JP2004162672A - Gear pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gear pump which eliminates or reducing knock pins so as to be effective for reducing the number of parts, achieves light weight, and restricts oil leak. <P>SOLUTION: This gear pump comprises a housing 1, a drive gear 4 provided to be rotatable, and a driven gear 5 driven by the drive gear 4. The housing 1 is parted in a shaft length direction of the drive gear 4 into a plurality of partial housing 11 and 12 facing each other, and having shaft holes 16 and 17. The driven gear 5 is composed of a shaft 50 inserted to the shaft holes 16 and 17 in the partial housings 11 and 12, and a rotary gear sleeve part 52 rotatably engaged with the shaft 50, and having a tooth part. The shaft 50 functions as a knock pin to position the partial housings 11 and 12. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a gear pump having a driving gear and a driven gear driven by the driving gear. INDUSTRIAL APPLICABILITY The present invention is applicable to, for example, an oil pump attached to a transmission case or an engine of a vehicle.
[0002]
[Prior art]
Conventionally, a gear pump generally includes a housing having a working chamber, a suction port communicating with the working chamber, and a discharge port communicating with the working chamber, a drive gear rotatably provided in the working chamber of the housing, and a housing. And a driven gear rotatably provided with the drive gear in the working chamber and driven by the drive gear. The driven gear is rotated with the rotation of the drive gear, whereby the working fluid such as oil is sucked into the working chamber from the suction port of the housing, and the sucked working fluid is discharged from the discharge port of the housing.
[0003]
As this gear pump, there is known a gear pump provided with a divided housing in which a housing is divided into a plurality of parts in an axial direction of a drive shaft. According to this, a through hole is formed in each divided housing, and a first knock pin separate from the driving gear and the driven gear is inserted into the insertion hole in a press-fit state, thereby positioning each divided housing. It is carried out. Further, a first knock pin having the divided housing positioned therein and another second knock pin are prepared, and the shaft end of the second knock pin is projected from the mounting surface of the housing of the gear housing. By inserting the gear pump housing and the mating member by inserting the gear pump into the positioning concave portion of the mounting surface, the gear pump housing is mounted on the mounting surface of the mating material by mounting bolts in this state.
[0004]
Conventionally, as a gear pump, as disclosed in Japanese Patent Application Laid-Open No. 2000-145655, a housing is formed by integrally assembling a plurality of divided housings in the axial direction of a drive shaft, and driving the housing. An oil seal that seals the outer peripheral surface of the shaft is provided, and the shaft end of the oil seal projects from the mounting surface of the housing. There is known a gear pump having a structure in which a shaft end of an oil seal projecting outward from a mounting surface of the housing is fitted into a concave portion of a mounting surface of a mating member and positioned. According to this, the housing of the gear pump can be positioned with respect to the mating member using the shaft end of the oil seal protruding from the mounting surface of the housing.
[0005]
[Patent Document 1] JP-A-2000-145655
[0006]
[Problems to be solved by the invention]
According to the gear pump using the above-mentioned knock pin, in addition to the drive gear and the driven gear, the first knock pin for positioning each divided housing is required, so that the number of parts is increased, and there is a limit in weight reduction and cost reduction.
[0007]
Further, since the second knock pin for positioning the housing in which the divided housing is integrated with the concave portion of the mounting surface of the mating member in addition to the first knock pin is required, the number of parts is further increased, and the weight is reduced. There is a further limit to cost reduction and cost reduction.
[0008]
According to the technique disclosed in Japanese Patent Application Laid-Open No. 2000-145655, the housing of the gear pump is covered with the mating member by utilizing the shaft end of the oil seal that protrudes outward from the mounting surface of the housing. Since the oil seal is positioned on the mounting surface, the oil seal may be damaged. When the oil seal, which is an important part for sealing the shaft portion of the drive gear, is damaged as described above, the sealing performance of the oil seal is reduced, and oil leakage may occur.
[0009]
The present invention has been made in view of the above circumstances, and can eliminate or reduce the number of knock pins, reduce the number of parts, contribute to weight reduction and cost reduction, and further provide a gear pump that is advantageous for suppressing oil leakage. The task is to provide.
[0010]
[Means for Solving the Problems]
A gear pump according to the present invention includes a housing having a working chamber, a suction port communicating with the working chamber, and a discharge port communicating with the working chamber,
A drive gear rotatably provided in the working chamber of the housing,
A driven gear provided rotatably with the drive gear in the working chamber of the housing and driven by the drive gear,
In a gear pump that discharges a working fluid sucked from a suction port by a rotation of a driving gear and a driven gear from a discharge port,
The housing is configured by stacking split housings having shaft holes that are divided into a plurality of pieces in the axial direction of the drive gear and face each other,
The driven gear has a shaft inserted into the shaft hole of the split housing to position the plurality of split housings, and a rotary gear sleeve portion having a fitting hole rotatably fitted to the shaft and a tooth portion meshing with the drive gear. And characterized in that:
[0011]
According to the gear pump according to the present invention, the fitting hole of the rotating gear sleeve portion of the driven gear is rotatably fitted to the shaft. The teeth of the rotary gear sleeve of the driven gear mesh with the drive gear, and the rotation of the drive gear causes the rotary gear sleeve of the driven gear having a pump function to rotate around the axis of the shaft. Thereby, the working fluid is sucked from the suction port of the housing, and the sucked working fluid is discharged from the discharge port of the housing. Here, when the gear pump is driven, the teeth of the rotary gear sleeve, which is an element of the driven gear, mesh with the drive gear as described above, and the rotary gear sleeve is rotated by the drive gear. However, rotation of the shaft, which is an element of the driven gear, is suppressed. Thus, the shaft is non-rotating or, if rotated, much less than the rotation of the rotating gear sleeve.
[0012]
According to the gear pump of the present invention, in positioning the divided housings, among the driven gears, a non-rotating or a rotation-reduced shaft as described above is used, and the shaft is used as a shaft of the divided housing. The plurality of divided housings are positioned by inserting them into the holes. Therefore, the shaft, which is an element of the driven gear, functions as the first knock pin according to the related art for positioning the divided housings. For this reason, the first knock pins conventionally used for positioning the divided housings are eliminated or the number of the first knock pins is reduced.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
According to a preferred embodiment of the gear pump according to the present invention, the number of divided housings is at least two, and a shaft which is an element of the driven gear is inserted into a shaft hole of the divided housing by press-fitting, and the shaft rotates around its axis. Doing so is deterred. In this way, rotation of the shaft, which is an element of the driven gear, around the axis of the shaft is suppressed, so that wear on the outer peripheral surface of the shaft is suppressed. Therefore, the function of the shaft as the first knock pin for positioning each divided housing is further improved, and the positioning accuracy of each divided housing constituting the housing can be further improved. Examples of the split housing include a first split housing having a working chamber and a second split housing which is addressed to an opening of the working chamber of the first split housing and closes the opening. The shaft may be hollow or solid.
[0014]
According to a preferred embodiment of the gear pump according to the present invention, the shaft has a guide passage for guiding the working fluid supplied between the shaft and the rotary gear sleeve to the working fluid retreating portion. In this case, since the working fluid is easily supplied between the shaft and the rotary gear sleeve portion, it is possible to further contribute to smoothly rotating the rotary gear sleeve portion having the pump function around the shaft.
[0015]
Further, according to a preferred embodiment of the gear pump according to the present invention, the bearing member is provided between the inner peripheral surface of the fitting hole of the rotary gear sleeve portion constituting the driven gear and the outer peripheral surface of the shaft. In this case, it is possible to further contribute to smoothly rotating the rotary gear sleeve portion having the pump function around the shaft while preventing the shaft from rotating around its axis. The bearing member preferably has a cylindrical shape coaxial with the shaft. The bearing member can be formed of a material having a good lubrication sliding property. The shaft preferably has a guide passage for guiding a working fluid such as oil supplied to the bearing member to a working fluid retreating section (for example, a drain section or a hydraulic device). In this case, the lubricating property of the bearing member is improved by the working fluid such as oil, so that the smooth rotation of the rotating gear sleeve with respect to the shaft can be further improved.
[0016]
According to a preferred embodiment of the gear pump according to the present invention, the housing has a mounting surface to be mounted on the mating member, and the shaft, which is an element of the driven gear, projects outward from the mounting surface of the housing and has a It has a shaft end protruding portion fitted into the positioning concave portion. When the gear pump is attached to the mating member, the positioning accuracy between the housing of the gear pump and the mating member can be improved by fitting the convex shaft end protruding portion of the shaft into the positioning concave portion of the mating member. That is, when the shaft, which is an element of the driven gear, has a shaft end protruding portion, the shaft can function as a first knock pin according to the related art, which positions the divided housings that constitute the housing. It can also function as the second knock pin according to the related art for positioning the housing of the gear pump and the mating member. As a result, the second knock pin according to the related art can be eliminated or its number can be reduced, which can further contribute to reduction in the number of parts and weight reduction. The amount of protrusion of the shaft end protruding portion of the shaft from the mounting surface of the housing can be appropriately selected.
[0017]
According to a preferred embodiment of the gear pump according to the present invention, the housing has a movement suppressing portion that suppresses movement of the shaft in a direction opposite to a direction in which the shaft end protrusion of the shaft projects. In this case, the movement of the shaft in the direction opposite to the direction in which the shaft end protruding portion of the shaft protrudes is suppressed by the movement suppressing portion. Accordingly, the knock pin function of the shaft, which is an element of the driven gear, is further ensured, and it is possible to contribute to the improvement of the positioning accuracy between the divided housings and the positioning accuracy between the housing and the mating member. In particular, even if the shaft end protruding portion abuts against the mating material, the shaft end protruding portion is prevented from retreating from the mounting surface of the housing, and the shaft end protruding portion of the shaft has a good protrusion amount. Is done. Therefore, the shaft can properly function as the second knock pin.
[0018]
【Example】
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a front view showing the internal structure of the gear pump, and is a view taken along the line II in FIG. FIG. 2 is a cross-sectional view showing a state where the gear pump is attached to a mating member.
[0019]
The gear pump according to the present embodiment is an oil pump that supplies oil as a working fluid by rotation of a gear, and is attached to a transmission case (counterpart) of a transmission for a vehicle.
[0020]
As shown in FIG. 1, the gear pump is a circumscribed gear pump, and includes a housing 1, one drive gear 4 rotatably provided on the housing 1, and a drive gear 4 rotatably provided with the drive gear 4. And a plurality of driven gears 5 (specifically, a set of two driven gears). The plurality of driven gears 5 are arranged so as to sandwich the driving gear 4.
[0021]
The housing 1 includes an operating chamber 15 including one driving chamber 15a and a plurality of (two sets of) driven chambers 15b communicating with each other, and a first suction port communicating with the operating chamber 15 via a communication passage 21w. 21, a first discharge port 23 communicating with the working chamber 15 via a communication passage 23w, a second suction port 22 communicating with the working chamber 15 via a communication passage 22w, and a communication passage 24w communicating with the working chamber 15. And a second discharge port 24 communicating with the second discharge port. The first suction port 21 and the second suction port 22 communicate with an oil supply path (not shown). The first discharge port 23 and the second discharge port 24 communicate with a hydraulic device (not shown), and the hydraulic device is operated by oil discharged from the first discharge port 23 and the second discharge port 24.
[0022]
As shown in FIG. 2, the drive gear 4 is rotatably provided in a drive chamber 15 a located at the center of the working chamber 15, and has a large number of external teeth 40 as teeth arranged in a circumferential direction. And a drive shaft portion 42 protruding from both ends in the axial direction of the drive gear body 41 and rotatably supported by a first bearing 42m.
[0023]
As shown in FIG. 2, one end 42 a of the drive shaft portion 42 is rotatably inserted into the first main hole 11 x of the first split housing 11 via a first bearing 42 m, and the other end of the drive shaft portion 42. The end 42b is rotatably inserted into the second main hole 12x of the second split housing 12 via the first bearing 42m. The male screw portion 42k formed on the other end portion 42b of the drive shaft portion 42 is equipped with a sprocket or the like (not shown) as a power transmission member.
[0024]
As shown in FIG. 2, the driven gear 5 includes a straight shaft 50 having an axis P2 (P3), and a cylindrical rotating gear sleeve 52 rotatably fitted to the shaft 50. I have. The shaft 50 has a hollow cylindrical shape, and is lightened. The shaft 50 is formed of a metal, for example, an iron-based material or an aluminum alloy material. The rotary gear sleeve portion 52 has a fitting hole 53 having a circular cross section that fits on the outer peripheral surface of the shaft 50, and external teeth 54 as tooth portions that mesh with the external teeth 40 of the drive gear 4.
[0025]
The two driven gears 5 have the same size. Therefore, the two rotary gear sleeves 52 have the same size, the conditions such as the number of teeth and the pitch of the external teeth 54 of the two rotary gear sleeves 52 are the same, and the two shafts 50 Are the same size.
[0026]
In FIG. 1, S1 indicates the pitch circle of the drive gear 4, S10 indicates the addendum circle of the drive gear 4, S2 indicates the pitch circle of the driven gear 5, and S20 indicates the addendum circle of the driven gear 5. Show.
[0027]
FIG. 2 shows a cross section of the gear pump in a state where the gear pump is attached to the counterpart member 100. As shown in FIG. 2, the housing 1 is divided into a plurality of pieces (two pieces in the embodiment) in the thickness direction, and the first split housing 11 on the side facing the counterpart material 100 and the backside facing the counterpart material 100. And a second split housing 12 located on the side of the second split housing. The thickness t1 of the first split housing 11 is set to be thicker than the thickness t2 of the second split housing 12.
[0028]
The first split housing 11 has a working chamber 15, a surrounding wall 11 t having a surrounding inner wall surface 11 u surrounding the working chamber 15, and a smooth mounting surface 11 s which is directed to the mounting surface 104 of the mating member 100. The first divided housing 11 and the second divided housing 12 are formed of a metal material, for example, an aluminum alloy material.
[0029]
As shown in FIG. 2, the first split housing 11 has a plurality of (two) first shaft holes 16 having a circular cross section facing the driven chamber 15b. The first shaft hole 16 has a circular cross section and penetrates through the thickness of the first split housing 11. The second split housing 12 has a second shaft hole 17 having a circular cross section facing the driven chamber 15. The second shaft hole 17 penetrates through the thickness of the second housing 12, has a circular cross section, and has an opening 17 m connected to the drain portion 200.
[0030]
As shown in FIG. 2, the first shaft hole 16 and the second shaft hole 17 face each other via the working chamber 15. One end 50 a of the shaft 50, which is an element of the driven gear 5, in the axial length direction is inserted into the first shaft hole 16 of the first split housing 11 by press fitting. The other end 50b of the shaft 50 in the axial length direction is inserted into the second shaft hole 17 of the second split housing 12 by press fitting. Thereby, the shaft 50 is coaxially held by the first divided housing 11 and the second divided housing 12.
[0031]
FIG. 5 shows a cross section in a state where one end 50 a of the shaft 50 is press-fitted into the first shaft hole 16. As shown in FIG. 5, one end 50a and the other end 50b of the shaft 50 have a circular cross section. By press fitting, the outer peripheral surface of the one end 50a of the shaft 50 and the inner peripheral surface of the first shaft hole 16 are in close contact with each other with high friction. Similarly, the outer peripheral surface of the other end 50b of the shaft 50 and the inner peripheral surface of the second shaft hole 17 are in close contact with each other with high friction. For this reason, rotation of the shaft 50 around the axis P2, P3 is suppressed.
[0032]
As shown in FIG. 2, a bearing member 55 is located in the working chamber 15 between the inner peripheral surface of the fitting hole 53 of the rotary gear sleeve portion 52, which is an element of the driven gear 5, and the outer peripheral surface of the shaft 50. It is provided as follows. The bearing member 55 has a cylindrical shape and is fixed in the fitting hole 53 of the rotating gear sleeve 52. A plurality (specifically, two) of the bearing members 55 are provided in series at intervals in the axial direction of the shaft 50. The bearing member 55 is for smooth rotation of the rotary gear sleeve 52 with respect to the shaft 50.
[0033]
As shown in FIG. 2, the shaft 50, which is an element of the driven gear 5, has a guide passage 56. The guide passage 56 guides oil as a working fluid supplied to the bearing member 55 to a drain portion 200 (generally, open to the atmosphere) on the low pressure side as a working fluid retreating portion. The guide passage 56 is formed by a first guide passage 57 extending in the radial direction of the shaft 50 and a second guide passage 58 extending in the axial direction of the shaft 50 and having a distal end opening 58p. The first guide passage 57 penetrates the peripheral wall portion of the shaft 50 in the thickness direction (radial direction), and the opening 57p on the outer peripheral side thereof faces between the two bearing members 55 to ensure oil suction performance. ing. The second guide passage 58 penetrates the shaft 50 in the axial direction.
[0034]
As shown in FIG. 2, a movement suppressing portion 13 w is formed on a wall portion of the second divided housing 12 of the housing 1 near the second shaft hole 17. The movement suppressing portion 13w can function as a stopper that abuts and engages with the shaft end surface of the other end portion 50b in the axial direction of the shaft 50, and the direction in which the shaft end projecting portion 59 of the shaft 50 projects (FIG. 2). (In the direction of arrow M2 shown in FIG. 2), the shaft 50 can be prevented from moving in the direction opposite to the direction of the arrow M1 shown in FIG.
[0035]
As shown in FIG. 2, one end 50 a of each shaft 50 has a shaft end protruding portion 59 that protrudes straight outward from the mounting surface 11 s of the first split housing 11 of the housing 1. As described above, according to the present embodiment, a structure is employed in which the shaft end projecting portion 59 of the shaft 50 is projected from the mounting surface 11s of the housing 1 toward the mating member 100 (in the direction of the arrow M2). However, when such a structure is employed, the press-fitting distance between the first split housing 11 and the first shaft hole 16 tends to increase, and the press-fitting operation tends to be difficult. In order to solve this, as shown in FIG. 2, the outer diameter of the shaft end protruding portion 59 of the shaft 50 is set smaller than the outer diameter of the other portion of the shaft 50. A ring-shaped evacuation space 59a is formed on the outer peripheral surface of the portion 59. For this reason, the press-fit distance Y1 between the first shaft hole 16 of the first split housing 11 and the shaft 50 is ensured while ensuring the amount of protrusion that causes the shaft end projecting portion 59 of the shaft 50 to protrude from the mounting surface 11s of the housing 1 in the direction of the arrow M2. The press-fit distance Y1 can be shortened while maintaining the knock pin function by securing the required amount (see FIG. 2). Therefore, there is an advantage that the operation of press-fitting the one end 50a of the shaft 50 into the shaft hole 16 becomes easy.
[0036]
Further, as described above, since the evacuation space 59a is formed so that the diameter of the one end 50a of the shaft 50 is reduced, the difference in structure between the one end 50a and the other end 50b of the shaft 50 can be easily visually recognized. It is visually recognized. For this reason, even in the case where the shaft 50 is attached manually, it is possible to prevent the one end portion 50a and the other end portion 50b of the shaft 50 from being misidentified and inserted into the first shaft hole 16 and the second shaft hole 17 of the housing 1. There are advantages that can be done.
[0037]
In FIG. 1, the rotation center line of the driving gear 4 is P1, the rotation center line of one driven gear 5 is P2, the rotation center line of the other driven gear 5 is P3, and the rotation center lines P1, P2, P3 are An imaginary line virtually connected is referred to as P4. As shown in FIG. 1, a through-hole 6a, a through-hole 6b, and a through-hole 6c having a circular cross section are arranged on one side of a virtual line P4 of the housing 1. Further, on the other side of the imaginary line P4, a through-hole 6d, a through-hole 6e, and a through-hole 6f having a circular cross section are arranged. Further, as shown in FIG. 1, the through holes 6a and 6f are provided at diagonal positions so as to sandwich the rotation center line P1 of the drive gear 4, which is a main component. The through-holes 6c and 6d are provided at diagonal positions so as to sandwich the rotation center line P1 of the drive gear 4, which is a main component. The through-hole 6b and the through-hole 6e are provided at diagonal positions so as to sandwich the rotation center line P1 of the drive gear 4, which is a main component. The bolt mounting hole 69 having a circular cross section is provided in the housing 1 at a diagonal position so as to sandwich the rotation center line P1 of the drive gear 4.
[0038]
According to the present embodiment, when assembling the housing 1 of the gear pump, one end 50a of the shaft 50 is inserted into the first shaft hole 16 of the first split housing 11 in a press-fit state, and the other end 50b of the shaft 50 is It is inserted into the second shaft hole 17 of the two-part housing 12 in a press-fit state. Thus, the positioning of the first split housing 11 and the second split housing 12 is performed by the shaft 50 that is an element of the plurality (two) of the driven gears 5.
[0039]
According to the present embodiment, the one end 50a of the shaft 50 and the first shaft hole 16 are tightly press-fitted to enhance the positioning function as a knock pin and to prevent the shaft 50 from rotating. . The other end portion 50b of the shaft 50 and the second shaft hole 17 are loosely press-fitted in order to enhance the press-fitting workability while maintaining the positioning function. One end 50a of the shaft 50 is inserted into the first shaft hole 16 of the first split housing 11 having the working chamber 15 in which important parts such as the drive gear 4 and the driven gear 5 are incorporated. Making the 50a and the first shaft hole 16 tightly press-fitted and increasing the accuracy as a knock pin by the one end 50a of the shaft 50 is effective in improving the engagement accuracy between the drive gear 4 and the driven gear 5. .
[0040]
Thereafter, as shown in FIG. 3, a mounting bolt 68 that can function as a housing mounting means is inserted into a bolt mounting hole 69 of the housing 1. The mounting bolt 68 has a bolt shaft 68a having a male screw 68b at one end, and a head 68c having a flange 68w provided at the other end of the bolt shaft 68a. Then, the head 68c of the mounting bolt 68 is turned to screw the male screw 68b at the tip of the mounting bolt 68 into the female screw 69m of the bolt mounting hole 69 of the first split housing 11. As a result, the flat contact surface 11r of the first split housing 11 and the flat contact surface 12r of the second split housing 12 come into close contact with each other, and the first split housing 11 and the second split housing 12 are stacked in the thickness direction thereof. The housing 1 is configured as a single unit. The diameter of the head 68c of the mounting bolt 68 is larger than the inner diameter of the bolt mounting hole 69.
[0041]
When the gear pump according to the present embodiment is mounted on the mounting surface 104 of the mating member 100, the fastening bolt 9 shown in FIG. 4 is used. As shown in FIG. 4, a fastening bolt 9 functioning as a gear pump fastening means includes a bolt shaft 92 having a male screw portion 91 at one end and a flange 93w formed at the other end of the bolt shaft 92. And a head 93. When the gear pump according to the present embodiment is mounted on the mounting surface 104 of the mating member 100, the mounting surface 11 s of the first split housing 11 of the housing 1 faces the mounting surface 104 of the mating member 100. Then, the shaft end protruding portion 59 of the shaft 50 protruding from the mounting surface 11s is fitted into and engaged with the concave portion 102 of the mating member 100. Thereby, the positioning between the housing 1 and the mating member 100 is performed.
[0042]
The fastening bolt 9 is inserted into the through hole 9 a of the housing 1, the bolt head 93 of the fastening bolt 9 is turned, and the male screw portion 91 of the fastening bolt 9 is screwed and fixed to the female screw portion 106 of the mating member 100. Similarly, the fastening bolts 9 are respectively inserted into the other through holes 6b, 6c, 6d, 6e, and 6f (see FIG. 1) of the housing 1 so that the male screw portions 91 of the fastening bolts 9 are connected to the female members of the mating member 100. It is screwed to the screw part 106. Thus, the gear pump according to the present embodiment is detachably attached to the attachment surface 104 of the mating member 100. According to the present embodiment, the concave portion 102 as the engaged portion formed on the mating member 100 has the bottom surface 102w and has a non-through hole shape. However, in some cases, the concave portion 102 may have a through-hole shape.
[0043]
With the gear pump attached to the attachment surface 104 of the mating member 100 as described above, the drive gear 4 is driven to rotate around the rotation center line P1 thereof in the direction of arrow A1 (see FIG. 1) by the power transmission member. Then, the rotary gear sleeve portion 52 of the driven gear 5 is driven to rotate around the rotation center lines P2 and P3 in the direction of arrow A2 (see FIG. 1). As a result, oil is supplied from the first suction port 21 to the first discharge port 23 and the second discharge port 24. Similarly, oil is supplied from the second suction port 22 to the first discharge port 23 and the second discharge port 24.
[0044]
As described above, according to the present embodiment, when positioning the first divided housing 11 and the second divided housing 12 constituting the housing 1 with each other, the shaft 50 which is an element of the driven gear 5 is used. The first divided housing 11 and the second divided housing 12 are inserted into the first shaft hole 16 of the first divided housing 11 and the second shaft hole 17 of the second divided housing 12, thereby positioning the first divided housing 11 and the second divided housing 12. Therefore, the shaft 50, which is an element of the driven gear 5, can function as the first knock pin according to the related art for positioning the divided housings. For this reason, the first knock pins conventionally used for positioning the divided housings can be eliminated or the number thereof can be reduced. Furthermore, the pin hole for inserting the first knock pin can be eliminated or reduced, which is advantageous for reducing the processing cost of the housing 1.
[0045]
In particular, according to this embodiment, as described above, the shaft 50 which is an element of the driven gear 5 is press-fitted into the first shaft hole 16 of the first split housing 11 and the second shaft hole 17 of the second split housing 12. Therefore, the rotation of the shaft 50 with respect to the first divided housing 11 and the second divided housing 12 is suppressed. Thereby, the knock pin function of the shaft 50 is properly ensured. Therefore, the positioning between the first divided housing 11 and the second divided housing 12 is performed with high accuracy.
[0046]
In attaching the gear pump to the mating member 100, the positioning between the housing 1 of the gear pump and the mating member 100 is performed by fitting the convex shaft end protruding portion 59 of the shaft 50 into the positioning concave portion 102 of the mating member 100. It can be carried out. That is, the shaft end protruding portion 59 of the shaft 50, which is an element of the driven gear 5, is provided with the first knock pin according to the related art, which positions the first split housing 11 and the second split housing 12 that constitute the housing 1. Besides functioning as a second knock pin according to the related art, which positions the housing 1 of the gear pump and the mating member 100. As a result, the second knock pin according to the related art can be eliminated or the number of the second knock pin can be reduced, and the number of parts can be reduced and the weight can be further reduced. Further, the number of pin holes into which the second knock pins are inserted can be eliminated or reduced, which is advantageous in reducing processing costs and can reduce costs.
[0047]
Further, according to the present embodiment, the shaft 50 which is an element of the driven gear 5 and functions as the first knock pin is supported by the first split housing 11 and the second split housing 12 of the housing 1. The clearance between the rotating gear sleeve 52 as an element and the inner wall surface forming the working chamber 15 of the housing 1 can be defined with high accuracy. Therefore, it is possible to contribute to improving the performance of the gear pump, and it is possible to reduce variation in the performance of the gear pump even in mass production of the gear pump.
[0048]
Further, according to this embodiment, as described above, since the bearing member 55 is provided between the inner peripheral surface of the shaft 50 and the outer peripheral surface of the shaft 50 of the rotary gear sleeve portion 52, the pump function is provided. The rotation of the shaft 50 coaxially arranged on the inner peripheral side of the rotating gear sleeve 52 can be suppressed while ensuring the smooth rotation of the rotating gear sleeve 52 that is performed. Therefore, wear and the like of the outer peripheral surface of the shaft 50 are suppressed, and the knock pin function of the shaft 50 can be maintained for a long time.
[0049]
According to the present embodiment, when the gear pump is driven, the oil as the working fluid is supplied to the bearing member 55, so that the rotating gear sleeve 52 can be smoothly rotated by the lubricity of the oil while fixing the shaft 50. Can be. Further, the oil that has reached the bearing member 55 reaches the second guide passage 58 via the first guide passage 57, and further from the tip opening 58p of the second guide passage 58 on the side of the second split housing 12, the drain portion 200 (generally Is released to the atmosphere.
[0050]
The air in the working chamber 15 at the time of assembling the gear pump can also be released using the first guide passage 57, the second guide passage 58, and the tip opening 58p of the shaft 50 described above.
[0051]
According to the present embodiment, as can be understood from the above description, since the driven gear 5 is a set of two driven gears, as shown in FIG. 4 is L1 and the distance between the shaft P3 of the shaft 50 of the other driven gear 5 and the shaft P1 of the drive shaft 42 of the drive gear 4 is L2. The distance L1 and the distance L2 are set at equal intervals. Since the drive gear 4 is arranged at an intermediate position between a plurality of (specifically, two) shafts 50 functioning as knock pins as described above, it is advantageous to increase the positioning accuracy of the drive gear 4 which is an important component. Therefore, the reliability of the gear pump can be improved.
[0052]
According to this embodiment, when the gear pump is driven, the rotary gear sleeve 52, which is an element of the driven gear 5, rotates, but the shaft 50, which is an element of the driven gear 5, does not rotate at all or does not substantially rotate. For this reason, the rotating mass of the driven gear 5 having a pump function can be reduced, which can contribute to reducing the torque required to rotate the driven gear 5.
[0053]
Furthermore, in this embodiment, since the housing 1 and the mating member 100 are positioned by the shaft 50 that can function as the first knock pin and the second knock pin, unlike the technique according to Japanese Patent Application Laid-Open No. 2000-145655, the housing is provided with an oil seal. Since the method of positioning with the counterpart material has been eliminated, the problem of damage to the oil seal can be avoided.
[0054]
(Other embodiments)
FIG. 6 shows a second embodiment of the present invention. This embodiment has the same configuration as the above-described embodiment, and has the same operation and effect. According to the present embodiment, as shown in FIG. 6, at least one of the one end 50a and the other end 50b of the shaft 50E that can function as a knock pin has a flat surface 50x that can function as a detent. Then, it is press-fitted into the first shaft hole 16 and the second shaft hole 17 of the first housing 11 having the flat surface 18. Thereby, the detent property of the shaft 50E is surely enhanced.
[0055]
FIG. 7 shows a third embodiment of the present invention. This embodiment has the same configuration as the above-described embodiment, and has the same operation and effect. According to the present embodiment, as shown in FIG. 7, the concave portion 102 provided on the mounting surface 104 of the mating member 100 is provided with the hydraulic device 107 as a working fluid retreating portion via the passage 105 of the mating member 100. Is communicated to. According to the present embodiment, a distal end opening 58p is formed at one end of the second guide passage 58 of the shaft 50F that is a component of the driven gear 5 and functions as a knock pin. However, the other end of the second guide passage 58 is closed by the closing portion 58s, and does not discharge oil. The oil discharged from the distal end opening 58p of the second guide passage 58 of the shaft 50F in the direction of arrow K1 (see FIG. 7) is supplied to the hydraulic device 107 via the passage 105 of the counterpart material 100.
[0056]
(Other)
According to the above-described embodiment, one end 50a of the shaft 50 is press-fitted into the first shaft hole 16 and the other end 50b of the shaft 50 is press-fitted into the second shaft hole 17, but the invention is not limited to this. Although one end 50a of the shaft 50 is press-fitted into the first shaft hole 16, the other end 50b of the shaft 50 can also be inserted into the second shaft hole 17 in a non-pressed state. In some cases, one end 50a of the shaft 50 is inserted into the first shaft hole 16 in a non-pressed state while securing the required accuracy of the knock pin of the shaft 50, and the other end 50b of the shaft 50 is inserted into the second shaft hole. 17 may be inserted without press-fitting.
[0057]
According to the above-described embodiment, two sets of driven gears 5 are provided for one driving gear 4, but in some cases, one driven gear 4 and one driven gear 5 are provided. A type gear pump may be used. In this case, since the driven gear 5 has only one shaft 50 having a knock pin function, it is preferable to provide a conventionally used normal knock pin. According to the above-described embodiment, the mating member 100 is the transmission case of the transmission, but is not limited thereto, and may be a cylinder block of the engine or another device. In addition, the present invention is not limited to only the above-described embodiments, and can be implemented with appropriate modifications without departing from the gist.
[0058]
The following technical idea can be understood from the above description.
(Additional Item 1) A housing having an operation chamber, a drive gear rotatably provided in the operation chamber of the housing, and a drive gear rotatably provided in the operation chamber of the housing together with the drive gear. And a driven gear,
The housing is configured by stacking divided housings having shaft holes that are divided into a plurality in the axial direction of the drive gear and that face each other,
The driven gear includes a shaft that is inserted into the shaft hole of the split housing to position the plurality of split housings, a fitting hole that is rotatably fitted to the shaft, and a tooth portion that meshes with the drive gear. And a rotating gear sleeve having the same. In this case, in positioning the divided housings, among the elements of the driven gear, a non-rotating or a rotation-suppressed shaft is used, and the shaft is inserted into a shaft hole of the divided housing to form a plurality of divided housings. The positioning of the housings can be performed.
[0059]
【The invention's effect】
As described above, according to the gear pump according to the present invention, in positioning the divided housings, among the elements of the driven gear, as described above, the non-rotating or using the shaft whose rotation is considerably suppressed, The shaft is inserted into the shaft hole of the divided housing to position the plurality of divided housings. Therefore, the shaft, which is an element of the driven gear, can function as the first knock pin according to the related art for positioning the divided housings. Therefore, the first knock pins conventionally used for positioning the divided housings can be eliminated or the number thereof can be reduced. Furthermore, the pin hole for inserting the first knock pin can be eliminated or reduced, which is advantageous for reducing the processing cost.
Also, unlike the technique according to Japanese Patent Application Laid-Open No. 2000-145655, the oil seal is not used for positioning, so that damage to the oil seal can be avoided and oil leakage is advantageously suppressed.
[Brief description of the drawings]
FIG. 1 is a front view of a state in which a drive gear and a driven gear are arranged in an operation chamber of a housing of a gear pump, and is a view taken along an arrow line II in FIG.
FIG. 2 is a sectional view showing a state in which a gear pump having a drive gear and a driven gear is attached to a mating member.
FIG. 3 is a cross-sectional view showing a state where a first split housing and a second split housing are integrated in a stacked state.
FIG. 4 is a cross-sectional view showing a state where the housing of the gear pump is mounted on a mounting surface of a mating member.
FIG. 5 is a cross-sectional view showing a state where one end of the shaft is press-fitted into a first shaft hole of a first housing.
FIG. 6 is a cross-sectional view showing a state where one end of a shaft is press-fitted into a first shaft hole of a first housing according to the second embodiment.
FIG. 7 is a cross-sectional view of a third embodiment in which a gear pump having a drive gear and a driven gear is attached to a mating member.
[Explanation of symbols]
In the figure, 1 is a housing, 11 is a first split housing, 11s is a mounting surface, 12 is a second split housing, 15 is a working chamber, 21 and 22 are suction ports, 23 and 24 are discharge ports, 4 is a drive gear, 40 is an external tooth, 5 is a driven gear, 50 is a shaft, 51 is external teeth (teeth), 52 is a rotating gear sleeve, 53 is a fitting hole, 54 is external teeth (teeth), 56 is a guide passage, 57 is a first guide passage, 58 is a second guide passage, 59 is a shaft end protruding portion, 100 is a mating member, 102 is a concave portion, and 104 is a mounting surface.

Claims (6)

A housing having a working chamber, a suction port communicating with the working chamber, and a discharge port communicating with the working chamber;
A drive gear rotatably provided in the working chamber of the housing,
A driven gear rotatably provided with the drive gear in the working chamber of the housing and driven by the drive gear,
A gear pump that discharges the working fluid sucked from the suction port by rotation of the drive gear and the driven gear from the discharge port.
The housing is configured by stacking divided housings having shaft holes that are divided into a plurality in the axial direction of the drive gear and that face each other,
The driven gear includes a shaft inserted into the shaft hole of the split housing to position the plurality of split housings, a fitting hole rotatably fitted to the shaft, and a tooth portion meshing with the drive gear. And a rotating gear sleeve portion. 2. The structure according to claim 1, wherein the number of the divided housings is at least two, and the shaft is inserted into the shaft hole of the divided housing by press-fitting, and the rotation of the shaft around its axis is suppressed. And gear pump. 3. The gear pump according to claim 1, wherein a bearing member is provided between an inner peripheral surface of the fitting hole of the rotary gear sleeve portion and an outer peripheral surface of the shaft. 4. 2. The gear pump according to claim 1, wherein the shaft has a guide passage for guiding a working fluid supplied between the shaft and the rotary gear sleeve to a working fluid retreating portion. The housing according to any one of claims 1 to 4, wherein the housing has an attachment surface attached to a mating member, and the shaft projects outward from the attachment surface of the housing and A gear pump having a shaft end protruding portion fitted into a concave portion for positioning a mating member. The movement restraint according to any one of claims 1 to 5, wherein the housing suppresses movement of the shaft in a direction opposite to a direction in which the shaft end protrusion of the shaft projects. A gear pump having a portion.

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