Reciprocating pump

Abstract

The present invention provides a reciprocating pump. The reciprocating pump comprises: a driving part including a first cylinder; a reciprocating member having a first end arranged inside the first cylinder and reciprocating in the axial direction of the first cylinder; a pump part including a second cylinder having an end of the reciprocating member arranged inside the second cylinder on the opposite side to the end; and a sealing member pressing member having a cylindrical shape, surrounding a part of the reciprocating member in the circumferential direction and arranged between the first cylinder and the second cylinder, with a through hole formed in the peripheral wall of the sealing member pressing member.

Description

Technical Field

[0001] The present disclosure relates to a reciprocating pump. Background Art

[0002] A reciprocating pump is disclosed in Japanese Patent Gazette No. 4-24551. The pump includes a crankcase as a driving part and a manifold connected to the crankcase. The crankcase includes a guide part for guiding the reciprocating member, and the manifold includes a pump chamber through which the top end side of the reciprocating part passes. A space is formed between the guide part and the pump chamber, and the pump chamber and the guide part are sealed liquid-tightly by sealing members. A hole connected to the oil pan is formed on the peripheral wall constituting the space. Summary of the invention

[0003] Problem that the invention aims to solve

[0004] In the above-mentioned reciprocating pump, the fluid leaked from the sealing member on the pump chamber side and the liquid (oil) leaked from the sealing member on the guide side are accumulated in the oil pan through the hole formed in the portion between the guide and the pump chamber. For example, when the oil accumulates in the portion between the guide and the pump chamber, it is considered that the oil has entered the interior of the pump chamber.

[0005] An object of the present disclosure is to provide a reciprocating pump that appropriately discharges liquid leaking from a pump unit and a driving unit.

[0006] Solutions for solving problems

[0007] A reciprocating pump of a technical solution comprises: a driving part (10) including a first cylinder (11); a reciprocating member (50) having a first end (51a) arranged inside the first cylinder (11) and reciprocating in the axial direction of the first cylinder (11); a pump part (30) including a second cylinder (31) having a second end (53a) of the reciprocating member (50) arranged inside the second cylinder (31) on the side opposite to the first end (51a); a sealing member pressing member (60) having a cylindrical shape, surrounding a part of the reciprocating member (50) in the circumferential direction, and arranged between the first cylinder (11) and the second cylinder (31); an annular first sealing member (70) arranged between the first cylinder (11) and the sealing member pressing member; The invention relates to a first cylinder (11) and a second cylinder (31) having a sealing member (60) and a sealing member pressing member (60) which are in sliding contact with the reciprocating member (50) to seal the inside of the second cylinder (31) in a liquid-tight manner; and an annular second sealing member (49) which is arranged between the second cylinder (31) and the sealing member pressing member (60) to slide in contact with the reciprocating member (50) to seal the inside of the second cylinder (31) in a liquid-tight manner. The peripheral wall (61) of the sealing member pressing member (60) is provided with: a first through hole (67); and a second through hole (69) which is formed at a position closer to the second sealing member (49) in the axial direction than the first through hole (67). When the reciprocating pump is placed on a horizontal plane, the first through hole (67) and the second through hole (69) are formed on the lower surface of the peripheral wall (61) of the sealing member pressing member (60).

[0008] Utilizing the above-mentioned reciprocating pump, the reciprocating member (50) disposed inside the first cylinder (11) and the second cylinder (31) reciprocates in the axial direction. The first seal (70) disposed between the first cylinder (11) and the seal pressing member (60) seals the inside of the first cylinder (11) in a liquid-tight manner. Similarly, the second seal (49) disposed between the second cylinder (31) and the seal pressing member (60) seals the inside of the second cylinder (31) in a liquid-tight manner. Therefore, when liquid exists in the first cylinder (11) and the second cylinder (31), the first seal (70) and the second seal (49) suppress the leakage of the liquid into the seal pressing member (60). A first through hole (67) close to the first seal (70) and a second through hole (69) close to the second seal (49) are provided on the lower surface of the seal pressing member (60). Thus, when the liquid in the first cylinder (11) leaks from the first seal (70) side, it is easy to discharge from the first through hole (67), and when the liquid in the second cylinder (31) leaks from the second seal (49) side, it is easy to discharge from the second through hole (69). In this way, since through holes corresponding to the liquid in each cylinder are provided, the liquid leaking from the seal can be appropriately discharged.

[0009] Alternatively, the first through hole (67) of one technical solution includes a first long hole-shaped portion (67a) having a length direction in a direction intersecting the axial direction. With this structure, liquid that has expanded in a direction intersecting the axial direction can be guided to the first through hole (67).

[0010] Alternatively, the first through hole (67) of one embodiment includes a second long hole-shaped portion (67b) having a length direction in the axial direction. With this structure, the liquid dripping along the reciprocating member (50) can be guided to the first through hole (67).

[0011] Alternatively, the sealing member pressing member (60) of one technical solution includes an annular end wall (63) that protrudes radially inward from the peripheral wall (61) and abuts against the first sealing member (70). Alternatively, a portion of the peripheral edge of the first through hole (67) is formed along the end wall (63). With this structure, liquid moving along the end wall (63) can be guided to the first through hole (67) without passing through the peripheral wall (61).

[0012] Alternatively, the sealing member pressing member (60) of one technical solution includes an annular partition wall (68) which protrudes radially inward from the peripheral wall (61) at a position between the first through hole (67) and the second through hole (69) in the axial direction. With this structure, it is possible to prevent the liquid leaking from the first cylinder (11) and the liquid leaking from the second cylinder (31) from mixing on the peripheral wall (61).

[0013] Effects of the Invention

[0014] As described above, according to one aspect of the present disclosure, it is possible to provide a reciprocating pump that appropriately discharges liquid leaking from a pump unit and a driving unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a cross-sectional view of an example of a reciprocating pump.

[0016] Figure 2 FIG. 1 is a perspective cross-sectional view showing an example of a seal pressing member.

[0017] Figure 3 FIG. 1 is a longitudinal sectional view showing an example of a seal pressing member.

[0018] Figure 4 yes Figure 1 A partial enlarged view of .

[0019] Figure 5 It is a perspective sectional view showing another example of a seal pressing member. DETAILED DESCRIPTION

[0020] Below, while referring to the attached Figure 1 While explaining an example of a reciprocating pump. In this specification, as an example of a reciprocating pump, a so-called horizontal triple plunger pump in which the plungers constituting the reciprocating member are arranged in three rows in parallel in the horizontal direction is explained. Among them, in the following description, "upper" and "lower" are defined based on the state of the reciprocating pump placed on a horizontal plane, and "front" and "rear" are defined based on the axial direction of the reciprocating member, with the pump side defined as the front and the drive side defined as the rear.

[0021] Figure 1 1 is a cross-sectional view showing one of the three plunger pumps constituting the reciprocating pump. In an example of a reciprocating pump 1, Figure 1 The pump structure shown has three pumps arranged in parallel along the X direction. Figure 1 As shown, the reciprocating pump 1 includes a driving unit 10, a pump unit 30, a reciprocating member 50, and a seal pressing member 60. The driving unit 10 includes a first cylinder 11. An example of the first cylinder 11 is formed in a crankcase 13. The crankcase 13 is hollow. The following components are arranged in the crankcase 13: a crankshaft 15; a connecting rod 17, which is rotatably connected to the crankshaft 15; and a piston pin 18, which connects the plunger rod 51 to the connecting rod 17 in a rotatable manner, thereby constituting a driving mechanism 19 for reciprocatingly driving the reciprocating member 50.

[0022] The first cylinder 11 is cylindrical and has an axial direction orthogonal to the axial direction of the crankshaft 15. In the example shown in the figure, the axial direction of the crankshaft 15 is along the X direction, and the axial direction of the first cylinder 11 is along the Y direction. Inside the first cylinder 11, the top end of the connecting rod 17 and the piston pin 18 can be arranged.

[0023] The crankcase 13 is filled with oil (first liquid) for lubrication and cooling of the drive mechanism 19. Therefore, in one example, the crankcase 13 is provided with an oil filling port 13a for injecting oil into the inner space and a drain plug 13b for discharging the oil. In addition, a support leg 13c for mounting the reciprocating pump 1 is formed on the outer surface of the crankcase 13. For example, when the reciprocating pump 1 is mounted in a manner that the support leg 13c abuts against the horizontal ground, the axial direction of the first cylinder 11 is substantially parallel to the horizontal plane.

[0024] The pump unit 30 is connected to the front end of the crankcase 13 constituting the drive unit 10. The pump unit 30 includes a second cylinder 31 having a cylindrical shape. An example of the pump unit 30 includes a first manifold 33 as a discharge manifold and a second manifold 35 as a water intake manifold. For example, a pump chamber 37 is provided in the first manifold 33. In addition, the second manifold 35 is connected to the first manifold 33 and the crankcase 13. The second manifold 35 includes a second cylinder 31 connected to the pump chamber 37. The second cylinder 31 is cylindrical and has an axis that coincides with the axis of the first cylinder 11.

[0025] The second manifold 35 abutting the crankcase 13 is provided with a suction port 39 for introducing a working liquid such as water into the pump chamber 37, and the first manifold 33 abutting the second manifold 35 is provided with a discharge port 32 for discharging the working liquid compressed in the pump chamber 37. A suction valve 38 is provided in a flow path 36 connecting the suction port 39 and the pump chamber 37, and a discharge valve 43 is provided in a flow path 41 connecting the pump chamber 37 and the discharge port 32.

[0026] The first manifold 33 and the second manifold 35 are connected by means of a connecting pipe 45. The connecting pipe 45 is a substantially cylindrical member. The connecting pipe 45 is arranged across the opening 37a of the pump chamber 37 formed in the first manifold 33 and the second cylinder 31 formed in the second manifold 35. The connecting portion between the pump chamber 37 and the second cylinder 31 is sealed liquid-tightly by the connecting pipe 45. A high-pressure seal 47 is provided on the inner side of the second cylinder 31 at a position on the rear side of the connecting pipe 45. The high-pressure seal 47 is in sliding contact with the plunger sleeve 53 discussed later to seal the inside of the second cylinder 31 liquid-tightly.

[0027] In the second cylinder 31 of the second manifold 35, a low-pressure seal 49 (second seal) having a sealing pressure lower than that of the high-pressure seal 47 is arranged at a position away from the high-pressure seal 47 toward the crankcase 13. The low-pressure seal 49 and the plunger sleeve 53 are in sliding contact to seal the inside of the second cylinder 31 liquid-tightly. In addition, in the second manifold 35, a water supply port 42 and a drain port 46 communicating with the inside of the second cylinder 31 are provided between the high-pressure seal 47 and the low-pressure seal 49. Cooling water can be supplied to the water supply port 42. The cooling water supplied to the water supply port 42 circulates in the space sealed by the high-pressure seal 47 and the low-pressure seal in the second cylinder 31. The cooling water cools the high-pressure seal 47, the plunger sleeve 53 and the low-pressure seal 49, and is discharged from the drain port 46.

[0028] The reciprocating member 50 includes a plunger rod 51 and a plunger sleeve 53. The plunger rod 51 includes a cylindrical portion disposed in the first cylinder 11. The plunger rod 51 is rotatably connected to the connecting rod 17 by means of a piston pin 18. The plunger sleeve 53 includes a cylindrical portion disposed in the second cylinder 31. The plunger sleeve 53 is connected to the front end of the plunger rod 51 by means of, for example, a bolt 55. In one example, the diameter of the plunger sleeve 53 is larger than the diameter of the plunger rod 51. In the illustrated example, at the connection position between the plunger sleeve 53 and the plunger rod 51, a flat washer 57 disposed at the end of the plunger sleeve 53 is clamped by the plunger sleeve 53 and the plunger rod 51. The diameter of the flat washer 57 is larger than the diameter of the plunger sleeve 53.

[0029] The reciprocating member 50 reciprocates in the axial direction in the first cylinder 11 and the second cylinder 31 by means of the connecting rod 17 and the piston pin 18 due to the rotation of the crankshaft 15. As the reciprocating member 50 reciprocates in the first cylinder 11 and the second cylinder 31, a pump action is performed by using the pump chamber 37 formed on the top end side of the second cylinder 31. At this time, the rear end 51a (first end) of the plunger rod 51 is arranged inside the first cylinder 11, and the front end 53a (second end) of the plunger sleeve 53 can be arranged inside the second cylinder 31. The connection portion between the plunger rod 51 and the plunger sleeve 53 is arranged inside the seal pressing member 60, and the seal pressing member 60 is arranged between the first cylinder 11 and the second cylinder 31.

[0030] The seal pressing member 60 is disposed between the first cylinder 11 and the second cylinder 31. The seal pressing member 60 has a cylindrical shape and surrounds a portion of the reciprocating member 50 in the circumferential direction. In the illustrated example, the seal pressing member 60 has a substantially cylindrical shape. For example, the connection portion between the plunger rod 51 and the plunger sleeve 53 is surrounded by the seal pressing member 60.

[0031] The seal pressing member 60 can push the low-pressure seal 49 toward the front side. In the example shown in the figure, a cylindrical gasket 48 is arranged between the seal pressing member 60 and the low-pressure seal 49. The seal pressing member 60 pushes the low-pressure seal 49 via the gasket 48. The inner diameter of the gasket 48 is, for example, slightly larger than the outer diameter of the plunger sleeve 53. In addition, a step portion 48a obtained by forming the outer diameter to be smaller is provided at the rear end of the gasket 48.

[0032] In addition, the seal pressing member 60 holds the oil seal 70 (first seal) and can push the oil seal 70 to the rear side. The oil seal 70 is a member that is in liquid-tight sliding contact with the outer peripheral surface of the plunger rod 51. The oil seal 70 suppresses leakage of oil in the crankcase 13. For example, the oil seal 70 is a member formed by covering a metal ring with a rubber member and has a circular ring shape.

[0033] Hereinafter, the shape of the seal pressing member 60 will be described in detail. Figure 2is a three-dimensional cross-sectional view of the sealing member pressing member 60, Figure 3 is a longitudinal sectional view of the sealing member pressing member 60. In addition, Figure 4 yes Figure 1 60 is a partially enlarged view and is a cross-sectional view showing a seal pressing member and its surroundings. The seal pressing member 60 includes a substantially cylindrical peripheral wall 61 and an annular end wall 63 protruding radially inward from the peripheral wall 61. In addition, a step portion 65 having an inner diameter larger than that of other parts is formed at the front end of the seal pressing member 60. In one example, the step portion 48a of the gasket 48 is engaged with the step portion 65 of the seal pressing member 60.

[0034] A first through hole 67 and a second through hole 69 are formed in the peripheral wall 61 of the sealing member pressing member 60. The first through hole 67 connects the inner side and the outer side of the peripheral wall 61. An example of the first through hole 67 has a roughly T-shaped shape formed by combining the first long hole shaped portion 67a and the second long hole shaped portion 67b. The first long hole shaped portion 67a is in a racetrack shape with the X direction intersecting the axial direction as the length direction. The second long hole shaped portion 67b is in a racetrack shape with the axial direction as the length direction. The first long hole shaped portion 67a is continuous with the rear side of the second long hole shaped portion 67b in a manner that the center positions in the X direction are consistent with each other, so that the first through hole is roughly T-shaped.

[0035] The second through hole 69 is formed at a position closer to the low pressure seal 49 than the first through hole 67 in the axial direction, that is, at a position on the front side. An example of the second through hole 69 has a roughly T-shaped shape formed by combining the first long hole shaped portion 69a and the second long hole shaped portion 69b. The first long hole shaped portion 69a is in a racetrack shape with the direction intersecting the axial direction as the length direction. The second long hole shaped portion 69b is in a racetrack shape with the axial direction as the length direction. The first long hole shaped portion 69a is continuous with the front side of the second long hole shaped portion 69b in a manner that the center positions in the X direction coincide with each other, so that the second through hole 69 is roughly T-shaped.

[0036] For example, the size of the first long hole shaped portion 67a, 69a in the longitudinal direction (X direction) is preferably substantially the same as the diameter of the plunger rod 51. Here, substantially the same as the diameter of the plunger rod 51 means, as an example, that the error between the diameter and the plunger rod 51 is ±20%.

[0037] The first through hole 67 and the second through hole 69 are preferably located on the lower surface side of the peripheral wall 61 of the seal pressing member 60 when the reciprocating pump 1 is placed on a horizontal surface. In one example, the center positions of the first through hole 67 and the second through hole 69 in the X direction coincide with the center line of the plunger rod 51 when viewed from the Z direction. That is, the first through hole 67 and the second through hole 69 are located directly below the plunger rod 51.

[0038] The end wall 63 protrudes radially inward from the peripheral wall 61 at the rear end of the peripheral wall 61 in the axial direction. The end wall 63 of one example is in the shape of an annular plate. The inner diameter of the end wall 63 is larger than at least the outer diameter of the plunger rod 51. In the illustrated example, a retaining portion 62 extending axially from the peripheral wall 61 is formed at a position further back than the end wall 63. The retaining portion 62 has a substantially cylindrical shape. The inner diameter of the retaining portion 62 is smaller than the inner diameter of the peripheral wall 61 and larger than the inner diameter of the end wall 63. The retaining portion 62 is a portion for retaining the oil seal 70. Therefore, it is preferred that the inner diameter of the retaining portion 62 is the same as the outer diameter of the oil seal 70, and the axial length of the retaining portion 62 is the same as the thickness of the oil seal 70. In addition, for one example of a reciprocating pump 1, the rear end portion of the seal pressing member 60 is engaged with the opening portion of the first cylinder 11. A positioning member 12 in the shape of an annular plate is arranged at the opening portion of the first cylinder 11. The seal pressing member 60 is restricted from moving backward by the positioning member 12. In addition, the positioning member 12 prevents the oil seal 70 held by the holding portion 62 from falling off. For example, when the oil seal 70 is held by the holding portion 62, the oil seal 70 abuts against the end wall 63 and the positioning member 12.

[0039] In one example, the rear end of the seal pressing member 60 and the opening of the first cylinder 11 may have a pair of engaging parts that engage with each other, so as to position the seal pressing member 60 in the circumferential direction. The pair of engaging parts may be a notch and a convex part that engages with the notch, a concave part formed in the axial direction and a convex part that engages with the concave part, etc., and there is no particular limitation as long as the circumferential positioning can be performed. By using a structure including such a pair of engaging parts, the seal pressing member 60 can be easily configured so that the first through hole 67 and the second through hole 69 are on the lower surface side in the circumferential direction.

[0040] A concave portion 62a formed continuously in the circumferential direction is provided on the outer periphery of the holding portion 62. An O-ring 66 is disposed in the concave portion 62a. The O-ring 66 seals the outer periphery of the holding portion 62 and the inner periphery of the opening portion of the first cylinder 11 in a liquid-tight manner.

[0041] In addition, the seal pressing member 60 of one example includes an annular partition wall 68. The partition wall 68 is formed continuously in the circumferential direction at a position between the first through hole 67 and the second through hole 69 in the axial direction. The partition wall 68 protrudes radially inward from the peripheral wall 61. The inner diameter of the partition wall 68 is larger than at least the outer diameter of the flat washer 57.

[0042] In addition, the axial distance L1 from the partition wall 68 to the first through hole 67 is smaller than the height L2 of the partition wall 68. Similarly, the axial distance L3 from the partition wall 68 to the second through hole 69 is smaller than the height L2 of the partition wall 68. The height L2 of the partition wall 68 is the size in the protruding direction (radial direction) relative to the inner surface of the peripheral wall 61.

[0043] In addition, a portion of the periphery of the first through hole 67 is formed along the end wall 63. In one example, the first through hole 67 includes a periphery formed along the outer edge of the end wall 63. In the illustrated example, the position of the periphery 67a1 on the rear side in the axial direction among the peripheries along the length direction of the first long hole-shaped portion 67a constituting the first through hole 67 is substantially aligned with the position of the outer edge of the end wall 63.

[0044] As described above, an example of a reciprocating pump 1 includes: a driving unit 10 including a first cylinder 11; a reciprocating member 50, whose end 51a is arranged inside the first cylinder 11 and reciprocates in the axial direction of the first cylinder 11; a pump unit 30 including a second cylinder 31, in which an end 53a of the reciprocating member 50 on the opposite side to the end 51a is arranged inside the second cylinder 31; and a sealing member pressing member 60 having a cylindrical shape. The seal pressing member 60 surrounds a part of the reciprocating member 50 in the circumferential direction and is arranged between the first cylinder 11 and the second cylinder 31; the annular oil seal 70 is arranged between the first cylinder 11 and the seal pressing member 60, and is in sliding contact with the reciprocating member 50 to make the first cylinder 11 liquid-tightly sealed; and the annular low-pressure seal 49 is arranged between the second cylinder 31 and the seal pressing member 60, and is in sliding contact with the reciprocating member 50 to make the second cylinder 31 liquid-tightly sealed. The peripheral wall 61 of the seal pressing member 60 is formed with: a first through hole 67; and a second through hole 69, which is formed at a position closer to the low-pressure seal 49 than the first through hole 67 in the axial direction. When the reciprocating pump 1 is placed on a horizontal plane, the first through hole 67 and the second through hole 69 are formed on the lower surface of the peripheral wall 61 of the seal pressing member 60.

[0045] In the above-mentioned reciprocating pump 1, the crankshaft 15 rotates, and the reciprocating member 50 connected to the crankshaft 15 by means of the connecting rod 17 and the piston pin 18 reciprocates. In the water absorption process, the reciprocating member 50 moves backward toward the drive unit 10 side, thereby reducing the pressure in the pump chamber 37. As a result, the suction valve 38 of the first manifold 33 is opened and the discharge valve 43 is closed. The used liquid is sucked into the pump chamber 37 through the suction port 39 and the suction valve 38. On the other hand, in the discharge process, the reciprocating member 50 moves forward toward the pump unit 30 side, thereby pressurizing the pump chamber 37. As a result, the suction valve 38 is closed and the discharge valve 43 is opened. The used liquid in the pump chamber 37 is discharged to the discharge port 32 through the discharge valve 43. That is, a pump action is performed.

[0046] The oil seal 70 disposed between the first cylinder 11 and the seal pressing member 60 seals the inside of the first cylinder 11 in a liquid-tight manner. Similarly, the low-pressure seal 49 disposed between the second cylinder 31 and the seal pressing member 60 seals the inside of the second cylinder 31 in a liquid-tight manner. Thus, the oil seal 70 suppresses leakage of the oil in the first cylinder 11 into the seal pressing member 60. Furthermore, the low-pressure seal 49 suppresses leakage of the cooling water and the working fluid in the second cylinder 31 into the seal pressing member 60.

[0047] When the sealing performance of the low-pressure seal 49 and the oil seal 70 is reduced due to aging or the like, oil may leak from between the oil seal 70 and the plunger rod 51, and cooling water may leak from between the low-pressure seal 49 and the plunger sleeve 53. The leaked oil and the like are discharged through the seal pressing member 60. For example, if the leaked oil accumulates inside the seal pressing member 60, it is considered that the oil that has come into contact with the plunger sleeve 53 enters the second cylinder 31 from between the low-pressure seal 49 and the plunger sleeve 53. For the above-mentioned reciprocating pump 1, a first through hole 67 is provided in the peripheral wall 61 of the seal pressing member 60. Thus, when the oil in the first cylinder 11 leaks from the oil seal 70 side, the oil is easily discharged from the first through hole 67.

[0048] Even if there is leakage from the low pressure seal 49, the leaked cooling water is easily discharged from the second through hole 69. In this way, since through holes corresponding to the liquid in each cylinder are provided, the liquid leaking from the seal can be appropriately discharged.

[0049] The first through hole 67 of one example includes a first long hole-shaped portion having a length direction in a direction intersecting the axial direction. In this structure, the liquid that has expanded in a direction intersecting the axial direction can be easily guided to the first through hole 67.

[0050] The first through hole 67 of one example includes a second long hole-shaped portion having a length direction in the axial direction. With this structure, the liquid dripping along the plunger can be easily guided to the first through hole 67.

[0051] The seal pressing member 60 of one example includes an annular end wall 63. The end wall 63 protrudes radially inward from the peripheral wall 61 and abuts against the oil seal 70. With this structure, the oil leaked from the oil seal 70 easily moves along the end wall 63. In the reciprocating pump 1 of one example, a portion of the peripheral edge (peripheral edge 67a1) of the first through hole 67 is formed along the end wall 63. Therefore, the oil moving along the end wall 63 is easily guided to the first through hole 67 without passing through the peripheral wall 61.

[0052] In addition, the seal pressing member 60 may not have the partition wall 68. In this case, it is considered that the oil leaked from the oil seal 70 and the cooling water leaked from the low-pressure seal 49 are mixed on the inner side of the seal pressing member 60. When the oil and the cooling water are mixed, the mixed liquid can contact each leaking part. In this case, for example, it is considered that the mixed liquid containing oil enters the second cylinder 31 from the contact part between the low-pressure seal 49 and the plunger sleeve 53. An example of the seal pressing member 60 includes an annular partition wall 68, which protrudes radially inward from the peripheral wall 61 at a position between the first through hole 67 and the second through hole 69 in the axial direction. With this structure, it is possible to suppress the mixing of the liquid leaked from the first cylinder 11 and the liquid leaked from the second cylinder 31 on the peripheral wall 61.

[0053] As mentioned above, although embodiment of this disclosure was described, a specific form is not limited to the above-mentioned example.

[0054] Figure 5 is a three-dimensional cross-sectional view showing another shape of the seal pressing member. In one example, it is possible to use Figure 5 The seal pressing member 160 of the reciprocating pump 1 is used to replace the seal pressing member 60 of the reciprocating pump 1. The seal pressing member 160 is different from the seal pressing member 60 only in the shapes of the first through hole and the second through hole. That is, the seal pressing member 160 includes a peripheral wall 61, an end wall 63, a retaining portion 62, and the like.

[0055] The first through hole 167 of the seal pressing member 160 communicates the inside and outside of the peripheral wall 61. The first through hole 167 has a long hole shape similar to the first long hole shaped portion 67a in the first through hole 67 of the seal pressing member 60. That is, the first through hole 167 has a racetrack shape with the direction intersecting the axial direction as the longitudinal direction. In addition, the position of the circumferential edge 167a on the rear side in the axial direction of the circumferential edge of the first through hole 167 along the longitudinal direction is substantially aligned with the position of the outer edge of the end wall 63.

[0056] The second through hole 169 of the seal pressing member 160 is formed at a position closer to the low pressure seal 49 than the first through hole 167 in the axial direction, that is, at a position on the front side. The second through hole 169 of an example has a long hole shape similar to the first long hole shape portion 69a in the second through hole 69 of the seal pressing member 60. That is, the second through hole 169 has a racetrack shape with the direction intersecting the axial direction as the longitudinal direction.

[0057] In addition, the shapes of the first through hole 167 and the second through hole 169 are not limited to the shapes exemplified above. For example, the shapes of the first through hole 167 and the second through hole 169 may be circular, elliptical, semicircular, etc., or polygonal such as a triangle or a quadrilateral. In addition, the first through hole 167 and the second through hole 169 may have shapes different from each other. In addition, for example, in the case of using a sealing member clamping member having only the first through hole 67 but not the second through hole 69, there is a possibility that the leaked oil is mixed with the cooling water, but even in this case, the leaked oil will move along the end wall and will not be easily guided to the first through hole through the peripheral wall.

Claims

1. A reciprocating pump, wherein: The reciprocating pump has: A driving unit, comprising a first cylinder; a reciprocating member, the first end of which is disposed inside the first cylinder and reciprocates in the axial direction of the first cylinder; a pump unit including a second cylinder in which a second end portion of the reciprocating member on the opposite side to the first end portion is disposed inside; a seal pressing member having a cylindrical shape, surrounding a portion of the reciprocating member in a circumferential direction, and arranged between the first cylinder and the second cylinder; an annular first seal member disposed between the first cylinder and the seal pressing member and in sliding contact with the reciprocating member to seal the first cylinder in a liquid-tight manner; and an annular second seal member disposed between the second cylinder and the seal pressing member and in sliding contact with the reciprocating member to seal the second cylinder in a liquid-tight manner; A first through hole is formed on the peripheral wall of the seal pressing member; and a second through hole is formed at a position closer to the second seal than the first through hole in the axial direction; When the reciprocating pump is placed on a horizontal surface, the first through hole and the second through hole are formed on the lower surface of the peripheral wall of the seal pressing member. The seal pressing member includes an annular end wall, which protrudes radially inward from the peripheral wall and abuts against the first seal. A portion of the periphery of the first through hole is formed along the end wall.

2. The reciprocating pump according to claim 1, wherein: The first through hole includes a first long hole-shaped portion having a longitudinal direction in a direction intersecting the axial direction.

3. The reciprocating pump according to claim 2, wherein: The first through hole includes a second long hole-shaped portion having a length direction in the axial direction.

4. The reciprocating pump according to any one of claims 1 to 3, wherein: The seal pressing member includes an annular partition wall that protrudes radially inward from the peripheral wall at a position between the first through hole and the second through hole in the axial direction.

Images