JP6765279B2 - Diaphragm pump - Google Patents

Description

The present invention relates to a diaphragm pump provided with a drive mechanism in which a drive body on the diaphragm side reciprocates when an inclined drive shaft rotates.

As a conventional diaphragm pump of this type, for example, there is one described in Patent Document 1.
The diaphragm pump disclosed in Patent Document 1 includes a diaphragm forming a part of a wall of a pump chamber and a drive mechanism for driving the diaphragm to increase or decrease the volume of the pump chamber.

The drive mechanism converts the rotation of the motor into reciprocating motion and transmits it to the diaphragm. A rotating body that rotates integrally with the output shaft of the motor and a drive body that has an arm connected to the reciprocating motion part of the diaphragm. , It is provided with a drive shaft that connects the rotating body and the drive body.
One end of the drive shaft is attached to a portion of the rotating body that is eccentric from the output shaft of the motor. Further, the drive shaft is inclined with respect to the output shaft of the motor. The direction in which the drive shaft is inclined is the direction in which the amount of eccentricity with respect to the output shaft is reduced at the other end of the drive shaft.
The other end of the drive shaft is inserted into a non-through hole formed in the drive body. A ball is interposed between the shaft end surface of the other end of the drive shaft and the bottom surface of the non-through hole. This ball receives an axial pressing force applied from the drive body to the drive shaft during operation of the diaphragm pump.

JP-A-2002-130134

In the drive mechanism described in Patent Document 1, there is a problem in the contact portion between the drive body and the ball. That is, the inner bottom surface of the non-through hole is worn by friction with the ball, and the temperature of the drive body rises due to friction between the drive body and the ball. If the drive body is worn or the temperature of the drive body rises in this way, the life of the diaphragm is shortened.
It is considered that the reason why the drive body is worn due to friction with the ball is that the rotation of the drive shaft is transmitted to the ball and the ball rotates with respect to the drive body together with the drive shaft.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a diaphragm pump in which wear and heat generation of a contact portion of a driving body with a ball are suppressed to be suppressed and a life is extended.

In order to achieve this object, the diaphragm pump according to the present invention has a diaphragm forming a part of a wall of the pump chamber, and the rotation of the motor is converted into a reciprocating motion and transmitted to the diaphragm to transmit the volume of the pump chamber. The drive mechanism includes a rotating body that rotates integrally with the output shaft of the motor, and one end of the rotating body is supported by a portion of the rotating body that is eccentric from the output shaft and the other end. The portion has a drive shaft inclined in a direction in which the amount of eccentricity with respect to the output shaft is reduced, and a non-through hole in which the other end of the drive shaft is rotatably fitted and is connected to a reciprocating portion of the diaphragm. A plurality of balls interposed between the drive body having an arm portion, the shaft end surface of the other end of the drive shaft, and the bottom surface of the non-through hole, and arranged in the axial direction of the drive shaft in a state of being in contact with each other. It is equipped with.

In the present invention, when the drive shaft rotates with respect to the drive body while a plurality of balls are sandwiched between the bottom surface of the non-through hole of the drive body and the shaft end surface of the drive shaft, the balls come into contact with the drive shaft. The rotational force is transmitted from the drive shaft. Since this ball is in contact with another adjacent ball by point contact, the contact portion between the balls blocks the transmission of the rotational force. Therefore, the ball in contact with the bottom surface of the non-through hole does not rotate, or even if it rotates, the amount of rotation is smaller than that of the ball of the conventional diaphragm pump.
Therefore, according to the present invention, it is possible to provide a diaphragm pump in which the wear and heat generation of the contact portion of the drive body in contact with the ball is suppressed to be small, and the life of the diaphragm pump is longer than that of the conventional one.

It is sectional drawing of the diaphragm pump by 1st Embodiment. It is sectional drawing which shows the main part enlarged. It is sectional drawing of the diaphragm pump by 2nd Embodiment.

(First Embodiment)
Hereinafter, an embodiment of the diaphragm pump according to the present invention will be described in detail with reference to FIGS. 1 and 2.
The diaphragm pump 1 shown in FIG. 1 is a so-called negative pressure pump, which is attached to a motor 2 located at the lowest position in FIG. 1 and is driven by the motor 2 to operate.
The diaphragm pump 1 includes a housing 3 fixed to a motor 2. The functional parts constituting the diaphragm pump 1 are held in the housing 3.

The housing 3 is formed in a columnar shape by combining a plurality of members in the axial direction of the motor 2, and is positioned on the same axis as the output shaft 4 of the motor 2. The plurality of members constituting the housing 3 include a bottomed cylindrical bottom body 5 attached to the motor 2, a cylindrical diaphragm holder 6 attached to an opening portion of the bottom body 5, and the diaphragm holder 6. A disk-shaped valve holder 8 attached to the opening portion via a diaphragm 7, which will be described later, and a lid body 9 attached so as to overlap the valve holder 8. The members constituting these housings 3 are made of a plastic material.

The diaphragm 7 is sandwiched and held by the diaphragm holder 6 and the valve holder 8. Further, the diaphragm 7 has a plurality of cup-shaped deformed portions 11 that open toward the valve holder 8. These deformed portions 11 are provided at positions where the diaphragm 7 is divided into a plurality of portions in the circumferential direction of the housing 3.
The opening portion of the deformed portion 11 is closed by the valve holder 8.

A pump chamber 12 is formed between the deformed portion 11 and the valve holder 8. That is, the diaphragm 7 forms a part of the wall of the pump chamber 12.
A connecting piece 13 projecting in the direction opposite to the pump chamber 12 is provided on the bottom wall 11a of the deformed portion 11 having a cup shape. In this embodiment, the bottom wall 11a and the connecting piece 13 correspond to the "reciprocating portion of the diaphragm" in the present invention.

A suction valve 14 is provided in a portion of the valve holder 8 that constitutes the wall of the pump chamber 12, and the suction passage 15 and the discharge passage 16 are open. The suction valve 14 has a shaft portion 14a formed of a rubber material, penetrating the valve holder 8 and fixed to the valve holder 8, and a valve body 14b in close contact with the wall surface of the valve holder 8 on the pump chamber 12 side. ing. The valve body 14b closes the opening portion of the suction passage 15.

The suction passage 15 is between the valve holder 8 and the lid main body 9 so that the suction fluid chamber 17 formed on the outer peripheral side of the housing 3 communicates with the suction fluid chamber 17 and the pump chamber 12. It is composed of a first through hole 18 formed in the valve holder 8 and a suction pipe 19 projecting from the outer peripheral portion of the lid main body 9. The internal space of the suction pipe 19 is connected to the suction fluid chamber 17.

The opening portion of the first through hole 18 on the pump chamber 12 side is closed by the valve body 14b of the suction valve 14. The suction fluid chamber 17 is formed in an annular shape located on the same axis as the housing 3, and is communicated with each pump chamber 12 via a first through hole 18 for each pump chamber 12.

The discharge passage 16 communicates between the valve holder 8 and the lid body 9 and the discharge fluid chamber 21 formed at the axial center of the housing 3, and the discharge fluid chamber 21 and the pump chamber 12. It is composed of a second through hole 22 bored in the valve holder 8 and a discharge pipe 23 projecting from the axial center of the lid body 9. The internal space of the discharge pipe 23 is connected to the discharge fluid chamber 21. A discharge valve 24 is provided in the discharge fluid chamber 21. The discharge valve 24 is made of a rubber material and has a valve body 24a that is in close contact with the wall surface of the valve holder 8 on the discharge fluid chamber 21 side. The valve body 24a closes the opening portion of the second through hole 22.

The discharge valve 24 and the suction valve 14 described above open and close as the volume of the pump chamber 12 increases or decreases. The discharge valve 24 is opened in a compression stroke in which the volume of the pump chamber 12 is reduced, and is closed in other cases. The suction valve 14 opens in an expansion stroke in which the volume of the pump chamber 12 increases, and is otherwise closed. The volume of the pump chamber 12 changes when the deformed portion 11 of the diaphragm 7 is pushed or pulled by the drive mechanism 25 described later.

The drive mechanism 25 includes a rotating body 26 attached to the output shaft 4 of the motor 2, a driving body 28 connected to the rotating body 26 via a drive shaft 27, and the like. The rotating body 26 rotates integrally with the output shaft 4. The rotating body 26 and the driving body 28 are made of a plastic material. The drive shaft 27 is made of a metal material.

The drive shaft 27 is supported by the rotating body 26 by fixing one end portion 27a of the driving shaft 27 to a portion of the rotating body 26 that is eccentric from the output shaft 4, and is inclined in a predetermined direction with respect to the output shaft 4. There is. The drive shaft 27 is fixed by press-fitting one end 27a of the drive shaft 27 into a shaft hole 26a formed in the rotating body 26. The direction in which the drive shaft 27 is inclined is a direction in which the amount of eccentricity with respect to the output shaft 4 at the other end 27b of the drive shaft 27 is reduced.

The drive body 28 has three functional units, which will be described later. The first functional unit is a spindle unit 31 to which the drive shaft 27 is connected. The spindle portion 31 is formed in a columnar shape. A non-through hole 32 that opens toward the motor 2 side is formed in the axial center portion of the main shaft portion 31. The other end 27b of the drive shaft 27 is rotatably fitted in the non-through hole 32. The bottom surface 33 of the non-through hole 32 and the shaft end surface 34 of the drive shaft 27 are flat surfaces, respectively. A plurality of balls 35 are interposed between the bottom surface 33 of the non-through hole 32 and the shaft end surface 34 of the drive shaft 27.

In this embodiment, the two balls 35 are arranged so as to be aligned in the axial direction of the drive shaft 27 in a state of being in contact with each other. The two balls 35 according to this embodiment are rotatably fitted in the non-through holes 32, respectively. That is, the outer diameter D1 of the ball 35 (see FIG. 2) and the outer diameter D2 of the drive shaft 27 are smaller than the hole diameter D3 of the non-through hole 32 by the clearance that allows rotation. As these balls 35, those used for general bearings can be used. In the following, of the two balls 35, one ball 35 in contact with the drive shaft 27 is referred to as a first ball 35A, and the other ball 35 in contact with the bottom surface 33 of the non-through hole 32 is referred to as a second ball 35B. ..

The second functional portion of the drive body 28 is an arm portion 36 connected to the bottom wall 11a of the deformed portion 11 of the diaphragm 7 and the connecting piece 13. The arm portion 36 is provided for each deformed portion 11 of the diaphragm 7, and extends radially outward from the spindle portion 31. The bottom wall 11a is in close contact with the arm portion 36, and the connecting piece 13 is fixed to the arm portion 36 in a state of penetrating the arm portion 36.

The third functional portion is a swing fulcrum shaft portion 37 located at the center of the drive body 28 and on the opposite side of the motor 2. The swing fulcrum shaft portion 37 serves as the swing center of the drive body 28, and protrudes from the axial center portion of the spindle portion 31 in the direction opposite to the motor 2. The tip of the swing fulcrum shaft portion 37 is formed in a hemispherical shape and is held in the circular recess 38 of the diaphragm holder 6. The swing fulcrum shaft portion 37 is in contact with the circular recess 38 so as to be rotatable about the axis and swingably in a direction in which the axis is inclined.

In the diaphragm pump 1 configured in this way, the rotating body 26 and the drive shaft 27 rotate around the output shaft 4 due to the rotation of the output shaft 4 of the motor 2, and the drive body 28 rotates around the swing fulcrum shaft portion 37. Swing around. Due to this swing, the arm portion 36 pushes or pulls the deformed portion 11. Therefore, the drive body 28 converts the rotation of the output shaft 4 into a reciprocating motion and transmits it to the deformed portion 11. When the deformed portion 11 of the diaphragm 7 is pulled toward the motor 2 by the arm portion 36, the volume of the pump chamber 12 increases, the suction valve 14 opens, and the fluid is sucked, as shown in the right half portion in FIG. It is sucked into the pump chamber 12 from the pipe 19 through the suction passage 15.

On the other hand, when the deformed portion 11 of the diaphragm 7 is pushed toward the valve holder 8 by the arm portion 36, the deformed portion 11 is compressed and the volume of the pump chamber 12 is reduced, as shown in the left half portion in FIG. , The discharge valve 24 is opened, and the fluid in the pump chamber 12 is discharged from the discharge pipe 23 through the discharge passage 16.

When the diaphragm pump 1 is operating, the drive body 28 is pushed toward the motor 2 by the reaction force when pushing the deformed portion 11. At this time, the first and second balls 35A and 35B are sandwiched between the bottom surface 33 of the non-through hole 32 of the drive body 28 and the shaft end surface 34 of the drive shaft 27. That is, the above-mentioned reaction force is received by the first and second balls 35A and 35B. When the drive shaft 27 rotates with respect to the drive body 28 in such a state, the rotational force is transmitted from the drive shaft 27 to the first ball 35A in contact with the drive shaft 27.

Since the first ball 35A is in contact with the adjacent second ball 35B by point contact, the contact portion between the first ball 35A and the second ball 35B blocks the transmission of the rotational force. Become. Therefore, the second ball 35B in contact with the bottom surface 33 of the non-through hole 32 does not rotate, or even if it rotates, the amount of rotation is smaller than that of the ball 35 of the conventional diaphragm pump 1.
Therefore, according to this embodiment, it is possible to provide the diaphragm pump 1 which has a longer life than the conventional one by suppressing wear and heat generation of the contact portion of the drive body 28 with the second ball 35B.

(Second Embodiment)
The diaphragm pump according to the present invention can be configured as shown in FIG. In FIG. 3, the same or equivalent members as those described with reference to FIGS. 1 and 2 are designated by the same reference numerals, and detailed description thereof will be omitted as appropriate.
The diaphragm pump 41 shown in FIG. 3 is a so-called positive pressure pump, and is formed so as to be different from the diaphragm pump 1 shown in FIG. 1 mainly in the following four locations and the others to be the same.

Of the four differences, the first difference is the suction passage 15. The suction passage 15 according to this embodiment has a third through hole 42 that replaces the suction pipe 19.
The second difference is the deformed portion 11 of the diaphragm 7. The bottom wall 11a of the deformed portion 11 according to this embodiment is formed thicker than the bottom wall 11a shown in FIG.

The third difference is the central portion of the drive body 28 and the central portion of the diaphragm holder 6. The driving body 28 according to this embodiment is not provided with the swing fulcrum shaft portion 37. Further, the circular recess 38 is not provided in the central portion of the diaphragm holder 6.
The fourth difference is the arm 36 of the drive body 28. The arm portion 36 according to this embodiment is formed so that the bottom wall 11a of the deformed portion 11 is substantially parallel to the end face of the valve holder 8 when the deformed portion 11 is compressed.
Even if the diaphragm pump 1 is formed in this way, the same effect as that of the first embodiment can be obtained because the plurality of balls 35 are provided in the non-through holes 32 of the drive body 28.

In the above-described embodiment, an example in which two balls 35 are used is shown. However, the number of balls 35 is not limited to such a limitation and can be 3 or more.

1,41 ... Diaphragm pump, 2 ... Motor, 4 ... Output shaft, 7 ... Diaphragm, 11a ... Bottom wall (reciprocating motion part), 12 ... Pump chamber, 13 ... Connecting piece (reciprocating motion part), 25 ... Drive mechanism, 26 ... Rotating body, 27 ... Drive shaft, 28 ... Drive body, 32 ... Non-through hole, 33 ... Bottom surface, 34 ... Shaft end face, 35 ... Ball, 36 ... Arm.

Claims (1)

The diaphragm that forms part of the wall of the pump chamber and
It is equipped with a drive mechanism that converts the rotation of the motor into reciprocating motion and transmits it to the diaphragm to increase or decrease the volume of the pump chamber.
The drive mechanism
A rotating body that rotates integrally with the output shaft of the motor,
A drive shaft whose one end is supported by a portion of the rotating body that is eccentric to the output shaft and whose other end is inclined in a direction in which the amount of eccentricity with respect to the output shaft is reduced.
A drive body having a non-through hole in which the other end of the drive shaft is rotatably fitted and an arm connected to a reciprocating portion of the diaphragm.
It is characterized by having a plurality of balls interposed between the shaft end surface of the other end of the drive shaft and the bottom surface of the non-through hole and arranged in the axial direction of the drive shaft in a state of being in contact with each other. Diaphragm pump.

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