JP2011214522A - Compression device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compression device having reduced noises and vibration without increasing its size.SOLUTION: The compression device includes a casing body 22 having a cylinder chamber S where a rotor 27 and vanes 28 have sliding motion, an exhaust passage 37 connecting the cylinder chamber S to an exhaust port 24A, and an expansion chamber 33 formed in the exhaust passage 37. The expansion chamber 33 is provided at the peripheral edge of the cylinder chamber S in the casing body 22.

Description

  The present invention relates to a compression device having a rotary compression element in a casing.

  Generally, a vacuum pump is known as a compression device provided with a rotary compression element in a casing. In this type of vacuum pump, a vacuum can be obtained by driving the rotary compression element with a drive device such as an electric motor. The vacuum pump is mounted, for example, in an engine room of an automobile and is used to generate a vacuum for operating a brake booster (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2003-222090

By the way, in this type of vacuum pump, since the rotary compression element is driven to compress and discharge the air sucked into the casing, large noise and vibration are generated when the air is discharged from the exhaust port. In order to reduce vibration, a silencer was installed at the exhaust port, or it was attached to the vehicle via a sturdy bracket with anti-vibration rubber. For this reason, there has been a problem that the number of parts increases and the vacuum pump becomes larger.
The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a compression device that reduces noise and vibration without increasing the size.

  In order to achieve the above object, the present invention provides a compression apparatus including a rotary compression element in a casing, wherein the casing includes a casing body in which a cylinder chamber in which the rotary compression element slides is formed, and the cylinder chamber. An exhaust path connecting the exhaust port and an expansion chamber formed in the exhaust path are provided, and the expansion chamber is provided in a peripheral portion of the cylinder chamber in the casing body.

  According to this configuration, since the expansion chamber is provided in the exhaust path, the compressed air flowing through the exhaust path expands and disperses in the expansion chamber and is attenuated by colliding with the partition walls of the expansion chamber and being attenuated. It is possible to reduce noise and vibration during the operation. Furthermore, since the expansion chamber is provided at the peripheral edge portion of the cylinder chamber in the casing body, the cylinder chamber and the expansion chamber can be integrally formed in the casing body, thereby suppressing an increase in size of the compression device. Can do.

  In this configuration, a Helmholtz resonance chamber branched from the exhaust path may be connected to the expansion chamber. This resonance chamber is connected to the expansion chamber via an orifice, and the cross-sectional area of the orifice, the length, the volume of the resonance chamber, etc. are set so that resonance that cancels the pressure pulsation of the compressed air flowing through the exhaust path occurs. ing. For this reason, by connecting the resonance chamber to the expansion chamber, the sound energy of the air expanded in the expansion chamber is oscillated and attenuated by the air spring in the orifice and the resonance chamber, so that the air discharged from the rotary compression element Pressure pulsation can be reduced, and noise and vibration during exhaust can be further reduced.

  The cylinder chamber is provided in a position deviated from the rotation center of the rotary compression element in the casing body, and the expansion chamber and the resonance chamber are arranged in parallel at a peripheral portion on the rotation center side of the cylinder chamber. You may do it. According to this configuration, by disposing the cylinder chamber eccentric from the rotation center of the rotary compression element, a large space can be secured in the casing body at the peripheral portion on the rotation center side of the cylinder chamber. For this reason, by arranging the expansion chamber and the resonance chamber in this space in parallel, it is not necessary to provide the expansion chamber and the resonance chamber outside the casing main body, and the casing main body can be downsized. Miniaturization can be achieved.

  In addition, an intake path that guides air to the cylinder chamber may be provided, and an intake side expansion chamber that expands the air flowing through the intake path may be provided in the intake path. According to this configuration, by providing the intake side expansion chamber in the intake path, the air sucked into the vacuum pump is attenuated by expansion and dispersion in the intake side expansion chamber, so that noise and vibration during intake are reduced. Can be achieved.

Further, the intake side expansion chamber may be formed along with the expansion chamber at a peripheral portion of the cylinder chamber in the casing body. According to this configuration, by providing the expansion chamber and the intake side expansion chamber at the peripheral portion of the cylinder chamber, the cylinder chamber, the expansion chamber, and the intake side expansion chamber can be integrally formed in the casing body. Increase in size can be suppressed.
Further, a desiccant may be accommodated in the intake side expansion chamber. According to this configuration, since moisture in the air flowing into the cylinder chamber through the intake passage can be removed, dry air can be supplied to the cylinder chamber, and condensation in the cylinder chamber and the rotary compression element can be prevented. it can. Therefore, corrosion and freezing of the rotary compression element can be prevented, and the life of the compression device can be extended.

  According to the present invention, since the expansion chamber is provided in the exhaust path, the compressed air flowing through the exhaust path expands and disperses in the expansion chamber and is attenuated by colliding with the partition wall of the expansion chamber and being attenuated. It is possible to reduce noise and vibration during the operation. Furthermore, since the expansion chamber is provided at the peripheral edge portion of the cylinder chamber in the casing body, the cylinder chamber and the expansion chamber can be integrally formed in the casing body, thereby suppressing an increase in size of the compression device. Can do.

It is a side fragmentary sectional view of the vacuum pump concerning this embodiment. It is the figure which looked at the vacuum pump from the front side. FIG. 3 is a sectional view taken along line III-III in FIG. 2. It is side part sectional drawing of the vacuum pump concerning another embodiment. It is side part sectional drawing of the vacuum pump concerning another embodiment.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments according to the invention will be described with reference to the drawings.
FIG. 1 is a side partial sectional view of a vacuum pump (compressor) 1 according to an embodiment of the present invention. FIG. 2 is a view of the vacuum pump 1 of FIG. 1 as viewed from the front side (right side in the figure). However, FIG. 2 illustrates a state in which members such as the pump cover 24 and the side plate 26 are removed in order to show the configuration of the cylinder chamber S. Moreover, in FIG. 2, the state which removed the attachment member 40 is shown. In the following description, for convenience of explanation, it is assumed that the directions indicated by the arrows at the top of FIGS. The front-rear direction is also referred to as the axial direction, and the left-right direction is also referred to as the width direction.

  A vacuum pump 1 shown in FIG. 1 is a rotary vane type vacuum pump, and is used as a negative pressure source of a brake booster (not shown) such as an automobile. In this case, the vacuum pump 1 is usually disposed in the engine room and connected to the brake booster via a vacuum tank (not shown). In addition, the use range of the vacuum pump 1 used for a motor vehicle etc. is -60kPa--80kPa, for example.

As shown in FIG. 1, the vacuum pump 1 includes an electric motor 10 and a pump main body 20 disposed on the electric motor 10, and the electric motor 10 and the pump main body 20 are integrally connected, The mounting member 40 is fixedly supported on a vehicle body 50 such as an automobile.
The mounting member 40 includes a mounting plate 41 provided with a rectangular protruding groove 41A extending in the width direction of the pump main body 20, and anti-vibration rubbers 42 and 42 fixed to the front end and the rear end of the mounting plate 41, respectively. These anti-vibration rubbers 42 and 42 are fitted and held in holes formed in the vehicle body. The mounting plate 41 is fixed to the lower surface of the pump body 20 with a bolt 43 by a protruding groove 41A.

The electric motor 10 has an output shaft 12 that extends from the approximate center of one end (front end) of the case 11 formed in a substantially cylindrical shape toward the pump body 20 (front side). The output shaft 12 rotates with reference to a rotation center X1 extending in the front-rear direction. A spline portion 12 </ b> B is formed at the tip end portion 12 </ b> A of the output shaft 12 so as to be fitted to a rotor 27, which will be described later, of the pump main body 20 and to prevent the rotor 27 from rotating. It is also possible to provide a key on the outer surface of the output shaft 12 to prevent the rotor 27 from spinning freely.
In the electric motor 10, when the power source (not shown) is turned on, the output shaft 12 rotates in the direction indicated by the arrow R (counterclockwise) in FIG. 2, thereby causing the rotor 27 to rotate in the same direction around the rotation center X1 ( It is designed to rotate in the direction of arrow R).

The case 11 includes a case main body 60 formed in a bottomed cylindrical shape and a cover body 61 that closes the opening of the case main body 60. The case main body 60 is formed by bending the peripheral edge portion 60A outward. Yes. The cover body 61 includes a disc part 61A formed to have substantially the same diameter as the opening of the case body 60, a cylindrical part 61B that is connected to the periphery of the disc part 61A and fits on the inner peripheral surface of the case body 60, and The cylindrical portion 61B is integrally formed with a bent portion 61C formed by bending the periphery of the cylindrical portion 61B outward. The disc portion 61A and the cylindrical portion 61B enter the case main body 60, and the bent portion 61C is inserted into the case main body 60. The peripheral edge portion 60A is abutted and fixed. As a result, one end (front end) of the case 11 is recessed inward in the electric motor 10, and a fitting hole 63 into which the pump body 20 is fitted in is formed.
A through hole 61D through which the output shaft 12 passes and a recess 61E that holds the outer ring of the bearing 62 that pivotally supports the output shaft 12 are formed in the approximate center of the disc portion 61A.

  As shown in FIG. 1, the pump body 20 includes a casing body 22 that is fitted into a fitting hole 63 formed on the front side of the case 11 of the electric motor 10, and a cylinder chamber that is press-fitted into the casing body 22. The cylinder part 23 which forms S, and the pump cover 24 which covers the said casing main body 22 from the front side are provided. In this embodiment, the casing body 22, the cylinder portion 23, and the pump cover 24 are provided to constitute a casing 31 of the vacuum pump 1.

  As shown in FIG. 2, the casing main body 22 is made of a metal material having high thermal conductivity such as aluminum, and the shape viewed from the front side is a substantially rectangular shape that is long in the vertical direction with the rotation center X1 as the center. Is formed. A communication hole 22A communicating with the cylinder chamber S provided in the casing main body 22 is formed in the upper portion of the casing main body 22, and a vacuum suction nipple 30 is press-fitted into the communication hole 22A. As shown in FIG. 1, the vacuum suction nipple 30 is a pipe bent in an approximately L shape. One end 30A of the vacuum suction nipple 30 is connected to an external device (for example, a vacuum tank (not shown)). A tube or tube for supplying negative pressure air is connected. In this embodiment, since the vacuum suction nipple 30 is press-fitted into the communication hole 22A of the casing main body 22, when the position where the external device is arranged is known in advance like a vehicle, the external device is arranged. It is only necessary to press-fit with the one end 30A facing in the direction in which the pipe or tube for supplying negative pressure air can be freely set with a simple configuration.

The casing body 22 is formed with a hole 22B with reference to the axial center X2 extending in the front-rear direction, and a cylinder 23 formed in a cylindrical shape is press-fitted into the hole 22B. The shaft center X2 is parallel to the rotation center X1 of the output shaft 12 of the electric motor 10 described above and, as shown in FIG. In this configuration, the shaft center X2 is decentered so that an outer peripheral surface 27B of the rotor 27, which will be described later, centered on the rotation center X1 is in contact with the inner peripheral surface 23A of the cylinder portion 23 formed on the basis of the shaft center X2. Yes.
The cylinder part 23 is made of the same metal material as the rotor 27 (in this embodiment, iron). In this configuration, the cylinder portion 23 and the rotor 27 have the same thermal expansion coefficient. Therefore, regardless of the temperature changes of the cylinder portion 23 and the rotor 27, the outer peripheral surface 27B of the rotor 27 and the cylinder portion 23 when the rotor 27 rotates. The contact with the inner peripheral surface 23A can be prevented.
Moreover, since the cylinder part 23 can be accommodated within the longitudinal range of the casing body 22 by press-fitting the cylinder part 23 into the hole 22B formed in the casing body 22, the cylinder part 23 is Projection from the casing body 22 is prevented, and the casing body 22 can be downsized.
Further, the casing body 22 is formed of a material having higher thermal conductivity than the rotor 27. According to this, heat generated when the rotor 27 and the vane 28 are rotationally driven can be quickly transmitted to the casing body 22, so that the casing body 22 can sufficiently dissipate heat.

  An opening 23B that connects the communication hole 22A of the casing body 22 and the inside of the cylinder chamber S is formed in the cylinder portion 23, and the air that has passed through the vacuum suction nipple 30 passes through the communication hole 22A and the opening 23B. Supplied in. For this reason, in this embodiment, the suction path 32 is formed by including the vacuum suction nipple 30, the communication hole 22 </ b> A of the casing body 22, and the opening 23 </ b> B of the cylinder portion 23. Discharge ports 22 </ b> C and 23 </ b> C that pass through the casing body 22 and the cylinder part 23 and discharge air compressed in the cylinder chamber S are provided below the casing body 22 and the cylinder part 23.

  Side plates 25 and 26 are disposed at the rear end and the front end of the cylinder portion 23, respectively. The side plates 25 and 26 are set to have a diameter larger than the inner diameter of the inner peripheral surface 23A of the cylinder portion 23, and are urged by the gaskets 25A and 26A to press against the front end and the rear end of the cylinder portion 23, respectively. It has been. Thus, a sealed cylinder chamber S is formed inside the cylinder portion 23 except for the opening 23B and the discharge ports 23C and 22C connected to the vacuum suction nipple 30.

  A rotor 27 is disposed in the cylinder chamber S inside the cylinder portion 23. The rotor 27 is formed in a thick cylindrical shape, and the output shaft 12 on which the above-described spline portion 12B is formed is fitted to the inner peripheral surface 27A. With this spline fitting configuration, the rotor 27 rotates integrally with the output shaft 12. The length of the rotor 27 in the front-rear direction is set to be approximately equal to the length of the cylinder portion 23, that is, the distance between the inner surfaces of the two side plates 25 and 26 facing each other. Further, as shown in FIG. 2, the outer diameter of the rotor 27 is such that the outer peripheral surface 27B of the rotor 27 maintains a minute clearance with the portion of the inner peripheral surface 23A of the cylinder portion 23 that is located obliquely downward to the right. Is set. Thereby, as shown in FIG. 2, a crescent-shaped space is formed between the outer peripheral surface 27 </ b> B of the rotor 27 and the inner peripheral surface 23 </ b> A of the cylinder portion 23.

  The rotor 27 is provided with a plurality (five in this example) of vanes 28 that divide a crescent-shaped space. The vane 28 is formed in a plate shape, and its length in the front-rear direction is set to be approximately equal to the distance between the mutually facing inner surfaces of the two side plates 25, 26, similar to the rotor 27. ing. These vanes 28 are disposed so as to freely enter and exit from guide grooves 27 </ b> C provided in the rotor 27. As the rotor 27 rotates, each vane 28 protrudes outward along the guide groove 27 </ b> C by centrifugal force, and the tip of the vane 28 comes into contact with the inner peripheral surface 23 </ b> A of the cylinder portion 23. As a result, the crescent-shaped space described above is divided into five compression chambers P surrounded by the two vanes 28 and 28 adjacent to each other, the outer peripheral surface 27B of the rotor 27, and the inner peripheral surface 23A of the cylinder portion 23. Partitioned. These compression chambers P rotate in the same direction as the rotor 27 rotates in the direction of arrow R accompanying the rotation of the output shaft 12, and the volume of the compression chamber P increases near the opening 23B, and decreases at the discharge port 23C. That is, the air sucked into one compression chamber P from the opening 23B by the rotation of the rotor 27 and the vane 28 is compressed while being rotated with the rotation of the rotor 27, and is discharged from the discharge port 23C. In this configuration, the rotary compression element is configured by including the rotor 27 and the plurality of vanes 28.

In this configuration, as shown in FIG. 2, the cylinder portion 23 is formed in the casing body 22 such that the axial center X2 of the cylinder portion 23 is eccentrically inclined leftward and upward with respect to the rotation center X1. Therefore, a large space can be secured in the casing main body 22 in the direction opposite to the direction in which the cylinder portion 23 is eccentric. The expansion chamber 33 communicating with the discharge ports 23C and 22C and the cylinder portion 23 are provided in this space. A resonance chamber 34 aligned with the expansion chamber 33 is formed at the peripheral edge of each.
The expansion chamber 33 and the resonance chamber 34 are partitioned by a rib 35 formed integrally with the casing body 22, and the expansion chamber 33 and the resonance chamber (resonator) 34 are connected to the rib 35 as shown in FIG. An orifice 35A is formed.
The expansion chamber 33 is formed as a large closed space below the cylinder portion 23 and communicates with an exhaust port 24 </ b> A formed in the pump cover 24. The compressed air that has flowed into the expansion chamber 33 expands and disperses in the expansion chamber 33, collides with the partition walls of the expansion chamber 33, and is irregularly reflected. Thereby, since the sound energy of compressed air is attenuated, noise and vibration during exhaust can be reduced. In the present embodiment, the exhaust passage 37 is configured by including discharge ports 22C and 23C, an expansion chamber 33, and an exhaust port 24A formed in the casing body 22 and the cylinder part, respectively.

By the way, in the vane-type vacuum pump 1, since the rotor 27 and the vane 28 rotate in the cylinder chamber S to compress the air, the compressed air is supplied from the discharge ports 23C and 22C of the cylinder chamber S to the expansion chamber 33. Are intermittently discharged. For this reason, in the discharge ports 23C and 22C of the cylinder chamber S, noise and vibration may be generated due to the pressure pulsation caused by the constant pulsation.
Therefore, in the present embodiment, the expansion chamber 33 is connected to the Helmholtz resonance chamber 34 branched from the exhaust passage 37. The resonance chamber 34 is formed so as to generate resonance that cancels the pressure pulsation of the compressed air flowing through the exhaust passage 37, and suppresses noise and vibration due to the pressure pulsation.
The resonance chamber 34 is designed to generate a resonance frequency that matches the fundamental frequency of the air pressure pulsation described above. Specifically, this resonance frequency is the orifice 35 A for connecting to the expansion chamber 33. The length and area of the resonance chamber 34 and the volume of the resonance chamber 34 are determined.
According to this configuration, by connecting the resonance chamber 34 to the expansion chamber 33 via the orifice 35A, the sound energy of the air expanded in the expansion chamber 33 is vibrated by the orifice 35A and the air spring in the resonance chamber 34. Since it is attenuated, the pressure pulsation of the air discharged by the rotation of the rotor 27 and the vane 28 can be reduced, and noise and vibration during exhaust can be further reduced.
Furthermore, in the present embodiment, by arranging the cylinder portion 23 eccentrically from the rotation center X1 of the rotor 27, a large space can be secured in the casing body 22 at the peripheral portion on the rotation center X1 side of the cylinder portion 23. it can. For this reason, since the expansion chamber 33 and the resonance chamber 34 can be integrally formed in the casing body 22 by arranging the expansion chamber 33 and the resonance chamber 34 in this space, the expansion chamber 33 and the resonance chamber 34 are integrally formed. Is not required to be provided outside the casing main body 22, and the casing main body 22 can be downsized, and the vacuum pump 1 can be downsized.

In addition, the casing body 22 has an intake side expansion chamber 38 formed at the peripheral edge of the cylinder portion 23 on the side where the cylinder portion 23 is eccentric. The intake side expansion chamber 38 is provided in the intake passage 32 that connects the vacuum suction nipple 30 and the cylinder chamber S described above. In the present embodiment, the ribs 36 and 39 provided integrally with the casing body 22 The expansion chamber 33 and the resonance chamber 34 are separated from each other.
According to this configuration, the air flowing in the intake passage 32 expands and disperses in the intake side expansion chamber 38 and is attenuated by colliding with the partition wall of the intake side expansion chamber 38 and being diffusely reflected. The noise and vibration during intake can be reduced.
Further, in the intake side expansion chamber 38, for example, a desiccant 65 such as silica gel or zeolite is disposed. The desiccant 65 is formed by fixing silica gel or zeolite particles so as not to pass through the discharge ports 23C and 22C, and removes moisture in the air flowing into the intake side expansion chamber 38. For this reason, since the air from which moisture has been removed by the desiccant 65 flows into the cylinder chamber S, dew condensation in the cylinder chamber S is prevented, and corrosion of the rotor 27 and the cylinder part 23 due to this dew condensation, Freezing in the cylinder chamber S can be prevented.

Further, since the suction side expansion chamber 38 is formed at the peripheral edge of the cylinder chamber S, the vacuum suction nipple 30 and the cylinder chamber S are communicated with each other through the suction side expansion chamber 38. For this reason, as long as the suction side expansion chamber 38 extends, the vacuum suction nipple 30 can be provided at an arbitrary place, and the vacuum suction nipple 30 can be provided according to the position where the vacuum pump 1 is installed in the vehicle. The mounting position can be changed.
In the present embodiment, the casing body 22 is formed with the expansion chamber 33, the resonance chamber 34, and the intake side expansion chamber 38 at the periphery of the cylinder portion 23. The expansion chamber 38 can be arranged in the casing body 22 in a well-organized manner. For this reason, it is not necessary to provide the intake side expansion chamber 38 outside the casing body 22, the casing body 22 can be downsized, and the vacuum pump 1 can be downsized.
In the present embodiment, the expansion chamber 33, the resonance chamber 34, and the intake side expansion chamber 38 are arranged on the peripheral edge of the cylinder portion 23, and the expansion chamber 33, the resonance chamber 34, and the intake side expansion chamber 38 are respectively connected to the ribs 35. 36, 39, the size of each expansion chamber 33, resonance chamber 34 and intake side expansion chamber 38 can be changed by changing the positions of these ribs 35, 36, 39. For example, after the size of the resonance chamber 34 is determined, the sizes of the expansion chamber 33 and the intake side expansion chamber 38 can be appropriately set.

  The pump cover 24 is disposed on the front side plate 26 via a gasket 26 </ b> A, and is fixed to the casing body 22 with bolts 66. As shown in FIG. 2, a seal groove 22D is formed on the front surface of the casing body 22 so as to surround the cylinder portion 23 and the expansion chamber 33, and an annular seal material 67 is disposed in the seal groove 22D. The pump cover 24 is provided with an exhaust port 24 </ b> A at a position corresponding to the expansion chamber 33. This exhaust port 24A is for exhausting the air that has flowed into the expansion chamber 33 to the outside of the machine (outside the vacuum pump 1), and this exhaust port 24A prevents the backflow of air from outside the machine into the pump. A check valve 29 is attached.

  As described above, according to the present embodiment, the casing 31 includes the casing body 22 in which the cylinder chamber S in which the rotor 27 and the vane 28 slide is formed, and the exhaust gas that connects the cylinder chamber S and the exhaust port 24A. Since the passage 37 and the expansion chamber 33 formed in the exhaust passage 37 are provided, and the expansion chamber 33 is provided at the peripheral edge of the cylinder chamber S in the casing body 22, the compressed air flowing through the exhaust passage 37 is expanded into the expansion chamber 33. It is possible to reduce noise and vibration when exhausting from the exhaust port 24 </ b> A to the outside of the apparatus by being attenuated by being diffused and dispersed in the interior and colliding with the partition wall of the expansion chamber 33 and being diffusely reflected. Further, since the expansion chamber 33 is provided at the peripheral edge of the cylinder chamber S in the casing body 22, the cylinder chamber S and the expansion chamber 33 can be integrally formed in the casing body 22, and the vacuum pump 1. Increase in size can be suppressed.

According to the present embodiment, since the Helmholtz resonance chamber 34 branched from the exhaust path 37 is connected to the expansion chamber 33 via the orifice 35A, the sound energy of the air expanded in the expansion chamber 33 is obtained. Is oscillated and attenuated by the air spring in the orifice 35A and the resonance chamber 34, the pressure pulsation of the air discharged from the cylinder chamber S can be reduced, and noise and vibration during exhaust are further reduced. be able to.
Furthermore, according to the present embodiment, the cylinder chamber S is provided at a position eccentric from the rotation center X1 of the rotor 27 and the vane 28 in the casing main body 22, and therefore the casing main body has a peripheral portion on the rotation center side of the cylinder chamber. A large space can be secured. For this reason, by arranging the expansion chamber and the resonance chamber in this space in parallel, it is not necessary to provide the expansion chamber and the resonance chamber outside the casing main body, and the casing main body can be downsized. Miniaturization can be achieved.

  Further, according to the present embodiment, since the intake passage 32 that guides air to the cylinder chamber S is provided, and the intake side expansion chamber 38 that expands the air flowing through the intake passage 32 is provided in the intake passage 32, the cylinder chamber S is provided. Since the air sucked into the air is attenuated by being expanded and dispersed in the intake side expansion chamber 38, noise and vibration not only during exhaust but also during intake can be reduced.

  Further, according to the present embodiment, the intake side expansion chamber 38 is formed alongside the expansion chamber 33 at the peripheral portion of the cylinder chamber S in the casing body 22, so that the expansion chamber 33 is formed at the peripheral portion of the cylinder chamber S. And the intake side expansion chamber 38, the cylinder chamber S, the expansion chamber 33, and the intake side expansion chamber 38 can be integrally formed in the casing main body 22, and an increase in size of the vacuum pump 1 can be suppressed. it can.

  Further, according to the present embodiment, since the desiccant 65 is accommodated in the intake side expansion chamber 38, moisture in the air flowing into the cylinder chamber S through the intake passage 32 can be removed, so that dried air is supplied to the cylinder chamber S. In addition, condensation in the cylinder chamber S, the rotor 27, and the vane 28 can be prevented. Therefore, corrosion and freezing of the rotor 27 can be prevented, and the life of the vacuum pump 1 can be extended.

Next, another embodiment will be described.
FIG. 4 is a side partial cross-sectional view of a vacuum pump 100 according to another embodiment.
In this other embodiment, the configuration differs from that described above in that the inside of the case 11 of the electric motor 10 is formed as a resonance chamber. About the same structure as the said structure, the same code | symbol is attached | subjected and description is abbreviate | omitted.
As shown in FIG. 4, the vacuum pump 100 includes a first orifice 33A provided in an expansion chamber 33 formed in the casing body 22, and a first orifice 33A formed in the cover body 61 of the case 11 and connected to the first orifice 33A. The expansion chamber 33 and the inside of the case 11 are connected through the first orifice 33 </ b> A and the second orifice 64. In this other embodiment, the space 11A in the case 11 functions as a Helmholtz resonance chamber.
In this other embodiment, for example, it is useful when the outer diameter of the pump body 20 is small and a resonance chamber cannot be formed in the peripheral portion of the cylinder portion 23, and the Helmholtz branched from the exhaust passage 37 to the expansion chamber 33. Since the case 11 as a resonance chamber of the type is connected via the first orifice 33A and the second orifice 64, the sound energy of the air expanded in the expansion chamber 33 is changed between the first orifice 33A and the second orifice 64 and the case. 11 is vibrated and attenuated by the air spring in the cylinder 11, so that pressure pulsation of air discharged from the cylinder chamber S can be reduced, and noise and vibration during exhaust can be further reduced.

FIG. 5 is a side partial cross-sectional view of a vacuum pump 200 according to another embodiment.
In this other embodiment, the configuration is different from that described above in that the inside of the case 11 of the electric motor 10 is formed as an intake side expansion chamber. About the same structure as the said structure, the same code | symbol is attached | subjected and description is abbreviate | omitted.
In this configuration, in the vacuum pump 200, the case body 60 constituting the case 11 of the electric motor 10 is formed with an intake port 60A1, and the above-described vacuum suction nipple 130 is connected to the intake port 60A1. The casing body 22 includes a first communication hole 71 extending in the axial direction, and a second communication hole 72 that communicates the first communication hole 71 and the opening 23 </ b> B of the cylinder portion 23. A communication hole 68 communicating with the first communication hole 71 is formed. Thus, the space 11A in the case 11 communicates with the cylinder chamber S through the communication hole 68, the first communication hole 71, the second communication hole 72, and the opening 23B, and includes these to form the intake path 132.
For this reason, in this other embodiment, since the space 11A in the case 11 is provided in the intake passage 132, the air sucked into the cylinder chamber S is attenuated by being expanded and dispersed in the space 11A. In addition, noise and vibration during intake can be reduced. Further, when the air flow that flows into the space in the case 11 through the vacuum suction nipple 130 cools a coil, a commutator, and the like (not shown) accommodated in the case 11, the air flow is arranged in a poor environment such as an engine room. However, a separate cooling device is not necessary, and the number of parts can be reduced.

Although the best embodiment for carrying out the present invention has been described above, the present invention is not limited to the above-described embodiment, and various modifications and changes can be made based on the technical idea of the present invention. It is. For example, in this embodiment, a vane-type vacuum pump is used as the compression device, but a scroll-type vacuum pump may be used as long as it includes a rotary compression element.
In the above-described embodiment, the exhaust chamber 33 is combined with the resonance chamber 34 (or the space 11A in the case 11). However, the resonance chamber is referred to as the intake expansion chamber 38 (or It may be combined with the space 11A) in the case 11.
4 may be combined with the vacuum pump 1 according to FIG. That is, not only the expansion chamber 33 and the resonance chamber 34 are provided in the peripheral portion of the cylinder portion 23 of the casing body 22, but also the expansion chamber 33 and the case 11 of the electric motor 10 are communicated with each other through the first orifice 33 A and the second orifice 64. The case 11 may be formed as a resonance chamber different from the resonance chamber 34. According to this configuration, it is possible to cope with pressure pulsations of different fundamental frequencies by appropriately changing the cross-sectional areas and lengths of the first orifice 33A and the second orifice 64 and the volume in the case 11.

1, 100, 200 Vacuum pump (compressor)
11 Case 11A Space (resonance chamber, intake side expansion chamber)
20 Pump body 22 Casing body 23 Cylinder part 24 Pump cover 24A Exhaust port 27 Rotor (rotary compression element)
28 Vane (Rotary compression element)
30, 130 Vacuum suction nipples 32, 132 Intake passage 33 Expansion chamber 33A First orifice 34 Resonance chamber 35A Orifice 37 Exhaust passage 38 Intake side expansion chamber 60 Case body 61 Cover body 64 Second orifice 65 Desiccant 68 Communication hole 71 First Communication hole 72 Second communication hole S Cylinder chamber X1 Center of rotation X2 Axis center

Claims (6)

In a compression device with a rotary compression element in the casing,
The casing includes a casing body in which a cylinder chamber in which the rotary compression element slides is formed, an exhaust path connecting the cylinder chamber and an exhaust port, and an expansion chamber formed in the exhaust path. A compression apparatus characterized in that a chamber is provided at a peripheral edge of the cylinder chamber in the casing body.   The compression apparatus according to claim 1, wherein a Helmholtz resonance chamber branched from the exhaust path is connected to the expansion chamber.   The cylinder chamber is provided in a position deviated from the rotation center of the rotary compression element in the casing body, and the expansion chamber and the resonance chamber are arranged in parallel at a peripheral portion on the rotation center side of the cylinder chamber. The compression apparatus according to claim 2.   The compression according to any one of claims 1 to 3, further comprising an intake passage for introducing air into the cylinder chamber, and an intake side expansion chamber for expanding the air flowing through the intake passage. apparatus.   The compression device according to claim 4, wherein the intake side expansion chamber is formed alongside the expansion chamber at a peripheral portion of the cylinder chamber in the casing body.   The compression apparatus according to claim 4 or 5, wherein a desiccant is accommodated in the intake side expansion chamber.

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