JP6347478B2 - Pump device - Google Patents

Description

  The present invention relates to an internal gear pump.

The gear pump includes an external gear pump and an internal gear pump (for example, trochoid pump: registered trademark).
Conventionally, the internal gear pump is used in a relatively low pressure region as compared with the external gear pump.
In recent years, an internal gear pump using a coolant (coolant, cutting fluid) as a working fluid has been proposed (see, for example, Patent Document 1).

However, since hard foreign matter (particles) exists in the coolant, the hard foreign matter causes the rotor of the internal gear pump to wear.
When the rotor is worn, a gap is formed between the end surfaces (side surfaces) of the inner rotor and the outer rotor, resulting in a problem that the volumetric efficiency is lowered and the discharge amount is lowered.
At the present time, no effective countermeasure has been proposed for the problem associated with the internal gear pump.

International Publication No. 2012/053231

  The present invention has been proposed in view of the above-described problems of the prior art, and suppresses the wear of the rotor of the internal gear pump, suppresses the formation of gaps at the end surfaces (side surfaces) of the inner rotor and the outer rotor, and reduces the volume. It aims at providing the pump apparatus which can prevent the fall of efficiency.

The pump device (100 to 100C, 200 to 200C) of the present invention has an internal gear pump (10) in which an inner rotor (13, 213) is inscribed in an outer rotor (12, 212), and the rotor (outer rotor) 12 and 212 and inner rotors 13 and 213) are provided with plate-like members (balance plates 7, 7A, 207, and 207A) on end surfaces (suction-side end surfaces: end surfaces that are separated from the drive source). The plates 7, 7A, 207, 207A) are made of a material having a hardness higher than that of the foreign matter in the coolant, and have a shape that does not block the suction port (150, Pi), and through holes (discharge pressure introduction holes 73, 73A) are formed. O-ring grooves (71, 71A, 72, 72A, 207a, 207b, 207k, which have a continuous shape and accommodate O-rings, 07J) is formed, a plate-like member (7,7A, 207,207A) of O- ring groove (71,71A, 72,72A, 207a, 207b , 207k, regions (E2 surrounded by 207j)) In this case, the discharge pressure of the internal gear pump (10) acts through the through holes (73, 73A) to press the plate-like members (7, 7A, 207, 207A) against the rotor (12, 13), and the outer rotor The discharge pressure of the inscribed gear pump (10) also acts on the region (E1) that is the gap between the inner rotor (13) and the inner rotor (13), and presses in a direction away from the rotor (12, 13), so that a plate-like member ( 7 (7A, 207, 207A), the area (E2) where the discharge pressure is introduced is the area (E1) where the discharge pressure in the gap between the outer rotor (12, 212) and the inner rotor (13, 213) acts. Area of The plate-like members (7, 7A, 207, 207A) are pressed toward the discharge side (the rotors 12, 13 side), which is set to be larger (E1 area <E2 area). It is said.

  In the present invention, the O-ring grooves (71, 72, 207a, 207b) are formed on the surface of the plate member (balance plate 7, 207) on the side separated from the rotor, and the O-ring is an O-ring. The groove (71, 72, 207a, 207b) is preferably mounted with a specified interference.

  Alternatively, in the present invention, it is preferable to form a blind space (blind hole BH) on the opposite side of the rotor of the plate-like member (balance plates 7A, 207A) and accommodate the elastic member (9) in the blind space.

  In the present invention, a second plate member (fixed plate 8) is disposed on the end surface of the rotor opposite to the plate member (balance plates 7, 7A, 207, 207A), and the second plate member ( 8) preferably has a shape that does not block the discharge port (140).

In the present invention, in the internal gear pump, the working fluid suction side and the discharge side may be arranged on different sides with respect to the rotation axis direction of the rotor.
Alternatively, the suction side and the discharge side of the working fluid may be arranged on the same side in the rotation axis direction of the rotor.

According to the present invention having the above-described configuration, plate-like members (balance plates 7, 7A, 207, 207A) are provided on the end surfaces (suction side end surfaces: end surfaces separated from the driving source) of the rotor (outer rotor and inner rotor). The plate-like member (balance plates 7, 7A, 207, 207A) is made of a material having high hardness and has a shape that does not block the suction port (150, Pi), and has a through hole (discharge pressure introduction hole 73). 73A), the plate-like member (7, 7A) is formed through the gap between the outer rotor (12, 212) and the inner rotor (13, 213) and the through hole (discharge pressure introducing hole 73, 73A). , 207, 207A), the discharge pressure (or pressurized working fluid) is introduced on the side away from the rotor.
Here, O-ring grooves (71, 71A, 72, 72A, 207a, 207b, 207k, 207j) are formed in the plate-like members (balance plates 7, 7A, 207, 207A), and the O-rings are formed. Since they are fitted, even if the discharge pressure is introduced into the plate-like members (7, 7A, 207, 207A) and the pressurized working fluid is supplied, leakage is prevented by the O-ring.

The area of the plate member (7, 7A, 207, 207A) where the discharge pressure is introduced is the area where the discharge pressure in the gap between the outer rotor (12, 212) and the inner rotor (13, 213) acts. Therefore, the plate-like members (7, 7A, 207, 207A) are pressed against the rotor side (the discharge side of the first to fourth embodiments: the left side of FIG. 1). Is done.
Even if the discharge pressure becomes zero or negative pressure, it is pressed by the interference of the O-ring and the elastic repulsive force of the elastic member (spring 9), so the rotor (12, 13, 212, 213) and the plate-like member ( 7, 7A, 207, 207A).

According to the present invention, since the plate-like members (7, 7A, 207, 207A) are made of a material having high hardness, they do not wear. On the other hand, the side surfaces of the rotor (12, 13, 212, 213) are worn, but the plate-like members (7, 7A, 207, 207A) pressed against the rotor are not worn and are kept flat. The side surfaces of the rotor (12, 13, 212, 213) are not worn unevenly. And about the part for which the rotor (12, 13, 212, 213) was worn out, the plate-like member (7, 7A, 207, 207A) is moved to the rotor side to reduce the clearance (gap). . As a result of the clearance (gap) being reduced, the volumetric efficiency is improved according to the pump device of the present invention.
Since the plate-like members (7, 7A, 207, 207A) have a shape that does not block the suction port (150, Pi) side, providing the plate-like members (7, 7A, 207, 207A) The intake of the working fluid into the contact gear pump is not hindered.

Here, since the force pressing the plate-like member (7, 7A, 207, 207A) to the rotor side is obtained from the discharge pressure of the internal gear pump, the discharge pressure is applied to the plate-like member when the internal gear pump is started. Does not work.
However, in the present invention, the plate-like member (7, 7A, 207, 207A) can be pressed to the rotor side by a mechanical force other than the discharge pressure of the internal gear pump.
For example, an O-ring is placed on the opposite side of the plate-like member (7, 207) from the rotor, and the O-ring is mounted in the O-ring groove (71, 72, 207a, 207b) with a specified interference. The elastic repulsive force of the O-ring acts on the plate members (7, 207), thereby pressing the plate members (7, 207) toward the rotor.
Alternatively, a blind space (blind hole BH) is formed on the end surface of the plate-like member (7A, 207A) on the opposite side of the rotor, and the elastic member (9) is accommodated in the blind space. : Spring repulsive force acts on the plate-like members (7A, 207A) to press the plate-like members (7A, 207A) toward the rotor.

Accordingly, in the present invention, the plate-like members (7, 7A, 207, 207A) are pressed toward the rotor even when the internal gear pump is started.
As described above, the plate-like members (7, 7A, 207, 207A) made of a material having high hardness do not wear and maintain a flat state, so the rotor (12, 13, 212) pressed there 213) The side surfaces do not wear unevenly. Then, the plate-like member (7, 7A, 207, 207A) is moved to the rotor side by the amount of wear of the rotor (12, 13, 212, 213), and the clearance (gap) is reduced (due to wear). Efficiency is improved.

It is front sectional drawing which shows 1st Embodiment of this invention. It is a side view of the rotor of the internal gear pump in 1st Embodiment. It is a figure which shows the balance plate in 1st Embodiment. It is a fragmentary sectional front view which shows the balance plate vicinity in 1st Embodiment. It is a figure which shows the fixed plate in 1st Embodiment. It is front sectional drawing which shows 2nd Embodiment of this invention. It is front sectional drawing which shows 3rd Embodiment of this invention. It is a figure which shows the balance plate in 3rd Embodiment. It is a partial section front view showing the balance plate neighborhood in a 3rd embodiment. It is front sectional drawing which shows 4th Embodiment of this invention. It is front sectional drawing which shows 5th Embodiment of this invention. It is a side view (Y arrow line view of FIG. 11) of 5th Embodiment. It is front sectional drawing which shows 6th Embodiment of this invention. It is front sectional drawing which shows 7th Embodiment of this invention. It is front sectional drawing which shows 8th Embodiment of this invention.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
First, a first embodiment of the present invention will be described with reference to FIGS.
In FIG. 1, the pump apparatus denoted as a whole by reference numeral 100 has an internal gear pump 10.
The internal gear pump 10 includes a gear case 11, an outer rotor 12, and an inner rotor 13. In FIG. 1, reference numeral 14 denotes a pump housing, and reference numeral 15 denotes a pump lower end plate (hereinafter abbreviated as “end plate”). The inner rotor 13 is fixed to the rotating shaft 5 by a key (not shown).
FIG. 2 shows a mode of pressurizing the working fluid by meshing the outer rotor 12 and the inner rotor 13.

2, the internal gear pump 10 of the embodiment rotates in the same direction (arrow R) while the seven inner teeth 12t of the outer rotor 12 and the six outer teeth 13t of the inner rotor 13 are engaged. ing.
The working fluid is pressurized by the meshing of the seven inner teeth 12 t of the outer rotor 12 and the six outer teeth 13 t of the inner rotor 13.

In FIG. 2, the working fluid in the hatched region E1 is pressurized.
The working fluid whose pressure has been increased in the region E1 (FIG. 2) is discharged from a discharge port 140 (shown by a broken line in FIG. 2) formed on the end face on the rotors 12 and 13 side to the discharge flow path of the pump housing 14 (FIG. 1). 1 is discharged from the discharge port 142 via 141.

In FIG. 1, the pump device 100 is provided with a primary cyclone 40 in a cyclone casing 45, and a plurality of secondary cyclones 50 are provided outward in the radial direction of the primary cyclone 40. The primary cyclone 40 and the secondary cyclone 50 are tapered members whose lower ends (foreign matter discharge ports 42 and 52) are reduced in diameter. In the vicinity of the lower end of the cyclone casing 45, an inflow port 45i for taking in the working fluid is formed.
Further, the pump device 100 includes an impeller 30 (cyclonic relay impeller) accommodated in the impeller housing 31.

A tapered guide member 55 is disposed below the primary cyclone 40, and a foreign matter discharging impeller 60 is provided further below.
The inner rotor 13, the cyclone relay impeller 30, and the foreign matter discharging impeller 60 are fixed to the rotary shaft 5 and are rotationally driven by an electric motor (not shown).

The flow (F1-F11: Fc1-Fc4) of the working fluid taken in from the inflow port 45i of the pump apparatus 100 is demonstrated.
The working fluid F1 taken in from the inflow port 45i ascends in the cyclone casing 45 (arrow F2), is folded at the ceiling of the guide member 312 and flows into the primary cyclone 40 (arrow F3).

The working fluid that has flowed into the primary cyclone 40 is dragged down by the rotating shaft 5 (arrow F4), and foreign matter having a large specific gravity (for example, foreign matter such as chips contained in the coolant) is discharged from the foreign matter discharge port 42. (Arrow Fc1 indicated by a dotted line), the clean working fluid rises to the position of the cyclone relay impeller 30 (arrow F5).
As the cyclone relay impeller 30 rotates, the working fluid is pressurized and flows into the secondary impeller 50 (arrow F6).

The working fluid that has flowed into the secondary cyclone 50 descends in a vortex (arrow F7), and a foreign substance having a large specific gravity descends and is discharged from the foreign substance discharge port 52, and slides down the tapered guide member 55 (arrow Fc2 indicated by a dotted line). ) The working fluid cleaned in two stages rises and flows through the suction pipe 21 provided on the suction plate 20 (arrow F8).
The working fluid passes through the flow path 22 of the suction plate 20 and is sucked into the internal gear pump 10 from the suction port 150 of the end plate 15 (arrow F9). Then, the pressure is increased by the internal gear pump 10 and discharged from the discharge port 142 of the pump housing 14 via the discharge port 140 and the discharge flow path 141 of the pump housing 14 (arrow F10, arrow F11). Although details will be described later, a part of the working fluid pressurized by the internal gear pump 10 (indicated by an arrow F10R) flows into a discharge pressure introducing hole 73 (FIG. 3) formed in the balance plate 7.
The working fluid (arrows Fc1 and Fc2) containing foreign matter discharged from the foreign matter discharge port 42 of the primary cyclone 40 and the foreign matter discharge port 52 of the secondary cyclone 50 is given dynamic pressure by the foreign matter discharge impeller 60 ( The arrow Fc3) is discharged out of the pump from the foreign matter discharge port 63 (arrow Fc4).

The pump device 100 shown in FIG. 1 has different working fluid suction sides (end plate 15 side) and discharge sides (pump housing 14 side) in the direction of the rotation shaft 5 of the internal gear pump 10 (vertical direction in FIG. 1). It is the type of pump that is arranged in.
As a rule of thumb that the inventor has grasped, in such a type of pump device, the rotors 12 and 13 of the internal gear pump 10 are arranged on the end plate 15 side (suction side: the lower side in FIG. 1), but on the pump housing 14 side ( A phenomenon occurs in which the wear amount is larger than that on the discharge side (upper side in FIG. 1).

In order to suppress the level difference caused by the wear in the rotors 12 and 13, the balance plate 7 (see FIG. 3) is arranged on the end plate 15 side (suction side: lower side in FIG. 1) in the gear pump 10 of the pump device 100. Has been. The balance plate 7 is made of a material having high hardness.
In FIG. 1, a balance plate mounting hole 15 h is formed in a surface 15 f that contacts the rotors 12 and 13 of the end plate 15, and the depth dimension of the balance plate mounting hole 15 h is slightly smaller than the thickness dimension of the balance plate 7. large. The balance plate 7 is mounted in the balance plate mounting hole 15h.

As shown in FIG. 3, the balance plate 7 has a planar shape in which two semicircles 7oa (large semicircle) and 7ob (small semicircle) having different radii connect the bases of each other.
In the portion where the semicircles 7oa and 7ob are connected, the semicircles 7oa and 7ob are smoothly connected via an arc r having a small radial dimension.
In FIG. 3, the center of curvature of the large semicircle 7 oa is denoted by reference symbol C1, and the center of curvature of the small semicircle 7 obs is denoted by reference symbol C2. In FIG. 3, the two curvature centers C1 and C2 are offset (in the vertical direction in FIG. 3).

O-ring grooves 71 and 72 are formed on the plane of the balance plate 7, and the O-ring grooves 71 and 72 are formed in an annular shape in plan view, and the cross-sectional shape thereof is rectangular.
The center C3 of the smaller O-ring groove 72 (radial dimension) is located on a horizontal line Lh (a one-dot chain line extending in the left-right direction in FIG. 3) passing through the center of curvature C1, and the center of curvature C1. On the other hand, it is offset to the left in FIG.
A through hole 7 i is formed inward of the small O-ring groove 72 in the radial direction. The through hole 7 i is concentric with the O-ring groove 72, and the radius of the through hole 7 i is smaller than the radius of curvature of the small O-ring groove 72. And the rotating shaft 5 (FIG. 1) is penetrated by the through-hole 7i.

Although not shown in FIGS. 1 and 3, O-rings (elastic members resistant to working fluid: made of rubber, for example) are inserted into the O-ring grooves 71 and 72.
At the bottom of the balance plate mounting hole 15h (see FIG. 1), an area E2 (in FIG. 3) surrounded by the two O-ring grooves 71 and 72 shown in FIG. The hatched area) is a sealed space (sealed space).
In the sealed space (the region E2 surrounded by the O-ring grooves 71 and 72 in FIG. 3: the hatched region in FIG. 3), two through-holes extending in the thickness direction of the balance plate 7 ( A discharge pressure introduction hole) 73 is formed, and a working fluid (working fluid indicated by an arrow F10R) enters through the through hole 73. The working fluid that has entered the sealed space (the hatched region E2 in FIG. 3) applies a pressing force that moves the balance plate 7 upward in FIG. 1 and presses the balance plate 7 against the rotors 12 and 13. .
The two discharge pressure introduction holes 73 of the balance plate 7 are arranged so that one of them is blocked by the inner rotor 13 and the other is not blocked.

Reference numeral 74 in FIG. 3 is a pin hole for inserting a non-illustrated detent pin. A rotation prevention pin (not shown) prevents the balance plate 7 from rotating (rotating due to the rotation of the rotating shaft 5).
Note that the pin hole 74 is a blind hole, and is open to the side where the O-ring grooves 71 and 72 are formed.

In FIG. 1, a fixed plate 8 is disposed on the upper side of the rotors 12 and 13 (on the opposite side of the balance plate 7) so as to be in contact with the rotors 12 and 13. The fixed plate 8 is made of a material having higher hardness than the rotors 12 and 13. Furthermore, it is preferable that the hardness is higher than a foreign substance that may be mixed in the coolant.
FIG. 5 shows details of the fixed plate 8.
In FIG. 5, the suction port 82 and the discharge port 81 are formed in the fixed plate 8. However, the suction port 82 of the fixed plate 8 may not be formed. When the suction port 82 of the fixed plate 8 is not formed, a seal pressure relief hole (not shown) needs to communicate with the suction chamber.

The fixed plate 8 (fixed plate in the first embodiment) of FIG. 5 is a pump of the type in which the suction side and discharge side of the working fluid are arranged on the same side in the rotational axis direction of the inner rotor (FIGS. 11 to 15). In order to make common with the fixed plate (common parts) in FIG. 2), only the suction port 82 and the discharge port 81 are formed. Here, when the rotation directions are different, the fixed plate in the pump (FIGS. 11 to 15) is turned over and used.
Reference numeral 84 in FIG. 5 is a mounting hole for the rotation stop pin, and reference numeral 8 i is an insertion hole for the rotating shaft 5.

In the internal gear pump 10, the gap between the outer rotor 12 and the inner rotor 13 is continuous from the suction side (lower side in FIG. 1) to the discharge side (upper side in FIG. 1). Accordingly, the discharge pressure of the internal gear pump 10 is determined in the gap between the outer rotor 12 and the inner rotor 13 (arrow F10R) and the discharge pressure introduction hole formed in the balance plate 7 in the pump rotation axis direction (vertical direction in FIG. 1). 73 is introduced to the lower end surface of the balance plate 7 in FIG. 1 (the bottom of the balance plate mounting hole 15h) and supplied (applied) to the sealed space (the hatched region E2 in FIG. 3). . Then, the balance plate 7 is pressed against the rotors 12 and 13 (upward in FIG. 1).
On the other hand, in FIG. 2, a hatched area E1 is a gap between the outer rotor 12 and the inner rotor 13 at a certain moment, and indicates an area where discharge pressure acts. And the discharge pressure of the area | region E1 which gave the hatching acts so that the balance plate 7 may be pressed below FIG. 1 (the direction away from the rotors 12 and 13).
As is clear from FIG. 2 and FIG.
Since the area of E <b> 1 is set to satisfy the area of E <b> 2, the pressure applied to the E <b> 2 side having the larger area (the lower side of the balance plate 7 in FIG. 1) is the E <b> 1 side having the smaller area (FIG. 1). The pressure applied to the upper side of the balance plate 7 in FIG. As a result, the balance plate 7 is pressed to the discharge side (upper side in FIG. 1: rotors 12 and 13 side).

Here, if the force that presses the balance plate 7 toward the discharge side (the upper side in FIG. 1) is too strong, the pressure applied to the region E2 side prevents the rotors 12 and 13 from rotating. On the other hand, if the force that presses the balance plate 7 toward the rotors 12 and 13 (the upper side in FIG. 1) is too weak, the volumetric efficiency decreases due to wear at the ends of the rotors 12 and 13.
In order to prevent such a problem from occurring, in the first embodiment, the position of the O-ring (that is, the position of the O-ring grooves 71 and 72) is determined. In other words, the positions of the O-ring grooves 71 and 72 do not hinder the rotation of the rotors 12 and 13 due to the pressure applied to the region E2, and the balance plate 7 is on the rotors 12 and 13 side (see FIG. 1). The volume efficiency is set at a position where the volume efficiency due to wear at the ends of the rotors 12 and 13 can be prevented from being lowered.
In the actual machine, the area of the region E2 is determined by experiment because it is affected by the pressure gradient of the discharge pressure leaking from the region E1 to the outer periphery of the outer rotor 12 and the inner periphery of the inner rotor 13.

In FIG. 3, the area E2 surrounded by the two O-ring grooves 71 and 72 is extremely small on the suction port (area indicated by the broken line Li in FIG. 3) side (lower side in FIG. 3). 140 (area Lo surrounded by a two-dot chain line in FIG. 3) is set to be large. This is because the pump discharge pressure is higher than the suction pressure, so that the pump discharge side region Lo on which the discharge pressure of the balance plate 7 acts is pressed against the rotors 12 and 13 with a large pressure. That is, the two O-ring grooves 71 and 72 press the pump discharge side region Lo, which is a region where the discharge pressure acts, in the balance plate 7 against the rotors 12 and 13 with a large pressure. , 13 is set so that the amount of pressing is equal.
On the other hand, the balance plate 7 has a shape that does not block the suction port 150 (reference numeral Li in FIG. 3) and does not prevent the working fluid from being sucked into the internal gear pump 10. In other words, on the suction side (lower side in FIG. 1), the region not blocked by the balance plate 7 constitutes the suction port 150 of the internal gear pump 10.

The balance plate 7 having such a structure presses the suction side (lower side in FIG. 1) end surfaces of the rotors 12 and 13 against the discharge side (upper side in FIG. 1) by the discharge pressure of the internal gear pump 10.
As described above, since the balance plate 7 is made of a material having high hardness, it does not wear and maintains a flat state. Therefore, the side surfaces of the rotors 12 and 13 pressed against the balance plate 7 do not wear unevenly. And about the part to which the rotors 12 and 13 were worn, the balance plate 7 moves to the rotors 12 and 13 side, and the clearance (gap) by wear decreases. Therefore, the volumetric efficiency of the internal gear pump 10 is improved.

As described above, the force pressing the balance plate 7 against the suction side (lower side in FIG. 1) end faces of the rotors 12 and 13 is obtained from the discharge pressure of the internal gear pump 10. Therefore, the discharge pressure does not act on the balance plate when the internal gear pump 10 is started.
On the other hand, in the first embodiment, an O-ring having a cross-sectional diameter larger than the depth of the O-ring grooves 71 and 72 is mounted in the O-ring grooves 71 and 72. As shown, the elastic repulsive force Fr of the O-ring OR acts on the O-ring grooves 71 and 72, and the balance plate 7 is attached to the rotor 12, by the elastic repulsive force Fr (acting upward in FIG. 4). 13 (not shown in FIG. 4) is pressed against the lower end surface.
In other words, in the first embodiment, for example, the initial pressure for pressing the balance plate 7 against the lower end surfaces of the rotors 12 and 13 at the time of startup is obtained by the elastic repulsive force Fr of the O-ring. Therefore, even when the discharge pressure of the internal gear pump 10 does not act on the balance plate 7, the balance plate 7 is pressed against the lower end surfaces of the rotors 12 and 13 in FIG. 4. Here, the balance plate 7 made of a material having high hardness does not wear and maintains a flat state, so that the side surfaces of the rotors 12 and 13 pressed against the balance plate 7 are worn unevenly. In other words, the formation of steps on the side surfaces of the rotors 12 and 13 is suppressed. Then, when the rotors 12 and 13 are worn, the balance plate 7 moves toward the rotors 12 and 13 and the clearance (gap) due to wear is reduced. As a result, the volumetric efficiency of the internal gear pump 10 is improved.

Next, a second embodiment of the present invention will be described with reference to FIG. In FIG. 6, the pump apparatus is generally indicated by reference numeral 100A.
In the first embodiment shown in FIGS. 1 to 5, the fixed plate 8 (FIG. 5) is provided on the discharge side of the internal gear pump 10 (above the rotors 12 and 13 in FIG. 1).
On the other hand, in 2nd Embodiment of FIG. 6, the fixed plate is not provided. From the inventors' experiments, it has been found that the rotor 12 and 13 are not significantly worn on the pump housing 14 side (discharge side: above the rotors 12 and 13 in FIG. 6). Therefore, the fixed plate can be omitted depending on the required specifications.
Other configurations and operational effects in the second embodiment of FIG. 6 are the same as those of the first embodiment of FIGS.

A third embodiment of the present invention will be described with reference to FIGS. In FIG. 7, the pump device is generally indicated by reference numeral 100B.
In the first and second embodiments of FIGS. 1 to 6, as shown in FIG. 4, when the internal gear pump 10 is started, the initial pressure (on the upper side in FIG. 1) is pressed against the balance plate 7 (the upper side). (For example, the force that presses the balance plate 7 against the end surfaces of the rotors 12 and 13 at the time of activation is obtained by the elastic repulsive force Fr of the O-ring).
On the other hand, in the third embodiment shown in FIGS. 7 to 9, the balance is not generated when the internal gear pump 10 is started by the elastic repulsive force of the spring (coil spring) 9 rather than the elastic repulsive force of the O-ring. An initial pressure (force that presses the balance plate 7A against the end faces of the rotors 12 and 13; force that moves upward in FIG. 9) is obtained to press the plate 7A toward the discharge side (upper side in FIG. 7).

As is apparent from a comparison between FIG. 9 and FIG. 4, in the third embodiment, the position of the O-ring grooves 71A, 72A or the O-ring OR (see FIG. 9) in the balance plate 7A is the same as that in the first embodiment. This is different from the second embodiment (see FIG. 4).
In FIG. 4 (first embodiment, second embodiment), the O-ring grooves 71 and 72 or the O-ring OR in the balance plate 7 are formed on the suction side (lower side in FIG. 4) end surface of the balance plate 7. Yes.
On the other hand, in FIG. 9 (third embodiment), the O-ring grooves 71A, 72A or the O-ring OR in the balance plate 7A are arranged on the suction side of the balance plate 7A in the rotation axis direction (vertical direction in FIG. 9). (Lower in FIG. 9) An area between the end face and the discharge side (upper part in FIG. 9) end face is disposed at a position along the outer peripheral face and inner peripheral face of the balance plate 7A. The inner O-ring 72 </ b> A faces the bush BS fitted and fixed to the end plate 15.

As shown in FIG. 9 (and FIG. 7), a blind hole BH is formed on the suction side (lower side of FIG. 7) end surface of the balance plate 7A, and a spring 9 is accommodated in the blind hole BH. Yes. The spring 9 is accommodated in a compressed state, and an elastic repulsive force acts in the direction in which the spring 9 extends.
As a result, the balance plate 7A is pressed against the discharge side (the upper side in FIGS. 7 and 9) by the elastic repulsion force of the spring 9 (the force by which the spring 9 extends), and the initial pressure (for example, startup) when the internal gear pump 10 is started. In some cases, a force for pressing the balance plate 7A against the end faces of the rotors 12 and 13 is obtained.

In FIG. 8, reference numeral 73A indicates a discharge pressure introducing hole 73, and reference numeral 74A indicates a mounting hole for a rotation stop pin.
Further, circles (dashed lines) indicated by G at both the left and right ends in FIG. 8 indicate contact positions of the two springs 9 set in the balance plate mounting hole 15h.
Note that the fixed plate 8 in the third embodiment is the same fixed plate 8 as in the first embodiment.

In the third embodiment in which the initial pressure at the start of the inscribed gear pump is obtained by the elastic repulsive force of the spring 9, the first embodiment and the second embodiment in which the initial pressure is obtained by the elastic repulsive force of the O-ring. In comparison, the amount (movement amount) of pressing the balance plate 7 </ b> A with elastic repulsion can be set larger than in the first and second embodiments.
Therefore, in the third embodiment, even when the amount of wear of the rotors 12 and 13 increases, the balance plate 7A that is made of a material having high hardness and does not wear and maintains a flat state is appropriately pressed against the side surfaces of the rotors 12 and 13. . Therefore, formation of a step on the side surfaces of the rotors 12 and 13 is suppressed. And since the balance plate 7 moves to the rotor 12 and 13 side and the clearance (gap) by wear reduces for the part which the rotors 12 and 13 wear, volume efficiency improves.
Other configurations and operational effects in the third embodiment of FIGS. 7 to 9 are the same as those of the embodiment of FIGS.

Next, a fourth embodiment of the present invention will be described with reference to FIG. In FIG. 10, the entire pump apparatus is indicated by reference numeral 100C.
In the third embodiment of FIGS. 7 to 9, a fixed plate 8 (similar to FIG. 5) is provided on the discharge side (upper side in FIG. 7) of the internal gear pump. On the other hand, in 4th Embodiment of FIG. 10, the fixing plate is not provided.
Other configurations and operational effects in the fourth embodiment of FIG. 10 are the same as those of the third embodiment of FIGS.

Next, a fifth embodiment of the present invention will be described with reference to FIGS. In FIG. 11, the pump apparatus is generally designated by the reference numeral 200.
The first to fourth embodiments of FIGS. 1 to 10 are pump devices of the type in which the suction side and discharge side of the working fluid are arranged on different sides with respect to the rotation axis direction of the inner rotor 13. It is the applied embodiment.
On the other hand, in the fifth embodiment of FIGS. 11 to 14, the working fluid is applied to a pump device in which the suction side and the discharge side of the working fluid are arranged on the same side with respect to the rotation axis direction of the inner rotor 213. It is a form.

11 and 12, the pump apparatus denoted as a whole by reference numeral 200 includes a rotation shaft 205, a gear case 211, an outer rotor 212, an inner rotor 213, a pump housing 214, an end cap 215, and a support member 216. Have. The support member 216, the pump housing 214, the gear case 211, and the end cap 215 are fixed to one body by two through bolts B1 and a washer nut NW. The support member 216 and the pump housing 214 are fastened by a bolt B2, and the end cap 215, the gear case 211, and the pump housing 214 are fastened by a bolt B3.
The rotary shaft 205 passes through the pump housing 214 and the inner rotor 213, and is supported by a bearing BG interposed in the pump housing 214 and a bearing BS interposed in the end cap 215.
Here, symbol K denotes a key for fixing the inner rotor 213 to the rotating shaft 205, symbol SW denotes a thrust washer, and symbol MS denotes an oil seal.

11, a balance plate mounting hole (blind hole) 215H for mounting the balance plate 207 is formed on the surface of the end cap 215 that contacts the rotors 212 and 213 (the left end surface of the end cap 215 in FIG. 11). Has been.
On the other hand, a fixed plate mounting hole (recessed portion) 214H for mounting the fixed plate 8 is formed on the surface of the pump housing 214 that contacts the rotors 212 and 213 (the right end surface of the pump housing 214 in FIG. 11). .

In FIG. 12, the working fluid is sucked into the pump device 200 as indicated by a white arrow Fi, flows through the pump device 200 as indicated by a dashed arrow, and the pump device 200 as indicated by a white arrow Fo. In FIG. 12, reference sign Pi indicates a suction port, and reference sign Po indicates a discharge port. As shown in FIG. 13, in the fifth embodiment, the suction port Pi exists on the same side as the discharge port Po in the rotation axis direction. Therefore, in FIG. 12, both are shown on the assumption that the suction port Pi and the discharge port Po are on the same side.
11 and 12, the outer rotor 212 and the inner rotor 213 rotate in the same direction, and the working fluid that has flowed in from the suction port Pi is increased in pressure by changing the volume of the gap between the gears of the rotors 212 and 213 and discharged. It is discharged out of the pump device 200 from the discharge port 214o of the pump housing 214 (FIG. 12) via the port Po.

The balance plate 207 (FIG. 11) in the pump device 200 has the same structure as the balance plate 7 (FIG. 3) in the first embodiment. However, since the rotation direction of the rotor is different, the balance plate 207 has a shape symmetrical with the XX axis of FIG. 3 with respect to the balance plate of FIG.
The balance plate 207 has an O-ring groove 207a having a large radial dimension and an O-ring groove 207b having a small radial dimension, and O-rings are fitted in the O-ring grooves 207a and 207b, respectively. The balance plate 207 has a through hole (similar to the discharge pressure introducing hole 73 in FIG. 3) and a pin hole for rotation prevention (similar to the pin hole 74 in FIG. 3).
The fixed plate 8 in the fifth embodiment also has a common structure with the fixed plate 8 in the first embodiment. However, when the rotor rotation direction is different, the fixed plate 8 in the fifth embodiment has a structure in which the fixed plate 8 in the first embodiment is turned upside down.

In the fifth embodiment shown in FIGS. 11 and 12, the balance plate 207 is pressed against the rotors 212 and 213 as in the first embodiment shown in FIGS. The initial pressure is obtained by the elastic repulsion of the O-ring.
Other configurations and operational effects in the fifth embodiment shown in FIGS. 11 and 12 are the same as those in the first embodiment shown in FIGS.

Next, a sixth embodiment of the present invention will be described with reference to FIG. In FIG. 13, the pump apparatus is generally indicated by reference numeral 200A.
In the fifth embodiment shown in FIGS. 11 and 12, the fixed plate 8 is provided on the drive source side (left side in FIG. 11) in the rotational axis direction of the internal gear pump.
On the other hand, in 6th Embodiment of FIG. 13, the fixed plate is not provided.
Other configurations and operational effects in the sixth embodiment of FIG. 13 are the same as those of the fifth embodiment of the fifth embodiment of FIGS. 11 and 12.

Next, a seventh embodiment will be described with reference to FIG. In FIG. 14, the entire pump apparatus is indicated by reference numeral 200B.
11 to 13, the initial pressure for pressing the balance plate 207 against the drive source side (left side in FIG. 11) when the discharge pressure does not act on the balance plate 207, such as when starting the internal gear pump, is the first embodiment. As in the second embodiment, the elastic repulsion of the O-ring is used.
On the other hand, in the seventh embodiment of FIG. 14, when the discharge pressure does not act on the balance plate 207A, such as when the internal gear pump is started, the initial pressure that presses the balance plate 207A to the drive source side (left side in FIG. 14) is As in the third and fourth embodiments, the elastic repulsion of the spring 209 is used.

The balance plate 207A (FIG. 14) in the pump device 200B has the same structure as the balance plate 7A (FIGS. 8 and 9) in the third embodiment. However, since the rotation direction of the rotor is different, the balance plate 207A has a shape symmetrical with the XX axis in FIG. 8 with respect to the balance plate 7A in FIG.
Also in the pump device 200B, even if the wear amount of the rotors 212 and 213 increases, the balance plate 207A that is made of a material having high hardness and does not wear and maintains a flat state is appropriately pressed against the side surfaces of the rotors 212 and 213. Therefore, the formation of steps on the side surfaces of the rotors 212 and 213 is suppressed. And since the balance plate 207A moves to the rotors 212 and 213 side due to wear of the rotors 212 and 213, the clearance (gap) due to wear is reduced, so that the volumetric efficiency is improved.
Other configurations and operational effects in the seventh embodiment of FIG. 14 are the same as those of the embodiment of FIGS.

Next, an eighth embodiment of the present invention will be described with reference to FIG. In FIG. 15, the entire pump device is denoted by reference numeral 200C.
In the seventh embodiment of FIG. 14, the fixed plate 8 is provided on the drive source side (left side in FIG. 14) in the rotation axis direction.
On the other hand, in the eighth embodiment of FIG. 15, no fixed plate is provided.
Other configurations and operational effects in the eighth embodiment of FIG. 15 are the same as those of the seventh embodiment of FIG.

It should be noted that the illustrated embodiment is merely an example, and is not a description to limit the technical scope of the present invention.
For example, in the illustrated embodiment, the balance plate is provided only on the suction side (right side in FIG. 1) and is not provided on the discharge side (left side in FIG. 1). On the other hand, it is also possible to provide the balance plate only on the discharge side (left side in FIG. 1). In that case, it is necessary to change the shape of the port from the illustrated embodiment.

5 ... Rotating shaft 7 ... Balance plate 8 ... Fixing plate 9 ... Spring 10 ... Internal gear pump 11 ... Gear case 12 ... Outer rotor 13 ... Inner rotor 14 ... Pump housing 15 ... End plate 20 ... Suction plate 30 ... Cyclone relay impeller 40 ... Primary cyclone 45 ... Cyclone casing 50 ... Secondary cyclone 60 ... Impeller for discharging foreign matter

Claims (3)

The outer rotor (12, 212) has an inscribed gear pump (10) in which the inner rotor (13 , 213) is inscribed, and a plate-like member (7, 7A ) is provided on the end face of the rotor (12, 13, 212, 213). 207, 207A) , and the plate-like member (7, 7A, 207, 207A) is made of a material having a hardness higher than that of the foreign matter in the coolant , and has a shape that does not block the suction port (150, Pi). holes (73,73A) are formed, a continuous shape and O- ring is accommodated O- ring groove (71,71A, 72,72A, 207a, 207b , 207k, 207j) are formed In the region (E2) surrounded by the O-ring grooves (71, 71A, 72, 72A, 207a, 207b, 207k, 207j) of the plate-like member (7, 7A, 207, 207A) The discharge pressure of the internal gear pump (10) acts through the through holes (73, 73A) to press the plate-like members (7, 7A, 207, 207A) toward the rotor (12, 13), and the outer rotor ( The discharge pressure of the internal gear pump (10) also acts on the region (E1) that is the gap between the inner rotor (13) and the inner rotor (13), and presses the plate member (7 7A, 207, 207A), the area (E2) where the discharge pressure is introduced is the area (E1) where the discharge pressure in the gap between the outer rotor (12, 212) and the inner rotor (13, 213) acts. A pump device characterized in that it is set to be larger than the area, and the plate-like members (7, 7A, 207, 207A) are pressed toward the rotor (12, 13) . The O-ring grooves (71, 72, 207a, 207b) are formed on the surface of the plate-like member (7, 207) on the side separated from the rotor, and the O-rings are O-ring grooves (71, 72, 207a, 207b) . The pump device according to claim 1, wherein the pump device is mounted with a specified interference . The pump device according to claim 1, wherein a blind space (BH) is formed on the opposite side of the rotor of the plate-like member (7A, 207A) , and the elastic member (9) is accommodated in the blind space.

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