JP3563453B2 - Variable phase piston pump - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a variable phase piston pump in which a plurality of pistons are arranged in a radial direction with respect to a rotor and the discharge volume thereof is variable.
[0002]
[Prior art]
There are no hydraulic pumps that produce a high pressure of about 210 kg / cm ² on the market other than the piston type pump at present, and there is no variable displacement type other than the swash plate type. This swash plate type piston pump changes the displacement of the piston by changing the stroke of the piston.However, where there is a problem with the link mechanism between the input shaft and the swash plate and the link mechanism between the piston and the swash plate, where reliability is truly required, The fact is that they are shunned. Oil leakage from the valve plate for switching the oil flow in and out of the cylinder chamber is also a major problem, and reducing oil leakage increases friction resistance, and if friction resistance is disliked, oil leakage cannot be ignored. Could not be resolved.
[0003]
In view of the above, the present applicant has previously proposed a hydraulic piston device (JP-A-2-256883) capable of varying the discharge capacity while keeping the piston stroke constant. This device has the advantage that it has a simpler structure than a conventional variable displacement pump and can be used for high pressure because it is a piston pump.
[0004]
[Problems to be solved by the invention]
However, in the above-mentioned conventional device (Japanese Patent Laid-Open No. 2-256883), since the inner peripheral surface of the stator or the outer peripheral surface of the eccentric cam is a perfect circle, 0 ° to 180 ° out of 360 ° is shifted to the suction side. For example, since the range of 180 ° to 360 ° is on the discharge side (high pressure side), a large load acts on the bearing portion of the rotating body, resulting in an increase in the size of the device and an adverse effect on durability. There was a problem.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, in the present invention, a flange-shaped disk portion and a shaft cylinder portion are provided on a rotor fixed to a shaft, and a bottomed cylinder hole that faces the center of the rotor from the outer peripheral surface of the disk portion. A plurality of holes are provided, and holes communicating with the bottoms of the cylinder holes are respectively provided on the outer peripheral surface of the shaft cylinder portion.The inner peripheral surfaces of the stator enclosing the disk portion are provided on both sides from the center of the rotor. A rectifying block formed on two semi-cylindrical surfaces having eccentric centers, a piston sliding along the inner peripheral surface of the stator in each of the cylinder holes, and enclosing an opening provided in the shaft cylinder portion. Independent rectifying grooves are provided on the inner surface for each 90-degree phase, and one of two sets of rectifying grooves facing the center of the rotor is connected to one of the suction and discharge holes of the pump. Of the pump Connected towards, constituting the variable phase type piston pump to the stator to rotate control on the rectifier block.
[0006]
Further, the stator of the above-described device of the first invention may be fixed, and the rotation of the rectifying block may be controlled with respect to the stator.
[0007]
[Action]
Since the piston pump of the present invention is configured as described above, the piston in each cylinder hole makes a two-stroke motion while the rotor makes one rotation. Therefore, if the other specifications are the same as those of the conventional pump described above, in which the piston moves one stroke while the rotor makes one rotation, the pump of the present invention has a double discharge rate. become.
[0008]
In addition, since the fluid pressure acting on the flow regulating groove in the flow regulating block of the present invention is equal to the fluid pressure opposing the center of the rotor, all loads due to the fluid pressure acting on the respective rotating bodies are balanced. Therefore, according to the present invention, the load acting on the bearing portion of each rotating body is reduced, so that the device is reduced in size and weight and the durability is improved accordingly.
[0009]
【Example】
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the figure, reference numeral 1 denotes an output shaft of a motor as a motor, and reference numeral 2 denotes a rotor fixed to the shaft 1 by a key 3. The rotor 2 is provided with a flange-shaped disk portion 2a and a shaft cylinder portion 2b, and a plurality of bottomed cylinder holes 4 are formed from the outer peripheral surface of the disk portion 2a toward the center of the rotor 2 (in this embodiment, 5) Provided at equally spaced positions.
[0010]
A hole 5 communicating with the bottom of each cylinder hole 4 is provided in the shaft cylinder portion 2b in parallel with the center line of the shaft, and a hole 6 orthogonal to the hole 5 is opened from the outer peripheral surface of the shaft cylinder portion 2b. The openings 6a are arranged on the same plane orthogonal to the center line of the shaft cylinder 2b.
[0011]
Also, the disk portion 2a of the inner peripheral surface of the stator 7 to the envelope of the rotor 2 around 0 (see FIG. 2) that is eccentric only l each side than 0 _1, 0 ₂ two radii R around the The semi-cylindrical surfaces 8, 9 are formed. A piston 10 is provided in each of the cylinder holes 4 to slide along the inner peripheral surfaces 8 and 9 of the stator 7.
[0012]
Reference numeral 11 (see FIGS. 2 and 3) denotes a roller rotatably fitted to the outer end portion of each piston 10, which is in contact with the inner peripheral surfaces 8, 9 of the stator 7 and rolls, and 10a (see FIG. 3). ) Is a small hole provided in a concave portion of the piston 10 that supports the roller 11, and oil leaked from the small hole 10 a lubricates the rotating surface of the roller 11. Reference numeral 12 denotes a coil spring provided in the piston 10, which acts to always push the piston 10 outward. If pressure is applied to the oil on the suction side, the oil is naturally pushed into the cylinder hole 4 and the coil spring 12 becomes unnecessary.
[0013]
13 (see FIG. 1) is a side plate applied to the open end surface of the stator 7, and 14 is a fastening bolt thereof. 15 is a ball bearing provided between the rotor 2 and the stator 7 and the side plate 13, and 16 is a snap ring.
[0014]
As shown in FIGS. 1 and 4, a rectifying block 17 is provided so as to enclose the shaft cylinder portion 2 b of the stator 2. The grooves 18, 19, 20, 21 are provided independently on the inner surface of the rectification block 17 for each 90 ° phase.
[0015]
One of the two sets of straightening grooves 18, 20 and 19, 21 facing the center 0 of the rotor 2 is connected to one of the suction and discharge holes 22, 23 of the pump via an oil passage 24. At the same time, the other of the two sets of rectifying grooves 19 and 21 are connected to the other of the pump suction and discharge holes 23 via an oil passage 25 so that the rotation of the stator 2 with respect to the rectifying block 17 can be controlled.
[0016]
In FIG. 1, reference numeral 26 denotes an end cap which is applied to the end surface of the shaft cylinder 2b of the rotor 2 and fastened to the shaft 1 by a bolt 27, and 28 seals the open end of the hole 5 in the shaft cylinder 2b. O-ring.
[0017]
Further, the stator 2 of the first invention may be fixed, and the rotation of the rectifying block 17 may be controlled with respect to the stator 2. The method of controlling the rotation of the stator 2 and the rectifying block 17 may be any method.
[0018]
Next, the operation of the variable phase piston pump of the present invention configured as described above will be described. When the output shaft 1 of the prime mover rotates and the stator 2 rotates in the direction of arrow A in FIGS. 2 and 4, the piston 10 located at the 0 ° phase in FIG. Along, so it continues to move out to the 90 ° phase. That is, the pump by the cylinder 4 and the piston 10 performs a suction operation from 0 ° to 90 °.
[0019]
Next, when the stator 2 is further rotated and the piston 10 moves from 90 ° to 180 °, during this time the piston 10 moves inward along the inner peripheral surface 8 of the stator 7, so that the pump is in the discharge stroke. .
[0020]
Further, when the stator 2 further rotates and the piston 10 moves from 180 ° to 270 °, the piston 10 moves outward along the inner peripheral surface 9 of the stator 7 during this time. When the angle is from 360 ° to 360 °, the piston 10 moves inward, and the pump enters the discharge stroke.
[0021]
That is, in the pump of the present invention, while the shaft 1 makes one rotation, the pump performs a stroke from suction to discharge twice. In this embodiment, there are five pistons 10 in the rotor 2, and each piston 10 performs the above-described operation in the same manner.
[0022]
As described above, when the phases of the stator 7 and the rectifying block 17 are in the phases shown in FIGS. 2 and 4, the rectifying grooves 18 and 20 are on the suction side, and the rectifying grooves 19 and 21 are on the discharge side. Therefore, in this case, oil is sucked from the suction hole 22 of the pump, and pressure oil is discharged from the discharge hole 23.
[0023]
Next, with the stator 7 rotated clockwise by 22.5 ° as shown in FIG. 5, when the piston at the phase of 0 ° rotates from 0 ° to 90 °, 0 From 22.5 ° to 22.5 °, the discharge oil enters, and from 22.5 ° to 90 °, the oil is sucked from the flow regulating groove 18. This phenomenon is the same in the range of 90 ° to 180 °, 180 ° to 270 °, and 270 ° to 0 °. That is, in this case, the range of 22.5 ° is the discharge stroke, and the range of 90 ° -22.5 ° = 67.5 ° is the suction stroke. Accordingly, since the range of 67.5 ° -22.5 ° = 45 ° is a net discharge stroke, the discharge amount of the pump in this case is の of that when the stator 7 is not rotated.
[0024]
Next, as shown in FIG. 6, when the piston in the phase of 0 ° is rotated from 0 ° to 90 ° in a state where the stator 7 is rotated 45 ° clockwise, the rectifying groove 18 has 0 ° to 45 °. °, the discharge oil enters, and from 45 ° to 90 °, the suction stroke takes place. In addition, the suction stroke is from 90 ° to 135 °, and the discharge stroke is from 135 ° to 180 °. Similarly, the flow of oil into and out of the flow straightening grooves 20 and 21 becomes zero.
[0025]
Also, as shown in FIG. 7, when the piston in the phase of 0 ° is rotated from 0 ° to 90 ° while the stator 7 is rotated 90 ° clockwise, the straightening groove 18 has a rotation of 0 ° to 90 °. °, the discharge oil enters, and from 90 ° to 180 °, the suction stroke through the straightening groove 19 is performed. This is opposite to the pump in the state of FIG. 2 and FIG.
[0026]
Therefore, according to the present invention, by rotating the stator 7 from the phase of 0 ° to 90 °, the discharge amount can be continuously changed to 0, and the directions of suction and discharge can be reversed. it can. Although the case where the phase of the stator 7 is changed has been described above, the same operation can be obtained by changing the phase of the rectifying block 17 instead of the stator 7.
[0027]
As described above, according to the present invention, it is possible to arbitrarily control the oil discharge direction and the displacement while keeping the rotation direction and the rotation speed of the rotor constant. Further, even if the rotation direction of the rotor is changed, the oil discharge direction can be reversed. Therefore, since the oil discharge direction can be controlled by shifting the phase of the stator 7 and the rectifying block 17 or changing the rotation direction of the rotor 2, when actually designing the hydraulic system, according to the present invention, The degree of freedom is expanded. In the above description, the present invention has been described as a pump. However, since the hydraulic pump can be used immediately as a hydraulic motor, it goes without saying that the present invention can be realized as a variable phase piston motor.
[0028]
【The invention's effect】
Since the piston pump of the present invention is configured as described above, the piston 10 in each cylinder hole 4 makes a two-stroke movement while the rotor 2 makes one rotation. Therefore, if the other specifications are the same as those of the conventional pump described above, in which the piston moves one stroke while the rotor makes one rotation, the pump of the present invention has a doubled discharge rate. Is obtained.
[0029]
Further, since the fluid pressures acting on the flow regulating grooves 18 to 21 in the flow regulating block 17 of the present invention are equal to each other facing the center of the rotor 2, all the loads due to the fluid pressure acting on the respective rotating bodies are balanced. Become like Therefore, according to the present invention, as a result of reducing the load acting on the bearing portion of each rotating body, it is possible to obtain the effect of reducing the size and weight of the device and improving the durability.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of the device of the present invention.
FIG. 2 is a sectional view taken along line XX of the apparatus of FIG. 1 with a side plate and a bearing removed.
FIG. 3 is a partial view showing a cross section of one of the pistons of FIG. 2;
FIG. 4 is a sectional view taken along line YY of FIG. 1;
FIG. 5 is an explanatory diagram of the operation when the stator of FIG. 2 is rotated 1/16.
FIG. 6 is an explanatory diagram of the operation when the stator of FIG. 2 is rotated by ８.
FIG. 7 is an explanatory diagram of an operation obtained by rotating the stator of FIG. 2 by 1/4 rotation.
[Explanation of symbols]
1 shaft (motor output shaft)
2 Rotor 2a Disk portion 2b Shaft tube portion 3 Key 4 Cylinder hole 5 Hole 6 Hole 6a Opening 7 Stator 8, 9 Semi-cylindrical surface (inner peripheral surface)
DESCRIPTION OF SYMBOLS 10 Piston 10a Small hole 11 Roller 12 Coil spring 13 Side plate 14 Fastening bolt 15 Ball bearing 16 Snap ring 17 Rectifying block 18, 19, 20, 21 Rectifying groove 22, 23 Pump suction / discharge hole 24, 25 Oil passage 26 End cap 27 Bolt 28 O-ring

Claims (2)

The rotor fixed to the shaft is provided with a flanged disk portion and a shaft cylinder portion, and a plurality of bottomed cylinder holes are provided from the outer peripheral surface of the disk portion toward the center of the rotor, and communicate with the bottom of each cylinder hole. Holes are formed in the outer peripheral surface of the shaft cylinder portion, respectively, and the inner peripheral surface of the stator enclosing the disk portion is formed in two semi-cylindrical surfaces having centers decentered on both sides from the center of the rotor. Then, a piston that slides along the inner peripheral surface of the stator is provided in each of the cylinder holes. Providing one of two sets of straightening grooves opposed to the center of the rotor to one of the suction and discharge holes of the pump, and connecting the other of the two sets of straightening grooves to the other of the suction and discharge holes of the pump; Connect the stator to the rectifier block. Variable phase type piston pump, characterized in that to be able to rotate control over. A variable phase piston pump, wherein the stator according to claim 1 is fixed, and rotation of the rectifying block is controlled with respect to the stator.

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