KR100755885B1 - Swash plate hydrostatic transmission - Google Patents

Abstract

The present invention relates to a swash plate hydrostatic transmission, which provides an easy and fine adjustment of the inclination angle of the swash plate using hydraulic pressure to provide a swash plate hydrostatic transmission that can improve driving stability and comfort of the vehicle. There is a purpose.

According to the present invention for achieving the above object, the swash plate pump unit 110 driven by the input shaft 111 connected to the power source of the vehicle and the output shaft driven by the hydraulic oil pressure sent from the pump unit 110 ( Swash plate-type motor unit 140 having a swash plate that is configured to adjust the speed ratio by adjusting the inclination angle of at least one of the swash plate 123 provided in the pump unit 110 and the motor unit 140 In the hydrostatic transmission, the pump unit 110 and the motor unit 140, the housing 161 coupled to the outside of the main body 101 is provided; Installed in the housing 161 is moved in the longitudinal direction by the hydraulic pressure acting on both end surfaces thereof is connected to the eccentric portion of the rotation support shaft 125 of the swash plate 123 and the swash plate 123 according to the movement A movable body 170 which rotates about the rotation support shaft 125; A spool 180 installed to be movable in a longitudinal direction in an inner passage 175 formed as a space blocked from the outside in the movable body 170; And an operation means for causing the spool 180 to reciprocate by an operation force by a vehicle driver, wherein three or more grooves 172a, 172b, and 172c are formed in the inner passage 175 of the movable body 170. In the groove 172a located in the middle of the grooves 172a, 172b, and 172c, a hydraulic oil supply path 173 connected to the hydraulic oil source of the vehicle is formed, and grooves 172b and 172c located at both sides thereof. First and second communication paths (174a, 174b) are formed in each of which communicates to the outer space in the longitudinal side of both sides of the movable body 170, the spool 180 is to correspond to the grooves (172a, 172b, 172c) Two or more swash plate type is provided with a protrusion (181a 181b) to block the supply passage (173) and the first and second communication passages (174a, 174b) or selectively communicate with either of them depending on the position Hydrostatic transmission is provided.

Description

Swash plate hydrostatic transmission {SWASH PLATE TYPE HYDROSTATIC TRANSMISSION}

1 is a cross-sectional view showing the internal configuration of a conventional swash plate hydrostatic transmission.

Figure 2 is a front view showing one embodiment of a swash plate hydrostatic transmission in accordance with the present invention.

3 is a sectional view taken along the line A-A 'of the hydrostatic transmission of the present invention shown in FIG.

4 is a plan view of the present invention hydrostatic transmission shown in FIG.

5 is a detailed sectional view of an operation valve which is a main part of the present invention.

6 is a cross-sectional view taken along the line B-B 'of the operation valve shown in FIG.

7A to 7C are cross-sectional views taken along the line C-C ', showing an operating state of the operation valve shown in FIG.

<Description of the symbols for the main parts of the drawings>

101: main body 110: pump unit

111: input shaft 113, 145: cylinder block

114, 146: cylinder 115, 147: piston

123, 143: swash plate 124: swash plate

125: rotation support shaft 140: motor unit

160: operation valve 161: housing

167: supply pipe 170: movable body

171: supply groove 172a, 172b, 172c: groove

173: supply passage 174a, 174b: communication passage

175: inner passage 180: spool

181a, 181b: protrusion 183: locking groove

185: through passage 190: operating mechanism

191: lever 192: working shaft

193: connecting lever 194: hook axis

195: spring

The present invention relates to a hydrostatic transmission consisting of a swash plate piston pump and a swash plate piston motor. More specifically, the swash plate angle of the pump or motor can be finely manipulated with a small force. A swash plate hydrostatic transmission that can be increased.

In general, hydrostatic transmission (Hydraustatic Transmission) is provided as a continuously variable transmission for changing the driving state in a variety of construction equipment, such as excavators and all-electric vehicles such as agricultural machinery such as tractors.

The hydrostatic transmission transmits power through the working oil, and rotates the hydraulic pump by a power source such as an engine of the vehicle to convert the rotational power of the power source into the pressure energy of the working oil, which is then converted into the rotating power through the hydraulic motor. It converts and transfers it to the drive shaft for driving. Among these hydrostatic transmissions, the internal structure of the hydrostatic transmission consisting of a combination of a swash plate piston pump and a swash plate piston motor is shown in FIG. 1.

In the conventional swash plate type hydrostatic transmission shown in FIG. 2, the pump unit 20 and the motor unit 30 having a similar structure are installed in parallel in the casing 10, and the pump unit 20 passes through the swash plate 21. A cylinder block 23 having a plurality of cylinders 24 is coupled to the installed input shaft 22, and a piston 25 inserted into each cylinder 24 of the cylinder block 23 carries the shoe 26. When the input shaft 22 is rotated by an external driving source, the cylinder block 23 is rotated while the piston 25 is reciprocated according to the inclination angle of the swash plate 21. The hydraulic fluid in the cylinder 24 is sent to the motor unit 30, and the motor unit 30 is provided with a cylinder block 31 having a plurality of cylinders 32 into which the hydraulic oil fed from the pump unit 20 flows. ) Is coupled to the output shaft 33, the piston (34) inserted into each cylinder (32) is sliding on the swash plate (36) It consists of chokdoen structure while each piston along the interior of the cylinder 32, the hydraulic oil pressure 34, the reciprocating motion pushes the swash plate 36 to thereby rotate the output shaft 33.

In addition, the swash plate 21 of the pump unit 20 is rotatably installed about an axis perpendicular to the input shaft 22 to adjust the inclination angle of the swash plate 21 to adjust the input shaft 22 of the pump unit 20. ) And the output shaft 33 of the motor unit 30, that is, the speed ratio is changed.

In the swash plate type hydrostatic transmission, the piston 25 is strongly adhered to the swash plate 21 of the pump unit 20 in a state of receiving axial force by the high-pressure hydraulic fluid, so that the inclination angle of the swash plate 21 is adjusted. A strong force that can overcome the pressing force by the piston 25 is required. However, in the conventional hydrostatic transmission, an operating lever (not shown) operated by the driver is directly connected to a rotation shaft (not shown) of the swash plate 21 to adjust the inclination angle of the swash plate 21 through the operating lever. Because the structure is controlled by direct operating force, not only is it difficult to operate due to the large amount of force required for shifting, but also the speed of the vehicle may suddenly rise or fall due to the difficulty of detailed operation. There was a problem in that when the stop occurs, running stability and comfort very bad.

The present invention is to solve the problems as described above, the object of the present invention is to easily and finely adjust the inclination angle of the swash plate using the hydraulic pressure to improve the running stability and comfort of the vehicle swash plate type To provide hydraulic transmission.

According to the present invention for achieving the above object, it consists of a swash plate pump unit driven by an input shaft connected to a power source of the vehicle and a swash plate type motor unit having an output shaft driven by the hydraulic oil pressure discharged from the pump unit In the swash plate hydrostatic transmission to adjust the speed ratio by adjusting the inclination angle of at least one of the swash plate provided in the pump unit and the motor unit, the housing coupled to the outside of the body casing provided with the pump unit and the motor unit ; A movable body installed in the housing and moved in the longitudinal direction by hydraulic pressure acting on both end surfaces thereof and connected to an eccentric portion of the rotation support shaft of the swash plate to rotate the swash plate about the rotation support shaft according to the movement; A spool installed to be movable in a longitudinal direction in an inner passage formed as a space blocked from the outside in the movable body; And an operation means for reciprocating the spool by an operating force by a vehicle driver, wherein three or more grooves are formed in an inner passage of the movable body, and the grooves located in the middle of the grooves are provided with a hydraulic oil supply source of the vehicle. A hydraulic oil supply path is formed to be connected, and grooves located at both sides thereof are formed with first and second communication paths communicating with spaces on both sides of the movable body, respectively, and at least two spools are formed at portions corresponding to the grooves. A swash plate hydrostatic transmission is provided which is provided with this protrusion to block the supply passage from the first and second communication passages or to selectively communicate with either of them depending on its position.

In the swash plate-type hydrostatic transmission of the present invention as described above, one side of the outer peripheral surface of the movable body is formed with a hydraulic oil supply groove communicating with the supply passage in a longitudinal direction, and the housing has a hydraulic oil supply pipe at its lower end inside the supply groove. Can be installed to enter.

In addition, the rotational arm is coupled to the rotational support shaft of the swash plate, the shaft holder is rotatably coupled to the connecting shaft provided in the radially outer side of the rotational arm, the shaft holder is a guide groove formed in the transverse direction in the movable body The shaft holder may be configured to rotate the swash plate while moving in the longitudinal direction when the movable body is inserted in the shaft.

In addition, a through passage may be formed in the spool in a longitudinal direction so that the spool may be moved along an inner passage of the movable body without generating back pressure.

And, a locking groove for connecting with the operation means is formed on one side of the outer circumferential surface of the spool, the operation means is coupled to the operating shaft rotatably coupled to one side of the housing, the operating shaft coupled to the housing of the driver An operation lever rotated by the operation lever, a connection lever coupled to the housing inner portion of the operation shaft and extending radially with respect to the operation shaft, and coupled to one side of the connection lever and inserted into a locking groove of the spool to rotate the operation shaft. In accordance with this may be made of a structure including a hook axis for forward / backward in the longitudinal direction of the spool.

The objects, features and advantages of the present invention described above will become more apparent from the following detailed description. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 2 is a front view showing an embodiment of a swash plate hydrostatic transmission according to the present invention, Figure 3 is a cross-sectional view taken along the line A-A 'of the present invention hydrostatic transmission shown in Figure 2, Figure 4 is Top view of the hydrostatic transmission shown.

As shown in Figures 2 to 4, the hydrostatic transmission according to the present invention is a swash plate of the pump unit 110 on the outside of the main body 101 consisting of the swash plate pump unit 110 and the swash plate motor unit 140 A hydraulic operation valve 160 for adjusting the inclination angle is provided so that the operating force input through the operation lever 191 operated by the driver is transmitted through the operation valve 160 to easily adjust the inclination angle of the swash plate 123. It is to be done.

Referring to the configuration of the hydrostatic transmission of the present invention in more detail, the pump unit 110 and the motor unit 140 of the main body 101 is similar to the conventional one, in the illustrated embodiment of the pump unit 110 An example in which the input shaft 111 and the output shaft 141 of the motor unit 140 are installed in parallel to the main body 101 and the transmission ratio is changed by adjusting the inclination angle of the swash plate 123 provided in the pump unit 110. It was.

The cylinder blocks 113 and 145 are coupled to the input shaft 111 and the output shaft 141, respectively, and the pistons 115 and 147 are provided to the cylinders 114 and 146 provided in the cylinder blocks 113 and 145, respectively. The pistons 115 and 147 are interviewed via the shoes 117 and 149 on the swash plates 123 and 143 provided around the input shaft 111 and the output shaft 141. When rotated by the driving source, the cylinder block 113 of the pump unit 110 is rotated, and the hydraulic oil is discharged according to the reciprocating motion of the piston 115, and the hydraulic oil is discharged into each cylinder 146 of the motor unit 140. As the piston 147 reciprocates and is introduced into the swash plate 123, the swash plate 123 rotates to transmit power to the driving driver of the vehicle through the output shaft 141.

The swash plate 123 of the pump unit 110 is seated on the swash plate support 124 rotatably installed within a predetermined angle range around the rotation support shaft 125 in the direction orthogonal to the input shaft 111, the inclination angle According to the hydraulic oil delivery speed and the amount to be sent out, in the following description, the swash plate 123 and the swash plate support 124 will be referred to as the swash plate 123. The hydrostatic transmission of the present invention has a structure that indirectly adjusts the inclination angle of the swash plate 123 through the operation valve 160.

5 is a cross-sectional view showing an internal configuration of the operation valve 160, FIG. 6 is a cross-sectional view taken along the line B-B 'of FIG. 5, and FIGS. 7A to 7C are cross-sectional views taken along the line C-C' of FIG. The operating state of 160 is shown.

As shown, the operation valve 160 is reciprocated by a housing 161 coupled to the outside of the main body 101 and a hydraulic vehicle installed inside the housing 161 and acting on both sides in the longitudinal direction. A movable body 170, a spool 180 provided in the movable body 170 so as to reciprocate in the longitudinal direction, and an operation mechanism for causing the spool 180 to reciprocate by an operating force by a vehicle driver ( 190).

A first communication port 163 for connecting the movable body 170 and the swash plate 123 is formed at one side of the side wall portion of the housing 161, and the spool 180 is opposite to the first communication port 163. ) And a second communication port 165 for the connection of the operation mechanism 190 is formed. In addition, a supply pipe 167 for supplying hydraulic oil into the housing 161 is coupled through the side wall of the housing 161. The supply pipe 167 is connected to the hydraulic pump line of the vehicle through the inside of the main body 101 or through an external conduit so as to supply the hydraulic oil at a predetermined pressure.

The movable body 170 is in the form of a cylindrical valve body reciprocating in the housing 161, the hydraulic oil supply groove 171 is formed long in the longitudinal direction on one side of the outer peripheral surface. The supply groove 171 is where the lower end of the supply pipe 167 is inserted, and forms a supply passage for the hydraulic oil, and at the same time, the movable body 170 is moved within the housing 161 by the lower end of the supply pipe 167. As a linear motion is possible but rotation is prevented. An inner sidewall portion of the supply groove 171 is provided with a supply passage 173 for supplying hydraulic oil into the movable body 170. The inner passage 175 of the movable body 170 in which the spool 180 is installed forms a space separated from the outside, and for this purpose, a blocking cap 176 and a sealing 177 are installed at both inlet portions, and the blocking The cap 176 is fixed so as not to be separated by the snap ring-type fixing ring 178 inserted into the fixing groove 179. Grooves (hereinafter, divided into first to third grooves 172a, 172b, and 172c) are formed in at least three places on the inner circumferential surface of the inner passage 175 of the movable body 170, which is located in the center The first and second communication lines 173 communicate with the first grooves 172a, and the second and third grooves 172b, 172c on both sides thereof communicate with both end surfaces of the movable body 170, respectively. Furnaces 174a and 174c are formed.

In addition, as a means for rotating the swash plate 123 in accordance with the movement of the movable body 170, the rotary arm 131 is coupled to the rotation support shaft 125 of the swash plate 123, this pivot arm 131 The shaft holder 135 is rotatably coupled to the connecting shaft 133 provided on the radially outer side of the shaft, and the shaft holder 135 is inserted into the guide groove 178 formed laterally in the movable body 170. When the movable body 170 is moved in the longitudinal direction, the shaft holder 135 moves in the lateral direction in the guide groove 178 while the swash plate 123 is rotated about the rotation support shaft 125 through the pivoting arm 131. It can be configured to rotate.

The spool 180 may block the supply passage 173 from the first and second communication passages 174a and 174b or selectively communicate with either one, depending on its position. At least two protrusions (hereinafter, divided into first and second protrusions 181a and 181b) having a width greater than the grooves 172a, 172b and 172c at positions corresponding to the grooves 172a, 172b and 172c It is formed in an annular shape, the engaging groove 183 for the connection with the operation mechanism 190 is formed on one side of the outer circumference. In addition, the through passage 185 is formed therein in the longitudinal direction so as to be freely moved along the inner passage 175 of the movable body 170 without the occurrence of back pressure.

The operation mechanism 190 is a means for moving the spool 180 forward or backward by a driver's operating force. In the illustrated embodiment, the operation mechanism 190 rotates the operation lever 191 to move the spool 180. Illustrated. The illustrated operation mechanism 190 includes a fixed plate 168 coupled to the outside of the second communication port 165 of the housing 161, and an operating shaft 192 rotatably coupled to the fixed plate 168. , The operation lever 191 coupled to the outer portion of the housing 161 of the operating shaft 192 and rotated by the driver, and the operating shaft 192 coupled to the inner portion of the housing 161 of the operating shaft 192. The coupling lever 193 extending in the radial direction with respect to the) and coupled to one side of the connecting lever 193 and inserted into the engaging groove 183 of the spool 180, according to the rotation of the operating shaft 192 A hook shaft 194 for forwarding / reversing the spool 180 in the longitudinal direction, a spring 195 installed to apply an elastic restoring force with respect to the rotational direction of the operating shaft 192, and both ends of the spring 195; It consists of a support (196) coupled to the fixing plate 168 to support.

Referring to the swash plate angle adjustment process by the operation valve in the hydrostatic transmission according to the present invention configured as described above are as follows.

As shown in FIG. 7A, when the first and second protrusions 181a and 181b of the spool 180 are positioned in the second and third recesses 172b and 172c of the movable body 170, the supply path 173. ) And the connection between the first communication path (174a) and the second communication path (174b) is blocked so that the supply of the hydraulic oil through the supply path 173 is not made, the movable body 170 to achieve a neutral state without movement do.

In this state, when the driver pushes or pulls the operation lever 191 to rotate the operating shaft 192, the hook shaft 194 is rotated so that the spool 180 moves along the inner passage 175 of the movable body 170. For example, when the spool 180 is moved to the position shown in FIG. 7B, the connection between the supply path 173 and the first communication path 174a is performed by the first protrusion 181a of the spool 180. While the blocked state is maintained, the supply passage 173 and the second communication passage 174b which are blocked by the second protrusion 181b communicate with each other, and the supplied hydraulic oil flows out of one side end surface of the movable body 170. It becomes possible. Accordingly, the movable body 170 is moved along the inside of the housing 161 by the hydraulic oil pressure applied thereto, thereby rotating the rotary support shaft 125 through the shaft holder 135 and the pivot arm 131 to allow the swash plate 123 to move. Tilt) in the corresponding direction. Since the movable body 170 is also moved while the swash plate 123 is rotated, when the swash plate 123 is rotated by a predetermined angle, as shown in FIG. 7C, both side protrusions 181a and 181b of the spool 180 are rotated. The connection between the supply path 173 and the first and second communication paths 174a and 174b is again blocked to stop the rotation of the swash plate 123.

In addition, when the operation lever 191 is operated in the opposite direction, the supply path 173 and the first communication path 174a communicate with each other so that the hydraulic oil is supplied in the opposite direction, and thus the movable body 170 in the opposite direction to the above-described process. Is moved so that the swash plate 123 is rotated in the opposite direction.

As described above, the hydrostatic transmission of the present invention does not rotate the swash plate 123 directly by the operating force of the operating lever 191, the hydraulic pressure is applied only through the operating lever 191 to move the spool 180 Since the swash plate 123 is rotated by, the operation lever 191 for adjusting the inclination angle of the swash plate 123 is very easy to operate, and the manipulation lever 191 is finely operated to finely control the swash plate 123. Since the angle of inclination can be finely adjusted, sudden shifting, sudden start and stop of the vehicle can be prevented, thereby improving driving stability and comfort.

On the other hand, when the hydraulic oil is supplied through the supply path 173 to one side of the space of the movable body 170 inside the housing 161 as described above, the operating oil in the opposite space so that the movable body 170 can be moved As a means for draining, the relief valves 162a and 162b are installed on both cover plates 161a and 161b of the housing 161, respectively. The relief means is not limited to the illustrated structure, and when the pressure is greater than or equal to a predetermined pressure, it may be made of a variety of conventional valve structures that can communicate the interior space of the housing 161 to the hydraulic oil tank side, and the pipeline outside the housing 161. It can also be connected via installation.

In addition, in the above-described embodiment, the structure of adjusting the inclination angle of the swash plate 123 provided in the pump unit 110 is illustrated, but the structure of adjusting the inclination angle of the swash plate 143 provided in the motor unit 140. Of course, the present invention can be applied to the hydrostatic transmission of.

In addition, as an example of the operating means for the driver to move the spool 180 by operating the rotational structure provided with the operating lever 191, the connecting lever 193, the hook shaft 194, etc. The present invention is not limited thereto, and any operation means having a conventional structure capable of moving the spool 180 by mechanically transmitting a driver's operating force is possible. For example, on the outer side of the member similar to the hook shaft 194, instead of the connection lever 193 and the operation lever 191, a manipulation stick or an operation handle which is linearly moved by a driver is combined. It may be.

The present invention described above is not limited to the above-described embodiment and the accompanying drawings, and various substitutions, modifications, and changes are possible within the scope without departing from the technical spirit of the present invention. It will be evident to those who have knowledge of.

As described above, according to the present invention, the swash plate is rotated while the movable body is moved by the pressure of the hydraulic oil supplied according to the movement of the spool, the inclination angle of the swash plate can be adjusted with a small force for moving the spool, so that the vehicle shifts. It is easy to operate, and prevents sudden starting, stopping and shifting of the vehicle through precise and fine operation, thereby improving driving stability and comfort.

Claims (5)

A swash plate type motor unit 140 having a swash plate type pump unit 110 driven by an input shaft 111 connected to a power source of the vehicle and an output shaft 141 driven by hydraulic oil pressure discharged from the pump unit 110. In the swash plate type hydrostatic transmission to adjust the speed ratio by adjusting the inclination angle of at least one of the swash plate 123 provided in the pump unit 110 and the motor unit 140, A housing 161 coupled to the outside of the main body 101 provided with the pump unit 110 and the motor unit 140; Installed in the housing 161 is moved in the longitudinal direction by the hydraulic pressure acting on both end surfaces thereof is connected to the eccentric portion of the rotation support shaft 125 of the swash plate 123 and the swash plate 123 according to the movement A movable body 170 which rotates about the rotation support shaft 125; A spool 180 installed to be movable in a longitudinal direction in an inner passage 175 formed as a space blocked from the outside in the movable body 170; And It includes operating means for reciprocating the spool 180 by the operating force by the vehicle driver, Three or more grooves 172a, 172b, and 172c are formed in the inner passage 175 of the movable body 170, and the grooves 172a located in the middle of the grooves 172a, 172b, and 172c are hydraulic oils of the vehicle. A hydraulic oil supply path 173 connected to the supply source is formed, and the first and second communication paths 174a, 174a, which communicate with the grooves 172b and 172c positioned at both sides thereof, respectively, to the outer space of the longitudinal side on both sides of the movable body 170. 174b) and two or more protrusions 181a and 181b are provided to correspond to the grooves 172a, 172b, and 172c. A swash plate hydrostatic transmission adapted to block or selectively communicate with either of the second communication paths (174a, 174b). The method of claim 1, A hydraulic oil supply groove 171 communicating with the supply path 173 is formed in the longitudinal direction on one side of the outer circumferential surface of the movable body 170, and a hydraulic oil supply pipe 167 is provided at the lower end of the housing 161. Swash plate hydrostatic transmission installed to enter the groove (171). The method of claim 1, The rotation arm 131 is coupled to the rotation support shaft 125 of the swash plate 123, and the shaft holder 135 is rotatable on the connecting shaft 133 provided on the radially outer side of the rotation arm 131. The shaft holder 135 is inserted into the guide groove 178 formed in the transverse direction in the movable body 170 so that the shaft holder 135 is the guide groove 178 when the movable body 170 is moved in the longitudinal direction. Swash plate-type hydrostatic transmission to rotate the swash plate 123 while moving in the transverse direction. The method according to any one of claims 1 to 3, A swash plate type hydrostatic transmission in which the through passage 185 is formed in the longitudinal direction to be moved along the inner passage 175 of the movable body 170 without generating back pressure inside the spool 180. The method according to any one of claims 1 to 3, A locking groove 183 is formed at one side of the outer circumferential surface of the spool 180 for connection with the operation means. The operation means includes an operating shaft 192 rotatably coupled to one side of the housing 161 and an operating lever 191 coupled to an outer portion of the housing 161 of the operating shaft 192 and rotated by a driver. And a coupling lever 193 coupled to an inner portion of the housing 161 of the operation shaft 192 and extending in a radial direction with respect to the operation shaft 192, and coupled to one side of the connection lever 193. Hydrostatic transmission including a hook shaft (194) is inserted into the locking groove (183) of the spool (180) to forward / backward in the longitudinal direction of the spool (180) in accordance with the rotation of the operating shaft (192).

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