JPH073033Y2 - Internal gear pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention eccentrically engages an external gear having external teeth with an internal gear having internal teeth to internally engage the internal gear by rotationally driving the external gear. The present invention relates to an internal gear pump in which a gear is driven to rotate to suck and discharge a liquid.

[Conventional technology]

Conventionally, an internal gear pump of this kind has been disclosed in Japanese Patent Publication No. 62-57835, in which an external gear having external teeth and an internal gear having internal teeth are eccentrically arranged so as to be internally meshed. Is rotatably accommodated in the external gear, and the internal gear that is in mesh with the internal gear is driven to rotate by the rotational drive of the external gear, and the liquid sucked from the suction flow path is pumped to the expansion region space formed between the internal gear and the external gear. It is conveyed to the area space and discharged from the discharge channel.

[Problems to be solved by the invention]

However, since the discharge amount discharged to the discharge passage is always constant during operation, in order to control the discharge pressure of the discharge passage, a relief valve is provided branching from the discharge passage and the discharge pressure is When the set pressure of the relief valve rises, the discharged liquid has to be discharged to a lower pressure side than the relief valve, which causes a problem that the discharged liquid is wasted.

The present invention solves such a problem, and provides an internal gear pump capable of controlling the discharge pressure without wasting the discharge liquid.

[Means for solving problems]

Therefore, according to the present invention, an internal gear having internal teeth and an external gear having external teeth are rotatably housed in the pump body so as to be in eccentric and internally meshed, and the internal gear is driven by rotation of the external gear. The gear communicates with the expansion region space and the pressure-feeding region space, which are formed between the internal gear and the external gear to face each other so as to follow the rotation of the internal gear and the external gear so that the liquid suction and discharge channels can be connected to the pump body. The pump main body is rotatably accommodated in the main body, and when the discharge pressure of the discharge flow passage and the set pressure based on the spring force act in opposition to each other, the pump main body does not reach the set pressure. Is provided with pressure control means for releasing the pressing of the pump body so as to allow the rotation of the pump body when the discharge pressure of the discharge passage rises to the set pressure while pressing the pump body to prevent the rotation of Pressure control means is provided between the external gear and the pump body. When the pump body is being pressed, the rotational drive force of the external gear is not transmitted to the pump body, and when the pressure control means releases the pressing of the pump body, the pump body is rotated synchronously with the external gear. A rotational driving force transmitting means for transmitting the rotational driving force of the external gear to the pump body is provided.

[Action]

In the configuration of the present invention, when the discharge output of the discharge passage does not reach the set pressure of the pressure control means, the pump body is pressed by the pressure control means and is prevented from rotating, and the rotation of the external gear inside the pump body is prevented. The internal gear is driven to rotate by driving, and the liquid sucked into the expansion region space from the suction flow passage is conveyed to the pressure feeding region space and discharged from the discharge flow passage to obtain the maximum discharge amount. When the discharge pressure of the discharge passage rises to the set pressure of the pressure control means, the pump body releases the pressure of the pressure control means, and the rotation driving force transmission means transmits the rotation driving force of the external gear. By rotating in synchronization with the external gear, the amount of liquid transported from the expansion region space to the pressure-feed region space becomes substantially zero, and the discharge amount from the discharge passage is reduced to substantially zero. For this reason, when the discharge pressure of the discharge channel rises to the set pressure of the pressure control means, the discharge amount can be reduced to substantially zero, and the discharge pressure is well controlled without wasting the discharge liquid. be able to.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. In FIGS. 1 and 2, reference numeral 1 is a main body, and a front cover member 3 is fastened and fixed to a housing 2 whose one side is opened so as to close the opening, and a housing hole 4 is formed inside. Reference numeral 5 denotes a pump main body rotatably accommodated in the accommodation hole 4 in the main body 1, and is constituted by connecting and fixing the front lid member 7 with a pin 8 so as to close the opening in a small housing 6 having an opening on one side. A small storage hole 9 is formed inside. Reference numeral 10 denotes an internal gear having internal teeth 10A, which is rotatably housed in a small housing hole 9 in the pump body 5. Reference numeral 11 denotes an external gear having an external gear 11A, and the internal gear 10A and the external gear 11A are internally meshed so that the internal gear 10A and the external gear 11A mesh internally.
It is eccentrically housed inside, and is rotatably supported by the bearings 12 and 13 on the main body 1 and the pump main body 5 and is integrally connected to a drive shaft 14 which is rotationally driven. Between the internal gear 10 and the external gear 11, an expansion area space 15 and a pressure feeding area space 16 are formed so as to face each other, and a liquid suction flow path 17 is provided in the expansion area space 15 and a liquid discharge flow is provided in the pressure feeding area space 16. The paths 18 are provided so as to communicate with each other. The suction flow passage 17 communicates with the flow passage 20 of the main body 1 through an annular groove 19 formed on one side surface of the pump body 5, and the discharge flow passage 18 has an annular groove 21 formed on the outer peripheral surface of the pump body 5. Through the flow path of the main body 1
It communicates with 22. Reference numeral 23 denotes a pressure control means, and a discharge path 25 branched from a flow path 22 communicating with the discharge flow path 18 with a gap in the axial direction to a sliding hole 24 continuous to the storage hole 4 in the main body 1. Open the discharge line 27 that connects to the pressure line 26 and the low pressure side, and
28 is slidably inserted into the sliding hole 24. On the spool 28, the discharge pressure of the discharge passage 18 acting via the discharge passage 25 and the set pressure based on the force of the spring 29 accommodated in the sliding hole 24 face each other, and the discharge pressure is set based on the force of the spring 29. When the pressure is not reached, the pressure line 26 and the discharge line 25 are shut off and the pressure line 26 and the discharge line are cut off.
When the discharge pressure rises to a set pressure based on the force of the spring 29, the pressure passage 26 and the discharge passage 25 are communicated with each other by communicating the pressure passage 26 and the discharge passage 25 with each other. A land portion 28A is formed so as to cut off between the paths 27. Reference numeral 30 denotes a pressing member integrally formed at the tip of the spool 28. When the discharge pressure does not reach the set pressure based on the spring 29 force, the spring 29 force presses the pump body 5 against the body 1 to rotate the pump body 5. When the discharge pressure rises to a set pressure based on the force of the spring 29, the pump body 5 is moved to the right from the first illustrated position to release the pressing of the pump body 5 against the body 1 to rotate the pump body 5. It is provided so as to be able to come into contact with and separate from one side surface of the pump body 5 so as to allow Reference numeral 31 denotes a rotational driving force transmitting means, which forms an annular groove 32 by annularly recessing the inner peripheral surface of the pump body 5 with which the drive shaft 14 integrally coupled with the external gear 11 is slidably contacted, to form an annular groove 32. A communication passage 34 connects the bottom surface and the pressure passage 26 of the pressure control means 23. An annular ring member 33 accommodated in the annular groove 32 is formed of an elastic material and has a self-expanding force.
When the pressing member 30 of the pressure control means 23 presses the pump main body 5 to the main body 1, the ring member 33 has the communication passage 34 and the pressure passage 26.
Since it is communicated with the discharge passage 27 via the shaft, the rotational driving force of the external gear 10 is not transmitted to the pump body 5 apart from the outer peripheral surface of the drive shaft 14 by the self-expanding force, and the pressing member 30 of the pressure control means 23 is used. Since the communication passage 34 communicates with the discharge passage 25 through the pressure passage 26 when the pump main body 5 is released from pressing the main body 1, the discharge pressure of the discharge passage 25 resists the self-expanding force. So that the bottom is pressed against the outer peripheral surface of the drive shaft 14 and the side is pressed against the side surface of the annular groove 32 so that the rotary drive of the external gear 10 is transmitted to the pump main body 5 so as to be contactable with and separable from the outer peripheral surface of the drive shaft ing.

Next, the operation of this configuration will be described.

In the first illustrated state, the pressing member 30 presses the pump main body 5 against the main body 1 by the force of the spring 29, and the spool 28 causes the pressure passage 26 and the discharge passage.
25 is cut off, the pressure passage 26 and the discharge passage 27 are communicated with each other, and the annular groove 32
Is communicated with the low pressure side through the communication passage 34, the pressure passage 26, and the discharge passage 27, the ring member 33 is separated from the outer peripheral surface of the drive shaft 14 by the self-expanding force, and the pump body 5 is prevented from rotating. When the drive shaft 14 is rotated to the right in this state from this state, the external gear 11 rotates in the same direction as the external gear 11A internally meshes with the internal gear 10A of the internal gear 10, and sucks the internal gear 10. The liquid sucked into the expansion area space 15 from the flow path 17 is conveyed to the pressure feeding area space 16 and discharged from the discharge flow path 18 to obtain the maximum discharge amount. The discharge pressure of the discharge flow path 18 is the set pressure based on the force of the spring 29, that is, in FIG.
When the spool 28 rises to the P1 point, the spool 28 moves to the right from the first illustrated state position so that the pressure passage 26 and the discharge passage 25 communicate with each other.
The pressing member 30 separates from the pump main body 5 to release the pressing of the pump main body 5 against the main body 1, and allows the pump main body 5 to rotate. The discharge pressure of the discharge passage 18 acts on the ring member 33 from the discharge passage 25 through the pressure passage 26 and the communication passage 34 against the self-expanding force of the ring member 33, and the bottom portion of the ring member 33 has the drive shaft 14 at its bottom. The side surface is pressed against the outer peripheral surface and the side surface is pressed against the side surface of the annular groove 32 to transmit the rotational driving force of the external gear 11 to the pump main body 5, and the pump main body 5 rotates synchronously with the external gear 11. Therefore, the amount of liquid transported from the expansion region space 15 to the pressure-feeding region space 16 becomes substantially zero, and the discharge amount from the discharge flow path 18 becomes the third amount.
It decreases to almost zero as shown in the figure. When the discharge amount from the discharge flow path 18 is substantially zero, the discharge pressure of the discharge flow path 18 decreases and the spring 29
When the set pressure based on the force is not reached, the spool 28, the pressing member 30, and the ring member 33 each return to the first illustrated state, the pump body 5 is prevented from rotating, and the maximum discharge amount from the discharge passage 18 is obtained. To be

In this operation, when the discharge pressure of the discharge flow path 18 rises to the set pressure based on the force of the spring 29, the pump body 5 rotates synchronously with the external gear 11, and the liquid from the expansion area space 15 to the pressure feeding area space 16 The discharge amount from the discharge flow path 18 is reduced to substantially zero by setting the carry amount of the discharge liquid to substantially zero, and thus the discharge pressure can be favorably controlled without wasting the discharge liquid.

FIG. 4 shows another embodiment of the present invention. The same parts as those of the first embodiment are designated by the same reference numerals and only different parts will be described. Reference numeral 35 denotes a tubular portion integrally formed with the pump main body 5, which projects outward from the main body 1 and is connected to an electric motor 37 having a variable rotation speed via a one-way clutch 36. The electric motor 37 rotates in the same direction as the drive shaft 14 at a rotation speed lower than the rotation speed of the drive shaft 14. 38 is the rotational speed of the tubular portion 35, that is, the pump body 5
The encoder that detects the number of revolutions of the engine and issues a signal according to the detected number of revolutions, 39 is a setter that issues a setting signal that sets the number of revolutions, 40 is a comparator, which is a signal from the encoder 38 and the setter 39 The set signals are compared, and the rotation speed of the electric motor 37 is controlled so that the difference becomes zero.

Next, the operation will be described.

When the setting device 39 issues a desired setting signal to control the electric motor 37 to a desired number of revolutions, the rotational driving force is transmitted to the tubular portion 35 via the one-way clutch 36, and the pressing member 30 of the pump body 5 moves. Although being pressed to prevent rotation, the pump body 5 rotates against the pressing force of the pressing member 30 at the number of rotations set by the setting device 39. The rotation speed of the pump main body 5 is lower than the rotation speed of the drive shaft 14, and the pump main body 5 rotates relative to the external gear 11 to obtain the maximum discharge amount of the discharge passage 18 according to the relative rotation amount. . The maximum discharge amount can be changed as desired by changing the setting signal to the setter 39 so that the relative rotation amounts of the pump body 5 and the external gear 11 are different and can be changed to Q1, Q2, Q3 shown in FIG. When the discharge pressure of the discharge passage 18 rises to the set pressure based on the spring 29, the rotational driving force of the external gear 11 is transmitted to the pump body 5 by the ring member 33, and the pump body 5 rotates synchronously with the external gear 11. However, the discharge amount is reduced to substantially zero as in the first embodiment. At this time, the rotation speed of the pump body 5 is higher than that of the electric motor 37, so that the one-way clutch 36 slips, and the rotational driving force of the electric motor 37 is not transmitted to the pump body 5.

[Effect of device]

As described above, according to the present invention, the internal gear having the internal teeth and the external gear having the external teeth are rotatably housed in the pump body so as to eccentrically and internally mesh with each other. The pump main body is connected to the expansion region space and the pressure feeding region space, which are formed to face each other between the internal gear and the external gear so that the internal gear is driven to rotate and sucks and discharges the liquid. The pump main body is rotatably housed in the main body, and when the discharge pressure of the discharge flow passage and the set pressure based on the spring force act oppositely and the discharge pressure of the discharge flow passage does not reach the set pressure, the pump The body is equipped with pressure control means that presses the pump body to prevent rotation of the body and releases the pressure of the pump body to allow rotation of the pump body when the discharge pressure in the discharge passage rises to a set pressure. , Pressure control means between external gear and pump body When pressing the pump body, the rotational drive force of the external gear is not transmitted to the pump body, and when the pressure control means releases the pressing of the pump body, the pump body rotates synchronously with the external gear. Since the rotational drive force transmission means for transmitting the rotational drive force of the external gear to the pump body is provided, the discharge amount is reduced to almost zero when the discharge pressure in the discharge flow path rises to the set pressure of the pressure control means. Therefore, the discharge pressure can be excellently controlled without wasting the discharge liquid.

Further, since the rotational drive force of the external gear is transmitted to the pump main body to rotate the pump main body synchronously with the external gear, the rotary drive source for rotating the pump main body synchronously with the external gear is special. There is an effect that can be done without requiring.

[Brief description of drawings]

1 to 3 show an embodiment of the present invention.
FIG. 1 is a longitudinal sectional view of an internal gear pump, FIG. 2 is a sectional view taken along line II-II in FIG. 1, FIG. 3 is a pump characteristic diagram of one embodiment, and FIG. FIG. 5 is a partial view of an internal gear pump showing another embodiment, and FIG. 5 is a pump characteristic view of another embodiment of the present invention. 1 ... Main body, 5 ... Pump main body, 10 ... Internal gear, 11 ... External gear, 1
7 ... Suction flow path, 18 ... Discharge flow path, 23 ... Pressure control means, 31 ... Rotational driving force transmission means.

Claims (1)

[Scope of utility model registration request] 1. An internal gear having internal teeth and an external gear having external teeth are rotatably housed in a pump body so as to eccentrically and internally mesh with each other, and the internal gear is driven by rotation of the external gear. So as to be driven to rotate to suck and discharge the liquid, the suction body and the discharge passage of the liquid are provided in the pump main body by respectively communicating with the expansion region space and the pressure feeding region space which are formed opposite to each other between the internal gear and the external gear. The pump body is rotatably accommodated in the body, and the pump body rotates when the discharge pressure of the discharge flow passage and the set pressure based on the spring force act oppositely and the discharge pressure of the discharge flow passage does not reach the set pressure. To prevent the pump body from rotating and to release the pressure of the pump body to allow the rotation of the pump body when the discharge pressure in the discharge channel rises to the set pressure. Between the gear and the pump body, the pressure control means is the pump main When pressing, the rotational drive force of the external gear is not transmitted to the pump body, and when the pressure control means releases the pressing of the pump body, the external gear is rotated so as to rotate in synchronization with the external gear. An internal gear pump provided with a rotational drive force transmission means for transmitting rotational drive force of a gear to a pump body.