JPS6198991A - Forced feed device of fluid - Google Patents

Abstract

PURPOSE:To enable a device to continuously force fluid to be fed from a delivery port through the other end of a helical groove, by circulating a ball, fitted to the helical groove, to run along a forced feed passage through rotation of a screw and transferring the fluid, introduced to one end of the forced feed passage, while the fluid is pressed by said ball. CONSTITUTION:If a ball 12, fitted to a helical groove 4, moves respectively along a forced feed passage 11 in accordance with rotation of a screw 3, working fluid in an actuator 22, being allowed to flow passing through a start end 4a of the helical groove 4 from a suction part 17, is introduced into the forced feed passage 11 in a rear side in the moving direction of the ball 12. If the helical groove 4 is again aligned to a part just below one end of a return passage 14, the next ball 12 is fitted to the helical groove 4, and forced feed device, holding the working fluid longitudinally between the balls 12 by its movement in the right direction, transfers the fluid in the right direction in the forced freed passage 11. In this way, the device, being of construction bringing the ball 12 into contact with the forced feed passage 11, decreases friction resistance in a contact part, and the device, enabling the ball 12 to be moved at a high speed and suppressing a reverse flow of the working fluid to a minimum limit, can continuously deliver the working fluid from a delivery port 18.

Description

[Detailed description of the invention] Industrial applications The present invention relates to an apparatus for pumping fluid such as hydraulic oil.

Problems to be Solved by the Prior Art and the Invention In a fluid pumping device, in order to precisely control the pumping flow rate of the fluid, it is desirable to use a method of continuously pumping the fluid. A well-known gear pump is a gear pump in which a pair of driving gears and a driven gear are meshed and housed in a casing, and fluid is discharged around the outer periphery of each gear by rotation of both gears. Pumps have the drawback that it is difficult to seal between the gear and the casing, and leaks are likely to occur, making it impossible to pump fluid under high pressure. There is also a known screw pump that uses the rotation of the screw shaft to push out the fluid in the thread groove of the female screw shaft through the screwing out of the male screw shaft, but is it possible to do this between the screw shaft and the casing in the same way? The drawback was that it was difficult to seal and the fluid could not be pumped under high pressure. On the other hand, plunger pumps, diaphragm pumps, etc. are suitable for high-pressure pumping of fluid, but since these pumps do not perform continuous pumping but intermittent pumping, they have large pulsations and cannot precisely control the pumping flow rate.

The present invention has been completed in view of the above points, and an object of the present invention is to provide a fluid pumping device that adopts a continuous pumping method so that the pumping flow rate can be precisely controlled, and also enables high-pressure pumping. purpose.

EXAMPLE Hereinafter, an example of the present invention will be described based on the accompanying drawings.

In the figure, a screw 3 having a single helical groove 4 with a semicircular cross-section formed on its outer circumferential surface is tightly fitted into a center hole 2 of a cylinder 1, and the screw 3 is tightly fitted into a center hole 2 of a cylinder 1 through a bearing 5.6. One end of the cylinder 1 is in contact with a cap 7 screwed onto one end of the cylinder 1 via a bearing 8, and the other end is connected to the screw 3 along the arrow A.
It is connected to a drive motor 9 that applies rotational force in the direction.

On the inner circumferential surface of the cylinder 1, one pressure passage 11 having a semicircular cross-sectional shape with the same radius as the spiral groove 4 is formed along the length direction, and an intersection point between the pressure passage 11 and the spiral groove 4. A sphere 12 having the same radius as the pressure passage 11 and the spiral groove 4 is tightly fitted into the space of the cylinder 1.
A return passage I4 for a sphere I2 having a circular cross section with the same radius as the sphere 12 is formed outside the part where the pressure passage 11 is formed, and both ends thereof are bent to communicate with both ends of the pressure passage 11. The spheres 12 are inserted into the return passage 14 in a row.

On both sides of the portion of the screw 3 where the spiral groove 4 is formed, a suction groove 15 communicating with the starting end 4a of the spiral groove 4 and a discharge groove 16 communicating with the terminal end 4b of the spiral groove 4 are provided. , the cylinder 1 is formed with a suction port 17 communicating with the suction@15 and a discharge port 18 communicating with the discharge groove 16, and the other end of the suction pipe 19, one end of which is connected to the suction port 17, is connected to the check valve 20. Actuator 2 such as a hydraulic motor
It is connected to the hydraulic oil discharge port 2, and the discharge port 1
The other end of the discharge pipe 23 is connected to the hydraulic oil supply port of the actuator 22 via the check valve 24, and between the discharge pipe 23 and the suction pipe 19, An IJ-F valve 25 is provided to release hydraulic oil to the suction pipe 19 when the pressure of the hydraulic oil in the discharge pipe 23 exceeds a set value.

Note that a seal 27 is fitted between the outer peripheral surface of the other end of the screw 3 and the inner peripheral surface of the cylinder 1 to prevent leakage of hydraulic oil.

Next, the operation of this embodiment will be explained.

Driven by the drive motor 9, the screw 3 moves along the arrow A in FIG.
When the spheres 12 are rotated in the direction, the spheres 12 fitted in the spiral grooves 4 move along the pressure-feeding passage 11 to the right in the figure. When the sphere 12 fitted in moves to the right along the pressure passage 11, the hydraulic fluid of the actuator 22 flows into the suction pipe 1.
9 through the suction port 17, through the suction groove 15 and the starting end 4a of the spiral groove 4, and into the pressure feeding passage 11 on the rear side in the direction of movement of the sphere 12, and the spiral groove 4 returns to one end of the return passage 14. When the next sphere 12 is aligned directly under the helical groove 4 , the next sphere 12 fits into the spiral groove 4 , and as the sphere 12 moves to the right, the hydraulic oil between the front and rear spheres 12 is sandwiched between the spheres 12 and flows into the pressure feeding passage 11 . When the sphere 12 is transferred to the right and reaches just below the other end, which is the entrance of the return passage 14, the sphere 12 is stopped from moving to the right and returns by pushing the series of spheres 12 in the return passage 14. As a result, the hydraulic oil in the pressure-feeding passage ll on the rear side of the sphere 12 passes through the terminal end 4b of the spiral groove 4 and the discharge groove 16, and is discharged from the discharge port 18, and then passes through the discharge pipe 23. and is supplied to the actuator 22.

In the above embodiment, the pressure passages 11 before and after the sphere 12 are slightly in communication with each other via the spiral groove 4, but the structure is such that the sphere 12 contacts the pressure passage 11, so that the friction of the contact portion is reduced. Since the resistance is small and it is possible to rotate the screw 3 at high speed and move the sphere 12 at high speed, backflow of the hydraulic oil is minimized and the hydraulic oil is continuously discharged from the discharge port 18. be able to.

Structure and effects of the invention.

In the fluid pumping device of the present invention, a screw having a spiral groove whose cross-sectional shape forms part of a circle on its outer peripheral surface is tightly fitted into a cylinder and freely rotatable around an axis. A pressure-feeding passage whose cross-sectional shape forms the remainder of the circle is formed along the length on the inner circumferential surface, and spheres are tightly fitted into the intersections of the diagnostic pressure-feeding passage and the spiral groove, respectively, and the outer part of the cylinder is A return passage for the spheres, in which the spheres travel in a row, is formed in communication with both ends of the pressure feeding passage, one end of the spiral groove being connected to the fluid intake port of the cylinder, and the other end being connected to the fluid discharge port of the cylinder. By circulating the sphere, which is connected to the outlet and fitted into the helical groove by rotation of the screw, in one direction along the pumping passage, the fluid is pumped from the fluid suction port through one end of the spiral Fj, 1. The fluid led to one end of the passage is transferred while being pressed by the sphere, and the fluid that reaches the end of the pressure passage is discharged from the fluid outlet through the other end of the spiral groove. By rotating the screw, the sphere circulates in one direction along the pressure passage, so that the fluid introduced into the pressure passage is sequentially pressed by the sphere and is continuously pumped. Since the sphere fits tightly into the intersection of the pressure passage and the spiral groove, there is very little communication between the pressure passages before and after the sphere, which suppresses fluid leakage as much as possible and allows high-pressure pumping of fluid. In addition, since the sphere can roll while moving along the pressure passage, frictional resistance is low, operating noise can be kept low, and wear on contact parts can be reduced, resulting in increased durability. It has the effect of improving sex.

[Brief explanation of drawings]

1 Niji cylinder 3: Screw 4: Spiral groove 4a: Starting end (of spiral groove 4) 4b= Terminating end (of spiral groove 4) 1
1: Pressure feeding passage 12: Sphere 17: Suction port 18: Discharge port

Claims (1)

[Claims] A screw having a spiral groove whose cross-sectional shape forms part of a circle on its outer circumferential surface is tightly fitted into the cylinder and freely rotates around the axis, and the inner circumferential surface of the cylinder has a cross-sectional shape as described above. A pressure-feeding passage forming the remainder of the circle is formed along the length direction, and spheres are tightly fitted at the intersections of the pressure-feeding passage and the spiral groove, respectively, and the spheres are arranged in a line on the outside of the cylinder. A return passage for the sphere traveling is formed in communication with both ends of the pressure feeding passage, one end of the spiral groove is communicated with the fluid intake port of the cylinder, the other end is communicated with the fluid discharge port of the cylinder, and the screw By causing the sphere fitted in the spiral groove by rotation to circulate in one direction along the pressure passage, the fluid guided from the fluid suction port to one end of the pressure passage through one end of the spiral groove is transferred to the sphere. A fluid pumping device characterized in that the fluid is transferred while being pressed by a fluid pump, and the fluid that reaches the other end of the pumping passage is discharged from the fluid discharge port through the other end of the spiral groove.