TWI619883B - Pumping device - Google Patents

Abstract

An object of the present invention is to provide a pump device capable of reducing more power consumption.

The pump device 1 according to the embodiment of the present invention includes a drive motor M, a first pumping portion 11 for vacuum exhaust having a first pump chamber and a first piston 21v, and a second pump The second pumping portion 12 for pressurization of the chamber and the second piston 21c. The second piston 21c leads the first piston 21v in phase by a rotational phase difference φ greater than 0° and less than 80°.

Description

Pump device

The present invention relates to a pump device having a vacuum pump and a pressurized pump.

It is known that a rocking piston type pump which is a kind of vacuum pump is used as a reciprocating mobile pump for inhaling and exhausting in a pump chamber by reciprocating motion of a piston in a cylinder, for example, as a vacuum pump and pressurization. The pump is widely used.

On the other hand, a composite pump device including two pistons for vacuum exhaust and pressurization that are simultaneously driven by a common motor is also widely known. In the method of driving such a pump device, a method of reciprocating the two pistons in opposite phases and a method of reciprocating the two pistons in the same phase are known (for example, refer to Patent Document 1 below). .

The former method, that is, the driving method in which the rotational phases of the two pistons reciprocate by 180°, has the advantages of maintaining the dynamic balance of each pump well and reducing the vibration of the entire pump device. The latter method, that is, a driving method for moving the two pistons to the top dead center or the bottom dead center simultaneously, can reduce the load variation of the driving source and can realize stable operation of the pump device.

[Advanced technical literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open No. Hei 7-310651

Recently, the pump device has sought to reduce power consumption, and even the above-mentioned composite pump device is expected to reduce more power consumption.

In view of the above circumstances, it is an object of the present invention to provide a pump device capable of reducing more power consumption.

In order to achieve the above object, a pump device according to an aspect of the present invention includes a drive motor, a first pumping portion for vacuum evacuation, and a second pumping portion for pressurization.

The drive motor has a first drive shaft and a second drive shaft. The drive motor is configured to enable the first drive shaft and the second drive shaft to rotate synchronously around the first shaft.

The first pumping portion has a first piston that reciprocates in a second axial direction perpendicular to the first axis by rotation of the first drive shaft, and a first piston that changes internal pressure by reciprocation of the first piston 1 pump room.

The second pumping portion has a second piston that reciprocates in the second axial direction by the rotation of the second drive shaft, and a second pump chamber that changes internal pressure according to reciprocation of the second piston. The second piston advances the first piston by a phase difference of a rotational phase difference of more than 0° and less than 80°.

1‧‧‧ pumping device

11‧‧‧vacuum pump

12‧‧‧Pressure pump

13‧‧‧ Drive Department

21, 21v, 21c‧ ‧ piston

22‧‧‧ Connecting rod

23‧‧‧Eccentric components

24‧‧‧ Sealing members

25‧‧‧screw components

26‧‧‧The Pufang Room

31,32‧‧‧ Bearings

41‧‧‧ screws

42‧‧‧ fixing screws

51,52‧‧‧weight

101‧‧‧1st outer casing

102‧‧‧2nd outer casing

103‧‧‧3rd outer casing

110‧‧‧Shell body

110a‧‧‧Fixed Department

110b‧‧‧ Tube

110h‧‧‧through hole

111‧‧‧ cylinder

112‧‧‧Help Putou

112a‧‧‧ Inhalation valve

112b‧‧‧Exhaust valve

113‧‧‧Help Putou

113a‧‧‧Intake chamber

113b‧‧‧Exhaust room

114a‧‧‧ suction port

114b‧‧‧Exhaust port

131‧‧‧Drive shaft

132‧‧‧ coil

221‧‧‧1st end

222‧‧‧2nd end

222a‧‧‧ fitting holes

230‧‧‧Base block

232,232v, 232c‧‧‧Eccentric shaft

M‧‧ motor

X, Y, Z‧‧ Direction

Fig. 1 is a front perspective view of a pump device according to an embodiment of the present invention.

Fig. 2 is a rear perspective view of the above pump device.

Figure 3 is a right side view of the above-described pump device.

Figure 4 is a left side view of the above-described pump device.

Fig. 5 is a vertical cross-sectional view showing a part of the vacuum pumping portion and the driving portion of the pumping device.

Fig. 6 is a view for explaining the relationship between the eccentric shaft on the vacuum pumping portion side of the pumping device and the eccentric shaft on the side of the pressurized pumping portion; (A) is a front view, and (B) is viewed from the vacuum pumping portion side. side view.

Figure 7 is an experimental result of driving the pump device in such a manner that the pressure inside the pump chamber of the vacuum section and the pressure inside the pump chamber of the pressurizing section are in phase; (A) is inside the pump chamber showing the vacuum section Time change of pressure and piston position, (B) is the time change of the pressure inside the pump chamber and the position of the piston, (C) is the pressure waveform of the pump chamber showing the vacuum section and the pressure of the pumping chamber of the pressurizing section The composite waveform of the waveform.

Figure 8 is an experimental result of driving the pump device in such a manner that the pressure inside the pump chamber of the vacuum section is opposite to the pressure inside the pump chamber of the pressurizing section; (A) is the interior of the pump chamber showing the vacuum section Time change of pressure and piston position, (B) is the time change of the pressure inside the pump chamber and the position of the piston, and (C) is the pressure waveform of the pump chamber showing the vacuum section and the pump of the pressurizing section. The composite waveform of the pressure waveform of the chamber.

Fig. 9 is an experimental result showing the relationship between the rotational phase difference of the piston of the pressurizing section with respect to the piston of the vacuum section and the motor current consumption.

The pressure inside the pump of the rocking piston pump will move with the piston It produces a cyclical change. For example, when the piston moves from the bottom dead center to the top dead center, the internal pressure of the pump chamber moves in the increasing direction due to the decrease in volume. When the piston moves from the top dead center to the lower dead point, the internal pressure of the pump chamber increases due to the volume. And move in a decreasing direction. At this time, in the vacuum pump, the pressure inside the pump chamber changes within the pressure range (underpressure) below atmospheric pressure. In the case of the pressurized pump, the pressure inside the pump chamber is in the pressure range above atmospheric pressure (positive pressure). Change within.

However, according to experiments by the inventors of the present invention, as described above, even if the piston for the vacuum pump reciprocates in the same phase as the piston for the pressurized pump, the internal pressures of the two pump chambers do not change synchronously. There will be a phase difference due to pressure changes between the two chambers. In addition, even if the rotational phase of the two pistons is controlled, the internal pressures of the vacuum pump and the pressurized pump are changed to the same phase, and the load of the motor is not the lowest value.

Therefore, the present invention constitutes a pump device as described below in order to achieve more power consumption of the pumping device.

In other words, the pump device according to the embodiment of the present invention includes a drive motor, a first pumping portion for vacuum evacuation, and a second pumping portion for pressurization.

The drive motor has a first drive shaft and a second drive shaft. The drive motor has a configuration in which the first drive shaft and the second drive shaft are synchronously rotated about the first axis.

The first pumping portion has a first piston that reciprocates in a second axial direction perpendicular to the first axis by rotation of the first drive shaft, and a first piston that changes internal pressure by reciprocation of the first piston 1 pump room.

The second pumping portion has a second piston that reciprocates in the second axial direction by the rotation of the second drive shaft, and a second pump chamber that changes internal pressure according to reciprocation of the second piston. The second piston advances the first piston by a phase difference of a rotational phase difference of more than 0° and less than 80°.

According to experiments confirmed by the inventors, although the top dead center of the piston of the first pumping portion of the vacuum exhausting is approximately the same as the pressure peak position of the pumping chamber, the top dead center of the piston of the second pumping portion is pressed and helped. The pressure peak position of the Pu room is inconsistent. In particular, in the second pumping department, before the piston moved to the top dead center, the pump room had reached the peak of pressure.

The above-described rotational phase difference can be appropriately set within a range of 0° or more and less than 80°. For example, when set to 40°±30°, the effect of reducing the power consumption can be achieved. When set to 40°±15°, the effect of reducing the power consumption can be achieved. By optimizing the rotation phase difference, it is possible to stably operate the pump device with low power consumption.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 to 4 are external views showing a pumping device according to an embodiment of the present invention. Fig. 1 is a front perspective view, Fig. 2 is a rear perspective view, Fig. 3 is a right side view, and Fig. 4 is a left side view.

The pump device 1 of the present embodiment has a vacuum pumping portion 11 (first pumping portion) as a vacuum section, a pressure pumping portion 12 (second pumping portion) as a pressurizing section, and a common driving vacuum pumping portion 11 and pressurizing The driving part 13 of the pumping department 12. The pump device 1 is used, for example, as a gas booster blower for use in a fuel cell system, or as a vacuum and pressurized pump for a medical analyzer.

The vacuum pumping portion 11 and the pressurized pumping portion 12 have a typical structure in common, and in the present embodiment, they are configured as a rocking piston pump.

The pump device 1 has a pump casing 100 including a first casing 101 constituting a part of the vacuum pumping portion 11, a second casing 102 constituting a part of the pressure pumping portion 12, and a part constituting the driving portion 13. The third outer casing 103.

Fig. 5 is a longitudinal sectional view showing a part of the structure of the vacuum pumping portion 11 and the driving portion 13. The X-axis, the Y-axis, and the Z-axis of Fig. 5 respectively indicate the three-axis directions orthogonal to each other. Further, the pressure pumping portion 12 has the same configuration as that of the vacuum pumping portion 11, and the vacuum pumping portion 11 will be mainly described.

The vacuum pump portion 11 has a first outer casing 101, a piston 21, a link 22 (rod), and an eccentric member 23.

The first outer casing 101 has a casing body 110, a cylinder 111, a pump head 112, and a head cover 113. The casing body 110, the cylinder 111, the pump head 112, and the pump head cover 113 are laminated and integrated with each other in the Z-axis direction.

The casing body 110 is connected to the third casing 103 for accommodating the motor M, and has a through hole 110h through which the connecting rod 22 passes. The housing body 110 has a fixing portion 110a that can fix a bearing 32 for rotatably supporting the driving shaft 131 of the motor M, and a cylindrical portion 110b for housing the coil 132 of the motor M. The drive shaft 131 is disposed in parallel with the Y-axis direction (the first axial direction), and is rotated about the Y-axis by the driving of the motor M. The bearing 32 is disposed between the body of the motor M and the eccentric member 23.

The cylinder 111 is disposed between the casing body 110 and the pump head 112, and houses a piston 21 that is slidable in the Z-axis direction. Bangtou 112 The system is disposed between the cylinder 111 and the pump head cover 113, and has an intake valve 112a and an exhaust valve 112b, respectively. The pump head cover 113 is disposed above the pump head 112, and has an intake chamber 113a communicating with the intake port 114a and an exhaust chamber 113b communicating with the exhaust port 114b. As shown in FIGS. 1 and 2, the intake port 114a and the exhaust port 114b are respectively provided on the side faces of the respective pump portions 11, 12 facing each other.

The piston 21 has a disk shape and is fixed to the first end portion 221 of the link 22 by a screw member 25. The piston 21 forms a pumping chamber 26 between the piston 21 and the pump head 112. The piston 21 reciprocates in a direction parallel to the Z-axis direction (second axis direction) inside the cylinder 111 to change the internal pressure of the pump chamber 26. Further, the piston 21 causes the pump chamber 26 to inhale and exhaust alternately through the intake valve 112a and the exhaust valve 112b to perform a predetermined pumping action.

The links 22 are coupled to each other between the piston 21 and the eccentric member 23. The link 22 has a first end portion 221 connected to the piston 21 and a second end portion 222 connected to the eccentric member 23. The first end portion 221 is formed in a circular shape having a diameter substantially the same as that of the piston 21. A disc-shaped sealing member 24 is attached between the piston 21 and the first end portion 221. The peripheral portion of the sealing member 24 is bent on the side of the pump chamber 26 so as to be slidable to the inner circumferential surface of the cylinder 111.

Further, in the pressurizing pump portion 12, the peripheral portion of the sealing member is bent on the side of the pump chamber as opposed to the above example.

A fitting hole 222a that is fitted to the eccentric shaft 232 of the eccentric member 23 is formed on the second end portion 222 of the link 22. The fitting hole 222a is mounted with a bearing 31 that rotatably supports the eccentric shaft 232.

The eccentric members 23 are coupled to each other so as to be housed in the third outer casing 103 Between the drive shaft 131 of the M and the connecting rod 22. The eccentric member 23 has a base block 230 of a substantially cylindrical shape. The surface of the base block 230 on the side of the motor M is connected to the drive shaft 131, and the surface on the side of the link 22 is formed with an eccentric shaft 232. The axis of the eccentric shaft 232 is eccentric to the drive shaft 131 so as to be offset with the rotation of the drive shaft 131. The drive shaft 131 is coupled to the base block 230 by screws 41 that are locked to the side surface of the base block 230.

The eccentric member 23 is mounted with a counter weight 51. The weight 51 is fixed to the side surface of the eccentric member 23 by a fixing screw 42 that is fixed to the side surface of the base block 230. The weight 51 is rotated together with the piston 21 and has a function of eliminating vibration generated when the eccentric shaft 232 of the link 22 rotates in accordance with the rotation of the drive shaft 131. The weight 51 is disposed at a position in the drive shaft 131 that is offset from the eccentric direction of the eccentric shaft 232.

In the vacuum pumping portion 11 constructed as described above, the eccentric member 23 is rotated about the drive shaft 131 by the drive of the motor M, whereby the eccentric shaft 232 is along a circumference having a radius corresponding to the amount of eccentricity from the drive shaft 131. And revolving around the drive shaft 131. The link 22 connected to the eccentric shaft 232 changes the rotation of the drive shaft 131 to the reciprocating movement of the piston 21 inside the cylinder 111. That is, inside the cylinder 111, the piston 21 reciprocates in the Z-axis direction while rocking in the X-axis direction in Fig. 5 . Thereby, the suction and exhaust of the pump chamber 26 are alternately performed, and the predetermined vacuum exhausting action generated by the vacuum pumping portion 11 is obtained.

On the other hand, the pressurizing pump portion 12 is configured similarly to the vacuum pumping portion 11, and the drive shaft 131 also protrudes toward the pressurizing pump portion 12, and is connected to the eccentric shaft (not shown) of the pressurizing pump portion 12. Thereby, the pressurized pump part 12 The vacuum pump unit 11 can be driven by the common motor M at the same time, and a predetermined pressurization (boost) action is performed.

Here, the vacuum pumping portion 11 and the pressure pumping portion 12 are driven at different phases from each other. In other words, in the present embodiment, the piston 21 (second piston) of the pressurizing pumping portion 12 is configured to advance the piston 21 (first piston) of the vacuum pumping portion 11 with a rotational phase difference of more than 0° and less than 80°.

In order to maintain the above-described rotational phase difference between the pistons, the eccentric shafts 232 of the respective pumps 11 and 12 in the present embodiment are at different positions. According to the present embodiment, since the eccentric member 23 is fixed to the drive shaft 131 only by the locking of the screw 41, it is easy to adjust the relative positions of the eccentric shafts 232 of the two pumps 11, 12.

Further, since the position of the weight fixed to the eccentric member 23 is related to the eccentric direction of the eccentric shaft 232, the rotational phase difference between the two pistons 21 can be easily confirmed even from the outside of the pump device 1. That is, as shown in FIGS. 1 to 4, the weight 52 of the pressurizing pump portion 12 is fixed to the rotational direction of the drive shaft 131 (in FIG. 3, it is a clockwise direction centered on the Y-axis, and FIG. 4 is The counter-clockwise direction centered on the Y-axis and the position of the counterweight 51 of the vacuum pumping portion 11 is advanced by the predetermined rotational phase difference (greater than 0° and less than 80°).

Fig. 6(A) and Fig. 6(B) are diagrams showing the relationship between the eccentric shaft 232v on the side of the vacuum pumping portion 11 and the eccentric shaft 232c on the side of the pressurized pumping portion 12: Fig. 6(A) is a front view, Fig. 6 (Fig. 6(A) B) is a side view viewed from the side of the vacuum pump portion 11. As shown in Fig. 6(B), the eccentric shaft 232c on the side of the pressurizing pump portion 12 is provided to eccentrically advance the eccentric shaft 232v on the side of the vacuum pump portion 11 with a predetermined rotational phase difference φ. Therefore, the piston 21v and the pressurized pump portion on the side of the vacuum pump portion 11 The pistons 21c on the 12 side are driven to each other by the phase difference φ, and the piston 21c reaches the top dead center faster than the piston 21v by the time corresponding to the phase difference φ.

The rotational phase difference φ is set within a suitable range of more than 0° and less than 80°. Thereby, the power consumption of the motor M can be reduced as compared with the driving of the two pistons 21v, 21c in the same phase (φ = 0). Further, when φ is set to 40° ± 15°, the low power consumption operation of the motor M described above can be stably maintained.

Fig. 7(A) is an experimental result showing the time variation of the pressure inside the pump chamber and the piston position in the vacuum pump, and Fig. 7(B) shows the pressure inside the pump chamber and the piston position in the pressurized pump. The experimental results of the time changes. In the figure, the experimental results of the operation when the solid line is 50 Hz and the dotted line is 60 Hz.

In addition, the pumping height of the pump apparatus used for the experiment was 40 kPa (absolute pressure) in the vacuum section (vacuum pump) and 220 kPaG (measured pressure) in the pressurizing section (pressurizing pump). The internal pressure of the pump room is measured by inserting the tube into a closed pump room. The piston position is used for the output of the accelerometer mounted on the lower part of the connecting rod. The cylinder diameter of each pump is φ 37mm, the eccentricity of the eccentric shaft is 3.3mm, and the number of rotations of the motor is about 1400rpm/1700rpm (50h/60h). The conditions of the experimental results shown in Figs. 8 and 9 are also the same.

In the vacuum section, the pressure system inside the pump chamber is synchronized with the piston position and in phase change (Fig. 7(A)). In contrast, in the pressurizing section, the pressure system inside the pump chamber is not synchronized with the piston position. A phase difference occurs between the two (Fig. 7(B)). More specifically, the piston of the pressurizing section experiences a pressure peak in the pump chamber before reaching the top dead center.

It is confirmed by the above experimental results that even if the pistons of the vacuum section and the pressurizing section are driven in the same phase, the pressure inside the pump chamber of each of the vacuum section and the pressurizing section does not change in the same phase, and the pressurizing section is The pump room reaches the maximum pressure faster than the vacuum chamber.

In addition, it has been experimentally confirmed that the pistons of the respective pumping portions are driven in the same phase, so that the internal pressures of the two pumping chambers of the first pumping portion and the second pumping portion are changed to opposite phases. The pump device can reduce the power consumption of the drive motor.

Here, when the time of the internal pressure changes to the opposite phase, the pressure waveform of the two puddle chambers typically has a phase of 180°, but is not limited thereto, as long as it has a substantial meaning to explain the phase relationship of the relationship of the opposite phases. Here, the opposite phase of the substantial meaning can be defined, for example, as a phase relationship that can reduce the power consumption more than when the two pistons are driven in the same phase.

When the pressure waveform of the pressure inside the pump chamber of the vacuum section and the pressure waveform of the pressure inside the pressurization section are in phase, the pump device for maintaining a predetermined phase difference between the piston of the pressurizing section and the piston of the vacuum section is formed. The piston of the pressurizing section is set to a rotational phase difference of up to 18 and less than 0° and less than 260° with respect to the piston of the vacuum section. The experimental results when the rotational phase difference is 220° are shown in Fig. 7(A) to Fig. 7(C). Fig. 7(C) shows a composite waveform of the pressure waveform of the pump chamber of the vacuum section and the pressure waveform of the pumping chamber of the pressurizing section.

On the other hand, the piston between the piston of the pressurizing section and the piston of the vacuum section is maintained in such a manner that the pressure waveform of the pressure inside the pump chamber of the vacuum section and the pressure waveform of the pressure inside the pumping chamber of the pressurizing section are opposite phases. In the case of a phase difference pump, the piston of the pressurizing section is set relative to the piston of the vacuum section. A rotational phase difference of up to greater than 0° and less than 80°. The experimental results when the rotational phase difference is 40° are shown in Fig. 8(A) to Fig. 8(C). Fig. 8(A) shows the time variation of the pressure inside the pump chamber and the piston position in the vacuum section, and Fig. 8(B) shows the time variation of the pressure inside the pump chamber and the piston position in the pressurizing section, Fig. 8(C) It is a composite waveform showing the pressure waveform of the pump chamber of the vacuum section and the pressure waveform of the pumping chamber of the pressurizing section.

Next, Fig. 9 is an experimental result showing the relationship between the rotational phase difference of the piston of the pressurizing section with respect to the piston of the vacuum section and the motor current consumption. The rotational phase difference of the horizontal axis represents the phase lead angle of the piston of the pressurizing section with respect to the piston of the vacuum section (in the direction of rotation of the drive shaft, the phase angle of the pressurizing side piston leads the piston of the vacuum side).

As shown in Fig. 9, it can be understood that the motor current value varies depending on the rotational phase difference φ of the piston of the pressurizing section with respect to the piston of the vacuum section. It is believed to be related to the balance of pressure changes between the chambers of each segment.

In this experimental example, the rotational phase difference φ of the lowest current value is 40°, and the pressure waveforms of the pump chambers of the respective stages are in opposite phase relationship as shown in Figs. 8(A) and (B). At this time, the composite waveform of the pressure inside the pump chamber of each section is as shown in Fig. 8(C), and the internal pressure of the pump chamber of each section cancels each other, so that the consumption current of the motor is minimized.

In contrast, the internal pressures of the pump chambers of the respective sections are in phase with each other (the rotational phase difference of the piston of the pressurizing section with respect to the piston of the vacuum section is +220°), as shown in Fig. 7(C). It is shown that the internal pressures of the pump chambers of each segment overlap each other and cause periodic load changes to the motor, which is considered to be the reason for increasing the current consumption.

Further, as shown in FIG. 9, when the power supply frequency is 50 Hz or 60 Hz, when the rotational phase difference φ is greater than 0° and less than 80°, compared to when the rotational phase difference is φ=0° (360°). Confirm that the drive current of the motor can be reduced. In particular, regardless of whether the power supply frequency is different or not, the current value can be constantly reduced in comparison with the rotational phase difference φ = 0° in the range of the rotational phase difference φ = 40° ± 30°. Furthermore, in the range of φ=40°±15°, the power consumption can be more effectively reduced, and the current value can be reduced by about 4.1% at 50 Hz, and the current value can be reduced by about 2.2% at 60 Hz.

Further, by setting the phase difference φ to 40°±15°, not only the current consumption but also the vibration generated when the pump device 1 is driven can be reduced. According to the experiment of the present inventors, for example, when φ=40°, the pistons of the vacuum section and the pressurizing section can reduce the X, Y and Z axis directions when compared with the same phase (φ=0°) (refer to the figure). 1) Vibration acceleration. This vibration reduction effect is confirmed regardless of the power frequency at 50 Hz or 60 Hz.

The embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and any modifications made without departing from the spirit of the invention are intended to be included in the scope of the invention.

For example, in the above embodiment, the vacuum pumping portion 11 and the pressure pumping portion 12 constituting the pumping device are each constituted by a rocking type piston pump. However, the present invention is not limited thereto, and may be, for example, a diaphragm type pump or the like. Reciprocating piston pump.

Moreover, the above embodiment is described by taking a pump device having a single drive motor and two pump portions as an example, but the present invention is also applicable to a plurality of arrays (for example, two groups) by the above-described drive motor and two pump portions. Forming a pump Yuan Zhipu device.

Claims (3)

A pump device includes a drive motor having a first drive shaft and a second drive shaft, and the first drive shaft and the second drive shaft are synchronously rotatable about a first axis; a pumping unit having a first piston that reciprocates in a second axial direction perpendicular to the first axis by rotation of the first drive shaft, and a first pump that changes internal pressure according to reciprocation of the first piston And a second pumping portion for pressurization, wherein the second piston reciprocating in the second axial direction by the rotation of the second drive shaft and the first internal pressure are changed according to the reciprocating movement of the second piston In the 2 pump chamber, the second piston advances the first piston by a phase difference of a rotational phase difference of more than 0° and less than 80°. The pump device of claim 1, wherein the aforementioned rotational phase difference is 40° ± 15°. The pump device according to claim 1, wherein the first pumping portion further includes a first weight that rotates around the first drive shaft together with the first piston; and the second pump portion further has a first weight The first weight is a second weight that rotates around the second drive shaft together with the second piston by the rotational phase difference.