Reciprocating pump

Abstract

To provide a reciprocating pump comprising a suction valve or a discharge valve providing higher seal performance.SOLUTION: A reciprocating pump comprises a suction valve for switching a flow state of liquid. The suction valve comprises a cylindrical member forming an internal flow passage through which the liquid flows, and a valve element capable of moving forward and backward in an axial direction with respect to the cylindrical member. The valve element comprises a rod part extending in the axial direction, and a head part comprising a conical surface-shaped seat surface whose diameter is gradually expanded as going from one side toward the other side in the axial direction. The cylindrical member comprises a conical surface-shaped valve seat to be brought into contact with or separated from an outer peripheral surface of the head part, and a pressure receiving outer peripheral surface provided in a region overlapping with the valve seat in the axial direction. The cylindrical member comprises the valve seat to be brought into contact with or separated from the outer peripheral surface of the head part, and the pressure receiving outer peripheral surface fitted to an inner peripheral surface of a cylinder via a gap communicating with a compression chamber, radially outside the valve seat.SELECTED DRAWING: Figure 2

Description

Technical Field

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

Background Art

[0002] Reciprocating pumps have been used as devices for compressing liquid hydrogen. This type of pump is capable of boosting the pressure of liquid hydrogen up to about 90 MPa, for example. Specifically, a reciprocating pump mainly includes a piston that reciprocates in the axial direction and a cylinder that covers the piston from the outside. As the piston reciprocates within the cylinder, the liquid hydrogen is sequentially compressed and taken out to the outside. The piston is driven by a drive unit.

[0003] An intake valve for supplying and discharging liquid and a discharge valve are provided in the piston. As an example of this type of valve, the one described in Patent Document 1 below is exemplified. In the valve device according to the fuel supply device described in Patent Document 1 below, an annular space communicating with a fuel passage that forms a fuel intake passage or a fuel discharge passage is formed in the vicinity of the seat surface periphery of the valve seat, and pressure is introduced into the annular space when the valve is closed. Thereby, with respect to the deformation that attempts to expand the inner diameter of the seat surface toward the outer diameter side in the radial direction, a deformation that attempts to return the inner diameter of the seat surface in the radial direction occurs, and it is said that the deformation of the seat portion can be offset.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the reciprocating pump for compressing liquid hydrogen as described above, a pressure of about 90 MPa at maximum is applied to the valve device. For this reason, just by forming the annular space as described above, sufficient sealing of the seat surface cannot be ensured, and as a result, there is a problem that the sealing performance of the valve device is insufficient.

[0006] The present disclosure has been made to solve the above problems, and an object thereof is to provide a reciprocating pump having a suction valve or a discharge valve that exhibits higher sealing performance.

Means for Solving the Problems

[0007] In order to solve the above problems, a reciprocating pump according to the present disclosure includes a pump body having a piston for compressing a liquid and a cylinder having a cylindrical shape centered on an axis and covering the piston from the outside, a drive unit for reciprocating the piston in the axial direction with respect to the cylinder, and a suction valve and a discharge valve provided in the cylinder for switching the flow state of the liquid. The suction valve includes a cylindrical member inserted into a housing hole formed at one end of the cylinder in the axial direction, and a valve body that can move forward and backward in the axial direction with respect to the cylindrical member. The valve body includes a rod portion extending in the axial direction, and a head portion provided at the other end of the rod portion in the axial direction and having a conical seat surface whose diameter gradually increases from one side in the axial direction to the other side. The cylindrical member has a conical valve seat that contacts or separates from the outer peripheral surface of the head portion, and a pressure-receiving outer peripheral surface that is fitted via a gap communicating with the compression chamber with respect to the inner peripheral surface of the cylinder outside the radial direction of the valve seat.

[0008] The reciprocating pump according to the present disclosure includes a pump body having a piston for compressing a liquid and a cylinder having a cylindrical shape centered on an axis and covering the piston from the outside, a drive unit for reciprocating the piston in the axial direction with respect to the cylinder, and a discharge valve provided in the cylinder for switching the flow state of the liquid. The discharge valve includes a second cylindrical member provided on the outer peripheral surface of the cylinder, having a cylindrical shape centered on a second axis extending in a direction intersecting the axis and having a conical second valve seat centered on the second axis, a second valve body that can move forward and backward in the second axis direction with respect to the second cylindrical member, and a casing that covers the second cylindrical member from the outside. The second valve body includes a second rod portion extending in the second axis direction, and a second head portion provided at an end of the second rod portion on the other side in the second axis direction, the second head portion having a conical second seat surface that gradually increases in diameter from one side to the other side in the second axis direction. An annular second seal groove centered on the second axis and recessed toward one side in the second axis direction to accommodate a seal ring is formed in an end surface of the second cylindrical member facing the other side in the second axis direction. In a cross-sectional view including the second axis, the apex angle formed by the second seat surface of the second valve body with respect to the second axis is 130° or more and 150° or less.

Advantages of the Invention

[0009] According to the present disclosure, it is possible to provide a reciprocating pump having a suction valve or a discharge valve that exhibits higher sealing performance.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0011] Hereinafter, a reciprocating pump 100 according to an embodiment of the present disclosure will be described with reference to FIGS. 1 to 5.

[0012] (Configuration of the reciprocating pump 100) The reciprocating pump 100 is a device for boosting a cryogenic liquid such as liquid hydrogen to a high pressure (about 90 MPa). As shown in FIG. 1, the reciprocating pump 100 includes a piston 1, a cylinder 2, a drive unit 3, a casing 4, a suction valve 5, a discharge pipe 6, and a discharge valve 7. The piston 1 and the cylinder 2 constitute the pump body 9.

[0013] (Configuration of the piston 1) The piston 1 has a columnar piston body 10 extending in the vertical direction and centered on an axis O, a wear ring 11 attached to the piston body 10, and a piston ring 12. The dimension of the piston body 10 in the radial direction is constant throughout the entire region in the direction of the axis O. The wear ring 11 is provided at the tip of the piston body 10. The wear ring 11 has an annular shape centered on the axis O and is formed of a resin material.

[0014] One wear ring 11 is provided at the lower end of the piston body 10, and another wear ring 11 is provided at a distance from the wear ring 11 in the direction of the axis O. A plurality (six as an example) of piston rings 12 arranged at intervals in the direction of the axis O are provided between these pair of wear rings 11. The wear ring 11 is provided to guide the piston body 10 along the inner peripheral surface of the cylinder 2 described later. On the other hand, the piston ring 12 is provided to maintain liquid tightness and air tightness with the inner peripheral surface of the cylinder 2. The configuration of the piston ring 12 will be described later.

[0015] (Configuration of the cylinder 2) The cylinder 2 has a bottomed cylindrical shape that covers the piston 1 from the outer peripheral side. The piston 1 is inserted into the cylinder 2 through the upper opening h of the cylinder 2. The space below the tip of the piston 1 inside the cylinder 2 is defined as the compression chamber 21. A discharge hole 2c that communicates the compression chamber 21 with the outside (the discharge valve 7 described later) is formed on the inner peripheral surface of the cylinder 2. An intake valve 5 for guiding liquid hydrogen to the compression chamber 21 is provided at the bottom of the cylinder 2. This intake valve 5 is capable of allowing liquid hydrogen to flow only in the direction from the outside of the cylinder 2 into the compression chamber 21. In other words, even when the pressure in the compression chamber 21 increases, liquid hydrogen does not flow out of the cylinder 2 through the intake valve 5.

[0016] A discharge pipe 6 is connected to the side surface of the cylinder 2 at the portion facing the compression chamber 21 described above. The discharge pipe 6 is provided to take out the liquid hydrogen compressed in the compression chamber 21 to the outside of the cylinder 2. A discharge valve 7 is provided on this discharge pipe 6. The discharge valve 7 is capable of allowing liquid hydrogen to flow only in the direction from the compression chamber 21 to the outside when the pressure in the compression chamber 21 reaches a predetermined value or more.

[0017] (Configuration of the drive unit 3) The above-described piston 1 reciprocates in the axial direction of axis O by being given a driving force by a driving unit 3 within a cylinder 2. The driving unit 3 reciprocates the piston 1 within the cylinder 2 by means of an electric motor (not shown) and a link mechanism.

[0018] (Configuration of the casing 4) The casing 4 is a container that covers the above-described cylinder 2 from the outside. The casing 4 has a bottomed cylindrical casing body 4a, a supply pipe 4b, and a gas discharge pipe 4c. The supply pipe 4b is a pipe for guiding liquid hydrogen from an external supply source into the casing body 4a (liquid storage chamber 44). The supply pipe 4b is provided near the bottom surface of the casing body 4a. The gas discharge pipe 4c is provided for discharging the components (gas components) vaporized within the liquid storage chamber 44 to the outside. The gas discharge pipe 4c is provided at a position spaced above the supply pipe 4b. Also, the liquid level of the liquid hydrogen within the liquid storage chamber 44 is adjusted so as to be positioned below this gas discharge pipe 4c. Incidentally, the above-described discharge pipe 6 extends to the outside of this casing 4.

[0019] (Configuration of the intake valve 5) Next, with reference to FIGS. 2 and 3, the configuration of the intake valve 5 will be described. As shown in FIG. 2, the discharge valve 7 is provided at one end (i.e., the lower side) in the direction of the axis O of the cylinder 2. Specifically, an opening (accommodation hole 50) having a circular cross-section centered on the axis O is formed at the lower end of the cylinder 2. A lid member 2a that covers the accommodation hole 50 from below is attached to the tip of the cylinder 2. The lid member 2a has a cylindrical shape centered on the axis O. The lid member 2a is fastened and fixed to the cylinder 2 by bolts 2b from below. A plurality of bolts 2b are provided at intervals in the circumferential direction. The intake valve 5 is inserted into the accommodation hole 50. On the inner peripheral surface of the accommodation hole 50, a lower inner peripheral surface 51, a recessed inner peripheral surface 52, and a protruding inner peripheral surface 53 are formed from one side to the other side in the direction of the axis O. The lower inner peripheral surface 51 has a cylindrical surface shape centered on the axis O. The lower inner peripheral surface 51 is the inner peripheral surface of the lid member 2a. The recessed inner peripheral surface 52 is connected to the upper side of the lower inner peripheral surface 51. The recessed inner peripheral surface 52 has a cylindrical surface shape centered on the axis O and has a larger inner diameter than the lower inner peripheral surface 51. The protruding inner peripheral surface 53 is connected to the upper side of the recessed inner peripheral surface 52. The protruding inner peripheral surface 53 has a cylindrical surface shape that protrudes inward more than the recessed inner peripheral surface 52 and the inner peripheral surface of the compression chamber 21. The surface connecting the protruding inner peripheral surface 53 and the recessed inner peripheral surface 52 is an upper stepped surface 54. Also, the surface connecting the protruding inner peripheral surface 53 and the lower inner peripheral surface 51 is a lower stepped surface 55.

[0020] The intake valve 5 includes a cylindrical member 30, a valve body 40, a disk member 60, a ring valve 70, an elastic member 80, and a bush 90. The cylindrical member 30 extends in the direction of the axis O over the protruding inner peripheral surface 53 and the recessed inner peripheral surface 52 described above. The cylindrical member 30 has a main body portion 32 having a valve seat 31 and an outer peripheral portion 33 provided on the outer peripheral side of the main body portion 32. The main body portion 32 has a cylindrical shape centered on the axis O. A valve seat 31 is formed on the end surface on the other side (i.e., the upper side) of the main body portion 32 in the direction of the axis O. The valve seat 31 has a conical surface shape centered on the axis O. In other words, in a cross-sectional view including the axis O, the diameter dimension gradually increases from one side to the other side in the direction of the axis O. The main body outer peripheral surface 34, which is the outer peripheral surface of the main body portion 32, is fitted in the protruding inner peripheral surface 53 with a clearance. That is, a slight clearance is formed between the main body outer peripheral surface 34 and the protruding inner peripheral surface 53. Therefore, the liquid in the compression chamber flows into the inside of this clearance. The main body outer peripheral surface 34 is formed in a region overlapping the valve seat 31 in the direction of the axis O. The main body outer peripheral surface 34 constitutes a pressure-receiving outer peripheral surface that receives the pressure from the liquid flowing into the above clearance and cancels the pressure applied to the valve seat 31. The outer peripheral portion 33 covers the outer peripheral side of the main body portion 32 so as to overlap one end portion of the main body portion 32 in the direction of the axis O. The outer peripheral portion 33 has a cylindrical shape centered on the axis O. The outer peripheral surface (outer outer peripheral surface 35) of the outer peripheral portion 33 is fitted in the recessed inner peripheral surface 52 with a clearance. That is, a slight clearance is formed between the outer outer peripheral surface 35 and the recessed inner peripheral surface 52.

[0021] The surface facing the other side in the axial direction of the axis O in the outer peripheral portion 33 is a stepped surface 36. The stepped surface 36 has an annular shape centered on the axis O. A seal groove 37 is formed in the stepped surface 36, which extends in the circumferential direction of the axis O and is recessed toward one side in the axial direction of the axis O. A seal ring 38 is accommodated in this seal groove 37. The seal ring 38 is provided to prevent leakage of liquid between the upper stepped surface 54 and the stepped surface 36 of the outer peripheral portion 33. Note that this seal groove 37 may be formed on the upper stepped surface 54 side. The seal ring 38 prevents further downward intrusion of the liquid that has flowed into the gap between the main body outer peripheral surface 34 and the protruding inner peripheral surface 53 described above. Further, the seal ring 38 is accommodated in the seal groove 37 in an elastically deformed state by fastening and fixing the lid member 2a to the cylinder 2 with bolts 2b.

[0022] The valve body 40 has a rod portion 41 and a head portion 42. The rod portion 41 has a rod shape extending in the axial direction of the axis O. The head portion 42 is integrally provided at the end of the rod portion 41 on the other side in the axial direction of the axis O. The head portion 42 gradually increases in diameter from one side to the other side in the axial direction of the axis O. The surface of the head portion 42 facing one side in the axial direction of the axis O forms a seat surface 43 that can be in contact with the valve seat 31 described above by being conical.

[0023] In a cross-sectional view including the axis O, the angle formed by this seat surface 43 with respect to the axis O, that is, the apex angle θ1, is preferably 80° or more and 100° or less. More preferably, the apex angle θ1 is 85° or more and 95° or less. Most preferably, the apex angle θ1 is 90°. Further, in a cross-sectional view including the axis O, the difference between the angle formed by the seat surface 43 with respect to the axis O and the angle formed by the valve seat 31 with respect to the axis O is preferably 0° or more and 1° or less. More preferably, the difference in this angle is 0° or more and 0.2° or less. Further, the maximum outer diameter of the valve body 40, that is, the outer diameter of the head portion 42, is preferably 30% or more and 80% or less of the maximum inner diameter of the cylinder 2. Most preferably, this numerical range is 70%.

[0024] The disk member 60 is provided to support the valve body 40 and the ring valve 70. The disk member 60 has a disk main body portion 61 and a flange portion 62. The disk main body portion 61 has a disk shape centered on the axis O. A plurality of communication holes 63 are formed in the disk main body portion 61 at intervals in the circumferential direction with respect to the axis O. These communication holes 63 are covered from the other side in the direction of the axis O by a ring valve 70 having an annular plate shape. Further, a through hole 64 through which the rod portion 41 of the valve body 40 is inserted is formed at the position (center position) of the axis O of the disk main body portion 61. The flange portion 62 projects from the edge on one side in the direction of the axis O of the disk main body portion 61 toward the outer peripheral side. The outer peripheral surface of the flange portion 62 abuts against the above-described recessed inner peripheral surface 52 from the radial direction and abuts against the lower stepped surface 55 from the direction of the axis O.

[0025] A housing groove 65 is formed on the surface of the disk main body portion 61 facing one side in the direction of the axis O so as to surround the through hole 64. The housing groove 65 is a bottomed cylindrical hole centered on the axis O. A coil spring as an elastic member 80 for biasing the valve body 40 is housed in this housing groove 65. Further, a bush 90 is attached to the rod portion 41 of the valve body 40. More specifically, the bush 90 is a double nut whose relative position in the direction of the axis O with respect to the rod portion 41 can be adjusted. The elastic member 80 exerts an elastic restoring force so as to extend toward both sides in the direction of the axis O between the bush 90 and the bottom surface of the housing groove 65. Thereby, the valve body 40 is biased toward one side (lower side) in the direction of the axis O and is normally in a closed valve state. On the other hand, when the piston 1 rises and the internal pressure of the compression chamber 21 decreases, the valve body 40 is pulled upward against the elastic force of the elastic member 80 by the differential pressure. Thereby, the intake valve 5 is in an open valve state (see FIG. 3).

[0026] (Configuration of discharge valve 7) Next, the configuration of the discharge valve 7 will be described with reference to FIGS. 4 and 5. As shown in FIG. 4, the discharge valve 7 has a valve casing 110, a lid member 110a, a second cylindrical member 120, an internal member 151a, an elastic member 131a, a second valve body 130, and a second seal ring 160.

[0027] The valve casing 110 has a cylindrical shape centered on a second axis X extending in a direction intersecting the above-mentioned axis O. Inside the valve casing 110, an accommodation space 150 for accommodating the second cylindrical member 120 and the second valve body 130 is formed. The accommodation space 150 has a rod accommodation portion 151, a head accommodation portion 152, and a cylindrical member accommodation portion 153 arranged in order from one side to the other side in the direction of the second axis X. These rod accommodation portion 151, head accommodation portion 152, and cylindrical member accommodation portion 153 all have a cylindrical shape centered on the second axis X. Among these, the inner diameter of the head accommodation portion 152 is the largest, and the inner diameter of the rod accommodation portion 151 is the smallest. The inner diameter of the cylindrical member accommodation portion 153 is an intermediate value between these. In the head accommodation portion 152, a discharge hole 152a for discharging the liquid to the discharge pipe 6 is formed. The discharge hole 152a extends in the radial direction with respect to the second axis X. Also, on the other side in the direction of the axis X of the valve casing 110, a lid member 110a is fastened and fixed by bolts 110b. Further, a discharge hole 154 through which the liquid flows is formed on the end face on the other side in the direction of the second axis X of the valve casing 110. In the open valve state, the liquid flowing in from the discharge hole 154 is discharged to the outside through a communication hole 120a formed in the second cylindrical member 120 described later.

[0028] The second cylindrical member 120 is inserted from the above-mentioned cylindrical member accommodation portion 153 to a midway position of the rod accommodation portion 151. The second cylindrical member 120 has a cylindrical shape centered on the second axis X. On the end face of the second cylindrical member 120 facing one side in the direction of the second axis X, a second valve seat 121 is formed. The second valve seat 121 has a conical surface shape by gradually increasing in diameter from the other side to the one side in the direction of the second axis X. On the end face of the second cylindrical member 120 facing the other side in the direction of the second axis X, a second seal groove 122 extending in the circumferential direction of the second axis X and recessed toward the one side in the direction of the second axis X is formed. A second seal ring 160 is accommodated in the second seal groove 122. The second seal ring 160 is accommodated in a state of being elastically deformed in the second seal groove 122 when the above-mentioned lid member 110a is pressed against the valve casing 110 by bolts 110b.

[0029] Also, an inner member 151a is attached to the end on the other side in the axial direction X of the second cylindrical member 120. The inner member 151a has a bottomed cylindrical shape centered on the axis X. On the other hand, one end on one side is open in the axial direction X, and the second valve body 130 described later is accommodated so as to be movable forward and backward in the axial direction X. An elastic member 131a that biases the second valve body 130 toward one side in the axial direction X is accommodated on the inner peripheral side of the inner member 151a. The elastic member 131a is a coil spring. A male screw is formed on the outer peripheral surface of the inner member 151a, and it is screwed into a female screw formed on the inner peripheral surface of the valve casing 110.

[0030] The second valve body 130 has a second rod portion 131 and a second head portion 132. The second rod portion 131 has a rod shape extending along the second axis X. A second head portion 132 is integrally provided at the end on the other side in the second axis X direction of the second rod portion 131. The second head portion 132 has a columnar shape centered on the second axis X. The second head portion 132 has an outer diameter dimension larger than that of the second rod portion 131. A second seat surface 133 that can come into contact with and separate from the above-described second valve seat 121 is formed on the end surface on the other side in the second axis X direction of the second head portion 132. The second seat surface 133 has a conical surface shape by gradually increasing in diameter from the other side in the second axis X direction toward the one side.

[0031] In a cross-sectional view including the second axis X, it is desirable that the apex angle θ2, which is the angle formed by the second sheet surface 133 with respect to the second axis X, be 130° or more and 150° or less. More desirably, this apex angle θ2 is 135° or more and 145° or less. Most desirably, this apex angle θ2 is 138° or more and 142° or less. That is, it is most desirable that the apex angle θ2 be 140°. Further, in a cross-sectional view including the second axis X, it is desirable that the difference between the angle formed by the second sheet surface 133 with respect to the second axis X and the angle formed by the second valve seat 121 with respect to the second axis X be 0° or more and 1° or less. More desirably, this angle difference is 0° or more and 0.2° or less. Also, it is desirable that the ratio of the outer diameter to the inner diameter of the second sheet surface 133 be 1.2 or more and 1.3 or less. More desirably, this ratio is 1.22 or more and 1.28 or less. Most desirably, this ratio is 1.25. In addition, it is desirable that the ratio of the outer diameter to the inner diameter of the second valve seat 121 be 1.6 or more and 2.0 or less. More desirably, this ratio is 1.7 or more and 1.9 or less. Most desirably, this ratio is 1.8.

[0032] (Function and effect) When operating the reciprocating pump 100 described above, first, with liquid hydrogen supplied into the cylinder 2 by the supply pipe 4b, the piston 1 is reciprocated in the cylinder 2 by the drive unit 3. As a result, the liquid hydrogen in the cylinder 2 is sequentially compressed to a high-pressure state (about 90 MPa as an example). The high-pressure liquid hydrogen is taken out to the outside through the discharge pipe 6.

[0033] Under the high pressure as described above, the suction valve 5 and the discharge valve 7 are also required to have corresponding pressure resistance performance and sealing performance. For this reason, in the present embodiment, each of the above-described configurations is adopted.

[0034] According to the above configuration, in addition to the outer peripheral surface 34 of the main body as the pressure-receiving outer peripheral surface receiving the pressure of the liquid flowing into the gap and canceling the pressure applied to the valve seat 31, since the apex angle is 80° or more and 100° or less (preferably 90°), a state can be created as if a hydrostatic pressure is acting. Thereby, the sliding on the sheet surface 43 can be suppressed. Particularly when the rigidity of the valve body 40 is relatively smaller than that of the valve seat 31, it is important to mainly suppress the relative sliding between the two. According to the above configuration, they will contact at an angle of about 45°. Therefore, there is no difference in the contact angle between the valve seat 31 and the valve body 40, and they can be evenly contacted. Thus, the surface pressure and deformation of the valve seat 31 become uniform, and it is possible to reduce the relative sliding and extreme single-sided contact.

[0035] According to the above configuration, the difference in the angle formed by the sheet surface 43 and the valve seat 31 with respect to the axis O is 0° or more and 1° or less. As a result, the sheet surface 43 and the valve seat 31 will contact (internally contact) with each other on the inner peripheral side. By internally contacting, it is possible to offset a part of the pressure of the fluid flowing into the gap of the sheet surface 43 from the outer peripheral side to the inner peripheral line contact position and the pressure acting from the rear flow side, and reduce the total differential pressure acting on the valve body 40. Therefore, since the surface pressure of the sheet surface 43 can be reduced, the possibility of damage can be significantly reduced even when the contact due to opening and closing the valve is repeated.

[0036] According to the above configuration, a stepped surface 36 is further formed on the outer peripheral side of the cylindrical member 30, and a seal groove 37 capable of accommodating the seal ring 38 is formed in the stepped surface 36. Thereby, by utilizing the pressure acting on the outer periphery of the valve seat 31, the deformation of the hollow cylindrical valve seat 31 opening to the outer peripheral side can be suppressed. Also, it is not necessary to form an annular groove on the outer peripheral side of the valve seat 31 as previously adopted. Thus, it is possible to achieve both miniaturization of the suction valve 5 and improvement of the sealing performance.

[0037] According to the above configuration, by setting the maximum outer diameter of the valve body 40 to 80% or less of the maximum inner diameter of the cylinder 2, it is possible to further enhance the sealing performance while suppressing the generation of liquid cavitation (foaming). It also leads to a reduction in the dead volume that causes efficiency degradation.

[0038] According to the above configuration, since the position of the bush 90 in the direction of the axis O is adjustable, it is possible to appropriately adjust the lift amount (the amount of movement in the direction of the axis O) of the valve body 40 determined by the position of the bush 90. Thereby, by adjusting the valve opening degree at the time of valve opening, an appropriate flow rate can be ensured, and it is possible to achieve both suppression of the generation of excessive impact force at the time of seating.

[0039] According to the above configuration, on the end face of the second cylindrical member 120 facing the other side in the direction of the second axis X, a second seal groove 122 having an annular shape centered on the second axis X is formed. By providing this second seal groove 122, it is possible to reduce the stress applied to the second cylindrical member 120 at the time of valve closing by the second seal groove 122. Thereby, stable operation of the discharge valve 7 can be ensured. Also, by accommodating the seal ring 38 in the second seal groove 122, it is possible to ensure the sealing performance between the second cylindrical member 120 and the casing 4. Furthermore, since both the second valve body 130 and the second cylindrical member 120 are rigid, by contacting each other at an angle of about 140°, which is an angle close to that of a flat plate, the wedge effect can be suppressed and the surface pressure can be made uniform. Also, surface contact between the two can be ensured, and an increase in relative slip and extreme single-sided contact can be prevented. Thereby, the sealing performance of the discharge valve 7 can be further improved.

[0040] According to the above configuration, the angle formed by the second valve seat 121 and the second seat surface 133 with respect to the second axis X is 0° or more and 1° or less. Thereby, the second valve seat 121 and the second seat surface 133 come into line contact. Therefore, instead of a flattened and uniform surface pressure, a line of surface pressure peaks is provided. Thus, leakage of the liquid passing between the second valve seat 121 and the second seat surface 133 can be suppressed. As a result, the sealing performance of the discharge valve 7 can be further improved.

[0041] According to the above configuration, by setting the ratio of the outer diameter to the inner diameter of the second sheet surface 133 to be 1.2 or more and 1.3 or less, the rigidity balance of the second valve body 130 can be optimized. Thereby, the relative slippage between the second valve seat 121 and the second valve body 130 can be reduced. As a result, the sealing performance of the discharge valve 7 can be further improved.

[0042] According to the above configuration, by setting the ratio of the outer diameter to the inner diameter of the second valve seat 121 to be 1.6 or more and 2.0 or less, the rigidity balance of the second valve body 130 can be optimized. Thereby, the relative slippage between the second valve seat 121 and the second valve body 130 can be reduced. As a result, the sealing performance of the discharge valve 7 can be further improved.

[0043] <Other Embodiments> The embodiments of the present disclosure have been described above. Note that various changes and modifications can be made to the above configuration without departing from the gist of the present disclosure. For example, in the above embodiment, an example of using the reciprocating pump 100 to compress liquid hydrogen has been described. However, the reciprocating pump 100 can also be suitably used for compressing cryogenic liquefied gases such as liquefied carbon dioxide, liquefied natural gas, and liquefied petroleum gas.

[0044] <Supplementary Note> The reciprocating pump 100 described in each embodiment is understood as follows, for example.

[0045] (1) The reciprocating pump 100 according to the first aspect includes a pump body 9 having a piston 1 for compressing a liquid and a cylinder 2 having a cylindrical shape centered on an axis O and covering the piston 1 from the outside, a drive unit 3 for reciprocating the piston 1 in the direction of the axis O with respect to the cylinder 2, and an intake valve 5 and a discharge valve 7 provided in the cylinder 2 for switching the flow state of the liquid. The intake valve 5 includes a cylindrical member 30 inserted into a housing hole 50 formed at one end of the cylinder 2 in the direction of the axis O, and a valve body 40 that can move forward and backward in the direction of the axis O with respect to the cylindrical member 30. The valve body 40 includes a rod portion 41 extending in the direction of the axis O, and a head portion 42 provided at the other end of the rod portion 41 in the direction of the axis O and having a conical seat surface 43 whose diameter gradually increases from one side to the other side in the direction of the axis O. The cylindrical member 30 has a conical valve seat 31 that abuts or separates from the outer peripheral surface of the head portion 42, and a pressure-receiving outer peripheral surface (main body outer peripheral surface 34) that is fitted via a gap communicating with the compression chamber 21 with respect to the inner peripheral surface of the cylinder 2 outside the radial direction of the valve seat 31.

[0046] According to the above configuration, the cylindrical member 30 has a pressure-receiving outer peripheral surface provided in a region overlapping the valve seat 31 in the direction of the axis O. Therefore, deformation of the cylindrical member 30 during valve closing is suppressed, and the sealing performance between the valve body 40 and the valve seat 31 can be improved.

[0047] (2) The reciprocating pump 100 according to the second aspect is the reciprocating pump 100 of (1), and in a cross-sectional view including the axis O, the apex angle, which is the angle formed by the seat surface 43 of the valve body 40 with respect to the axis O, is 80° or more and 100° or less.

[0048] According to the above configuration, since the apex angle is 80° or more and 100° or less, the seat surface 43 and the valve seat 31 come into contact with each other at an angle of about 45° with respect to each other. Therefore, the surface pressure and deformation of the valve seat 31 become uniform, and it is possible to reduce relative sliding and extreme single-sided contact.

[0049] (3) The reciprocating pump 100 according to the third aspect is the reciprocating pump 100 of (2), and in a cross-sectional view including the axis O, the difference between the angle formed by the seat surface 43 with respect to the axis O and the angle formed by the valve seat 31 with respect to the axis O is 0° or more and 1° or less.

[0050] According to the above configuration, the difference between the angles formed by the seat surface 43 and the valve seat 31 with respect to the axis O is 0° or more and 1° or less. Therefore, seal performance and damage due to extreme single-sided contact can be suppressed.

[0051] (4) The reciprocating pump 100 according to the fourth aspect is the reciprocating pump 100 according to any one of the aspects (1) to (3), and the cylindrical member 30 further has a stepped surface 36 that extends outward from the edge on one side in the axial direction O of the pressure-receiving outer peripheral surface, and an annular seal groove 37 that is centered on the axis O and is recessed toward one side in the axial direction O to accommodate the seal ring 38 is formed in the stepped surface 36.

[0052] According to the above configuration, a stepped surface 36 is further formed on the outer peripheral side of the cylindrical member 30, and a seal groove 37 capable of accommodating the seal ring 38 is formed in the stepped surface 36. Thereby, by utilizing the pressure acting on the outer periphery of the valve seat 31, deformation in which the hollow cylindrical valve seat 31 opens to the outer peripheral side can be suppressed.

[0053] (5) The reciprocating pump 100 according to the fifth aspect is the reciprocating pump 100 according to any one of the aspects (1) to (4), and the maximum outer diameter of the valve body 40 is 30% or more and 80% or less of the maximum inner diameter of the cylinder 2.

[0054] According to the above configuration, by setting the maximum outer diameter of the valve body 40 to 30% or more and 80% or less of the maximum inner diameter of the cylinder 2, the occurrence of liquid cavitation (foaming) can be suppressed, which can contribute to improving the performance of the reciprocating pump 100.

[0055] (6) The reciprocating pump 100 according to the sixth aspect is the reciprocating pump 100 according to any one of the aspects (1) to (5), and further includes a bush 90 provided on the outer peripheral side of the rod portion 41 and an elastic member 80 that biases the bush 90 toward one side in the direction of the axis O. The position of the bush 90 in the direction of the axis O is configured to be adjustable.

[0056] According to the above configuration, it is possible to adjust the appropriate flow rate according to the operating conditions and the lift amount that can suppress excessive impact loads.

[0057] (7) The reciprocating pump 100 according to the seventh aspect is the reciprocating pump 100 according to any one of the aspects (1) to (6), and the discharge valve 7 is provided on the outer peripheral surface of the cylinder 2 and has a second cylindrical member 120 having a conical second valve seat 121 centered on a second axis X extending in a direction intersecting the axis O and having a cylindrical shape centered on the second axis X, a second valve body 130 that can move forward and backward in the direction of the second axis X with respect to the second cylindrical member 120, and a casing 4 that covers the second cylindrical member 120 from the outside. The second valve body 130 has a second rod portion 131 extending in the direction of the second axis X and a second head portion 132 provided at the end of the second rod portion 131 on the other side in the direction of the second axis X and having a conical second seat surface 133 whose diameter gradually increases from one side to the other side in the direction of the second axis X. On the end surface of the second cylindrical member 120 facing the other side in the direction of the second axis X, a second seal groove 122 having an annular shape centered on the second axis X and recessed toward one side in the direction of the second axis X so as to accommodate the seal ring 38 is formed. In a cross-sectional view including the second axis X, the apex angle formed by the second seat surface 133 of the second valve body 130 with respect to the second axis X is 130° or more and 150° or less.

[0058] According to the above configuration, on the end face of the second cylindrical member 120 facing the other side in the direction of the second axis X, a second seal groove 122 having an annular shape centered on the second axis X is formed. By providing this second seal groove 122, it becomes possible to reduce the stress applied to the second cylindrical member 120 during valve closing by means of the second seal groove 122. Thereby, stable operation of the discharge valve 7 can be ensured.

[0059] (8) The reciprocating pump 100 according to the eighth aspect is the reciprocating pump 100 of (7), and in a cross-sectional view including the second axis X, the difference between the angle formed by the second sheet surface 133 with respect to the second axis X and the angle formed by the second valve seat 121 with respect to the second axis X is 0° or more and 1° or less.

[0060] According to the above configuration, leakage of liquid passing between the second valve seat 121 and the second sheet surface 133 can be suppressed. As a result, the sealing performance of the discharge valve 7 can be further improved.

[0061] (9) The reciprocating pump 100 according to the ninth aspect is the reciprocating pump 100 of (7) or (8), and the ratio of the outer diameter to the inner diameter of the second sheet surface 133 is 1.2 or more and 1.3 or less.

[0062] According to the above configuration, by setting the ratio of the outer diameter to the inner diameter of the second sheet surface 133 to be 1.2 or more and 1.3 or less, the rigidity balance of the second valve body 130 can be optimized. Thereby, relative slippage between the second valve seat 121 and the second valve body 130 can be reduced.

[0063] (10) The reciprocating pump 100 according to the tenth aspect is the reciprocating pump 100 according to any one of the aspects from (7) to (9), and the ratio of the outer diameter to the inner diameter of the second valve seat 121 is 1.6 or more and 2.0 or less.

[0064] According to the above configuration, by setting the ratio of the outer diameter to the inner diameter of the second valve seat 121 to be 1.6 or more and 2.0 or less, the rigidity balance of the second valve body 130 can be optimized. Thereby, the relative slip between the second valve seat 121 and the second valve body 130 can be reduced.

[0065] (11) The reciprocating pump 100 according to the second aspect includes a pump body 9 having a piston 1 that compresses a liquid and a cylinder 2 having a cylindrical shape centered on an axis O and covering the piston 1 from the outside, a drive unit 3 that reciprocates the piston 1 in the direction of the axis O with respect to the cylinder 2, and a discharge valve 7 provided in the cylinder 2 for switching the flow state of the liquid. The discharge valve 7 includes a cylindrical second cylindrical member 120 centered on a second axis X extending in a direction intersecting the axis O and provided on the outer peripheral surface of the cylinder 2, a second valve body 130 that can move forward and backward in the direction of the second axis X with respect to the second cylindrical member 120, and a casing 4 that covers the second cylindrical member 120 from the outside. The second valve body 130 includes a second rod portion 131 extending in the direction of the second axis X, and a second head portion 132 provided at an end of the second rod portion 131 on the other side in the direction of the second axis X and having a conical second seat surface 133 that gradually increases in diameter from one side in the direction of the second axis X to the other side. An annular second seal groove 122 centered on the second axis X and recessed toward one side in the direction of the second axis X to accommodate a seal ring 38 is formed in an end surface of the second cylindrical member 120 facing the other side in the direction of the second axis X. In a cross-sectional view including the second axis X, the apex angle, which is the angle formed by the second seat surface 133 of the second valve body 130 with respect to the second axis X, is 130° or more and 150° or less.

[0066] According to the above configuration, an annular second seal groove 122 centered on the second axis X is formed in an end surface of the second cylindrical member 120 facing the other side in the direction of the second axis X. By providing this second seal groove 122, it becomes possible to release the stress applied to the second cylindrical member 120 during valve closing through the second seal groove 122. Thereby, stable operation of the discharge valve 7 can be ensured.

Description of Symbols

[0067] 1…Piston 2…Cylinder 3…Drive unit 4…Casing 5…Suction valve 6…Discharge pipe 7…Delivery valve 9…Pump body 10…Piston body 11…Wearing ring 12…Piston ring 21…Compression chamber 30…Cylindrical member 31…Valve seat 32…Body part 33…Outer peripheral part 34…Outer peripheral surface of the body 35…Outer outer peripheral surface 36…Step surface 37…Seal groove 38…Seal ring 40…Valve body 4a…Casing body 41…Rod part 4b…Supply pipe 42…Head part 4c…Gas discharge pipe 43…Seat surface 44…Liquid storage chamber 50…Accommodation hole 51…Lower inner peripheral surface 52…Sunken inner peripheral surface 53…Projecting inner peripheral surface 54…Upper step surface 55…Lower step surface 60…Disk member 61…Disk body part 62…Flange part 63…Communication hole 64…Through hole 65…Accommodation groove 70…Ring valve 80…Elastic member 90…Bush 100…Reciprocating pump 110…Valve casing 120…Second cylindrical member 121…Second valve seat 122…Second seal groove 130…Second valve body 131…Second rod part 132…Second head part 133…Second seat surface 150…Accommodation space 160…Second seal ring 151…Rod accommodation part 152…Head accommodation part 153…Cylindrical member accommodation part 154…Discharge hole 160…Second seal ring h…Opening O…Axis X…Second axis

Claims

1. A pump body having a piston for compressing a liquid and a cylinder having a cylindrical shape centered on an axis and covering the piston from the outside, a drive unit for reciprocating the piston in the axial direction with respect to the cylinder, an intake valve and a discharge valve provided in the cylinder for switching the flow state of the liquid, comprising: The intake valve a cylindrical member inserted into a housing hole formed at one end of the cylinder in the axial direction, a valve body that can move forward and backward in the axial direction with respect to the cylindrical member, having: The valve body has a rod portion extending in the axial direction and a head portion provided at the other end of the rod portion in the axial direction and having a conical seat surface whose diameter gradually increases from one side in the axial direction to the other side. The cylindrical member a conical valve seat that contacts or separates from the outer peripheral surface of the head portion, a pressure-receiving outer peripheral surface that is fitted via a gap communicating with the compression chamber with respect to the inner peripheral surface of the cylinder outside the radial direction of the valve seat, a reciprocating pump.

2. The reciprocating pump according to claim 1, wherein in a cross-sectional view including the axis, the apex angle formed by the seat surface of the valve body with respect to the axis is 80° or more and 100° or less.

3. The reciprocating pump according to claim 2, wherein in a cross-sectional view including the axis, the difference between the angle formed by the seat surface with respect to the axis and the angle formed by the valve seat with respect to the axis is 0° or more and 1° or less.

4. The cylindrical member further has a stepped surface that extends from the edge on one side in the axial direction of the pressure-receiving outer peripheral surface to the outer peripheral side, and a seal groove having an annular shape centered on the axis and recessed toward one side in the axial direction is formed in the stepped surface so as to be able to accommodate a seal ring. The reciprocating pump according to any one of claims 1 to 3.

5. The reciprocating pump according to any one of claims 1 to 3, wherein the maximum outer diameter of the valve body is 60% or more and 80% or less of the maximum inner diameter of the cylinder.

6. a bush provided on the outer peripheral side of the rod portion, an elastic member for urging the bush toward one side in the axial direction, further comprising: The reciprocating pump according to any one of claims 1 to 3, wherein the position of the bush in the axial direction is configured to be adjustable.

7. The discharge valve A second cylindrical member provided on the outer peripheral surface of the cylinder, having a cylindrical shape centered on a second axis extending in a direction intersecting the axis and having a conical second valve seat centered on the second axis; A second valve body that can move forward and backward in the second axis direction with respect to the second cylindrical member; A casing that covers the second cylindrical member from the outside; and has The second valve body has a second rod portion extending in the second axis direction, and a second head portion provided at an end of the second rod portion on the other side in the second axis direction, having a conical second seat surface that gradually increases in diameter from one side to the other side in the second axis direction. On the end face of the second cylindrical member facing the other side in the second axis direction, a second seal groove is formed that is annular centered on the second axis and is recessed toward the one side in the second axis direction so as to accommodate a seal ring. In a cross-sectional view including the second axis, the apex angle, which is the angle formed by the second seat surface of the second valve body with respect to the second axis, is 130° or more and 150° or less. The reciprocating pump according to any one of claims 1 to 3.

8. In a cross-sectional view including the second axis, the difference between the angle formed by the second seat surface with respect to the second axis and the angle formed by the second valve seat with respect to the second axis is 0° or more and 1° or less. The reciprocating pump according to claim 7.

9. The ratio of the outer diameter to the inner diameter of the second seat surface is 1.2 or more and 1.3 or less. The reciprocating pump according to claim 7.

10. The ratio of the outer diameter to the inner diameter of the second valve seat is 1.6 or more and 2.0 or less. The reciprocating pump according to claim 7.

11. A pump body having a piston for compressing liquid and a cylinder having a cylindrical shape centered on an axis and covering the piston from the outside; A drive unit that reciprocates the piston in the axial direction with respect to the cylinder; A discharge valve provided in the cylinder for switching the flow state of the liquid; and includes The discharge valve is provided on the outer peripheral surface of the cylinder, and has a cylindrical second cylindrical member centered on a second axis extending in a direction intersecting the axis; A second valve body that can move forward and backward in the second axis direction with respect to the second cylindrical member; A casing that covers the second cylindrical member from the outside; and has The second valve body includes a second rod portion extending in the second axial direction, and a second head portion provided at an end of the second rod portion on the other side in the second axial direction, the second head portion having a conical second seat surface that gradually increases in diameter from one side to the other side in the second axial direction. On the end face of the second cylindrical member facing the other side in the second axial direction, a second seal groove is formed that is annular with the second axis as the center and is recessed toward the one side in the second axial direction so as to be able to accommodate a seal ring. A reciprocating pump in which, in a cross-sectional view including the second axis, the apex angle, which is the angle formed by the second seat surface of the second valve body with respect to the second axis, is 130° or more and 150° or less.

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