Pump equipment and outboard motors

Abstract

To provide a pump device which achieves reduction of costs and simplification of a structure, etc., to prevent salt damage and secure functional reliability without performing expensive rust-proofing treatment, and to provide an outboard motor equipped with the pump device.SOLUTION: A pump device includes a housing that includes an insertion hole, into which a drive shaft driven by an engine is inserted, and is applied to an outboard motor. The pump device includes a resin cover member 50 which is fixed to the housing H to cover an outer wall surface 10a of the housing H in a region having the insertion hole 11a. The cover member 50 has a small-diameter insertion hole 54a having an inner diameter smaller than the insertion hole 11a to allow the drive shaft 3 to be rotatably inserted thereto.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a pump device applied to the lubrication system of an engine such as an outboard motor, and more particularly to a pump device arranged in the area where the engine crankshaft and the propeller drive shaft are connected, and an outboard motor equipped with the pump device. [Background technology]

[0002] A known conventional outboard motor includes an engine, a body (housing), a propeller, a drive shaft connected to the engine crankshaft to drive the propeller, and an oil pump located in the area where the drive shaft is connected to the crankshaft and fixed to the lower end of the engine (see, for example, Patent Document 1).

[0003] In this outboard motor, the drive shaft is inserted into the oil pump and connected to the crankshaft. Although the drive shaft is disposed inside the fuselage, it is disposed in an area exposed to seawater and in a seawater atmosphere. Therefore, seawater or seawater splashes that travel along the drive shaft may enter the oil pump through the opening and cause functional problems due to salt damage.In addition, because the underside of the oil pump is exposed, there is a risk that salt damage may similarly cause surface corrosion, rust, etc.

[0004] Another known outboard motor includes an engine, a body (housing), a propeller, a drive shaft connected to the engine crankshaft to drive the propeller, an oil pump located in the area where the drive shaft is connected to the crankshaft and fixed to the lower end of the engine, and a sealant that provides a liquid-tight seal around the drive shaft inside the oil pump (see, for example, Patent Document 2).

[0005] In this outboard motor, seawater or seawater splashes that have traveled down the drive shaft enter the oil pump through the opening and reach the seal, and although further infiltration is prevented, there is still a risk of functional impairment due to salt damage inside the oil pump.In addition, because the underside of the oil pump is exposed, there is also a risk of surface corrosion, rust, etc., caused by salt damage. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 3042013 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-82124 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a pump device and an outboard motor equipped with the same that can prevent salt damage and ensure functional reliability while achieving cost reduction and a simplified structure without the need for expensive rust prevention treatment. [Means for solving the problem]

[0008] The present invention 1st The pump device is adapted for use in an outboard motor and includes a housing including an insertion hole into which a drive shaft driven by the engine is inserted, and further includes a resin cover member fixed to the housing so as to cover an outer wall surface of the housing in an area including the insertion hole, the housing includes a cylindrical portion that protrudes cylindrically about the axis of the drive shaft to define the insertion hole and a portion of the outer wall surface; The cover member has a small-diameter insertion hole having an inner diameter smaller than that of the insertion hole so that the drive shaft can be rotatably passed through the insertion hole. an annular flange portion in close contact with an outer wall surface around the base of the cylindrical portion; an outer peripheral wall portion covering the outer peripheral surface of the cylindrical portion; a bottom wall portion covering the end surface of the cylindrical portion; and an inner cylindrical portion extending inward in the axial direction from the bottom wall portion to be fitted closely into the insertion hole and to define the small-diameter insertion hole, It is composed of:

[0012] A second pump device of the present invention is a pump device for use in an outboard motor, comprising a housing including an insertion hole into which a drive shaft driven by the engine is inserted, the pump device including a resin cover member fixed to the housing so as to cover an outer wall surface of the housing in an area including the insertion hole, the housing including a cylindrical portion that protrudes cylindrically about the axis of the drive shaft so as to define the insertion hole and a part of the outer wall surface, The cover member is a small-diameter insertion hole having an inner diameter smaller than that of the insertion hole so that the drive shaft can be rotatably inserted therein;An annular flange portion that is in close contact with the outer wall surface around the base of the cylindrical portion, an outer peripheral wall portion that covers the outer peripheral surface of the cylindrical portion, a bottom wall portion that covers the end face of the cylindrical portion, and an axial line extending from the bottom wall portion. of a cylindrical tip portion extending outward in the direction to define a small diameter insertion hole; It is composed of:

[0013] Furthermore, a third pump device of the present invention is a pump device for use in an outboard motor, comprising a housing including an insertion hole into which a drive shaft driven by the engine is inserted, the pump device further comprising a resin cover member fixed to the housing so as to cover an outer wall surface of the housing in an area including the insertion hole, the housing including a cylindrical portion that protrudes cylindrically about the axis of the drive shaft so as to define the insertion hole and a part of the outer wall surface, The cover member is a small-diameter insertion hole having an inner diameter smaller than that of the insertion hole so that the drive shaft can be rotatably inserted therein; An annular flange portion that is in close contact with the outer wall surface around the base of the cylindrical portion, an outer peripheral wall portion that covers the outer peripheral surface of the cylindrical portion, a bottom wall portion that covers the end face of the cylindrical portion, and an axial line extending from the bottom wall portion. of The insertion hole is tightly fitted to the inside of the insertion hole and the axis is of an elongated cylindrical portion extending outward in the direction to define a small diameter insertion hole; It is composed of:

[0014] the above 1st In the pump device, The inner cylindrical part is A configuration including a helical ridge portion formed in a spiral shape around the axis may be employed to define the small diameter insertion hole. In the second pump device, the cylindrical tip portion may include a helical ridge portion formed in a helical shape about the axis so as to define the small diameter insertion hole. In the third pump device, the long cylindrical portion may include a helical ridge portion formed in a helical shape about the axis so as to define the small diameter insertion hole.

[0015] In the above pump device, the cover member may have a bottom wall portion including an annular protrusion that annularly contacts the end surface of the cylindrical portion.

[0016] In the above pump device, the cover member may have an outer wall including a plurality of linear protrusions that extend in the axial direction and are arranged around the axis so as to be in close contact with the outer surface of the cylindrical portion.

[0017] In the pump device, the plurality of linear protrusions may be formed to have a height dimension that allows the cover member to be press-fitted into the cylindrical portion of the housing.

[0018] The above pump device may have a configuration including a pump element accommodated in a housing, the pump element including an inner rotor that is connected to the engine crankshaft and driven to rotate, and an outer rotor that moves in conjunction with the inner rotor.

[0019] In the above pump device, the housing may include an annular seal member disposed inside the cylindrical portion so as to be in close contact with the outer peripheral surface of the drive shaft that is inserted through the insertion hole and connected to the crankshaft.

[0020] In the above pump device, a configuration may be adopted in which the housing includes a second annular seal member arranged to be in close contact with the outer circumferential surface of the crankshaft in a region between the pump element and the annular seal member in the axial direction.

[0021] In the above pump device, the housing may be configured to include an annular close contact area in which a flange portion of the oil pan is in close contact with the outer wall surface outside the area covered by the cover member so that the outer wall surface is positioned inside the oil pan included in the outboard motor.

[0022] The outboard motor of the present invention is an outboard motor comprising an engine including an engine body, a crankshaft extending vertically in the engine body, an oil pan fixed to the engine body for storing oil, and a pump device fixed to the engine body for circulating the oil; a fuselage for holding the engine; a drive shaft connected to the crankshaft and rotating around an axis extending vertically; and a propeller rotated by the drive shaft, and employs a pump device having any of the above configurations as the pump device. [Effects of the Invention]

[0023] The pump device having the above configuration can achieve low costs and simplified structure without the need for expensive rust prevention treatment, can prevent salt damage, and ensures functional reliability. Furthermore, an outboard motor equipped with this pump device can prevent salt damage, and ensures functional reliability. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a schematic diagram showing an outboard motor to which a pump device according to the present invention is applied; [Figure 2] 1 is a perspective view showing an external appearance of a pump device according to an embodiment of the present invention, viewed obliquely from above. [Figure 3] 1 is a perspective view showing an external appearance of a pump device according to an embodiment of the present invention, as viewed obliquely from below. [Figure 4] 1 is an exploded perspective view of a pump device according to one embodiment, viewed obliquely from above. [Figure 5] 1 is an exploded perspective view of a pump device according to an embodiment, viewed obliquely from below. [Figure 6] 2 is a partial cross-sectional view showing the relationship between a pump device according to one embodiment, a crankshaft and a drive shaft of an engine mounted on an outboard motor, and an oil pan. FIG. [Figure 7] 1 is a perspective view of a housing main body that constitutes a housing of a pump device according to one embodiment, viewed obliquely from above. [Figure 8] 1 is a perspective view of the cover member according to a first embodiment, as a cover member included in a pump device according to one embodiment, seen obliquely from above. FIG. [Figure 9] 2 is a cross-sectional view of the cover member according to the first embodiment, taken along a vertical plane passing through the axis of a drive shaft included in the outboard motor. FIG. [Figure 10] 3 is a partially enlarged cross-sectional view showing a state in which the cover member according to the first embodiment is attached to the housing H (housing body 10) of a pump device applied to an outboard motor. FIG. [Figure 11] FIG. 10 is a perspective view showing the cover member according to the second embodiment, as viewed obliquely from above. [Figure 12] 10 is a cross-sectional view of a cover member according to a second embodiment taken along a vertical plane passing through the axis of a drive shaft included in an outboard motor. FIG. [Figure 13]10 is a partially enlarged cross-sectional view showing a state in which a cover member according to a second embodiment is attached to a housing H (housing body 10) of a pump device applied to an outboard motor. FIG. [Figure 14] FIG. 10 is a perspective view showing the cover member according to the third embodiment, as viewed obliquely from above. [Figure 15] 10 is a cross-sectional view of a cover member according to a third embodiment taken along a vertical plane passing through the axis of a drive shaft included in an outboard motor. FIG. [Figure 16] 10 is a partially enlarged cross-sectional view showing a state in which a cover member according to a third embodiment is attached to a housing H (housing body 10) of a pump device applied to an outboard motor. FIG. [Figure 17] FIG. 10 is an external perspective view of a cover member according to a fourth embodiment, as viewed obliquely from above. [Figure 18] FIG. 10 is a cross-sectional view of a cover member according to a fourth embodiment, taken along a vertical plane passing through the axis of a drive shaft included in an outboard motor. [Figure 19] 10 is a partially enlarged cross-sectional view showing a state in which a cover member according to a fourth embodiment is attached to a housing H (housing body 10) of a pump device applied to an outboard motor. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0025] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. A pump device M according to one embodiment is applied to an internal combustion engine 1 mounted on an outboard motor A. As shown in FIG. 1, the outboard motor A includes an engine 1, a body 2 that holds the engine 1, a drive shaft 3 that is connected to the crankshaft 1b of the engine 1 and extends in the direction of the axis S, a propeller 4 that is rotated by the drive shaft 3 via a transmission mechanism, and a bracket 5 for attaching it to the hull. Here, the crankshaft 1b and the drive shaft 3 are positioned on an axis S that extends in the vertical direction (up-down direction) in the outboard motor A. As shown in FIG. 1, the engine 1 includes an engine body 1a, a crankshaft 1b that rotates around an axis S, an oil pan 1c fixed to the lower end of the engine body 1a to store oil, and a pump device M fixed to the lower end of the engine body 1a.

[0026] 1, in the outboard motor A, the pump unit M is disposed so that most of the housing H is disposed within the oil pan 1c and the area connecting the drive shaft 3 is exposed to the external seawater atmosphere. The pump unit M sucks up oil from within the oil pan 1c through the oil strainer 1d, discharges the pressurized oil through an intake passage and a discharge passage in the housing H, and sucks up and circulates the oil that has flowed within the engine body 1a and returned to the oil pan 1c as indicated by the two-dot chain line.

[0027] As shown in Figures 2 to 5, the pump device M includes a housing H, which includes a housing main body 10 and a housing cover 20, an inner rotor 30 and an outer rotor 40, which include pump elements Pe, screws b for fastening the housing cover 20 to the housing main body 10, and a cover member 50.

[0028] The housing body 10 is made of a metal material such as steel, cast iron, sintered steel, or aluminum alloy and is formed into a bottomed concave shape that opens to one side in the direction of the axis S, i.e., opens vertically upward when applied to the outboard motor A. As shown in Figures 5 and 7, the housing body 10 has an outer wall surface 10a, a cylindrical portion 11 that defines a portion of the outer wall surface 10a and protrudes downward around the axis S, a joint surface 12, a pump accommodating recess 13, an intake passage 14, a discharge passage 15, six screw holes 16a that open to the joint surface 12, and four through holes 16b.

[0029] The cylindrical portion 11 defines an insertion hole 11a on the axis S, and includes an outer circumferential surface 11b, an end face 11c continuous with the lower end of the outer circumferential surface 11b, and an annular recess 11d formed inward of the insertion hole 11a in the direction of the axis S. Here, the outer circumferential surface 11b and the end face 11c form part of the outer wall surface 10a of the housing main body 10. The insertion hole 11a is formed as a circular hole with the axis S as its center so that the drive shaft 3 can be inserted therein.

[0030] 6, the annular recess 11d defines a fitting inner circumferential surface 11d1 centered on the axis S and a thrust receiving surface 11d2 perpendicular to the direction of the axis S. Two small-diameter seal members Sr1 serving as annular seal members are stacked and fitted into the annular recess 11d so as to be in close contact with the fitting inner circumferential surface 11d1 and the thrust receiving surface 11d2. The small-diameter seal member Sr1 is in close contact with the outer circumferential surface 3a of the drive shaft 3 inserted through the insertion hole 11a and is, for example, a lip seal (oil seal).

[0031] 4 and 7, the joining surface 12 is a flat surface perpendicular to the axis S so that the joining surface 22 of the housing cover 20 is joined from the direction of the axis S. Two positioning pins P for aligning the housing cover 20 are fitted onto the joining surface 12 in the area around the pump accommodating recess 13, and an annular seal groove 12a in which the seal member Gr is disposed is also formed. Here, as the seal member Gr, a seal member molded from a liquid sealant or rubber or the like is used.

[0032] As shown in Figures 4, 6, and 7, the pump accommodating recess 13 is an area that accommodates the pump element Pe (inner rotor 30 and outer rotor 40), and has a small-diameter inner circumferential surface 13a, a thrust surface 13b, a large-diameter inner circumferential surface 13c, and an annular recess 13d. The small diameter inner peripheral surface 13a receives the cylindrical portion 30a of the inner rotor 30 so as to be rotatable about the axis S. The thrust surface 13b receives one end surfaces 31, 41 of the inner rotor 30 and the outer rotor 40 in the direction of the axis S. The large-diameter inner peripheral surface 13c supports the outer peripheral surface 43 of the outer rotor 40 so as to be rotatable about an axis S1 parallel to the axis S.

[0033] 6, the annular recess 13d is formed closer to the insertion hole 11a than the small-diameter inner circumferential surface 13a in the direction of the axis S, and defines a fitting inner circumferential surface 13d1 centered on the axis S and a thrust receiving surface 13d2 perpendicular to the axis S. A large-diameter seal member Sr2 serving as a second annular seal member is fitted into the annular recess 13d so as to be in close contact with the fitting inner circumferential surface 13d1 and the thrust receiving surface 13d2. The large-diameter seal member Sr2 is in close contact with the outer circumferential surface 1b1 of the crankshaft 1b inserted through the insertion hole 21 of the housing cover 20, and is, for example, a lip seal (oil seal). That is, the second annular seal member (large diameter seal member Sr2) is disposed in close contact with the outer circumferential surface 1b1 of the crankshaft 1b in the region between the pump element Pe and the annular seal member (small diameter seal member Sr1) in the direction of the axis S.

[0034] When applied to the outboard motor A and in use, the suction passage 14 is formed as a groove-like passage having a substantially rectangular cross section that opens vertically upward, and extends horizontally from a suction port 14a that opens vertically downward at its upstream end to a pump chamber suction port 14b of the pump accommodating recess 13.

[0035] When applied to the outboard motor A and in use, the discharge passage 15 is formed as a groove-like passage with a substantially rectangular cross section that opens vertically upward, and extends horizontally from its downstream end (the position opposite to the discharge port 25a that opens vertically upward and is formed in the housing cover 20) to the pump chamber discharge port 15b that faces the pump accommodating recess 13.

[0036] The six screw holes 16a are for screwing in screws b that connect the housing cover 20 to the housing body 10 around the pump accommodating recess 13 and in the area of ​​the joining surface 12. The four through holes 16b are for passing bolts (not shown) that join the housing H (housing body 10 and housing cover 20) to the engine body 1a in the area of ​​the joining surface 12.

[0037] The housing cover 20 is connected to the housing body 10 to close it, and is made of a material such as steel, cast iron, sintered steel, or aluminum alloy. The housing cover 20 is formed in a concave shape with a bottom that opens to the other side in the direction of the axis S, i.e., that opens vertically downward when applied to the outboard motor A. As shown in FIGS. 4 and 5, the housing cover 20 includes an insertion hole 21, a joint surface 22, a suction passage 24, a discharge passage 25, six circular holes 26a, and four through holes 26b.

[0038] The insertion hole 21 is formed as a circular hole centered on the axis S so that the lower end connecting portion of the crankshaft 1b can be inserted therein. 5, the joint surface 22 is a flat surface perpendicular to the axis S so as to be joined to the joint surface 12 of the housing body 10 in the direction of the axis S. Two positioning holes h, into which the positioning pins P of the housing body 10 are fitted, are formed in the joint surface 22 in areas facing each other around the pump accommodating recess 13. Furthermore, the joint surface 22 defines a thrust surface 22a, in an area around the insertion hole 21, that receives the other end surfaces 32, 42 of the inner rotor 30 and the outer rotor 40.

[0039] When applied to the outboard motor A and in use, the suction passage 24 is formed as a groove-like passage having a substantially rectangular cross section that opens vertically downward, and extends horizontally from its upstream end (the position opposite to the suction port 14a formed in the housing body 10 that opens vertically downward) to the pump chamber suction port 24b facing the pump accommodating recess 13 of the housing body 10.

[0040] When applied to the outboard motor A and in use, the discharge passage 25 is formed as a groove-like passage having a substantially rectangular cross section that opens vertically downward, and extends horizontally from a discharge port 25a that opens vertically upward at its downstream end to a pump chamber discharge port 25b that faces the pump accommodating recess 13.

[0041] The six circular holes 26a are formed in opposing areas around the pump accommodating recess 13 and in the area of ​​the joining surface 22 so as to receive screws b for joining the housing cover 20 to the housing body 10. The four through holes 26b are for passing bolts (not shown) that join the housing H (housing body 10 and housing cover 20) to the engine body 1a in the area of ​​the joining surface 22.

[0042] 4 to 6, the pump element Pe is disposed in the pump accommodating recess 13 of the housing body 10, and defines a pump chamber that expands and contracts to perform a pumping action on the oil, including a suction stroke, a pressurizing stroke, and a discharge stroke. Here, the inner rotor 30 and the outer rotor 40 are trochoid rotors having trochoidal teeth.

[0043] The inner rotor 30 is made of a metal material such as steel or sintered steel and is formed as an external gear with teeth following a trochoid curve, and is equipped with a cylindrical portion 30a that protrudes in the direction of the axis S to be fitted onto the small-diameter inner peripheral surface 13a, one end surface 31 that slides on the thrust surface 13b of the housing body 10, the other end surface 32 that slides on the thrust surface 22a of the housing cover 20, and a fitting hole 33 into which the lower end connecting portion of the crankshaft 1b is fitted. The inner rotor 30 rotates integrally with the crankshaft 1b in the direction of arrow R about the axis S, as shown in FIG.

[0044] The outer rotor 40 is made of a metal material such as steel or sintered steel and is formed as an internal gear having teeth that can mesh with the inner rotor 30, and has one end face 41 that slides on the thrust surface 13b of the housing body 10, the other end face 42 that slides on the thrust surface 22a of the housing cover 20, and a cylindrical outer peripheral surface 43 centered on the axis S1. The outer peripheral surface 43 comes into slidable contact with the large-diameter inner peripheral surface 13c of the housing body 10.

[0045] The outer rotor 40 rotates in the same direction as the inner rotor 30 about the axis S1 at a slower speed than the inner rotor 30 while being linked to the rotation of the inner rotor 30 about the axis S1. Furthermore, as the inner rotor 30 and the outer rotor 40 rotate while partially meshing with each other, a pump chamber that expands and contracts between them is defined, and a pumping action including a suction stroke, pressurization stroke, and discharge stroke occurs continuously.

[0046] As shown in FIG. 6, the cover member 50 is fixed to the housing H (housing main body 10) so as to cover the area of ​​the housing H (housing main body 10) that includes the insertion hole 11a into which the drive shaft 3 is inserted and that is exposed from the oil pan 1c. In other words, the housing H (housing main body 10) is formed to include an annular close contact area Ca in which the flange portion 1c1 of the oil pan 1c is in close contact with the outer wall surface 10a outside the area covered by the cover member 50 so that the outer wall surface 10a is positioned inside the oil pan 1c included in the outboard motor A.

[0047] The cover member 50 is made of a resin material having excellent heat resistance, water resistance, and impact resistance, such as a polyamide resin material, and is formed in a bottomed cylindrical (cap-shaped) shape as shown in Figures 3, 6, 8, and 9, and is provided with an annular flange portion 51, an outer peripheral wall portion 52, a bottom wall portion 53, and a tip cylindrical portion 54.

[0048] The annular flange portion 51 forms an annular flat surface perpendicular to the axis S so as to come into close contact with the outer wall surface 10a around the base of the cylindrical portion 11 of the housing body 10 in an annular shape. The outer peripheral wall portion 52 forms a cylindrical wall to cover the outer peripheral surface 11b of the cylindrical portion 11 of the housing body 10. Further, on the inner peripheral surface of the outer peripheral wall portion 52, a plurality of (here, 12) linear protrusions 52a extending in the direction of the axis S and arranged at equal intervals around the axis S are formed. The multiple linear protrusions 52a are formed to a height dimension that allows the outer peripheral wall 52 of the cover member 50 to be press-fitted into (the outer peripheral surface 11b of) the cylindrical portion 11. Here, the height dimension refers to the amount by which the multiple linear protrusions 52a protrude radially inward, perpendicular to the axis S, from the inner peripheral surface.

[0049] The bottom wall portion 53 forms a flat surface perpendicular to the axis S at the tip (lower end) of the outer peripheral wall portion 52 so as to cover the end surface 11c of the cylindrical portion 11 of the housing body 10. In addition, an annular protrusion portion 53a that comes into annular contact with the end surface 11c of the cylindrical portion 11 is formed on the inner surface of the bottom wall portion 53. When the cover member 50 is fitted to the cylindrical portion 11, the annular protrusion 53a increases the contact surface pressure with the end face 11c, thereby improving the sealing performance.

[0050] The cylindrical tip portion 54 extends from the bottom wall portion 53 outward (downward) in the direction of the axis S over a predetermined length L, and defines a small diameter insertion hole 54a into which the drive shaft 3 is rotatably inserted. The small diameter insertion hole 54a is a circular hole centered on the axis S, and has an inner diameter smaller than that of the insertion hole 11a of the housing body 10. In other words, the small diameter insertion hole 54a is formed with an inner diameter dimension that allows rotation of the drive shaft 3 with a small gap between it and the outer peripheral surface 3a of the drive shaft 3. Here, the "micro gap" refers to a gap that does not come into contact with the outer peripheral surface 3a of the drive shaft 3 and cannot allow seawater or seawater droplets to enter.

[0051] In the tip cylindrical portion 54, the small diameter insertion hole 54a forming a minute gap with the outer peripheral surface 3a of the drive shaft 3 is formed over a predetermined length L, so that the area of ​​the minute gap can be set longer in the direction of the axis S compared to when the small diameter insertion hole is formed by the thickness of the bottom wall portion 53. This increases the passage resistance between the small diameter insertion hole 54a and the drive shaft 3, and effectively blocks seawater or seawater splashes that try to enter the inside of the housing body 10.

[0052] Next, the assembly work of the pump device M having the above-mentioned configuration will be described. For assembly, the housing H (housing body 10, housing cover 20), pump element Pe (inner rotor 30 and outer rotor 40), two small diameter seal members Sr1, a large diameter seal member Sr2, a cover member 50, two positioning pins P, a hex screw b, and a seal member Gr are prepared.

[0053] First, the two positioning pins P, the two small-diameter seal members Sr1, the large-diameter seal member Sr2, and the pump element Pe are assembled to the housing body 10. Specifically, two positioning pins P are fitted into fitting holes in the joint surface 12, two small-diameter sealing members Sr1 are fitted into the annular recess 11d, and a large-diameter sealing member Sr2 is fitted into the annular recess 13d, and the pump element Pe is incorporated into the pump accommodating recess 13.

[0054] Next, a seal member Gr is applied or placed on the joining surface 12, and the housing cover 20 is assembled to the housing main body 10. Specifically, the housing cover 20 is joined to the housing body 10 from the direction of the axis S so that the positioning pin P is fitted into the positioning hole h and the joint surface 22 is joined to the joint surface 12, and six screws b are screwed into the screw holes 16a through the circular holes 26a.

[0055] Finally, the cover member 50 is brought close to the cylindrical portion 11 that defines the insertion hole 11a of the housing body 10 that constitutes the housing H from the outside in the direction of the axis S and assembled. Specifically, the cover member 50 is pressed into the housing H (the cylindrical portion 11 of the housing main body 10) so that the annular flange portion 51 is in close contact with the outer wall surface 10a around the base of the cylindrical portion 11, the multiple straight protrusion portions 52a of the outer wall portion 52 are in close contact with the outer surface 11b of the cylindrical portion 11, and the annular protrusion portion 53a of the bottom wall portion 53 is in close contact with the end face 11c of the cylindrical portion 11. This fixes the cover member 50 to the housing H, completing the assembly of the pump device M. Note that the assembly procedure is not limited to the above, and other procedures may also be used.

[0056] As described above, the resin cover member 50 is fixed to cover the outer wall surface 10a of the housing H in the area including the insertion hole 11a, thereby achieving cost reduction and structural simplification without the need for expensive rust prevention treatment, while preventing salt damage due to exposure to a seawater atmosphere and ensuring functional reliability.

[0057] Here, the cover member 50 has a small-diameter insertion hole 54a with an inner diameter smaller than the insertion hole 11a of the housing H so that the drive shaft 3 can pass through freely and rotate freely. This increases the resistance of the flow path leading to the inside of the housing H, and makes it possible to prevent the intrusion of seawater or seawater splashes, etc., compared to when there is only the insertion hole 11a, and to prevent salt damage such as rust and malfunctions due to rust.

[0058] Furthermore, the housing H includes a cylindrical portion 11 as a convex tubular portion that protrudes cylindrically outward (downward) around the axis S of the drive shaft 3 to define the insertion hole 11a, and the cover member 50 includes an annular flange portion 51 that is in close contact with the outer wall surface 10a around the base of the cylindrical portion 11, an outer peripheral wall portion 52 that covers the outer peripheral surface 11b of the cylindrical portion 11, a bottom wall portion 53 that covers the end face 11c of the cylindrical portion 11, and a tip cylindrical portion 54 that extends outward (downward) from the bottom wall portion 53 in the direction of the axis S to define the small diameter insertion hole 54a, so that the housing H and the cover member 50 can be made to have a simple form, which contributes to simplifying the structure.

[0059] As shown in Figure 10, the cover member 50 includes an annular protrusion 53a that annularly abuts against the end face 11c of the cylindrical portion 11 at the bottom wall portion 53, thereby increasing the contact surface pressure between the bottom wall portion 53 and the end face 11c and efficiently blocking seawater or seawater splashes that attempt to infiltrate between the bottom wall portion 53 and the end face 11c. Furthermore, since the cover member 50 includes a plurality of straight protrusions 52a that extend in the direction of the axis S at the outer wall portion 52 so as to be in close contact with the outer peripheral surface 11b of the cylindrical portion 11 and are arranged around the axis S, the contact surface pressure between the outer peripheral wall portion 52 and the outer peripheral surface 11b can be increased, and in particular, since the plurality of straight protrusions 52a are formed with a height dimension that allows the cover member 50 to be press-fitted into the cylindrical portion 11 of the housing H, the cover member 50 can be easily fixed to the housing H by press-fitting.

[0060] As shown in FIG. 6, the housing H includes a second annular seal member (large diameter seal member Sr2) arranged in close contact with the outer peripheral surface 1b1 of the crankshaft 1b in the region between the pump element Pe and the annular seal member Sr1 in the direction of the axis S, thereby preventing oil from flowing down the crankshaft 1b toward the insertion hole 11a.

[0061] On the other hand, since the housing H has an annular sealing member (two small diameter sealing members Sr1) arranged on the side closer to the insertion hole 11a, even if seawater or seawater splashes or the like enter through the insertion hole 11a, the annular sealing member (two small diameter sealing members Sr1) can reliably block these intrusions. Here, the cover member 50 is positioned outside the annular seal members (two small diameter seal members Sr1), so that it is possible to reliably prevent the intrusion of seawater or seawater splashes outside the insertion hole 11a.

[0062] Next, the pump operation of the pump device M in the outboard motor A will be briefly described. When the engine 1 starts, the crankshaft 1b rotates, which in turn rotates the drive shaft 3, which in turn rotates the propeller 4 via a transmission mechanism. Furthermore, the rotation of the crankshaft 1b starts the pump device M. Specifically, the inner rotor 30 rotates in the direction of arrow R, and the outer rotor 40 rotates in the same direction in conjunction with the rotation, causing the pump chamber to expand and contract, thereby generating a pumping action.

[0063] The oil drawn up through the suction port 14a via the oil strainer 1d flows through the suction passages 14 and 24 and is drawn into the pump chamber through the pump chamber suction ports 14b and 24b located on both end faces of the pump element Pe. Next, the pressurized oil flows from the pump chamber discharge ports 15b and 25b located on both end faces of the pump element Pe through the discharge passages 15 and 25 and is discharged from the discharge port 25a to be supplied to a destination in the engine 1. The oil supplied to the engine 1 passes through locations required for lubrication and then returns to the oil pan 1c through a predetermined discharge port. The oil in the oil pan 1c is then drawn up again by the pump device M and circulated.

[0064] The pump device M configured as described above can achieve low costs and a simplified structure without the need for expensive rust prevention treatment, can prevent salt damage, and ensure functional reliability. Therefore, with the outboard motor A equipped with the pump device M, the pump device M operates reliably without being damaged by salt, ensuring functional reliability of the engine 1 that rotates the drive shaft 3.

[0065] 11 to 13 show a cover member 150 according to the second embodiment, and the same components as those of the cover member 50 according to the first embodiment described above are given the same reference numerals and descriptions thereof will be omitted. The cover member 150 of the second embodiment is formed in a bottomed cylindrical shape (cap-shaped) using the same resin material as described above, and has an annular flange portion 51, an outer peripheral wall portion 52, a bottom wall portion 53, and an inner cylindrical portion 154.

[0066] The inner cylindrical portion 154 extends inward (upward) from the bottom wall portion 53 in the direction of the axis S over a predetermined length L1, and defines a small-diameter insertion hole 154a that fits tightly into the insertion hole 11a and into which the drive shaft 3 is rotatably inserted. The small diameter insertion hole 154a is a circular hole centered on the axis S, and has an inner diameter smaller than that of the insertion hole 11a of the housing body 10. In other words, the small diameter insertion hole 154a is formed with an inner diameter dimension that allows rotation of the drive shaft 3, with a small gap between it and the outer peripheral surface 3a of the drive shaft 3.

[0067] In the inner cylindrical portion 154, the small diameter insertion hole 154a forming a minute gap with the outer peripheral surface 3a of the drive shaft 3 is formed over a predetermined length L1, so that the area of ​​the minute gap can be set longer in the direction of the axis S compared to when the small diameter insertion hole is formed by the thickness of the bottom wall portion 53. This increases the passage resistance between the small diameter insertion hole 154a and the drive shaft 3, and effectively blocks seawater or seawater splashes that try to infiltrate the inside of the housing body 10.

[0068] Furthermore, as shown in FIG. 13, the inner cylindrical portion 154 is tightly fitted into the insertion hole 11a, so that it can reliably cover the insertion hole 11a, and the outer wall portion 52 and the inner cylindrical portion 154 are arranged to cooperate to radially sandwich the cylindrical portion 11. In other words, when the cover member 150 is fitted into the cylindrical portion 11 of the housing H, the multiple straight protrusions 52a of the outer wall portion 52 come into close contact with the outer surface 11b, and the inner cylindrical portion 154 comes into close contact with the insertion hole 11a, so that the cover member 150 can be more firmly pressed into and fixed to the cylindrical portion 11. Other functions and effects of the cover member 150 are similar to those of the cover member 50 described above.

[0069] 14 to 16 show a cover member 250 according to a third embodiment, and the same components as those of the cover member 50 according to the first embodiment described above are given the same reference numerals and descriptions thereof will be omitted. The cover member 250 of the third embodiment is formed in a bottomed cylindrical shape (cap-shaped) using the same resin material as described above, and has an annular flange portion 51, an outer peripheral wall portion 52, a bottom wall portion 53, and a long cylindrical portion 254 that penetrates the bottom wall portion 53 in the direction of the axis S.

[0070] The long cylindrical portion 254 has a configuration that combines the aforementioned tip cylindrical portion 54 and inner cylindrical portion 154, and extends from the bottom wall portion 53 outward (downward) in the direction of the axis S by a predetermined length L and also extends from the bottom wall portion 53 inward (upward) in the direction of the axis S by a predetermined length L1, and is tightly fitted into the insertion hole 11a and defines a small-diameter insertion hole 254a into which the drive shaft 3 is rotatably inserted. The small diameter insertion hole 254a is a circular hole centered on the axis S, and has an inner diameter smaller than that of the insertion hole 11a of the housing body 10. In other words, the small diameter insertion hole 254a is formed with an inner diameter dimension that allows rotation of the drive shaft 3, with a small gap between it and the outer peripheral surface 3a of the drive shaft 3.

[0071] In the long cylindrical portion 254, the small diameter insertion hole 254a forming a minute gap with the outer peripheral surface 3a of the drive shaft 3 is formed over a predetermined length L2 (= L + L1 + plate thickness), so the area of ​​the minute gap can be set longer in the direction of the axis S compared to when the small diameter insertion hole is formed by the plate thickness of the bottom wall portion 53. This increases the passage resistance between the small diameter insertion hole 254a and the drive shaft 3, and effectively blocks seawater or seawater splashes that attempt to enter the inside of the housing body 10.

[0072] Furthermore, as shown in FIG. 16, the long cylindrical portion 254 is tightly fitted into the insertion hole 11a, so that it can reliably cover the insertion hole 11a, and the outer wall portion 52 and the long cylindrical portion 254 are arranged to cooperate to radially sandwich the cylindrical portion 11a. Therefore, similar to the cover member 150 described above, the cover member 250 can be press-fitted and fixed to the cylindrical portion 11 more firmly. Other functions and effects of the cover member 250 are similar to those of the cover member 50 described above.

[0073] 17 to 19 show a cover member 350 according to a fourth embodiment, and the same components as those of the cover member 50 according to the first embodiment described above are given the same reference numerals and descriptions thereof will be omitted. The cover member 350 of the fourth embodiment is formed in a bottomed cylindrical shape (cap-shaped) using the same resin material as described above, and has an annular flange portion 51, an outer peripheral wall portion 52, a bottom wall portion 53, and a tip cylindrical portion 354.

[0074] The tip cylindrical portion 354 extends from the bottom wall portion 53 outward (downward) in the direction of the axis S over a predetermined length L, and defines a small diameter insertion hole 354a into which the drive shaft 3 is rotatably inserted. The small diameter insertion hole 354a is a circular hole centered on the axis S, and has a spiral ridge formed on its inner wall surface with projections and recesses, the inner diameter of the ridge being smaller than that of the insertion hole 11a of the housing body 10. In other words, the small diameter insertion hole 354a is formed with an inner diameter dimension that allows rotation of the drive shaft 3, with a small gap between it and the outer peripheral surface 3a of the drive shaft 3.

[0075] In the tip cylindrical portion 354, a small diameter insertion hole 354a is formed as a helical ridge portion so as to form a small gap with the outer peripheral surface 3a of the drive shaft 3, over a predetermined length L. Therefore, the area of ​​the small gap can be set longer in the direction of the axis S than when a small diameter insertion hole is formed with the thickness of the bottom wall portion 53. This increases the passage resistance between the small diameter insertion hole 354a and the drive shaft 3, effectively blocking seawater or seawater splashes that attempt to infiltrate the inside of the housing body 10. In particular, because the inner wall surface of the small diameter insertion hole 354a is formed as a helical ridge, the passage between the small diameter insertion hole 354a and the outer peripheral surface 3a of the drive shaft 3 has a labyrinth structure that repeatedly contracts and expands. This absorbs the kinetic energy of seawater or seawater splashes that attempt to infiltrate, efficiently preventing their intrusion. In particular, because it is formed in a spiral shape, the relative rotational movement of the small diameter insertion hole 354a (helical ridge portion) and the drive shaft 3 creates a feed screw action of the helical ridge portion, and even if seawater or the like enters the small diameter insertion hole 354a, it can be sent downward in the direction of the axis S.

[0076] In the above embodiment, cover members 50, 150, 250, and 350 are shown as cover members that cover the area including the convex tubular portion (cylindrical portion 11) of the housing H, but this is not limited to this, and cover members of other shapes may be used as long as they cover the outer wall surface of the housing in the area including the insertion hole into which the drive shaft 3 is inserted. For example, in a configuration in which the cover member includes an annular flange portion that is in close contact with the outer wall surface around the base of the cylindrical portion of the housing, an outer peripheral wall portion that covers the outer peripheral surface of the cylindrical portion, and a bottom wall portion that covers the end face of the cylindrical portion, the bottom wall portion may define a small diameter insertion hole.

[0077] In the above embodiment, the convex cylindrical portion of the housing is shown as a cylindrical portion 11 that protrudes cylindrically around the axis S, but this is not limited to this, and a polygonal (e.g., hexagonal) convex cylindrical portion or a convex cylindrical portion having another shape may be used as long as it is covered by a cover member and the cover member can be fixed to the housing.

[0078] In the above embodiment, the tip cylindrical portion 354 of the cover member 350 includes a configuration including a helical ridge portion formed in a spiral shape around the axis S to define the small diameter insertion hole 354a, but this is not limited to this, and a configuration may be adopted in which the small diameter insertion hole 154a of the inner cylindrical portion 154 of the cover member 150 includes a helical ridge portion, or a configuration may be adopted in which the small diameter insertion hole 254a of the long cylindrical portion 254 of the cover member 250 includes a helical ridge portion.

[0079] In the above embodiment, cover members 50, 150, 250, and 350 are shown that are fixed to the housing H by press-fitting, but this is not limited to this, and any cover member that can be fixed to the housing may be used that is fixed using a snap-fit ​​structure, a bayonet structure, or the like.

[0080] As described above, the pump device of the present invention can achieve low costs and simplified structure without the need for expensive rust prevention treatment, can prevent salt damage, and can ensure functional reliability, so it is not only applicable to engines mounted on outboard motors, but is also useful in other engines, oil and other fluid circulation equipment, etc., where there is a concern about the intrusion of foreign matter through insertion holes. [Explanation of symbols]

[0081] A Outboard motor S axis (vertical direction) 1 engine 1b Crankshaft 1b1 Crankshaft outer surface 1c Oil pan 1c1 Oil pan flange 2. Torso 3 drive shaft 3a Outer surface of drive shaft 4 propellers M Pumping Device H Housing Sr1 small diameter seal (annular seal) Sr2 large diameter seal member (second annular seal member) 10 Housing body (housing) 10a Exterior wall Ca ring close contact region 11 Cylindrical portion (convex cylindrical portion) 11a Insertion hole 11b Outer surface (outer wall surface) 11c End surface (outer wall surface) 20 Housing cover (housing) PE Pump Element 30 Inner rotor (pump element) 40 outer rotor (pump element) 50 Cover member 51 Annular flange 52 Outer wall 52a Multiple linear ridges 53 Bottom wall 53a Annular protrusion 54 Tip cylindrical part 54a Small diameter insertion hole 150 Cover member 154 Inner cylindrical part 154a Small diameter insertion hole 250 Cover material 254 Long cylindrical section 254a Small diameter insertion hole 350 Cover member 354 Tip cylindrical part 354a Small diameter insertion hole (spiral ridge)

Claims

1. 1. A pump device for use in an outboard motor, comprising: a housing including an insertion hole into which a drive shaft driven by an engine is inserted; a resin cover member fixed to the housing so as to cover an outer wall surface of the housing in a region including the insertion hole; the housing includes a cylindrical portion that protrudes cylindrically about an axis of the drive shaft to define the insertion hole and a portion of the outer wall surface; The cover member includes a small-diameter insertion hole having an inner diameter smaller than that of the insertion hole so that the drive shaft can be rotatably inserted therein, an annular flange portion in close contact with an outer wall surface around the base of the cylindrical portion, an outer peripheral wall portion covering the outer peripheral surface of the cylindrical portion, a bottom wall portion covering an end face of the cylindrical portion, and an inner cylindrical portion extending inward in the axial direction from the bottom wall portion to be closely fitted into the insertion hole and to define the small-diameter insertion hole. A pump device characterized by:

2. A pump device for use in an outboard motor, comprising a housing including an insertion hole into which a drive shaft driven by an engine is inserted, a resin cover member fixed to the housing so as to cover an outer wall surface of the housing in a region including the insertion hole; the housing includes a cylindrical portion that protrudes cylindrically about an axis of the drive shaft to define the insertion hole and a portion of the outer wall surface; The cover member includes a small-diameter insertion hole having an inner diameter smaller than that of the insertion hole so that the drive shaft can be rotatably inserted therein, an annular flange portion in close contact with an outer wall surface around the base of the cylindrical portion, an outer peripheral wall portion covering the outer peripheral surface of the cylindrical portion, a bottom wall portion covering an end face of the cylindrical portion, and a tip cylindrical portion extending outward from the bottom wall portion in the axial direction to define the small-diameter insertion hole. A pump device characterized by:

3. A pump device for use in an outboard motor, comprising a housing including an insertion hole for inserting a drive shaft driven by an engine, a resin cover member fixed to the housing so as to cover an outer wall surface of the housing in a region including the insertion hole; the housing includes a cylindrical portion that protrudes cylindrically about an axis of the drive shaft to define the insertion hole and a portion of the outer wall surface; The cover member includes a small-diameter insertion hole having an inner diameter smaller than that of the insertion hole so that the drive shaft can be rotatably inserted therein, an annular flange portion in close contact with an outer wall surface around the base of the cylindrical portion, an outer peripheral wall portion covering the outer peripheral surface of the cylindrical portion, a bottom wall portion covering an end face of the cylindrical portion, and a long cylindrical portion extending inward in the axial direction from the bottom wall portion to be closely fitted into the insertion hole and extending outward in the axial direction to define the small-diameter insertion hole. A pump device characterized by:

4. The inner cylindrical portion includes a helical ridge portion formed in a spiral shape around the axis to define the small diameter insertion hole.

2. The pump device according to claim 1.

5. The tip cylindrical portion includes a spiral ridge portion formed in a spiral shape around the axis to define the small diameter insertion hole, 3. The pump device according to claim 2.

6. The long cylindrical portion includes a helical ridge portion formed in a spiral shape around the axis to define the small diameter insertion hole.

4. The pump device according to claim 3.

7. The cover member includes an annular protrusion at the bottom wall portion that annularly contacts the end surface of the cylindrical portion.

4. A pump device according to claim 1, wherein the pump device comprises:

8. The cover member includes, on the outer peripheral wall portion, a plurality of linear protrusions extending in the direction of the axis so as to be in close contact with the outer peripheral surface of the cylindrical portion and arranged around the axis.

4. A pump device according to claim 1, wherein the pump device comprises:

9. The plurality of linear protrusions are formed to have a height dimension that allows the cover member to be press-fitted into the cylindrical portion of the housing.

9. The pump device according to claim 8.

10. a pump element housed in the housing; The pump element includes an inner rotor that is connected to a crankshaft of the engine and is driven to rotate, and an outer rotor that moves in conjunction with the inner rotor.

10. A pump device according to claim 1, wherein the pump device comprises:

11. the housing includes an annular seal member disposed inside the cylindrical portion so as to be in close contact with an outer circumferential surface of the drive shaft, which is inserted through the insertion hole and connected to the crankshaft; 11. The pump device according to claim 10.

12. the housing includes a second annular seal member disposed in close contact with an outer circumferential surface of the crankshaft in a region between the pump element and the annular seal member in the axial direction; 12. The pump device according to claim 11.

13. the housing includes an annular contact area in which an outer wall surface outside the area covered by the cover member is disposed inside an oil pan included in an outboard motor and in which a flange portion of the oil pan comes into annular contact with the outer wall surface, 13. A pump device according to any one of claims 1 to 12.

14. an engine including an engine body, a crankshaft extending vertically in the engine body, an oil pan fixed to the engine body for storing oil, and a pump device fixed to the engine body for circulating the oil; a fuselage that holds the engine; a drive shaft connected to the crankshaft and rotatable about an axis extending in the vertical direction; a propeller rotated by the drive shaft, The pump device is a pump device according to any one of claims 1 to 13. An outboard motor characterized by:

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