JP6740262B2 - Vacuum pump - Google Patents

Description

The present invention relates to a vacuum pump.

Conventionally, as a vacuum pump such as a vane pump, there is known a vacuum pump including a casing (body) attached to a driving machine such as a motor and a rotating body that is rotated by the driving machine in a cylinder chamber of the casing (for example, See Patent Document 1). In this type of vacuum pump, a rotating body that is rotated by a driving machine is driven in a cylinder chamber to discharge air in the device connected to the vacuum pump and reduce the pressure in the device.

The rotating body of the vacuum pump described in Patent Document 1 is provided with a cylindrical rotor and a plurality of plate-shaped vanes provided so as to be retractable from guide grooves formed in the rotor. The vane divides the cylinder chamber and projects from the guide groove by the centrifugal force generated as the rotor rotates, and rotates with the rotor while contacting the inner peripheral surface of the cylinder chamber.

JP2012-167590A

In the above vacuum pump, the axial end surface of the rotor is in contact with a sliding plate such as a carbon plate. Therefore, it is unavoidable that the sliding plate is worn by sliding with the rotor, but it is required to suppress the wear of the sliding plate.

The present invention has been made in view of these circumstances, and an object thereof is to provide a vacuum pump capable of suppressing wear of a sliding plate.

A vacuum pump that solves the above problems, an output shaft that transmits a driving force of a motor, the output shaft penetrates, a rotating body that is rotated by the output shaft, and a cylindrical cylinder that houses the rotating body, While closing one opening of the cylinder, the output shaft penetrates, and a first sliding plate that comes into contact with one axial end surface of the rotating body, and the other opening of the cylinder is closed, and A second sliding plate that comes into contact with the other axial end surface of the rotating body, and a biasing member that is provided between the output shaft and the rotating body and that biases the rotating body toward the first sliding plate side. And a member.

The pressure in the cylinder decreases as the rotating body is rotated by the output shaft, but the pressure on the first sliding plate side of the rotating body becomes the second pressure because the output shaft penetrates the first sliding plate side. The inventors have found that the pressure becomes higher than the pressure on the sliding plate side and the rotating body is attracted to the second sliding plate side. Therefore, according to the above configuration, by the biasing member biasing the rotating body toward the first sliding plate side, the movement of the rotating body toward the second sliding plate side can be suppressed, and the sliding plate Wear can be suppressed.

The vacuum pump includes a connecting member that is provided on the output shaft and allows relative movement in the axial direction with the rotating body, and the urging member is attached between the connecting member and the rotating body. Is preferred.

According to the above configuration, by attaching the biasing member to the connecting member provided on the output shaft, it is easier to attach the biasing member than directly attaching the biasing member to the output shaft.
In the vacuum pump, when the rotating body rotates, the biasing member moves the rotating body to the first sliding plate side by shortening an axial distance between the output shaft and the rotating body. Pushing is preferred.

According to the above configuration, a biasing member such as a compression spring is provided between the output shaft and the rotary body, and the axial distance between the output shaft and the rotary body is shortened, whereby the rotary body is slid on the first slide. A biasing force that pushes to the plate side is generated.

In the vacuum pump, the urging member causes the rotating body to move toward the first sliding plate side due to a longer axial distance between the output shaft and the rotating body when the rotating body rotates. It is preferable to draw.

According to the above configuration, a biasing member such as a tension spring is provided between the output shaft and the rotating body, and the axial distance between the output shaft and the rotating body becomes longer, so that the rotating body first slides. A biasing force that pulls toward the plate is generated.

Regarding the vacuum pump, a cylinder-shaped body that houses the cylinder and has a bottom through which the output shaft penetrates, a lid that closes an opening of the body, the first sliding plate, and the bottom of the body It is preferable to provide a first spring provided between them and a second spring provided between the second sliding plate and the lid.

According to the above configuration, the movement of the first sliding plate can be absorbed by the first spring, and the movement of the second sliding plate can be absorbed by the second spring. Therefore, it is possible to suppress wear of the sliding plate due to sliding with the rotating body.

According to the present invention, wear of the sliding plate can be suppressed.

Sectional drawing which shows the internal structure of 1st Embodiment of a vacuum pump. Sectional drawing which shows operation|movement of the vacuum pump of the same embodiment. Sectional drawing which shows the internal structure of 2nd Embodiment of a vacuum pump. Sectional drawing which shows the internal structure of the modification of a vacuum pump. Sectional drawing which shows the internal structure of the modification of a vacuum pump. Sectional drawing which shows the internal structure of the modification of a vacuum pump.

(First embodiment)
Hereinafter, a first embodiment of the vacuum pump will be described with reference to FIGS. 1 and 2.
As shown in FIG. 1, the vacuum pump 1 includes a motor (not shown), a body 20 into which the output shaft 10 for transmitting the driving force of the motor is inserted, and a lid 25 assembled to the body 20. The vacuum pump 1 is a dry pump that does not contact the oil taken in with the air taken in by using no lubricating oil in the pump chamber.

The body 20 is a component made of metal such as aluminum and is provided on the output shaft 10 side of the motor. That is, the body 20 also functions as a lid that closes the case of the motor. A cylindrical space 20A is formed in the body 20. The body 20 is provided with a body inlet 23 that takes in air into the body 20, and a body outlet 24 that discharges air from the body 20. The lid 25 is fixed to the body 20 with a bolt (not shown).

A through hole 21A through which the output shaft 10 of the motor penetrates is formed in the center of the bottom portion 21 of the body 20. The through hole 21A of the bottom portion 21 is formed at a position deviated from the center of the bottom portion 21 of the body 20. An annular bearing portion 22 is formed around the through hole 21A of the bottom portion 21. The bearing portion 22 supports the output shaft 10 of the motor.

A cylindrical cylinder 30 is housed in the space 20A of the body 20. The inside of the cylinder 30 corresponds to the pump chamber. The cylinder 30 is made of metal such as iron and has a cylindrical shape. The cylinder 30 is attached to the body 20 by being press-fitted into the body 20. A pump chamber inlet 31 for taking air into the pump chamber and a pump chamber outlet 32 for discharging air from the pump chamber are formed through the cylinder 30. The pump chamber inlet 31 communicates with the body inlet 23. The pump chamber outlet 32 communicates with the body outlet 24.

A rotor 40, which is a rotating body, is housed in the cylinder 30. A plurality of carbon plate-shaped vanes 43 are housed in the rotor 40 so as to be retractable. The rotor 40 is made of metal such as iron. The rotor 40 has a plurality of vane housing grooves (not shown) for housing the vanes 43. The rotor 40 is provided with a through hole 41 through which the output shaft 10 penetrates. The output shaft 10 and the rotor 40 rotate integrally as the output shaft 10 engages with the engagement groove 42 formed in the rotor 40. Further, the output shaft 10 and the rotor 40 can be relatively moved in the axial direction by the engagement groove 42.

A recess 44 is formed in the center of the rotor 40 opposite to the motor side. The recess 44 is coaxial with the through hole 41. The inner diameter of the recess 44 is longer than the inner diameter of the through hole 41. A disk 12 as a connecting member is inserted through the tip portion 11 of the output shaft 10, and the disk 12 is prevented from coming off by a C ring 13. Therefore, the disc 12 cannot move to the tip side of the output shaft 10 with respect to the C ring 13. The outer diameter of the disc 12 is the same as the inner diameter of the recess 44.

A compression spring 45 as a biasing member is provided between the disc 12 and the bottom portion 44A of the recess 44. The compression spring 45 is attached to the disc 12 and the bottom portion 44A of the recess 44. The compression spring 45 is compressed when the distance between the output shaft 10 and the rotor 40 in the axial direction is shortened, and an urging force that pushes the rotor 40 toward the motor is generated (see FIG. 2 ).

The opening of the cylinder 30 on the motor side is referred to as a first opening 33, and the opening of the cylinder 30 opposite to the motor is referred to as a second opening 34. The first opening 33 of the cylinder 30 is closed by the first sliding plate 35. The first sliding plate 35 is installed between the bottom portion 21 of the body 20 and the rotor 40, and the rotor 40 can slide. The first sliding plate 35 is formed with a through hole 35A through which the output shaft 10 of the motor penetrates. The second opening 34 of the cylinder 30 is closed by the second sliding plate 36. The second sliding plate 36 is installed between the lid 25 and the rotor 40, and the rotor 40 can slide. The first sliding plate 35 and the second sliding plate 36 are made of a material such as carbon having a small friction coefficient with respect to the vanes 43, and are formed in a disc shape.

A first disc spring 26 is provided between the first sliding plate 35 and the bottom portion 21 of the body 20. The first disc spring 26 is compressed when the first sliding plate 35 tries to move toward the bottom portion 21 of the body 20, and generates a biasing force that pushes the first sliding plate 35. A second disc spring 27 is provided between the second sliding plate 36 and the lid 25. The second disc spring 27 is compressed when the second sliding plate 36 tries to move to the lid 25 side, and generates an urging force that pushes the second sliding plate 36.

Here, the assembly of the vacuum pump 1 will be described.
First, the output shaft 10 of the motor is inserted into the body 20 from the bottom portion 21 of the body 20. The output shaft 10 penetrates the through hole 21A.

Subsequently, the first disc spring 26 is installed on the bottom portion 21 of the space 20A of the body 20 while being inserted into the output shaft 10. Subsequently, the first sliding plate 35 is placed on the first disc spring 26 in the space 20A of the body 20 while being inserted into the output shaft 10.

Next, the cylinder 30 is press-fitted into the space 20A of the body 20. Then, the body inlet 23 and the pump chamber inlet 31 are collectively formed by cutting. Further, the body outlet 24 and the pump chamber outlet 32 are collectively formed by cutting.

Subsequently, the rotor 40 is inserted into the output shaft 10 while being engaged with the engagement groove 42 of the output shaft 10, and is installed inside the cylinder 30 and on the first sliding plate 35. Then, the compression spring 45 is installed in the bottom portion 44A of the recess 44 of the rotor 40 while being inserted into the output shaft 10. Then, the disk 12 is installed in the recess 44 of the rotor 40 and on the compression spring 45 while being inserted into the output shaft 10. Then, the C ring 13 is attached to the tip portion 11 of the output shaft 10 to prevent the disc 12 from coming off.

Subsequently, the second sliding plate 36 is installed on the rotor 40 while closing the second opening 34 of the cylinder 30. Then, the second disc spring 27 is installed on the second sliding plate 36. Then, the opening of the space 20A of the body 20 is closed by the lid 25, and the lid 25 is fixed to the body 20 with a bolt (not shown).

Next, the operation of the vacuum pump 1 configured as described above will be described.
A substantially crescent-shaped space is formed in the cylinder 30 by a rotor 40 that is eccentrically mounted inside the cylinder 30. When the rotor 40 is rotated by driving the motor, the vanes 43 are projected to the outside in the radial direction of the rotor 40 by the centrifugal force along the vane housing groove, and the tips thereof are brought into contact with the inner peripheral surface of the cylinder 30. As a result, the substantially crescent-shaped space in the cylinder 30 is divided into a plurality of compression chambers surrounded by the plurality of vanes 43, the outer peripheral surface of the rotor 40, and the inner peripheral surface of the cylinder 30.

These compression chambers move in the same direction as the rotor 40 rotates. When the compression chamber moves, the volume of the compression chamber increases near the pump chamber inlet 31 and decreases at the pump chamber outlet 32. That is, the air sucked into the compression chamber from the pump chamber inlet 31 is compressed as the rotor 40 rotates, and is discharged from the pump chamber outlet 32. In the cylinder 30, since the rotor 40 and the vanes 43 rotate in the cylinder 30 to compress the air, the compressed air is intermittently discharged from the pump chamber outlet 32.

As shown in FIG. 2, when the vacuum pump 1 is operating, when the rotor 40 is rotated by driving the motor, the pressure in the cylinder 30 is reduced. However, since the output shaft 10 penetrates the first sliding plate 35 side of the rotor 40, the pressure of the first sliding plate 35 side of the rotor 40 becomes higher than the pressure of the second sliding plate 36 side, The rotor 40 is attracted to the second sliding plate 36 side. At this time, when the rotor 40 tries to move to the second sliding plate 36 side, the compression spring 45 biases the rotor 40 to the first sliding plate 35 side, so that the second sliding plate 36 side of the rotor 40. To move to. Even if the output shaft 10 of the motor tries to move to the second sliding plate 36 side, the movement can be absorbed by the compression spring 45. Further, since a slight movement of the first sliding plate 35 is absorbed by the first disc spring 26 and a slight movement of the second sliding plate 36 is absorbed by the second disc spring 27, the first sliding plate 35 Also, the wear of the second sliding plate 36 can be suppressed.

As described above, according to this embodiment, the following effects can be achieved.
(1) Since the compression spring 45 biases the rotor 40 toward the first sliding plate 35 side, the movement of the rotor 40 toward the second sliding plate 36 side can be suppressed, and the first sliding plate 35 Also, the wear of the second sliding plate 36 can be suppressed.

(2) By attaching the compression spring 45 to the connecting member fixed to the output shaft 10, the compression spring 45 can be attached more easily than directly attaching the compression spring 45 to the output shaft 10.
(3) Since the compression spring 45 is provided between the output shaft 10 and the rotor 40, and the axial distance between the output shaft 10 and the rotor 40 is shortened, the rotor 40 is pushed toward the first sliding plate 35 side. Power is generated.

(4) The movement of the first sliding plate 35 can be absorbed by the first disc spring 26, and the movement of the second sliding plate 36 can be absorbed by the second disc spring 27. Therefore, it is possible to suppress wear of the first sliding plate 35 and the second sliding plate 36 due to sliding with the rotor 40.

(Second embodiment)
Hereinafter, the second embodiment of the vacuum pump will be described with reference to FIG. The vacuum pump of this embodiment is different from that of the first embodiment in that two urging members are installed. Hereinafter, differences from the first embodiment will be mainly described.

As shown in FIG. 3, a second recess 47 is formed in the center of the rotor 40 of the vacuum pump 1 on the motor side. The second recess 47 is coaxial with the through hole 41. The inner diameter of the recess 47 is longer than the inner diameter of the through hole 41. A second disc 14 as a connecting member is inserted near the first sliding plate 35 of the output shaft 10. The outer diameter of the second disc 14 is the same as the inner diameter of the second recess 47.

A tension spring 48 as a biasing member is provided between the second disc 14 and the bottom portion 47A of the second recess 47. The tension spring 48 is attached to the second disc 14 and the bottom portion 47A of the second recess 47. The tension spring 48 is extended by increasing the axial distance between the output shaft 10 and the rotor 40, and an urging force that pulls the rotor 40 toward the motor is generated.

In the vacuum pump 1, the compression spring 45 and the tension spring 48 suppress the movement of the rotor 40 toward the second sliding plate 36, so that the first sliding plate 35 and the second sliding plate 36 are not worn. Can be suppressed.

As described above, according to the present embodiment, the following effects can be obtained in addition to the effects (1) to (4) of the first embodiment.
(5) A tension spring 48 is provided between the output shaft 10 and the rotor 40, and the axial distance between the output shaft 10 and the rotor 40 is increased to pull the rotor 40 toward the first sliding plate 35 side. Power is generated.

In addition, the above-described embodiment can be implemented in the following forms in which this is appropriately modified.
The compression spring 45 of the second embodiment may be omitted and the rotor 40 may be biased only by the tension spring 48. For example, as shown in FIG. 4, the disk 12 and the compression spring 45 of the second embodiment are omitted, the C ring 13 is attached to the tip portion 11 of the output shaft 10, and the output shaft 10 is connected by the C ring 13. The rotor 40 is prevented from coming off. When the rotor 40 tries to move to the second sliding plate 36 side, the tension spring 48 urges the rotor 40 to the first sliding plate 35 side, so that the rotor 40 moves to the second sliding plate 36 side. Suppress.

-In each above-mentioned embodiment, you may employ|adopt the compression spring 45 as another biasing member. For example, as shown in FIG. 5, a wave washer 55 may be adopted instead of the compression spring 45. The wave washer 55 is installed between the disc 12 and the bottom portion 44A of the recess 44 of the rotor 40. Wave washers are easier to install than compression springs. Further, as shown in FIG. 6, a disc spring 65 may be adopted instead of the compression spring 45. The disc spring 65 is installed between the disk 12 and the bottom portion 44A of the recess 44 of the rotor 40. Belleville springs are easier to install than compression springs.

In each of the above-described embodiments, the C ring 13 is attached to the tip portion 11 of the output shaft 10 to prevent it from coming off. However, if the C ring 13 can be prevented from coming off from the output shaft 10, another fixing member is not limited to the C ring. May be adopted.

-In each above-mentioned embodiment, although the 1st disc spring 26 and the 2nd disc spring 27 were provided, not only a disc spring but other springs, such as a wave washer, may be provided.
-In each said embodiment, the structure of the 1st disc spring 26 and the 2nd disc spring 27 may be abbreviate|omitted. In this case, the first sliding plate 35 is installed in direct contact with the bottom portion 21 of the body 20, and the second sliding plate 36 is installed in direct contact with the lid 25.

In each of the above embodiments, the disks 12 and 14 as the connecting members are attached to the output shaft 10, but the connecting member may be omitted and the biasing member may be attached directly to the output shaft 10.

DESCRIPTION OF SYMBOLS 1... Vacuum pump, 10... Output shaft, 11... Tip part, 12... Disc as a connecting member, 13... C ring, 14... Second disc as a connecting member, 20... Body, 20A... Space, 21... Bottom portion, 21A... Through hole, 22... Bearing portion, 23... Body inlet, 24... Body outlet, 25... Lid, 26... First disc spring as first spring, 27... Second disc spring as second spring, 30... Cylinder, 31... Pump chamber inlet, 32... Pump chamber outlet, 33... First opening, 34... Second opening, 35... First sliding plate, 35A... Through hole, 36... Second sliding plate , 40... Rotor, 41... Through hole, 42... Engagement groove, 43... Vane, 44... Recess, 44A... Bottom, 45... Compression spring as biasing member, 47... Second recess, 47A... Bottom, 48... A tension spring as a biasing member, 55... Wave washer, 65... Disc spring.

Claims (7)

An output shaft that transmits the driving force of the motor,
A rotating body which the output shaft penetrates and which is rotated by the output shaft,
A cylindrical cylinder that houses the rotating body,
A first sliding plate that closes one opening of the cylinder, penetrates the output shaft, and contacts one end face in the axial direction of the rotating body;
A second sliding plate that closes the other opening of the cylinder and is in contact with the other axial end surface of the rotating body;
A biasing member that is provided between the output shaft and the rotating body and that biases the rotating body toward the first sliding plate side ,
It said biasing member is a vacuum pump wherein the rotary body that occur biasing force when moving in the axial direction. A connecting member which is provided on the output shaft and allows relative movement in the axial direction with the rotating body;
The vacuum pump according to claim 1, wherein the biasing member is attached between the connecting member and the rotating body. The urging member pushes the rotating body toward the first sliding plate by reducing the axial distance between the output shaft and the rotating body when the rotating body rotates. The vacuum pump according to 2. The urging member pulls the rotating body toward the first sliding plate by increasing the axial distance between the output shaft and the rotating body when the rotating body rotates. The vacuum pump according to 2. A cylindrical body that houses the cylinder and has a bottom through which the output shaft penetrates;
A lid for closing the opening of the body,
A first spring provided between the first sliding plate and the bottom of the body;
The vacuum pump according to claim 1, further comprising a second spring provided between the second sliding plate and the lid. The biasing members are installed on both sides of the rotating body in the axial direction.
The vacuum pump according to any one of claims 1 to 5. The biasing member is installed in a recess provided in the rotating body.
The vacuum pump according to any one of claims 1 to 6.

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