8). A sealing ring (9) is provided on the hole wall of the annular hole, which is pressed between the shift fork shaft (2) and the hole wall of the annular hole.

3. The transfer case hydraulic-pneumatic shifting mechanism according to claim 1, characterized in that: The cylinder liner (3) and the inner wall of the housing (1) are connected by a sealing sleeve.

4. The transfer case hydraulic-pneumatic shifting mechanism according to claim 1, characterized in that: The cylinder liner (3) is provided with a seat plate (10) fixed to the inner wall of the housing (1). The seat plate (10) has a through hole in the center for the shift fork shaft (2) to pass through. The rear end of the return spring (5) is mounted on the seat plate (10).

5. The transfer case hydraulic-pneumatic shifting mechanism according to claim 1, characterized in that: It also includes a shift indicator switch (11) triggered by the shift fork shaft (2). The shift indicator switch (11) has a telescopic trigger rod (111). An installation cavity (12) is provided at the tail end of the inner cavity of the housing (1). An installation position (121) for installing the shift indicator switch (11) is provided on the side wall of the installation cavity (12). The shift indicator switch (11) is installed on the installation position (121). The trigger rod (111) of the shift indicator switch (11) extends into the installation cavity (12) and can touch the tail end of the shift fork shaft (2).

6. The transfer case hydraulic-pneumatic shifting mechanism according to claim 5, characterized in that: The trigger rod (111) is perpendicular to the shift fork shaft (2). A guide slope (21) is provided at the tail end of the shift fork shaft (2). When the shift fork shaft (2) shifts gears backward, the guide slope (21) contacts the lower end of the trigger rod (111) and causes the trigger rod (111) to slide on the guide slope, forcing the trigger rod (111) to retract and trigger the shift indicator switch (11) to open.

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