KR100898028B1 - Variable hydraulic pump - Google Patents

Abstract

The present invention relates to a variable hydraulic pump, a low pressure pump; A high pressure pump connected to the low pressure pump and configured to discharge the pumped oil from the pump at high pressure; The oil pumped to the low pressure pumping part is supplied to the high pressure pumping part, the oil pumped from the high pressure pumping part is supplied to the hydraulic device side, and a part of the low pressure oil supplied from the low pressure pumping part to the high pressure pumping part is If the oil pressure supplied from the high pressure pump to the hydraulic device is greater than the set pressure, the oil supplied to the hydraulic device is recovered to the oil tank, and the oil of the high pressure pump is not supplied to the high pressure pump. The low pressure pump, the high pressure pump, the relief valve is connected to the hydraulic device so that when the high pressure pumped by the hydraulic device, the excess oil pumped from the low pressure pump to the high pressure pump is recovered to the oil tank.

Therefore, it is possible to perform low pressure pumping and high pressure pumping with one pump, and during low pressure pumping, some of the hydraulic pressure is directly supplied to the hydraulic device without passing through the high pressure pumping part, and when the hydraulic device is overloaded, a part of the oil discharged to the oil outlet Is returned to the oil tank, and when the hydraulic system is overloaded, excess oil flowing into the oil inlet is recovered to the oil tank.

Low pressure pump, high pressure pump, pump body assembly, relief valve, valve body

Description

Variable hydraulic pump

The present invention relates to a variable hydraulic pump, and more particularly, it is possible to perform low pressure pumping and high pressure pumping with one pump, and during low pressure pumping, some of the hydraulic pressure is directly supplied to the hydraulic device without passing through the high pressure pumping unit. If the overload is not only part of the oil discharged to the oil outlet is recovered to the oil tank, but when the hydraulic device is overloaded, it relates to a variable hydraulic pump in which excess oil flowing into the oil inlet is recovered to the oil tank.

As is well known, the hydraulic pump is a device for converting mechanical energy supplied from the outside into pressure energy of the working oil of the hydraulic system. Such a hydraulic pump has a gear type for pressurizing by using a gap between a pair of rotating gears, a vane type for compressing hydraulic fluid using a vane connected coaxially with a rotating shaft, and a plurality of cylinders installed vertically or in parallel. There is a rotary piston type in which the volume is made smaller according to the rotational direction of the rotating shaft, and a reciprocating piston type in which the hydraulic oil in the cylinder is pressurized by a piston by converting the rotary motion into a linear reciprocating motion.

These hydraulic pumps are connected to hydraulic devices, including legendary tools, hydraulic rams, which open or pull narrowed gaps, and hydraulic spreaders, which are used to cut or deploy obstacles underwater or on the ground. Will be supplied.

For example, when lifting a heavy object by operating a cylinder rod of a hydraulic device that requires high pressure, a large amount of low pressure oil is supplied to the hydraulic device until the cylinder rod is in contact with the heavy material, so the cylinder rod in a no-load state is rapidly moved to the heavy material side. You have to. When the cylinder rod is rapidly advanced by the low pressure pumping and comes into contact with the heavy material, the low pressure pumping does not lift the heavy material. In this case, the oil of high pressure is supplied little by little to the hydraulic device side, so that the weight is slowly lifted.

However, such a conventional hydraulic pump is made of only one low pressure pump or a high pressure pump, and the low pressure pump and the high pressure pump is not made at the same time does not operate the hydraulic device efficiently.

 That is, the low pressure pump has the advantage of quickly operating the cylinder rod of the hydraulic device in the no-load state, but the driving force of the hydraulic device is greatly reduced, there is a problem that can not lift the weight. While the high pressure pump greatly improves the driving force of the hydraulic device, the feed speed until the cylinder rod is in contact with the heavy material is very slow, which lowers the working efficiency.

An object of the present invention for solving the above problems is to provide a variable hydraulic pump that can perform a low pressure pump and a high pressure pump with one pump.

It is another object of the present invention to provide a variable hydraulic pump that allows some of the hydraulic pressure to be supplied directly to the hydraulic device without passing through the high pressure pumping part.

Still another object of the present invention is to provide a variable hydraulic pump that allows a part of oil discharged to the oil outlet to be recovered to the oil tank when the hydraulic device is overloaded.

Still another object of the present invention is to provide a variable hydraulic pump that allows excess oil flowing into the oil inlet to be recovered to the oil tank when the hydraulic device is overloaded.

Variable hydraulic pump of the present invention for achieving the above object, the drive motor; A drive shaft connected to the drive motor and receiving power therefrom; A low pressure pump connected to a lower end of the drive shaft and driven by the power transmitted therefrom for sucking and pumping oil in the oil tank; A high pressure pump connected to the drive shaft and driven by the power transmitted therefrom and connected to the low pressure pump to pump back oil pumped therefrom to discharge the oil at high pressure; The oil pumped to the low pressure pumping part is supplied to the high pressure pumping part, the oil pumped from the high pressure pumping part is supplied to the hydraulic device side, and a part of the low pressure oil supplied from the low pressure pumping part to the high pressure pumping part is If the oil pressure supplied from the high pressure pump to the hydraulic device is greater than the set pressure, the oil supplied to the hydraulic device is recovered to the oil tank, and the oil of the high pressure pump is not supplied to the high pressure pump. And a relief valve connected to the low pressure pump, the high pressure pump, and a hydraulic device such that oil pumped from the low pressure pump to the high pressure pump is recovered to the oil tank when the high pressure pump is performed by the hydraulic device. Characterized in that made.

One feature of the variable hydraulic pump of the present invention is that the drive shaft has a motor connection part connected to the motor shaft of the driving motor at one end, a low pressure pump connection part connected to the low pressure pump part at the other end, and operating the high pressure pump part on the shaft. High pressure pump eccentric cam is formed.

Another characteristic of the variable hydraulic pump of the present invention is that the high pressure pump unit is connected to the relief valve, and the pump lower housing for discharging and discharging oil supplied from the circumference of the high pressure pump unit, and installed in the upper portion of the pump lower housing A pump upper housing for discharging oil supplied from the pump lower housing to the oil outlet side of the relief valve, and one end connected to the pump upper housing and the other end connected to the oil outlet of the relief valve to discharge from the pump upper housing. A pipe for guiding oil to be supplied to the relief valve, and installed in an installation space between the pump lower housing and the pump upper housing and coupled to the high pressure pump eccentric cam of the drive shaft to supply oil introduced into the pump lower housing to the upper pump portion. Pumped into the housing and vice versa It consists of a pump body assembly that blocks the

Another characteristic of the variable hydraulic pump of the present invention is that the pump lower housing has an inlet through which the oil pumped from the low pressure pump unit is connected to the relief valve, and is connected to the inlet and the periphery of the pump lower housing. The oil is formed in a U-shape so that the oil flowing into the inlet side is diffused around the pump lower housing, the oil connected to the flow path and connected to the pump body assembly, and supplies the oil introduced into the flow path to the pump body assembly side. To the exit.

Another characteristic of the variable hydraulic pump of the present invention is that the pump upper housing is connected to the pump body assembly and has an inlet through which oil is pumped therein, and a U-shaped shape around the pump upper housing connected to the inlet. A flow path is formed, an outlet connected to the flow path for discharging oil introduced therein, and a pipe hole connected to one end of the outlet and the pipe and discharged to the outlet side into a pipe.

Another feature of the variable hydraulic pump of the present invention is that the pump body assembly is coupled to the circumference of the pump lower housing and the upper pump housing and a case pipe for forming an installation space therebetween, and installed in the installation space and the An operating bearing coupled to the high pressure pump eccentric cam and an inlet and an outlet are respectively installed at four sides of the actuating bearing to supply oil flowing from the lower pump housing to the upper pump housing, and a pumping space is formed between the inlet and the outlet. A pump body connected to the cylinder chamber and inserted into the cylinder chamber of the pump body and having one end contacting the circumference of the actuating bearing so that the actuating bearing eccentrically moves straight along the cylinder chamber. While in motion, suction the inlet side oil of the pump body into the pumping space A spool for pumping oil in the pumping space to the outlet side of the pump body, a flange coupled to one end of the spool, and one end supported by the flange and the other end supported by the pump body, thereby being advanced by the operation bearing. It consists of a restoring spring that reverses.

Further features of the present invention, the variable hydraulic pump, the inlet and outlet of the pump body, the first check cap and the second check cap coupled to the inlet and outlet, respectively, the inside of the first check cap and the second check cap Is provided in the first steel ball and the second steel ball to open and close the inlet and outlet, and provided between the first check cap and the first steel ball, the second check cap and the second steel ball and A first check valve and a second check valve, each of which includes a first spring and a second spring, which elastically support a second steel ball toward the inlet and the outlet, are installed.

Another feature of the variable hydraulic pump of the present invention, the relief valve is connected to the outlet of the low-pressure pumping unit, the oil inlet through which the pumped oil flows, the high-pressure pumping unit and the hydraulic device is pumped from the outlet An oil outlet for supplying oil to the hydraulic device, an inlet of the oil inlet and the high pressure pump, and a high pressure pump supply passage for supplying the oil inlet to the inlet of the oil inlet, and the oil inlet and the oil outlet; When the oil is connected to the oil tank and the oil is high pressure pumped to the hydraulic device side, the excess oil pumped to the oil inlet side is recovered to the oil tank, and if the pumping pressure of the oil outlet side is greater than the set pressure, some of the oil is the oil. An oil tank recovery flow path for returning to the tank, and the high pressure pump supply flow path and the oil outlet And a first connection passage through which some of the low pressure oil supplied from the low pressure pumping unit to the high pressure pumping unit is not supplied to the high pressure pumping unit but is supplied to the hydraulic device through the oil outlet, and the oil outlet and oil tank recovery passage. A second connection flow path connected to the second oil outlet to allow the oil outlet side oil supplied to the hydraulic device to be recovered to the oil tank when the oil pressure supplied from the high pressure pump to the hydraulic device is greater than a set pressure; Connected to an oil inlet and an oil tank recovery passage, such that when the oil of the high pressure pump part is pumped into the hydraulic device at a high pressure, excess oil flowing into the oil inlet side is recovered to the oil tank through the oil tank recovery passage. A valve body consisting of three connection flow paths; A ball provided at one end of the first connection channel connected to the oil outlet to open and close the first connection channel, and provided inside the oil outlet and supported at one end of the ball to direct the ball to the first connection channel side. A first opening / closing valve comprising an elastically supporting spring and a pressure adjusting bolt fastened to the valve body and supported at an end of the spring to adjust elasticity of the spring; A rod guide coupled to one end of a second connection passage connected to the oil tank recovery passage and having a through hole connected to the second connection passage at the center thereof, and a relief body fastened to the valve body so as to face the rod guide; And a relief rod coupled to the relief body to open and close the through hole of the rod guide, and provided inside the relief body and having one end supported by the relief rod so that one end of the relief rod is elastic to the rod guide. A second opening / closing valve comprising a relief spring configured to be supported by the relief spring, and a set screw fastened to the relief body and supported at an end of the relief spring to adjust elasticity of the relief spring; A ball which is provided at one end of the third connection passage connected to the oil tank recovery passage to open and close the third connection passage, a ball support shaft coupled to the valve body and supporting the ball, and on one side of the ball support shaft. A block fastened to the valve body to be positioned, a disc spring provided inside the block and having one end supported by the ball support shaft such that an end of the wing ball support shaft is elastically supported by the ball, and fastened to the block A third open / close valve made of a set screw supported at an end of the disk spring to adjust the elasticity of the disk spring; A spool installed so as to slide along the third connection passage and having an end supported by the ball of the third open valve, and provided at the oil outlet and having one end supported by the spool so that one end of the spool is elastic to the ball. Ball operation means made of a spring to be supported by, and a set screw fastened to the valve body and supported at the end of the spring to adjust the elasticity of the spring.

According to the present invention as described above, when the driving motor is driven, the low pressure pump and the high pressure pump are simultaneously driven, so that a large amount of low pressure oil is supplied to the hydraulic device to quickly drive the hydraulic device in a no-load state, and load the hydraulic device. When the high pressure pump is caught by the high-pressure oil is driven to drive the hydraulic device. Therefore, the low pressure pumping and the high pressure pumping are performed by one variable hydraulic pump, and the hydraulic device in the no-load state and the load state can be efficiently driven.

In the present invention, the oil of some of the various oils introduced into the high pressure pump supply passage through the oil inlet is discharged to the oil outlet through the first connection passage without being passed through the high pressure pumping portion and is supplied directly to the hydraulic device. Therefore, when supplying oil to the no-load hydraulic device at the beginning of the hydraulic supply, a large amount of low-pressure oil may be supplied to quickly operate the hydraulic device until the load is applied.

In addition, when the variable hydraulic pump of the present invention is overloaded, the oil pressure discharged to the oil outlet pushes the relief valve of the second opening / closing valve to open the second connection flow path, so that the excess oil discharged to the oil outlet is second. It enters the oil tank recovery channel through the connecting channel and is recovered to the oil tank. Therefore, it is possible to protect the variable hydraulic pump from being damaged since it is prevented from overloading the variable hydraulic pump of the present invention.

When the variable hydraulic pump is overloaded, the oil pressure discharged to the oil outlet pushes the spool of the ball operating means, and the third connection flow path is opened while the ball of the third opening / closing valve is pushed, and thus the oil at the low pressure pumping part is opened. Excess oil flowing into the inlet is recovered to the oil tank through the third connecting channel. Therefore, when the variable hydraulic pump of the present invention is overloaded, the excess oil flowing into the oil inlet is not supplied to the high pressure pump supply flow line and is immediately recovered to the oil tank, thereby protecting the variable hydraulic pump dually.

Specific features and advantages of the present invention will become more apparent from the following description with reference to the accompanying drawings.

1 is a schematic partial sectional view showing a hydraulic supply circuit leading to a low pressure pump, a relief valve, and a high pressure pump in an oil tank of the variable hydraulic pump of the present invention, and FIG. 2 is a schematic partial sectional view showing the bottom of FIG. 3 is a partially enlarged view of FIG. 1. Figures 4a to 4e is a view showing a pump lower housing, Figures 5a to 5e is a view showing a pump upper load housing, Figures 6a and 6b is a front view and a bottom view showing a drive shaft. 7A and 7B are schematic plan views and partial excerpt sectional views showing the pump body assembly, and FIGS. 8A to 8I are views showing the valve body. 9A to 9C are cross-sectional views illustrating a process in which low pressure pumping and high pressure pumping are performed through a relief valve, and FIG. 10 is a hydraulic device through an oil outlet of a relief valve of oil introduced into a pump upper housing of a high pressure pumping unit through a low pressure pumping unit. It is a schematic partial sectional view which shows the state supplied to.

The variable hydraulic pump of the present invention includes a drive motor 10, a low pressure pump 30, a high pressure pump 40, and a relief valve 110.

The drive shaft 20 is connected to the drive motor 10 and receives power therefrom, as shown in FIGS. 1, 3, 6A, and 6B. The driving shaft 20 has a motor connecting portion 21 connected to the motor shaft 11 of the driving motor 10 at one end thereof, a low pressure pump connecting portion 22 connected to the low pressure pumping portion 30 at the other end thereof, and an axial shape. The high pressure pump eccentric cam 23 is formed to operate the high pressure pump 40.

The low pressure pumping part 30 is connected to the lower end of the drive shaft 20 as shown in FIGS. 1 and 2, and is driven by the power transmitted therefrom to suck and pump oil in the oil tank 1. A filter 33 is connected to the inlet 31 of the low pressure pumping unit 30, and when the low pressure pumping unit 30 is driven, oil in the oil tank 1 passes through the filter 33 to the inlet 31. Is inhaled. The oil sucked into the inlet 31 of the low pressure pumping unit 30 is supplied to the oil inlet 121 of the relief valve 110 to be described later through the outlet 32.

The high pressure pump 40 is connected to the drive shaft 20 and driven by the power transmitted therefrom, as shown in FIGS. 1 and 3, and connected to the low pressure pump 30 to return oil pumped therefrom. Pump and discharge at high pressure. The high pressure pump 40 is divided into a pump lower housing 50, a pump upper housing 60, a pipe 70, and a pump body assembly 80.

The pump lower housing 50 is connected to the relief valve 110 as shown in FIGS. 1, 3, and 4A to 4E to disperse oil supplied therefrom to the circumference of the high pressure pump 40. Let's do it. The pump lower housing 50 is connected to the relief valve 110 and the inlet 51 into which the oil pumped from the low pressure pumping unit 30 flows in, and the inlet 51 is connected to the pump lower housing 50. It is formed in the circumference c-shaped so that the oil flowing into the inlet 51 side is diffused to the circumference of the pump lower housing 50, connected to the flow path 52 and connected to the pump body assembly 80 It consists of an outlet 53 for supplying the oil introduced into the flow path 52 to the pump body assembly 80 side.

The pump upper housing 60 is installed on the upper portion of the pump lower housing 50 as shown in FIGS. 1, 3, and 5A to 5E to supply oil supplied from the pump lower housing 50 to the relief valve 110. ) To the oil outlet 122 side. The upper pump housing 60 is connected to the pump body assembly 80, the inlet 61 is introduced into the pumped oil from the inlet 61, the inlet 61 is connected to the pump upper housing 60 in the c-shape around 10 and an outlet 63 connected to the flow path 62 to discharge the oil introduced therein, and connected to one end of the outlet 63 and the pipe 70 so that the outlet ( It consists of a pipe hole 64 leading the oil discharged to the 63) side to the pipe 70.

The pipe 70 has one end connected to the pipe hole 64 of the pump upper housing 60 and the other end of the oil outlet 122 of the relief valve 110 as shown in FIGS. 5C, 5E, 9A, and 10. ) Is connected to the top to guide the oil discharged from the pump upper housing (60) to the relief valve (110).

The pump body assembly 80 is installed in the installation space 86 between the pump lower housing 50 and the pump upper housing 60 as shown in Figs. 1, 3, 7A, and 7B, and the drive shaft 20 Coupled to the high pressure pump eccentric cam (23) of the pump pumps the oil introduced into the pump lower housing (50) to the pump upper housing (60) and vice versa to prevent backflow.

The pump body assembly 80 is provided with a case pipe 70 coupled to the circumference of the pump lower housing 50 and the pump upper housing 60 to form an installation space 86 therebetween. In the installation space 86 formed by the case pipe 70, an operation bearing 82 coupled to the high pressure pump eccentric cam 23 is provided. Pump bodies 83 are provided at four sides of the actuating bearing 82 to supply oil flowing from the pump lower housing 50 to the pump upper housing 60. The pump body 83 has an inlet 83a connected to the outlet 53 of the pump lower housing 50 and an outlet 83b connected to the inlet 61 of the pump upper housing 60. . A pumping space 83c is formed between the inlet 83a and the outlet 83b, and a cylinder chamber 83d is connected to the pumping space 83c.

The spool 84 is inserted into the cylinder chamber 83d of the pump body 83. One end of the spool 84 is in contact with the circumference of the actuating bearing 82 so that when the actuating bearing 82 eccentrically moves, the spool 84 moves the reciprocating oil along the cylinder chamber 83d while reciprocating linearly. The oil is sucked into the pumping space 83c and the oil in the sucked pumping space 83c is pumped to the outlet 83b side of the pump body 83. The flange 85 is coupled to one end of the spool 84. A restoring spring 87 is installed between the flange 85 and the pump body 83. The restoration spring 87 has one end supported by the flange 85 and the other end supported by the pump body 83 to reverse the spool 84 advanced by the operation bearing 82.

On the other hand, the inlet 83a and the outlet 83b of the pump bodies 83 are provided with the 1st check valve 90 and the 2nd check valve 100, respectively.

As shown in FIG. 7B, the first check valve 90 includes a check socket 94 coupled to the inlet 83a, a first check cap 91 coupled to the check socket 94, and a first check valve 94. The first steel ball 92 provided inside the check cap 91 to open and close the inlet 83a, and the first steel ball 92 between the first check cap 91 and the first steel ball 92 It consists of a first spring 93 which elastically supports 92 to the inlet (83a) side.

As shown in FIG. 7B, the second check valve 100 is provided inside the second check cap 101 and the second check cap 101 to open and close the outlet 83b. A second spring provided between the second steel ball 102 and the second check cap 101 and the second steel ball 102 to elastically support the second steel ball 102 toward the outlet 83b. It consists of 103.

Relief valve 110, as shown in Figs. 1, 2, 3, 8a to 8i, 9a to 9c, 10, low pressure pump 30, high pressure pump 40, hydraulic pressure Is connected to the device (2). The relief valve 110, the oil pumped to the low pressure pumping unit 30 is supplied to the high pressure pumping unit 40 side, the oil pumped from the high pressure pumping unit 40 is supplied to the hydraulic device 2 side, low pressure Some of the low pressure oil supplied from the pumping unit 30 to the high pressure pumping unit 40 is not supplied to the high pressure pumping unit 40 but is supplied directly to the hydraulic apparatus 2. In addition, when the oil pressure supplied from the high pressure pump 40 to the hydraulic device 2 is greater than the set pressure, the oil supplied to the hydraulic device 2 is recovered to the oil tank 1, and the high pressure pump 40 When the oil is pumped at a high pressure by the hydraulic apparatus 2, the oil excessively pumped from the low pressure pump 30 to the high pressure pump 40 is recovered to the oil tank 1.

The relief valve 110 will be described in more detail as follows.

The valve body 120, the first opening and closing valve 130, the second opening and closing valve 140, the third opening and closing valve 150, ball operation means 160 is composed of.

The valve body 120 is provided with an oil inlet 121 and an oil outlet 122 as shown in FIGS. 8A to 8I, 9A to 9C, and 10. The oil inlet 121 is connected to the outlet 32 of the low pressure pumping unit 30 by a hose and the oil pumped therefrom is introduced therein. The oil outlet 122 has one end connected to the outlet 53 of the high pressure pump 40 and the other end connected to the hydraulic device 2 to supply the oil pumped from the outlet 53 to the hydraulic device 2. do.

The valve body 120 is connected to the inlet 51 of the pump lower housing 50 of the oil inlet 121 and the high pressure pump 40 to supply the oil introduced into the oil inlet 121 to the high pressure pump 40. The high pressure pump supply passage 123 is formed to supply to the side. On one side of the high-pressure pump supply passage 123, an oil tank recovery passage 124 is formed to be parallel thereto. The oil tank recovery passage 124 is connected to the oil inlet 121 and the oil outlet 122 and is connected to the oil tank 1. Therefore, when the variable hydraulic pump is overloaded, oil that is excessively pumped to the oil inlet 121 is recovered to the oil tank 1, and when the pumping pressure of the oil outlet 122 is greater than the set pressure, a part of the oil tank ( 1) to recover.

The first connection passage 125 is connected to the high pressure pump supply passage 123 and the oil outlet 122 of the valve body 120. The first connection passage 125 is a part of the low-pressure oil supplied from the low pressure pumping portion 30 to the high pressure pumping portion 40 is not supplied to the high pressure pumping portion 40 directly through the oil outlet 122 To the device (2).

The second connection passage 126 is connected to the oil outlet 122 and the oil tank recovery passage 124 of the valve body 120. When the oil pressure supplied from the high pressure pump 40 to the hydraulic device 2 is greater than the set pressure, the second connection passage 126 is partially oiled at the oil outlet 122 supplied to the hydraulic device 2. Recover to tank (1).

A third connection passage 127 is connected to the oil outlet 122, the oil inlet 121, and the oil tank return passage 124 of the valve body 120. When the oil of the high pressure pump 40 is high pressure pumped into the hydraulic device 2, the third connection flow path 127 is an oil that is excessively introduced into the oil inlet 121 to the oil through the oil tank recovery flow path 124. Recover to tank (1).

As shown in FIG. 9A, the first opening / closing valve 130 is provided at one end of the first connection passage 125 connected to the oil outlet 122 to open and close the first connection passage 125. And a spring 132 provided inside the oil outlet 122 and having one end supported by the ball 131 to elastically support the ball 131 toward the first connection flow path 125, and the valve body 120. It is fastened to and supported on the end of the spring 132 is made of a pressure adjusting bolt 133 to adjust the elasticity of the spring 132.

The second opening / closing valve 140 is coupled to one end of the second connection passage 126 connected to the oil tank return passage 124 and connected to the second connection passage 126 at the center, as shown in FIG. 9A. A rod guide 141 having a hole 142 is formed therein, and a relief body 143 fastened to the valve body 120 so as to face the rod guide 141. The relief body 143 is coupled to the relief body 143 so as to slide to open and close the through hole 142 of the rod guide 141. One end of the relief body 143 is provided with a relief spring 145 so that one end of the relief 144 may be elastically supported by the rod guide 141. The set screw 146 is fastened to the relief body 143 by being supported at the end of the relief spring 145 to adjust the elasticity of the relief spring 145.

As shown in FIGS. 9A to 9C, the third open / close valve 150 includes a ball 151, a ball support shaft 152, a block 153, a disk spring 154, and a set screw 155. The ball 151 is provided at one end of the third connection passage 127 connected to the oil tank recovery passage 124 to open and close the third connection passage 127. The ball support shaft 152 is coupled to the valve body 120 to slide and supports the ball 151. The block 153 is fastened to the valve body 120 so as to be located at one side of the ball support shaft 152. The disk spring 154 is provided inside the block 153 and one end is supported by the ball support shaft 152 so that the end of the ball support shaft 152 is elastically supported by the ball 151. The set screw 155 is fastened to the block 153 and is supported at the end of the disk spring 154 to adjust the elasticity of the disk spring 154.

The ball operating means 160 is composed of a spool 161, a spring 162, and a set screw 163, as shown in FIGS. 9A to 9C. The spool 161 is installed to slide along the third connection passage 127, and an end thereof is supported by the ball 151 of the third opening / closing valve 150. The spring 162 is provided at the oil outlet 122 and one end is supported by the spool 161 so that one end of the spool 161 is elastically supported by the ball 151. The set screw 163 is fastened to the valve body 120 and supported at the end of the spring 162 to adjust the elasticity of the spring 162.

The variable hydraulic pump of the present invention having such a configuration is operated as follows.

When the driving motor 10 is driven, the drive shaft 20 is rotated. When the drive shaft 20 is rotated, the low pressure pump 30 and the high pressure pump 40 connected thereto are simultaneously driven. When the low pressure pump 30 is driven, oil in the oil tank 1 is sucked into the inlet 31 through the filter 33. The sucked oil flows into the oil inlet 121 of the valve body 120 of the relief valve 110 through the outlet 32.

The oil introduced into the oil inlet 121 is introduced into the inlet 51 of the pump lower housing 50 of the high pressure pump 40 through the high pressure pump supply passage 123. The oil introduced into the inlet 51 diffuses around the pump lower housing 50 through the flow path 52 and then flows into the pumping space 83c of the pump body assembly 80 through the outlet 53. The oil introduced into the pumping space 83c flows into the inlet 61 of the pump upper housing 60 through the outlet 83b. The oil introduced into the flow path 62 through the inlet 61 is discharged to the outlet 63 and discharged to the pipe 70 through the pipe hole 64 connected to the outlet 63.

Here, the pump body assembly 80 performs the pumping of the oil introduced into the pump lower housing 50 to the pump upper housing 60, which will be described in detail as follows. When the drive shaft 20 and the high-pressure pump eccentric cam 23 is rotated, the operation bearing 82 is eccentrically rotated to sequentially advance four spools 84 arranged radially. When the spool 84 is advanced, the pumping space 83c is compressed and the first check valve 90 is kept closed and the second check valve 100 is opened. That is, as the pumping space 83c is compressed, the oil therein pushes the steel ball 102 of the second check valve 100 upward, and as a result, the outlet 83b is opened while the spring 103 is compressed. The compressed oil in the pumping space 83c is supplied to the pump upper housing 60 through the outlet 83c.

The spool 84 advanced by the actuating bearing 82 is retracted as the actuating bearing 82 is further rotated and the compressed restoring spring 87 is restored. When the spool 84 is reversed, the pumping space 83c is vacuumed, and the first check valve 90 is opened by the suction force, and the second check valve 100 is closed. That is, when the pumping space 83c is vacuumed, the first steel ball 92 is pushed upward by the suction force therein and the pumping pressure of the outlet 53 of the pump lower housing 50, and thus the inlet 83a is pushed upward. ) Is opened, and the oil inside the pump lower housing 50 is supplied to the pumping space 83c. As this operation is repeated, the oil in the pump lower housing 50 is pumped into the pump upper housing 60.

The oil pumped into the pump upper housing 60 flows into the oil outlet 122 of the relief valve 110 through the pipe 70 connected to the pipe hole 64 and the hydraulic device 2 connected to the oil outlet 122. Is supplied.

On the other hand, various oils introduced into the high pressure pump supply passage 123 through the oil inlet 121 may not be temporarily supplied to the high pressure pump 40 having the small flow paths 52 and 62. Therefore, the oil pressure acts on the high pressure pump supply passage 123, and the ball 131 of the first opening / closing valve 130 is pushed to open the first connection passage 125 by the oil pressure. Therefore, some of the oil of a large amount of oil supplied to the high pressure pump supply passage 123 is discharged to the oil outlet 122 through the first connection passage 125 without passing through the high pressure pump 40 and the hydraulic device (2) Supplied immediately.

In addition, when the hydraulic device 2 is overloaded, the oil pressure of the oil outlet 122 is increased. When the oil pressure of the oil outlet 122 rises and rises more than the set pressure, the hydraulic pressure acts on the second connection passage 126 to push the relief rod 144 of the second open / close valve 140. When the relief rod 144 is pushed, the through hole 142 of the rod guide 141 is opened to open the second connection passage 126. Accordingly, excessive hydraulic pressure acting on the oil outlet 122 is applied to the second connection passage 126. ) Is discharged to the oil tank recovery passage 124, and is recovered to the oil tank (1).

When the hydraulic pressure of the oil outlet 122 is increased due to the overload of the hydraulic device 2, the spool 161 is advanced along the third connection flow path 127 by the oil pressure that rises, so that the third opening / closing valve ( The ball 151 of the 150 is pushed and thus the third connection passage 127 is opened. Therefore, a part of the oil flowing into the oil inlet 121 from the low pressure pumping unit 30 is not directly supplied to the high pressure pumping unit 40 and is immediately recovered to the oil tank 1 through the third connection passage 127.

This invention has the following advantages.

First, when the driving motor 10 is driven, the low pressure pump 30 and the high pressure pump 40 are driven simultaneously, so that a large amount of low pressure oil is supplied to the hydraulic device 2 so that the hydraulic device 2 in the no-load state can be supplied. When driven quickly, when the load is applied to the hydraulic device 2, the high pressure oil is pumped by the high pressure pump 40 to drive the hydraulic device (2). Therefore, while the low pressure pumping and the high pressure pumping are performed by one variable hydraulic pump, it is possible to efficiently drive the hydraulic apparatus 2 in the no-load state and the load state.

Second, the oil of some of the various oils introduced into the high pressure pump supply passage 123 through the oil inlet 121 does not go through the high pressure pump 40 and the oil outlet 122 through the first connection passage 125. Is discharged to and supplied directly to the hydraulic unit (2). Therefore, when oil is supplied to the hydraulic device 2 in the no-load state, which is the initial stage of hydraulic supply, the hydraulic device 2 can be quickly operated until a load is applied by supplying a large amount of low-pressure oil.

Third, when the variable hydraulic pump of the present invention is overloaded, the oil pressure discharged to the oil outlet 122 pushes the relief rod 144 of the second opening / closing valve 140 to open the second connection passage 126. Accordingly, the excess oil discharged to the oil outlet 122 flows into the oil tank recovery passage 124 through the second connection passage 126 and is recovered to the oil tank 1. Therefore, it is possible to protect the variable hydraulic pump from being damaged since it is prevented from overloading the variable hydraulic pump of the present invention.

Fourth, when the variable hydraulic pump is overloaded, the oil pressure discharged to the oil outlet 122 pushes the spool 161 of the ball operating means 160, and the ball 151 of the third opening / closing valve 150 is pushed. The third connection passage 127 is opened, so that the excess oil flowing into the oil inlet 121 from the low pressure pump 30 is recovered to the oil tank 1 through the third connection passage 127. Therefore, when the variable hydraulic pump of the present invention is overloaded, the excess oil flowing into the oil inlet 121 is not supplied to the high pressure pump supply passage 123 and is recovered immediately to the oil tank 1 so that the variable hydraulic pump is doubled. I can protect it.

1 is a schematic partial cross-sectional view showing a hydraulic supply circuit leading to a low pressure pump, a relief valve, a high pressure pump in an oil tank of the variable hydraulic pump of the present invention.

2 is a schematic partial cross-sectional view showing the bottom of FIG.

3 is a partially enlarged view of FIG. 1;

4a to 4e show the pump lower housing

5a to 5e show the pump upper housing

6A and 6B are a front view and a bottom view showing a drive shaft

7A and 7B are schematic plan and partial excerpt cross-sectional views showing the pump body assembly.

8a to 8i show the valve body

9A through 9C are cross-sectional views illustrating a process in which low pressure pumping and high pressure pumping are performed through a relief valve.

10 is a schematic partial cross-sectional view showing a state where the oil introduced into the pump upper housing of the high pressure pumping unit through the low pressure pumping unit is supplied to the hydraulic device through the oil outlet of the relief valve.

* Description of the symbols for the main parts of the drawings *

1: Oil tank 2: Hydraulic device

10: drive motor 11: motor shaft

20: drive shaft 21: motor connection

22: low pressure pump connection 23: high pressure pump core cam

30: low pressure pump 31, 51, 61, 83a: inlet

32,53,63,83b: outlet 33: filter

40: high pressure pump 50: pump lower housing

53: Euro 60: pump upper housing

64: pipe hole 70: pipe

80: pump body assembly 81: case pipe

82: operating bearing 83: pump body

83c: pumping space 83d: cylinder chamber

84161: Spool 85: Flange

86: installation space 87: restore spring

90: first check valve 91: first check cap

92: first steel ball 93: first spring

100: second check valve 101: second check cap

102: second steel ball 103: second spring

110: relief valve 120: valve body

121: oil inlet 122: oil outlet

123: high pressure pump supply flow path 124: oil tank recovery flow path

125: first connection channel 126: second connection channel

127: third connection passage 130: first opening and closing valve

131,151: Ball 132,162: Spring

133: pressure adjusting bolt 140: second opening and closing valve

141: road guide 142: through hole

143: relief body 144: relief

145: relief spring 146,155,163: set screw

150: third open and close valve 152: ball support shaft

153: block 154: disk spring

160: ball operating means

Claims (8)

Drive motor 10; A drive shaft 20 connected to the drive motor 10 to receive power therefrom; A low pressure pump 30 connected to the lower end of the drive shaft 20 and driven by the power transmitted therefrom for sucking and pumping oil in the oil tank 1; A high pressure pump 40 connected to the drive shaft 20 and driven by the power transmitted therefrom and connected to the low pressure pump 30 to pump the oil pumped therefrom and discharge the oil at high pressure; The oil pumped to the low pressure pumping part 30 is supplied to the high pressure pumping part 40, the oil pumped from the high pressure pumping part 40 is supplied to the hydraulic device 2, and the low pressure pumping part 30 is supplied. Some of the low pressure oil supplied from the high pressure pump 40 to the high pressure pump 40 is not supplied to the high pressure pump 40, but is supplied directly to the hydraulic device 2, from the high pressure pump 40 to the hydraulic device (2) If the oil pressure supplied to) is greater than the set pressure, the oil supplied to the hydraulic device 2 is recovered to the oil tank 1, the oil of the high pressure pump 40 is a high pressure to the hydraulic device (2) When pumped, the low pressure pumping unit 30, the high pressure pumping unit 40, the hydraulic pressure so that oil pumped excessively from the low pressure pumping unit 30 to the high pressure pumping unit 40 is recovered to the oil tank 1. Relief valve 110 is connected to the device (2); variable hydraulic pump comprising a. The method of claim 1, wherein the drive shaft 20, The motor connecting portion 21 is connected to the motor shaft 11 of the driving motor 10 at one end, the low pressure pump connecting portion 22 connected to the low pressure pumping portion 30 at the other end, and the high pressure pumping portion on the shaft ( Variable hydraulic pump, characterized in that the high-pressure pump eccentric cam 23 is formed to operate 40. The method of claim 2, wherein the high pressure pump 40, A pump lower housing 50 connected to the relief valve 110 to disperse oil supplied therefrom to the circumference of the high pressure pump 40; A pump upper housing 60 installed at an upper portion of the pump lower housing 50 to discharge oil supplied from the pump lower housing 50 to an oil outlet 122 side of the relief valve 110; One end is connected to the pump upper housing 60 and the other end is connected to the oil outlet 122 of the relief valve 110 to supply oil discharged from the pump upper housing 60 to the relief valve 110. Guiding pipe 70, Installed in the installation space 86 between the pump lower housing 50 and the pump upper housing 60 and coupled to the high pressure pump eccentric cam 23 of the drive shaft 20 introduced into the pump lower housing 50. A variable hydraulic pump, comprising a pump body assembly (80) for pumping oil into the pump upper housing (60) and vice versa. According to claim 3, The pump lower housing 50, An inlet 51 connected to the relief valve 110 and into which oil pumped from the low pressure pump 30 is introduced; A flow path 52 connected to the inlet 51 and formed in a U-shape around the pump lower housing 50 so that oil introduced into the inlet 51 can be diffused around the pump lower housing 50. Wow, Variable hydraulic pressure, characterized in that the outlet 53 is connected to the flow path 52 and connected to the pump body assembly 80 to supply the oil introduced into the flow path 52 to the pump body assembly 80 side. Pump. The pump upper housing (60) of claim 3, wherein An inlet 61 connected to the pump body assembly 80 and into which oil is pumped therefrom; A flow path 62 connected to the inlet 61 and formed in a U shape around the pump upper housing 60; An outlet 63 connected to the flow path 62 to discharge oil introduced thereto; Variable pressure pump, characterized in that made of a pipe hole (64) connected to one end of the outlet (63) and the pipe (70) to guide the oil discharged to the outlet (63) side to the pipe (70). According to claim 3, The pump body assembly 80, A case pipe 70 coupled to the periphery of the pump lower housing 50 and the pump upper housing 60 to form an installation space 86 therebetween; An operating bearing 82 installed in the installation space 86 and coupled to the high pressure pump eccentric cam 23; Inlet 83a and outlet 83b are formed to be installed at four sides of the actuating bearing 82 and to supply oil flowing from the pump lower housing 50 to the pump upper housing 60, and the inlet 83a. A pumping space (83c) is formed between the outlet (83b) and the pump body (83c) to which the cylinder chamber (83d) is connected to the pumping space (83c); A linear reciprocating movement along the cylinder chamber 83d when the operating bearing 82 is eccentrically inserted into one of the cylinder chambers 83d of the pump body 83 and one end is in contact with the circumference of the operating bearing 82. While the inlet-side oil of the pump body 83 to the pumping space (83c) and the spool 84 for pumping oil in the pumped space (83c) to the outlet (83b) side of the pump body 83 and , A flange 85 coupled to one end of the spool 84, A variable spring comprising one end supported by the flange 85 and the other end supported by the pump body 83 to restore the spool 84 advanced by the actuating bearing 82. Hydraulic pump. According to claim 6, Inlet (83a) and outlet (83b) of the pump body (83), The first check cap 91 and the second check cap 101 coupled to the inlet 83a and the outlet 83b, respectively, and are provided inside the first check cap 91 and the second check cap 101. And the first steel ball 92 and the second steel ball 102 to open and close the inlet 83a and the outlet 83b, the first check cap 91 and the first steel ball 92, and the second check. It is provided between the cap 101 and the second steel ball 102 to elastically support the first steel ball 92 and the second steel ball 102 toward the inlet (83a) and outlet (83b) side Variable hydraulic pump, characterized in that the first check valve (90) and the second check valve (100) consisting of a first spring (93) and the second spring (103) is installed. The method of claim 1, wherein the relief valve 110, It is connected to the outlet 32 of the low-pressure pumping unit 30, the oil inlet 121 is introduced into the pumped therein, the outlet 53 of the high-pressure pumping unit 40 and the hydraulic device 2 is connected to the The oil outlet 122 for supplying the oil pumped from the outlet 53 to the hydraulic device 2 and the inlet of the oil inlet 121 and the high pressure pump 40 are introduced into the oil inlet 121. A high pressure pump supply passage 123 for supplying oil to the high pressure pumping part 40 and the oil inlet 121 and the oil outlet 122 are connected to the oil tank 1 so that the oil is connected to the hydraulic device ( 2) When the high pressure pump to the side to the oil inlet 121, the oil is pumped excessively to the oil tank (1) is recovered and if the pumping pressure of the oil outlet 122 side is greater than the set pressure of some of the oil Oil tank recovery passage 124 to recover to the tank 1, the high-pressure pump supply passage 123 and oil Some of the low pressure oil which is connected to the sphere 122 and supplied from the low pressure pumping unit 30 to the high pressure pumping unit 40 is not supplied to the high pressure pumping unit 40 without being directly supplied to the hydraulic outlet through the oil outlet 122. It is connected to the first connection passage 125 and the oil outlet 122 and the oil tank recovery passage 124 to be supplied to the device (2) is supplied from the high pressure pump 40 to the hydraulic device (2) If the oil pressure is greater than the set pressure, the second connection passage 126 and the oil outlet 122 to allow the oil outlet 122 side partial oil supplied to the hydraulic device 2 to be recovered to the oil tank (1) ), Connected to the oil inlet 121, the oil tank recovery passage 124, when the oil of the high pressure pump 40 is high pressure pumped into the hydraulic device 2, excessively flows into the oil inlet 121. To the third connection passage 127 through which the oil is recovered to the oil tank 1 through the oil tank recovery passage 124. Luer binary valve body 120 and; A ball 131 provided at one end of the first connection passage 125 connected to the oil outlet 122 to open and close the first connection passage 125, and provided inside the oil outlet 122 and once The spring 132 is supported by the ball 131 to elastically support the ball 131 toward the first connection flow path 125, and the valve body 120 is fastened to the A first opening / closing valve (130) formed of a pressure adjusting bolt (133) supported at an end to adjust elasticity of the spring (132); A rod guide 141 coupled to one end of the second connection passage 126 connected to the oil tank recovery passage 124 and having a through hole 142 connected to the second connection passage 126 at the center thereof; A relief body 143 fastened to the valve body 120 so as to face the rod guide 141 and a slide body 143 coupled to the relief body 143 to open and close the through hole 142 of the rod guide 141. The relief rod 144 and the relief body 143 are provided in the interior and one end is supported by the relief 144 so that one end of the relief 144 is elastically supported by the rod guide 141. A second opening and closing of the relief spring 145 and the set screw 146 fastened to the relief body 143 and supported at the end of the relief spring 145 to adjust the elasticity of the relief spring 145. A valve 140; A ball 151 which is provided at one end of the third connection passage 127 connected to the oil tank recovery passage 124 to open and close the third connection passage 127, and is slidably coupled to the valve body 120. A ball support shaft 152 supporting the ball 151, a block 153 fastened to the valve body 120 to be located at one side of the ball support shaft 152, and provided inside the block 153. And a disk spring 154 having one end supported by the ball support shaft 152 so that an end of the ball support shaft 152 is elastically supported by the ball 151, and fastened to the block 153 and the disk spring. A third opening / closing valve (150) which is supported at an end of the (154) and comprises a set screw (155) for adjusting the elasticity of the disk spring (154); The spool 161 is installed to slide along the third connection passage 127 and the end is supported by the ball of the third open / close valve 150, and is provided at the oil outlet 122 and one end of the spool ( A spring 162 supported by the 161 so that one end of the spool 161 is elastically supported by the ball 151, and fastened to the valve body 120 and supported by an end of the spring 162. Ball hydraulic means consisting of a set screw (163) for adjusting the elasticity of the spring (162); Variable hydraulic pump, characterized in that consisting of.

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