JP7169516B2 - Gear pump manufacturing method - Google Patents

Description

The present invention relates to a method for manufacturing a gear pump .

Patent Literature 1 proposes a gear pump used as a booster for pumping molten resin to a pressing die or the like. The gear pump includes a casing, a gear portion (gear) and a shaft portion integrally formed, a pair of gear rotors arranged in a mutually meshing state inside the casing, and bearing portions (side shafts) rotatably supporting the gear rotors. a plate (a facing portion that faces the side surface of the gear rotor); The casing includes a cylindrical casing main body (main body portion) with both ends in the axial direction open, and bearing retainers (end members) fastened to both ends of the casing main body with fasteners (bolts).

In Japanese Patent Laid-Open No. 2002-100000, the bearing retainer is adjusted by using a push bolt that pushes the bearing toward the gear and a pull bolt that pulls the bearing toward the bearing retainer. A first technique has been proposed for adjusting the gap (so-called side clearance) between the and the gear portion. A second technique has been proposed in which a rod of a hydraulic cylinder passes through a bearing retainer and presses the bearing toward the gear to adjust the gap between the bearing and the gear.

JP 2015-1204 A

In order to reduce leakage (internal leakage) of the working fluid inside the casing and increase the flow efficiency, the gap between the bearing and the gear must be kept within the range where metal contact between the bearing and the gear does not occur. is required to be as small as possible. Therefore, it is necessary to adjust the gap between the bearing portion and the gear portion with high accuracy, for example, on the order of microns.
However, in the first technique using the push bolt and the pull bolt, when narrowing the gap between the bearing portion and the gear portion, the push bolt must be rotated in one direction and the pull bolt must be rotated in the other direction at the same time. not. For this reason, it is difficult to position the bearing portion at an appropriate position with high accuracy, and therefore it is difficult to adjust the gap between the bearing portion and the gear portion to a high degree.

In addition, in the second technique that uses the expansion and contraction of the rod of the hydraulic cylinder, it is difficult to adjust the position of the rod with high accuracy, so it is difficult to adjust the gap between the bearing portion and the gear portion with high accuracy. .
SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of manufacturing a gear pump that can adjust a gap between a gear and a facing portion facing a side surface of the gear with high accuracy.

The invention of claim 1 comprises a housing including a hollow main body and an end member arranged at an end of the main body, a pair of gears meshed with each other inside the housing, and a gear of the end member. a facing portion that is provided separately from the end member so as to abut against the side surface of the gear and is float-supported in the pump axial direction inside the housing so as to face the side surface of the gear; A gap adjusting means for adjusting the gap between the facing portion and the gear by adjusting the gap between the facing surfaces of the member, the gap adjusting means being interposed between the facing surfaces of the end member and the body portion. A gear pump manufacturing method for manufacturing a gear pump comprising a gap adjusting means including an elastic member and a mechanical driving means for moving the end member toward the main body against the elastic member , With the gear pump rotating at a predetermined number of revolutions (N), the end member is continuously or intermittently moved toward the main body by the mechanical driving means, and the state quantity (η) related to the number of revolutions is ), and stopping the mechanical driving means when the detected state quantity reaches a threshold value (η0) to position the end member with respect to the main body (S2); a fixing step (S3) of fixing the end member positioned with respect to the body portion in the positioning step to the body portion (S3).
According to a second aspect of the invention, there is provided a housing including a hollow main body portion and an end member arranged at an end portion of the main body portion, a pair of gears meshed with each other inside the housing, and a gear side of the end member. a facing portion provided separately from the end member so as to be in contact with the surface of the housing, supported floating in the axial direction of the pump inside the housing and facing the side surface of the gear; gap adjusting means for adjusting the gap between the facing portion and the gear by adjusting the gap between the facing surfaces of the end member and the gear, wherein at least one of the facing surface of the end member and the facing surface of the body portion gap adjusting means including an elastic convex portion which is provided and abuts against the other in an elastically deformed state; and mechanical driving means for moving the end member toward the main body portion against the elastic convex portion. wherein the end member is continuously or intermittently moved toward the main body by the mechanical drive means while the gear pump is rotated at a predetermined number of revolutions (N). to the main body by detecting a state quantity (η) related to the number of revolutions, and stopping the mechanical drive means when the detected state quantity reaches a threshold value (η0). A method for manufacturing a gear pump, comprising a positioning step (S2) of positioning the end member, and a fixing step (S3) of fixing the end member positioned with respect to the body portion in the positioning step to the body portion. I will provide a.
According to a third aspect of the present invention, there is provided a housing including a hollow main body portion and an end member arranged at an end portion of the main body portion, a pair of gears meshed with each other inside the housing, and a gear side of the end member. a facing portion provided separately from the end member so as to be in contact with the surface of the housing, supported floating in the axial direction of the pump inside the housing and facing the side surface of the gear; gap adjusting means for adjusting the gap between the facing portion and the gear by adjusting the gap between the facing surfaces of the end member and the main body portion, the elastic gap adjusting means interposed between the facing surfaces of the end member and the body portion and a gap adjustment means including a member and a mechanical drive means for moving the end member toward the main body against the elastic member, wherein the mechanical drive means moves through the insertion hole of the end member. a gear pump or a housing including a hollow body and an end member disposed at an end of the body; and A pair of gears meshing with each other is provided separately from the end member so as to be in contact with the gear-side surface of the end member, and is float-supported within the housing in the axial direction of the pump. gap adjusting means for adjusting the gap between the facing portion and the gear by adjusting the gap between the facing portion facing the side surface and the facing surfaces of the body portion and the end member, the gap adjusting means comprising: an elastic convex portion provided on at least one of the facing surface and the facing surface of the main body portion and contacting the other in an elastically deformed state; and moving the end member toward the main body portion against the elastic convex portion. gap adjusting means including mechanical driving means for allowing the gear pump to rotate, wherein the mechanical driving means is a bolt inserted through the insertion hole of the end member and coupled to the threaded hole of the main body. A method for manufacturing a gear pump, wherein the end member is continuously or intermittently moved toward the main body by the mechanical driving means while the gear pump is rotating at a predetermined number of revolutions (N). while detecting a state quantity (η) related to the number of revolutions, and stopping the mechanical drive means when the detected state quantity reaches a threshold value (η0), thereby moving the end member relative to the main body. and a fixing step (S3) of fixing to the body portion the end member positioned with respect to the body portion in the positioning step (S3). .

As in claim 4 , in any one of claims 1 to 3, the state quantity may be any one of flow efficiency, rate of change of flow rate efficiency, torque, and rate of change of torque. good.

In each of claims 1 to 3, in the positioning step, the end member is continuously or intermittently moved toward the main body by the mechanical driving means while rotating the gear pump at a predetermined number of revolutions. Detect state quantities associated with numbers. When the detected state quantity reaches a threshold value, the driving of the mechanical driving means is stopped to position the end member with respect to the main body. Next, in the fixing step, the end member positioned with respect to the main body is fixed to the main body. As a result, the gap between the gear and the opposing portion that moves integrally with the end member can be adjusted with high accuracy so that the required pump performance can be obtained.

In the fourth aspect of the invention, the end member is positioned with respect to the main body when the state quantity, which is any one of the flow efficiency, the rate of change of the flow rate efficiency, the torque, and the rate of change of the torque, reaches a threshold value. By doing so, the gap between the facing portion and the gear can be adjusted with high accuracy.

FIG. 1(a) is a front view of a gear pump according to a first embodiment of the present invention, and FIG. 1(b) is a side view of the gear pump. FIG. 1B is a schematic cross-sectional view of the gear pump, corresponding to the cross-sectional view taken along line II-II in FIG. 1B. 1 is a schematic exploded perspective view of a gear pump; FIG. FIG. 3 is a sectional view taken along IV-IV in FIG. 2; 4 is a flow chart of a method for manufacturing a gear pump; FIG. 4 is a block diagram of a positioning device used in the positioning process; FIG. 5 is a graph showing the relationship between clearance and flow efficiency; 1 is a schematic cross-sectional view of a gear pump according to a reference embodiment of the invention; FIG. FIG. 5 is a schematic cross-sectional view of a gear pump according to a second embodiment of the invention; FIG. 5 is a schematic cross-sectional view of a gear pump according to a third embodiment of the invention;

Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment)
FIG. 1(a) is a front view of a gear pump 1 according to a first embodiment of the present invention, and FIG. 1(b) is a side view of the gear pump 1. FIG. As shown in FIGS. 1A and 1B, the gear pump 1 includes a housing 2, a gear pair of a drive gear 8 and a driven gear 9, a support shaft 10 (corresponding to the pump shaft 3) of the drive gear 8, It comprises a support shaft 11 for the driven gear 9 , a pair of opposed portions 12 and 13 , a gap adjusting means 40 and a plurality of fixing mechanisms 60 . The pair of facing portions 12 and 13 are made of, for example, an aluminum alloy. A portion of the pump shaft 3 protrudes from the housing 2 . Power for driving the gear pump 1 is transmitted to the pump shaft 3 .

The housing 2 includes a hollow body portion 4 and a pair of plate-like end members 5 and 6 . The main body 4 is made of an aluminum alloy, for example, and the pair of end members 5 and 6 are made of an iron alloy, for example. The body portion 4 is arranged between the pair of end members 5 and 6 with respect to the pump axial direction X, which is the axial direction of the pump shaft 3 . A pair of end faces 4a and 4b of the main body 4 and end faces 5a and 6a of a pair of end members 5 and 6 are opposed to each other with predetermined intervals L1 and L2 therebetween in the pump axial direction X. .

The drive gear 8 and the driven gear 9 are housed inside the housing 2 together with a pair of facing portions 12 and 13 in a state of meshing with each other. A gear pair of a driving gear 8 and a driven gear 9 is arranged between a pair of opposed portions 12 and 13 with respect to the pump axial direction X. As shown in FIG. A pair of opposed portions 12 and 13 function as support portions that rotatably support the drive gear 8 and the driven gear 9 via the corresponding support shafts 10 and 11 . When the gear pump 1 is driven, gaps h1 and h2 (so-called side clearances) are formed between the drive gear 8 and the driven gear 9 and the facing portions 12 and 13 in the axial direction X of the pump.

The clearance adjustment means 40 includes a pair of elastic members 41 and drive bolts 42 as a plurality of mechanical drive means. The gap adjusting means 40 adjusts the gap L1 . By adjusting L2, the function of adjusting the gaps h1 and h2 between the pair of gears of the drive gear 8 and the driven gear 9 and the facing portions 12 and 13 is achieved.

The elastic member 41 is an annular member interposed between the opposing surfaces of the main body 4 and the corresponding end members 5 and 6 (between the end surfaces 4a and 5a and between the end surfaces 4b and 6a) ( See also Figure 3). Referring to FIG. 1(a), the elastic member 41 is elastically compressed in the axial direction X of the pump. The drive bolt 42 is arranged parallel to the axial direction X of the pump.
The drive bolt 42 is threaded and fixed to the main body 4 through the end members 5 and 6 . The drive bolt 42 generates a mechanical drive force that moves the end members 5 and 6 toward the main body 4 against the elastic repulsive force of the elastic member 41 .

FIG. 2 is a cross-sectional view taken along line II-II in FIG. In some cross sections in FIG. 2, hatching indicating cross sections is omitted.
As shown in FIGS. 1(b) and 2, each fixing mechanism 60 includes an arm portion 61 provided integrally with the end members 5 and 6, and a fixing bolt 62 extending in a direction perpendicular to the axial direction X of the pump. include. As shown in FIG. 2, the arm portion 61 has an elongated hole 61a extending in the axial direction X of the pump. The fixing bolt 62 is inserted through the elongated hole 61 a of the arm portion 61 and screwed into the threaded hole of the main body portion 4 to be fixed. Thereby, the fixing mechanism 60 functions to fasten the end members 5 and 6 to the body portion 4 .

FIG. 3 is an exploded perspective view of the gear pump 1. FIG. FIG. 4 is a sectional view taken along line IV-IV of FIG. As shown in FIGS. 2 and 4, the body portion 4 of the housing 2 is formed with a receiving hole 21 extending through the pair of end faces 4a and 4b in the axial direction X of the pump. The drive gear 8 and the driven gear 9 , the pair of gear support shafts 10 and 11 , and the pair of facing portions 12 and 13 are arranged inside the accommodation hole 21 .

As shown in FIG. 3, the body portion 4 of the housing 2 has a pair of side surfaces 4c and 4d facing each other in a direction perpendicular to the axial direction X of the pump. A suction port 22 communicating with the receiving hole 21 is opened in one side surface 4c, and a discharge port 23 communicating with the receiving hole 21 is opened in the other side surface 4d. The accommodation hole 21 is constituted by a pair of cylindrical holes 24 and 25 which have central axes C1 and C2 parallel to each other and communicate with each other in a state of being arranged in parallel.

Each elastic member 41 of the gap adjusting means 40 surrounds the accommodation hole 21, and elastically moves between each end surface 4a, 4b of the body portion 4 of the housing and the corresponding end surfaces 5a, 6a of the end members 5, 6. are placed in a compressed state. Each elastic member 41 functions as a sealing member that restricts leakage of working fluid from the inside of the housing 2 to the outside.
As shown in FIG. 2, the pair of opposing portions 12 and 13 are arranged in the housing hole 21 with a distance therebetween so as to define a gear chamber 50 therebetween. As shown in FIGS. 2 and 4, the driving gear 8 and the driven gear 9 are arranged in a gear chamber 50 and mesh with each other. In other words, as shown in FIG. 2, the pair of opposed portions 12 and 13 are arranged on both sides of the gear pair of the driving gear 8 and the driven gear 9 with respect to the axial direction X of the pump.

The pair of opposing portions 12 and 13 rotatably support the pair of gear support shafts 10 and 11 while being held by the housing 2 within the accommodation hole 21 . Further, the gear support shaft 10 supports the drive gear 8 so as to rotate together, and the gear support shaft 11 supports the driven gear 9 so as to rotate together. In FIG. 4, the directions of rotation of the drive gear 8 and the driven gear 9 interlocking therewith are indicated by arrows.
As shown in FIG. 2, the gear support shaft 10 of the drive gear 8 is inserted through the insertion hole 5e of the end member 5 and extended to the outside. The gear support shaft 10 constitutes the pump shaft 3 . The axial direction of the gear support shaft 10 corresponds to the axial direction X of the pump.

As shown in FIG. 4, when the gear chamber 50 is viewed from the axial direction of the gear support shafts 10 and 11, in the gear chamber 50, on both sides of the meshing position MP between the two gears 8 and 9, there are intakes of working fluid. A low-pressure chamber 51 communicating with the port 22 and a high-pressure chamber 52 communicating with the working fluid discharge port 23 are formed. These low-pressure chamber 51 and high-pressure chamber 52 are connected to a suction destination and a discharge destination (not shown) via a suction port 22 and a discharge port 23, respectively.

When driving the gear pump 1 in which both gears 8 and 9 rotate, the working fluid introduced into the low pressure chamber 51 through the suction port 22 is received between the teeth of the driving gear 8 and the driven gear 9 facing the low pressure chamber 51, Due to the rotation of the gears 8 and 9, it is conveyed in a sealed state between the teeth and the inner peripheral surface 21a of the receiving hole 21, and delivered to the high-pressure chamber 52.
As shown in FIG. 3 , the facing portion 13 has a “figure 8” shape that fits into the accommodation hole 21 . The opposing portion 13 includes a pair of disk-shaped portions 26 and 27 that are accommodated in the pair of cylindrical hole portions 24 and 25 of the accommodation hole 21, respectively. The outer peripheral surfaces of the pair of disk-shaped portions 26 and 27 are continuous with each other to form a peripheral side surface 33 of the opposing portion 13 . Each disk-shaped portion 26, 27 is fitted into the corresponding cylindrical hole portion 24, 25 by a clearance fit.

The facing portion 13 includes a first end surface 31 on the side of the gear pair, a second end surface 32 on the side of the end member 6 , a peripheral side surface 33 , and a pair of support holes 34 and 35 . Each of the support holes 34, 35 consists of a cylindrical hole formed concentrically with the corresponding disk-shaped portions 26, 27. As shown in FIG. The support hole 34 has a central axis C3, and the support hole 35 has a central axis C4. Each support hole 34 , 35 penetrates through the first end surface 31 and the second end surface 32 .

As shown in FIG. 2, the bearing bushes 20 are fitted and held in the support holes 34 and 35, respectively. The facing portions 12 and 13 rotatably support the gear support shafts 10 and 11 via bearing bushes 20 held in the support holes 34 and 35, respectively.
The facing portions 12 and 13 are supported so as to float in the axial direction X of the pump. When the gear pump 1 is in operation (when both the gears 8 and 9 rotate), the pressure in the gear chamber 50 creates gaps h1 and h2 (so-called side clearances) between the facing portions 12 and 13 and the gears 8 and 9. equivalent) is formed. During rotation of both gears 8, 9, the working fluid in the gaps h1, h2 performs a lubricating function.

Next, a method for manufacturing the gear pump 1 will be described with reference to the flow chart shown in FIG. The gear pump manufacturing method includes a preparation step (step S1), a positioning step (step S2), and a fixing step (step S3).
In the preparation process of step S1, the gear pump 1 in the manufacturing stage in which the gaps h1 and h2 have not been adjusted is prepared. Specifically, in the gear pump 1 at the manufacturing stage, the distance L1 between the end surfaces 4a and 5a of the body portion 4 and the end member 5 is set to a predetermined amount, and the distance between the end surfaces 4b and 6a of the body portion 4 and the end member 6 is set to a predetermined amount. It is assembled with the interval L2 set to a predetermined amount. The predetermined amount is set rather large so that the gaps h1 and h2 corresponding to the side clearance laths are within the range of 0.5 to 1 mm, for example.

In the positioning process of step S2, at least one of the end members 5 and 6 is fixed to the body portion by the drive bolt 42 while the gear pump 1 in the manufacturing stage prepared in the preparation process is rotated at a predetermined number of revolutions N (1/min). While continuously moving to the 4 side, for example, the flow rate efficiency η (corresponding to the volumetric efficiency) is detected as a state quantity related to the rotation speed. The end members 5 and 6 are positioned in the axial direction X of the pump with respect to the main body 4 by stopping the driving of the driving bolt 42 when the detected flow efficiency η reaches the pre-stored threshold value η ₀ . . When the gear pump 1 is operated, conditions such as the viscosity of the working fluid (for example, temperature conditions related to the viscosity) are matched with the conditions for rated operation.

In the positioning process, the fixing bolt 62 of the fixing mechanism 60 is inserted through the elongated hole 61a of the arm portion 61 and temporarily tightened to the screw hole 4f of the main body portion 4. As shown in FIG. Therefore, the fixing bolt 62 and the long hole 61a are relatively movable in the axial direction X of the pump. That is, the end members 5 and 6 can move toward the main body portion 4 side.
In the step S2 positioning process, the positioning device 70 shown in FIG. 6 is used. The configuration and function of the positioning device 70 will be described. The positioning device 70 includes a pump motor 71 , a rotational speed sensor 72 , a driver motor 73 , a rotational position sensor 74 , a flow rate sensor 75 and a controller 80 .

The pump motor 71 rotationally drives the pump shaft 3 of the gear pump 1 in the manufacturing stage. A rotation speed sensor 72 is provided in the pump motor 71 and detects the rotation speed of the pump motor 71 . The driver motor 73 rotates a driver (not shown) for screwing each driving bolt 42 of the gap adjusting means 40 . A rotational position sensor 74 is provided in the driver motor 73 and detects the rotational position of the driver motor 73 . The flow rate sensor 75 detects the flow rate Q (discharge flow rate) of the gear pump 1 in the manufacturing stage.

The control unit 80 includes a pump motor control unit 81 , a drive circuit 82 , a driver motor control unit 83 , a drive circuit 84 , a flow efficiency calculation unit 85 and a determination unit 86 .
The pump motor control unit 81 drives and controls the pump motor 71 via the drive circuit 82 based on the rotation speed of the pump motor 71 detected by the rotation speed sensor 72 . Specifically, the pump motor control unit 81 drives and controls the pump motor 71 so that the rotation speed of the pump shaft 3 of the gear pump 1 reaches a predetermined rotation speed N (for example, the rated rotation speed).

The driver motor control section 83 drives and controls the driver motor 73 via the drive circuit 84 based on the rotational position detected by the rotational position sensor 74 . Specifically, the driver motor control unit 83 drives and controls the driver motor 73 so as to screw the drive bolt 42 continuously or stepwise.
The flow rate Q (·/min) detected by the flow rate sensor 75 and the rotation speed N (1/min) given from the pump motor control section 81 are input to the flow rate efficiency calculation section 85 . The flow rate efficiency calculator 85 calculates the flow rate efficiency η using the following formula (1) based on the input flow rate Q, the input rotation speed N, and the pre-stored pump capacity q (cm3/rev). to calculate The calculated flow efficiency η is output to the determination section 86 .

η=1000×Q/(q×N) (1)
The determination unit 86 compares the flow efficiency η input from the flow efficiency calculation unit 85 with a pre-stored threshold η0, and outputs a signal to the driver motor control unit 83 when the flow efficiency η reaches the threshold η0. Then, the driver motor controller 83 is caused to stop driving the driver motor 73 , and a signal is output to the pump motor controller 81 to cause the pump motor controller 81 to stop driving the pump motor 71 . As a result, the corresponding end members 5 and 6 are positioned with respect to the body portion 4 in a state in which the gaps h1 and h2 between the facing portions 12 and 13 and the gears 8 and 9 are adjusted to required values.

FIG. 7 shows the relationship between the gap h1 (h2) between the facing portions 12, 13 and the gears 8, 9 and the flow efficiency η. As shown in FIG. 7, as the gap h1 (h2) decreases, the internal leakage decreases, so the flow efficiency η increases progressively. On the other hand, if the clearance h1 (h2) becomes excessively small, there is a possibility that the facing portions 12, 13 and the gears 8, 9 may come into metal contact. Therefore, when the flow efficiency η reaches the threshold value η0, the movement of the end members 5 and 6 is stopped so that the minimum clearance h1 (h2) is ensured within the range where metal contact does not occur. .

In the fixing process of step S3 in FIG. 5 , the end members 5 and 6 positioned with respect to the main body 4 in the positioning process are fixed to the main body 4 by the fixing bolts 62 of the fixing mechanism 60 . Thus, the gear pump 1 is completed.
In the gear pump 1 of the present embodiment, the mechanical driving means (driving bolt 42) of the gap adjusting means 40 is an elastic member that is elastically compressed between the facing surfaces of the body portion 4 and the end members 5, 6 of the housing 2. The end members 5 and 6 are moved toward the main body 4 while being preloaded by 41 . Therefore, the gaps L1 and L2 between the facing surfaces of the main body 4 and the end members 5 and 6 are adjusted with high accuracy in a state where looseness or the like related to the mechanical driving means (driving bolt 42) is removed. Along with this adjustment, the opposed portions 12, 13 are moved toward the gears 8, 9 together with the end members 5, 6, so that the gaps h1, h2 between the opposed portions 12, 13 and the gears 8, 9 are set as required. can be adjusted with high precision to obtain a pump performance of

In particular, in the gear pump 1, which is likely to cause variations in pump performance due to the combination of parts with variations in dimensional accuracy, the gaps h1, h2 between the opposing parts 12, 13 and the gears 8, 9 are provided for each individual. can be adjusted with high precision to achieve the desired pump performance.
Further, since the drive bolt 42 inserted through the insertion holes 5b and 6b of the end members 5 and 6 and coupled to the screw hole 4e of the main body 4 is used as the mechanical drive means, the structure can be simplified.

In the manufacturing method of the gear pump 1 of the present embodiment, in the positioning step, the gear pump 1 is rotated at a predetermined rotation speed N, and the end members 5 and 6 are moved by the mechanical driving means (driving bolts 42) to the body portion 4. While continuously or intermittently moving to the side, the state quantity (flow efficiency η) related to the rotation speed is detected. When the detected state quantity (flow efficiency η) reaches a threshold value, the driving of the mechanical driving means (driving bolt 42 ) is stopped to position the end members 5 and 6 with respect to the main body 4 . Thereby, the gaps h1 and h2 between the facing portions 12 and 13 which move integrally with the end members 5 and 6 and both gears and 8 and 9 can be adjusted with high precision so as to obtain the required pump performance. In the fixing step, the fixing bolts 62 of the fixing mechanism 60 fasten the end members 5 and 6 to the body portion 4 after the gaps h1 and h2 are adjusted. Thus, the gear pump 1 is completed.

Since the direction in which the fixing bolt 62 of the fixing mechanism 60 is screwed is perpendicular to the direction in which the end members 5 and 6 are moved by the drive bolt 42 (parallel to the axial direction X of the pump), the gaps h1 and h2 after adjustment is suppressed from changing.
( Reference form)
FIG. 8 is a schematic cross-sectional view of a gear pump 1P of a reference embodiment of the invention. The gear pump 1P of the reference embodiment shown in FIG. 8 differs from the gear pump 1 of the first embodiment shown in FIG. aluminum alloy, etc.). In this reference embodiment, the same effects as those of the first embodiment can be obtained. Also, the number of parts can be reduced and the structure can be simplified.
( Second embodiment)
FIG. 9 is a schematic cross-sectional view of a gear pump 1Q according to a second embodiment of the invention. The gear pump 1Q of the second embodiment shown in FIG. 9 differs from the gear pump 1 of the first embodiment shown in FIG. It is composed of, for example, an elastic convex portion 41Q having a chevron-shaped cross section and a driving bolt 42, which are integrally formed of copper alloy).

A plurality of elastic projections 41Q are provided on the end faces 5a and 6a of the end members 5Q and 6Q, and are arranged in a ring so as to surround the accommodation hole 21 of the body portion 4. As shown in FIG. The elastic convex portion 41Q may be a single annular convex portion provided on each of the end surfaces 5a and 6a.
In this embodiment, the same effects as those of the first embodiment can be obtained. Also, the number of parts can be reduced and the structure can be simplified.
( Third embodiment)
FIG. 10 is a schematic cross-sectional view of a gear pump 1R according to a third embodiment of the invention. The gear pump 1R of the third embodiment shown in FIG. 10 differs from the gear pump 1 of the first embodiment shown in FIG. ) and the drive bolt 42, for example, an elastic convex portion 41R having a chevron-shaped cross section integrally formed.

A plurality of elastic convex portions 41R are provided on each of the end surfaces 4a and 4b of the body portion 4R, and are arranged in a ring so as to surround the accommodation hole 21 of the body portion 4R. The elastic convex portion 41R may be a single annular convex portion provided on each of the end faces 4a and 4b.
In this embodiment, the same effects as those of the first embodiment can be obtained. Also, the number of parts can be reduced and the structure can be simplified.

The invention is not limited to each of the above embodiments. For example, instead of the flow efficiency η, any one of the rate of change (increase rate) of the flow efficiency η, the torque (driving torque), and the rate of change (increase rate) of the torque is used as the state quantity detected in the positioning process. may be used and compared to respective thresholds. Further, the operation of the gear pump 1 in the positioning process may be performed under the severest temperature condition (high temperature).

Although not shown, in the first embodiment of FIG. 2, an elastic member 41 is provided on one of the facing surfaces (end surfaces 4a, 5a; end surfaces 4b, 6a) of the main body 4 and the end members 5, 6. A recess may be formed to accommodate the portion.
Moreover, although not shown, in the third embodiment of FIG. 9, the opposing portions 12 and 13 may be formed integrally with the corresponding end members 5Q and 6Q from a single material. In the fourth embodiment, each opposing portion 12, 13 may be integrally formed with the corresponding end member 5, 6 from a single material.

Moreover, although not shown, the elastic member 41 and the elastic projections 41Q and 41R may have the function of partitioning the inside of the housing 2 into a high pressure side and a low pressure side. Moreover, the present invention can be applied not only to the external gear pump as in each of the above embodiments, but also to an internal gear pump (not shown). In addition, the present invention can be modified in various ways within the scope of the claims.

1; 1P; 1Q; 1R... gear pump, 2... housing, 3... pump shaft, 4; , 5a, 6a end face (facing face) 8 driving gear 9 driven gear 10, 11 gear support shaft 12, 13; 12P, 13P facing portion 21 housing hole 40; Gap adjusting means 41 Elastic member 41Q; 41R Elastic convex portion 42 Drive bolt (mechanical drive means) 60 Fixing mechanism 61 Arm portion 61a Long hole 62 Fixing bolt 70 ...positioning device, h1, h2 ... clearance, L1, L2 ... interval, N ... rotation speed, Q ... flow rate, q ... pump capacity, η ... flow rate efficiency (state quantity related to rotation speed), η ₀ ... threshold value, X …pump axial direction

Claims (4)

a housing including a hollow body portion and an end member disposed at an end of the body portion;
a pair of gears meshed with each other inside the housing;
a facing portion provided separately from the end member so as to be in contact with the gear-side surface of the end member, is supported in a floating manner in the pump axial direction inside the housing, and faces the side surface of the gear;
gap adjusting means for adjusting the gap between the facing portion and the gear by adjusting the gap between the facing surfaces of the body portion and the end member, wherein the facing surfaces between the end member and the body portion gap adjusting means including an elastic member interposed between them and a mechanical driving means for moving the end member toward the main body against the elastic member; A manufacturing method comprising:
With the gear pump rotating at a predetermined number of revolutions, the end member is continuously or intermittently moved toward the main body by the mechanical driving means, and a state quantity related to the number of revolutions is detected. a positioning step of positioning the end member with respect to the body portion by stopping the mechanical driving means when the state quantity obtained reaches a threshold value;
and a fixing step of fixing the end member positioned with respect to the body portion in the positioning step to the body portion. a housing including a hollow body portion and an end member disposed at an end of the body portion;
a pair of gears meshed with each other inside the housing;
a facing portion provided separately from the end member so as to be in contact with the gear-side surface of the end member, is supported in a floating manner in the pump axial direction inside the housing, and faces the side surface of the gear;
gap adjusting means for adjusting the gap between the facing portion and the gear by adjusting the gap between the facing surfaces of the body portion and the end member, wherein the gap between the facing surface of the end member and the body portion is adjusted an elastic convex portion provided on at least one of the opposing surfaces and abutting against the other in an elastically deformed state; and a mechanical driving means for moving the end member toward the main body portion against the elastic convex portion. a gear pump comprising a gap adjusting means including
A method for manufacturing a gear pump, comprising:
With the gear pump rotating at a predetermined number of revolutions, the end member is continuously or intermittently moved toward the main body by the mechanical driving means, and a state quantity related to the number of revolutions is detected. a positioning step of positioning the end member with respect to the body portion by stopping the mechanical driving means when the state quantity obtained reaches a threshold value;
and a fixing step of fixing the end member positioned with respect to the body portion in the positioning step to the body portion. a housing including a hollow body portion and an end member disposed at an end of the body portion;
a pair of gears meshed with each other inside the housing;
a facing portion provided separately from the end member so as to be in contact with the gear-side surface of the end member, is supported in a floating manner in the pump axial direction inside the housing, and faces the side surface of the gear;
gap adjusting means for adjusting the gap between the facing portion and the gear by adjusting the gap between the facing surfaces of the body portion and the end member, wherein the facing surfaces between the end member and the body portion gap adjusting means including an elastic member interposed between them, and mechanical driving means for moving the end member toward the main body against the elastic member, wherein the mechanical driving means , a gear pump which is a bolt inserted through an insertion hole of the end member and coupled to a threaded hole of the main body, or
a housing including a hollow body portion and an end member disposed at an end of the body portion;
a pair of gears meshed with each other inside the housing;
a facing portion provided separately from the end member so as to be in contact with the gear-side surface of the end member, is supported in a floating manner in the pump axial direction inside the housing, and faces the side surface of the gear;
gap adjusting means for adjusting the gap between the facing portion and the gear by adjusting the gap between the facing surfaces of the body portion and the end member, wherein the gap between the facing surface of the end member and the body portion is adjusted an elastic convex portion provided on at least one of the opposing surfaces and abutting against the other in an elastically deformed state; and a mechanical driving means for moving the end member toward the main body portion against the elastic convex portion. and a gap adjusting means including a gap adjusting means, wherein the mechanical driving means is a bolt inserted through the insertion hole of the end member and coupled to the threaded hole of the main body.
A method for manufacturing a gear pump, comprising:
With the gear pump rotating at a predetermined number of revolutions, the end member is continuously or intermittently moved toward the main body by the mechanical driving means, and a state quantity related to the number of revolutions is detected. a positioning step of positioning the end member with respect to the body portion by stopping the mechanical driving means when the state quantity obtained reaches a threshold value;
and a fixing step of fixing the end member positioned with respect to the body portion in the positioning step to the body portion. 4. The method of manufacturing a gear pump according to claim 1 , wherein said state quantity is any one of flow rate efficiency, rate of change of said rate of flow efficiency, torque, and rate of change of said torque.

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