阅读说明：本技术 静液压无级变速装置 (Hydrostatic stepless speed change device ) 是由 沙俊炎 许敏 邢可 于 2020-04-28 设计创作，主要内容包括：本发明属于农业收割设备技术领域,涉及一种静液压无级变速装置,包括壳体,所述壳体上安装伺服变量机构、机械伺服阀,机械伺服阀通过油路连接伺服变量机构,以对伺服变量机构的变量活塞的前进与后退进行控制；所述伺服变量机构包括变量阀体,变量活塞滑动配合设置于所述变量阀体内腔中,变量活塞通过滑块、连接块与泵斜盘连接,变量阀体上设置第一伺服变量机构控制口、第二伺服变量机构控制口,所述第一伺服变量机构控制口、第二伺服变量机构控制口分别与变量活塞的两腔相连通。该变速装置采用伺服变量机构和机械伺服阀,能满足使用静液压传动装置的市场需求。(The invention belongs to the technical field of agricultural harvesting equipment, and relates to a hydrostatic stepless speed change device which comprises a shell, wherein a servo variable mechanism and a mechanical servo valve are arranged on the shell, and the mechanical servo valve is connected with the servo variable mechanism through an oil way so as to control the advancing and retreating of a variable piston of the servo variable mechanism; the servo variable mechanism comprises a variable valve body, a variable piston is arranged in an inner cavity of the variable valve body in a sliding fit mode, the variable piston is connected with a pump swash plate through a sliding block and a connecting block, a first servo variable mechanism control port and a second servo variable mechanism control port are arranged on the variable valve body, and the first servo variable mechanism control port and the second servo variable mechanism control port are respectively communicated with two cavities of the variable piston. The speed change device adopts a servo variable mechanism and a mechanical servo valve, and can meet the market demand of using the hydrostatic transmission device.)

1. A hydrostatic continuously variable transmission, characterized by: the servo variable valve comprises a shell (1), wherein a servo variable mechanism (22) and a mechanical servo valve (18) are installed on the shell (1), and the mechanical servo valve (18) is connected with the servo variable mechanism (22) through an oil way so as to control the forward and backward movement of a variable piston (35) of the servo variable mechanism (22);

the servo variable mechanism (22) comprises a variable valve body (34), a variable piston (35) is arranged in an inner cavity of the variable valve body (34) in a sliding fit mode, the variable piston (35) is connected with a pump swash plate (16) through a sliding block (33) and a connecting block (32), a first servo variable mechanism control port (34-1) and a second servo variable mechanism control port (34-2) are arranged on the variable valve body (34), and the first servo variable mechanism control port (34-1) and the second servo variable mechanism control port (34-2) are respectively communicated with two cavities of the variable piston (35);

the pump main shaft (12) and the motor main shaft (6) are rotatably arranged in a cavity on one side inside the shell (1), wherein the pump main shaft (12) is connected with a pump cylinder body (13) in a key mode, the motor main shaft (6) is connected with a motor cylinder body (9) in a key mode, a plurality of plunger holes are formed in the pump cylinder body (13), a pump plunger (11) is arranged in each plunger hole in a matched mode, a pump plunger spring (10) is arranged in an inner cavity of the pump plunger (11), one end of each pump plunger spring (10) is tightly propped against a closing-in portion of the axial end portion of the inner cavity of the pump plunger (11), the other end of each pump plunger spring is tightly pressed on the pump cylinder body (13), a pump swash plate (16) is further sleeved on the motor main shaft (6), a pump thrust plate (17) is arranged in a cavity on one side, close to the pump cylinder body (13), of the pump swash plate (16) is provided, a pump valve plate (14) is arranged on the pump main shaft (12) in a fitting manner corresponding to the axial outer end face of the pump cylinder body (13), an oil supplementing pump (19) is further mounted on the shell (1), and the oil supplementing pump (19) is driven by the pump main shaft (12);

a valve sleeve (43) is arranged in the mechanical servo valve (18), a valve core (42) is arranged in the valve sleeve (43), a valve core groove (42-3) is arranged in the middle of the valve core (42), a feedback rod (44) is arranged on the valve sleeve (43) along the radial direction of the valve core (42), the servo valve body (47) is provided with a P oil inlet, an R oil return port, a first mechanical servo valve control port (47-1) and a second mechanical servo valve control port (47-2), the servo valve body (47) is provided with a first mechanical servo valve control port (47-1) and a second mechanical servo valve control port (47-2), the first mechanical servo valve control port (47-1) is communicated with the first servo variable mechanism control port (34-1), and the second mechanical servo valve control port (47-2) is communicated with the second servo variable mechanism control port (34-2).

2. The hydrostatic continuously variable transmission of claim 1, wherein: set up adjusting screw (39) in the centre bore of variable piston (35), first spring (37) are established to adjusting screw (39) go up the cover, set up first spring holder (36), spring cap (38) respectively corresponding to the axial both ends of first spring (37) on adjusting screw (39), and spring cap (38) are fixed in the axial outer end of variable piston (35) inner chamber, and first spring holder (36) paste the inner chamber baffle setting of tight variable piston (35).

3. The hydrostatic continuously variable transmission of claim 1, wherein: still rotate in the one side cavity in casing (1) and set up motor main shaft (6), key joint motor cylinder body (9) on motor main shaft (6), set up a plurality of plunger holes on motor cylinder body (9), set up one motor plunger (2) respectively in every corresponding plunger hole, set up motor plunger spring (3) in the inner chamber of motor plunger (2), the axial one end top of motor plunger spring (3) is tightly in the axial closing part of motor plunger (2), the axial other end of motor plunger spring (3) compresses tightly on motor cylinder body (9), set up motor valve plate (4) on motor main shaft (6) corresponding to the axial outside terminal surface of motor cylinder body (9), still set up motor thrust plate (24) on motor main shaft (6), motor thrust plate (24) surface laminating sets up motor boots (25), motor boots (25) are connected with motor plunger (2).

4. The hydrostatic continuously variable transmission of claim 3, wherein: one axial end of the motor spindle (6) is rotatably supported through the needle roller bearing (5), and the other axial end of the motor spindle is rotatably supported through the cylindrical roller bearing.

5. The hydrostatic continuously variable transmission of claim 3, wherein: the motor valve plate (4) is uniformly provided with a plurality of motor oil distribution windows in a circumferential shape.

6. The hydrostatic continuously variable transmission of claim 1, wherein: one end of the pump main shaft (12) close to the oil supplementing pump (19) is rotatably supported through a cylindrical roller bearing (20).

7. The hydrostatic continuously variable transmission of claim 1, wherein: a low-pressure overflow valve (15) is arranged in the shell (1) corresponding to the upper part of the pump cylinder body (13).

8. The hydrostatic continuously variable transmission of claim 1, wherein: the pump valve plate (14) is uniformly provided with a plurality of pump oil distribution windows in a circumferential shape.

9. The hydrostatic continuously variable transmission of claim 1, wherein: the axial outer end of the valve core (42) is connected with a handle (46), an adjusting screw (45) is further arranged on the servo valve body (47), the lower end of the adjusting screw (45) is connected with the feedback rod (44), a second spring seat (48) is further arranged on the servo valve body (47), a second spring (49) is arranged on the second spring seat (48), and the second spring (49) is tightly pressed on the spring seat (48).

Technical Field

The invention belongs to the technical field of agricultural harvesting equipment, and relates to a hydrostatic stepless speed change device.

Background

In the field of the current small-sized agricultural harvesting machinery, such as rice harvesters, corn harvesters and the like, the installation space is small, so that the hydraulic stepless speed change device is not provided with a servo variable mechanism and a mechanical servo valve, and the defect that the operation of a user is laborious and can not meet the requirements of the domestic agricultural machinery market is overcome.

Disclosure of Invention

The hydrostatic stepless speed change device adopts a servo variable mechanism and a mechanical servo valve, and can meet the market demand of using the hydrostatic transmission device.

According to the technical scheme of the invention: a hydrostatic continuously variable transmission, characterized by: the servo variable mechanism is arranged on the shell, and the mechanical servo valve is connected with the servo variable mechanism through an oil way so as to control the forward and backward movement of a variable piston of the servo variable mechanism;

the servo variable mechanism comprises a variable valve body, a variable piston is arranged in an inner cavity of the variable valve body in a sliding fit mode, the variable piston is connected with a pump swash plate through a sliding block and a connecting block, a first servo variable mechanism control port and a second servo variable mechanism control port are arranged on the variable valve body, and the first servo variable mechanism control port and the second servo variable mechanism control port are respectively communicated with two cavities of the variable piston;

a pump main shaft and a motor main shaft are rotatably arranged in a cavity on one side inside the shell, wherein the pump main shaft is in key connection with a pump cylinder body, the motor main shaft is in key connection with a motor cylinder body, the pump cylinder body is provided with a plurality of plunger holes, a pump plunger is respectively matched and arranged in each plunger hole, a pump plunger spring is arranged in an inner cavity of the pump plunger, one end of the pump plunger spring is tightly pressed against a closing-in part at the axial end part of the inner cavity of the pump plunger, the other end of the pump plunger spring is tightly pressed on the pump cylinder body, the motor main shaft is further sleeved with a pump swash plate, a pump thrust plate is arranged in the cavity on one side of the pump swash plate, which is close to the pump cylinder body, the surface of the thrust plate is attached with a plurality of pump sliding shoes, the pump sliding shoes are connected with the pump plunger, a pump;

the servo valve comprises a mechanical servo valve body, a valve sleeve, a valve core groove, a feedback rod, a P oil inlet, an R oil return port, a first mechanical servo valve control port and a second mechanical servo valve control port, wherein the valve sleeve is arranged in the mechanical servo valve, the valve core groove is arranged in the middle of the valve core, the feedback rod is radially installed on the valve sleeve along the valve core, the servo valve body is provided with the P oil inlet, the R oil return port, the first mechanical servo valve control port and the second mechanical servo valve control port are arranged on the servo valve body, the first.

As a further improvement of the invention, an adjusting screw rod is arranged in a central hole of the variable piston, a first spring is sleeved on the adjusting screw rod, a first spring seat and a spring cover are respectively arranged on the adjusting screw rod corresponding to the two axial ends of the first spring, the spring cover is fixed at the outer axial end of the inner cavity of the variable piston, and the first spring seat is arranged close to the inner cavity partition plate of the variable piston.

As a further improvement of the invention, a motor spindle is further rotatably arranged in a cavity on one side in the housing, a motor cylinder body is connected to the motor spindle through a key, a plurality of plunger holes are arranged on the motor cylinder body, a motor plunger is respectively arranged in each corresponding plunger hole, a motor plunger spring is arranged in an inner cavity of the motor plunger, one axial end of the motor plunger spring is tightly pressed against an axial closing part of the motor plunger, the other axial end of the motor plunger spring is tightly pressed on the motor cylinder body, a motor valve plate is arranged on the motor spindle corresponding to the axial outer side end face of the motor cylinder body, a motor thrust plate is further arranged on the motor spindle, a motor sliding shoe is arranged on the surface of the motor thrust plate in an attaching manner, and the motor sliding shoe is connected with the motor plunger.

As a further improvement of the present invention, one axial end of the motor main shaft is rotatably supported by a needle bearing, and the other axial end is rotatably supported by a cylindrical roller bearing.

As a further improvement of the invention, the motor port plate is uniformly provided with a plurality of motor oil distribution windows in a circumferential shape.

As a further improvement of the invention, one end of the pump main shaft close to the oil replenishing pump is rotatably supported by a cylindrical roller bearing.

As a further improvement of the invention, a low-pressure relief valve is arranged in the housing corresponding to the upper part of the pump cylinder body.

As a further improvement of the invention, the pump port plate is uniformly provided with a plurality of pump oil distribution windows in a circumferential shape.

As a further improvement of the invention, the axial outer end of the valve core is connected with a handle, the servo valve body is also provided with an adjusting screw, the lower end of the adjusting screw is connected with the feedback rod, the servo valve body is also provided with a second spring seat, the second spring seat is provided with a second spring, and the second spring is tightly pressed on the spring seat.

The invention has the technical effects that: the product of the invention has reasonable and ingenious structure, the position of the oil supplementing pump adopts a mode of directly connecting the shaft and the rotor pair, the spline is cancelled, the assembly is simplified, and the cost can be effectively reduced; the casing is provided with a servo variable mechanism and a mechanical servo valve, so that stepless speed change is facilitated.

Drawings

FIG. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a sectional view taken along line a-a in fig. 1.

Fig. 3 is an axial end view of the present invention.

Fig. 4 is a front view of the pump port plate.

Fig. 5 is a front view of the motor port plate.

Fig. 6 is a schematic structural view of a valve body flow passage.

Fig. 7 is a schematic structural diagram of a servo variable mechanism.

Fig. 8 is a sectional view taken along line B-B in fig. 7.

Fig. 9 is a schematic end view of a variable valve body.

Fig. 10 is a schematic view of a mechanical servo valve.

Fig. 11 is an M-direction view of fig. 10.

Fig. 12 is a sectional view taken along line C-C in fig. 10.

Fig. 13 is a cross-sectional view taken along line D-D of fig. 10.

Fig. 14 is a front view of the valve cartridge.

Detailed Description

The following further describes embodiments of the present invention with reference to the drawings.

In fig. 1 to 14, the variable displacement pump includes a housing 1, a motor plunger 2, a motor plunger spring 3, a motor port plate 4, a needle bearing 5, a motor spindle 6, an oil seal 7, a valve body 8, a motor cylinder 9, a pump plunger spring 10, a pump plunger 11, a pump spindle 12, a pump cylinder 13, a pump port plate 14, a low-pressure relief valve 15, a pump swash plate 16, a pump thrust plate 17, a mechanical servo valve 18, an oil replenishment pump 19, a cylindrical roller bearing 20, a flat key 21, a servo variable mechanism 22, a pump shoe 23, a motor thrust plate 24, a motor shoe 25, a left end cover 26, a first needle bearing 27, a screw 28, a positioning pin 29, a second needle bearing 30, an end cover 31, a connecting block 32, a slider 33, a variable valve body 34, a first servo variable mechanism control port 34-1, a second servo variable mechanism control port 34-2, a variable piston 35, a first spring seat 36, a first spring 37, a second needle bearing, The valve core structure comprises a spring cover 38, an adjusting screw rod 39, a left cover plate 40, a locking nut 41, a valve core 42, a valve core groove 42-3, a valve sleeve 43, a feedback rod 44, an adjusting screw 45, a handle 46, a servo valve body 47, a second spring seat 48, a second spring 49 and the like.

As shown in fig. 1, the present invention is a hydrostatic continuously variable transmission, including a housing 1, a servo variable mechanism 22 and a mechanical servo valve 18 are mounted on the housing 1, and the mechanical servo valve 18 is connected to the servo variable mechanism 22 through an oil path to control the forward and backward movement of a variable piston 35 of the servo variable mechanism 22.

As shown in fig. 7 to 9, the servo variable mechanism 22 includes a variable valve body 34, a variable piston 35 is disposed in an inner cavity of the variable valve body 34 in a sliding fit manner, the variable piston 35 is connected to the pump swash plate 16 through a slider 33 and a connecting block 32, the connecting block 32 is positioned with the pump swash plate 16 through a positioning pin 29, the connecting block 32 is fastened to the pump swash plate 16 through a screw 28, one end of the pump swash plate 16 is rotatably supported on the left end cover 26 through a first needle bearing 27, the other end of the pump swash plate 16 is rotatably supported on the end cover 31 through a second needle bearing 30,

the variable valve body 34 is provided with a first servo variable mechanism control port 34-1 and a second servo variable mechanism control port 34-2, and the first servo variable mechanism control port 34-1 and the second servo variable mechanism control port 34-2 are respectively communicated with two cavities of the variable piston 35.

A pump main shaft 12 and a motor main shaft 6 are rotatably arranged in a cavity at one side inside the shell 1, wherein the pump main shaft 12 is connected with a pump cylinder body 13 through a key, the motor main shaft 6 is connected with a motor cylinder body 9 through a key, a plurality of plunger holes are arranged on the pump cylinder body 13, a pump plunger 11 is respectively arranged in each plunger hole in a matching way, a pump plunger spring 10 is arranged in the inner cavity of the pump plunger 11, one end of the pump plunger spring 10 is tightly pressed against the closing-in part of the axial end part of the inner cavity of the pump plunger 11, the other end is tightly pressed on the pump cylinder body 13, the motor spindle 6 is also sleeved with a pump swash plate 16, a pump thrust plate 17 is arranged in the cavity of one side of the pump swash plate 16 close to the pump cylinder body 13, the surface of the thrust plate 17 is attached with a plurality of pump sliding shoes 23, the pump piston shoes 23 are connected with the pump plunger 11, the pump main shaft 12 is provided with a pump port plate 14 corresponding to the outer axial end face of the pump cylinder body 13 in an attaching mode, the shell 1 is further provided with an oil supplementing pump 19, and the oil supplementing pump 19 is driven by the pump main shaft 12.

As shown in fig. 10 to 14, a valve sleeve 43 is disposed inside the mechanical servo valve 18, a valve core 42 is disposed inside the valve sleeve 43, a valve core groove 42-3 is disposed in the middle of the valve core 42, a feedback rod 44 is radially mounted on the valve sleeve 43 along the valve core 42, a P oil inlet and an R oil return port, a first mechanical servo valve control port 47-1 and a second mechanical servo valve control port 47-2 are disposed on the servo valve body 47, the servo valve body 47 is provided with a first mechanical servo valve control port 47-1 and a second mechanical servo valve control port 47-2, the first mechanical servo valve control port 47-1 is communicated with the first servo variable mechanism control port 34-1, and the second mechanical servo valve control port 47-2 is communicated with the second servo variable mechanism control port 34-2.

An adjusting screw rod 39 is arranged in a central hole of the variable piston 35, a first spring 37 is sleeved on the adjusting screw rod 39, a first spring seat 36 and a spring cover 38 are respectively arranged at two axial ends of the adjusting screw rod 39 corresponding to the first spring 37, the spring cover 38 is fixed at the outer axial end of an inner cavity of the variable piston 35, and the first spring seat 36 is arranged close to an inner cavity partition of the variable piston 35. The left end of the variable valve body 34 is fastened with a left cover plate 40, the adjusting screw 39 penetrates out of the left cover plate 40, and the outer end of the adjusting screw 39, which extends out of the left cover plate 40, is in threaded connection with a locking nut 41.

Still rotate in the cavity of one side in the casing 1 and set up motor spindle 6, key connection motor cylinder body 9 on the motor spindle 6, set up a plurality of plunger holes on the motor cylinder body 9, every corresponding plunger hole sets up a motor plunger 2 respectively, set up motor plunger spring 3 in the inner chamber of motor plunger 2, the axial one end top of motor plunger spring 3 is in the tight axial closing part in motor plunger 2, the axial other end of motor plunger spring 3 compresses tightly on motor cylinder body 9, set up motor valve plate 4 corresponding to the axial outside terminal surface of motor cylinder body 9 on the motor spindle 6, still set up motor thrust plate 24 on the motor spindle 6, motor thrust plate 24 surface laminating sets up motor slipper 25, motor slipper 25 is connected with motor plunger 2.

One axial end of the motor spindle 6 is rotatably supported by the needle roller bearing 5, and the other axial end is rotatably supported by the cylindrical roller bearing.

As shown in fig. 4 and 5, the motor port plate 4 is circumferentially and uniformly provided with a plurality of motor oil distribution windows, and the pump port plate 14 is circumferentially and uniformly provided with a plurality of pump oil distribution windows.

As shown in fig. 1, one end of the pump main shaft 12 close to the oil replenishment pump 19 is rotatably supported by a cylindrical roller bearing 20, and a low-pressure relief valve 15 is provided in the housing 1 above the pump cylinder 13.

As shown in fig. 10 and 13, the axial outer end of the valve core 42 is connected to a handle 46, an adjusting screw 45 is further provided on the servo valve body 47, the lower end of the adjusting screw 45 is connected to the feedback rod 44, a second spring seat 48 is further provided on the servo valve body 47, a second spring 49 is provided on the second spring seat 48, and the second spring 49 is pressed against the spring seat 48.

As shown in fig. 1 to 14, the working principle of the present invention is as follows: the pump main shaft 12 is driven by a prime mover to rotate the pump cylinder body 13, and due to the combined action of the pump swash plate 16, the pump thrust plate 17 and the pump plunger spring 10, the pump shoe 23 is always attached to the pump thrust plate 17, and the pump plunger 11 and the pump cylinder body 13 form a closed space. When the pump plunger 11 moves from the bottom dead center to the top dead center, the oil suction process is completed, otherwise, when the pump plunger 11 moves from the top dead center to the bottom dead center, the oil pressing process is completed, the hydraulic oil in the corresponding valve body flow passage (shown in figure 6) is sucked into the inner cavity of the pump plunger 11 through the oil distribution window (shown in figure 4) of the pump flow distribution plate 14 in the oil suction process, when the pump plunger 11 rotates to the other side, the oil pressing process is started, and the hydraulic oil is discharged through the kidney-shaped groove at the other end. Similarly, the hydraulic oil discharged from the pump side moves the motor plunger 2 from the bottom dead center to the top dead center, whereas the oil return process is completed when the motor plunger 2 moves from the top dead center to the bottom dead center. The low pressure oil sucked by the pump and the high pressure oil discharged by the pump are respectively connected with the kidney-shaped grooves at the two sides of the motor through valve body flow passages (figure 6), so that the motor plunger 2 is pushed under the action of hydraulic pressure to drive the motor cylinder body 9, and further the motor main shaft 6 rotates to output torque outwards. The above steps are that the pump main shaft 12 and the motor main shaft 6 respectively complete one rotation, and one oil absorption and oil discharge process is realized.

The variable valve body of the servo variable mechanism 22 is provided with a control port 1 and a control port 2 (figure 9) which are connected with the mechanical servo valve 8, and the control port 1 and the control port 2 are respectively connected with two cavities of a variable piston 35.

According to different opening directions of the mechanical servo valve, hydraulic oil enters a servo variable mechanism control port 1 or a servo variable mechanism control port 2 to push a variable piston to displace, and the angle of a pump swash plate 16 is changed through a sliding block 33 in the displacement process of the variable piston 35, so that the displacement of the pump is changed. When the variable piston 35 displaces, the feedback rod 44 is toggled to rotate, the oil circuit is closed, so that hydraulic oil stops entering the servo variable mechanism control port 1 or the servo variable mechanism control port 2, when the variable piston 35 stops displacing, the angle of the pump swash plate 16 stops changing, and the displacement of the hydraulic pump is kept unchanged.

As shown in fig. 10, in the initial state, the oil ports are not communicated with each other, and the variable piston two chambers (fig. 7 and 8) and the R oil return port are not communicated with each other. The clockwise rotation of the operating handle 46 can drive the valve core 42 to rotate the valve core 42 clockwise by an angle, so that the oil inlet P is communicated with the mechanical servo valve control port 1, and the oil passages of the mechanical servo valve control port 2 and the oil return port R (fig. 14). Hydraulic oil enters from the oil inlet P, flows into the control port 1 on the mechanical servo valve 18 through an oil path, enters the control port 2 of the servo variable mechanism 22 to enable the variable piston 35 to move leftwards, the variable piston 35 pushes the feedback rod 44 to rotate clockwise, and the valve sleeve 43 is pushed to rotate clockwise. When the valve sleeve 43 rotates, the valve sleeve 43 and the valve core 42 rotate by the same angle, and the oil path is closed.

In addition, spring cup 36 acts on valve core 42 via a spring force, and when handle 46 is released, spring 37 in spring cup 36 may return valve core 42.