JP5554122B2 - Vacuum pump - Google Patents

Description

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

  In general, a vacuum pump having a rotary compression element in a casing is known. 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 kind of vacuum pump, since the casing temperature rises by driving the rotary compression element and compressing air in the casing, it is desirable to cool (heat radiation) the casing. In this case, in order to secure a large heat radiation area, a configuration in which a mounting base is attached to the electric pump and a cylinder body is stacked on the mounting base to form a casing is conceivable. In this configuration, the casing is the shaft of the electric motor. There is a problem that the vacuum pump is enlarged in the direction.
The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a vacuum pump in which the casing is downsized while ensuring heat dissipation.

In order to achieve the above object, the present invention provides a vacuum pump having a rotary compression element in a casing, wherein the casing includes a casing body and a cylinder portion that is disposed in the casing body and on which the rotary compression element slides. The casing main body and the cylinder part each include a communication hole that passes through the casing main body and the cylinder part and communicates with the cylinder part, and a suction pipe is provided in the communication hole, and a tip of the suction pipe is provided. It is engaged with the communicating hole of the cylinder part .

According to this configuration, the casing main body and the cylinder part each include a communication hole that penetrates the casing main body and the cylinder part and communicates with the cylinder part, and the suction pipe is provided in the communication hole. Since the tip is engaged with the communication hole of the cylinder part, for example, when a material having a higher thermal expansion coefficient than the cylinder part is used for the casing body, even if the press-fitting allowance of the cylinder part decreases due to thermal expansion, Since the tip of the tube engages with the communication hole of the cylinder part, it is possible to prevent rotation and prevention of the cylinder part from being rotated.

In this configuration, the casing may include a casing body formed of a material having higher thermal conductivity than the rotary compression element, and a cylinder portion that is press-fitted into the casing body . According to this configuration, since the casing is configured by press-fitting the cylinder portion into the casing body , the casing can be reduced in size. In addition, since the casing body is made of a material having higher thermal conductivity than the rotary compression element, the heat generated when the rotary compression element is activated can be quickly transferred to the casing body, so that the casing body can sufficiently dissipate heat. can do.

  The cylinder portion may be formed of a material having a thermal expansion coefficient substantially equal to that of the rotary compression element. According to this configuration, it is possible to suppress a change in the clearance between the rotary compression element and the cylinder portion due to a temperature change, and it is possible to prevent contact between the outer peripheral surface of the rotary compression element and the inner peripheral surface of the cylinder portion.

  In the casing body, the cylinder portion is disposed at a position eccentric from the rotation center of the rotary compression element, and an expansion chamber communicating with the cylinder portion is formed at a peripheral portion on the rotation center side of the cylinder portion. May be. According to this configuration, there is no need to provide an expansion chamber outside the casing body, and the casing body can be downsized, and the vacuum pump can be downsized.

  According to the present invention, since the casing is configured by press-fitting the cylinder portion into the casing body, the casing can be downsized. In addition, since the casing body is made of a material having higher thermal conductivity than the rotary compression element, the heat generated when the rotary compression element is activated can be quickly transferred to the casing body, so that the casing body can sufficiently dissipate heat. 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. It is a perspective view which shows the back side of a casing main body. A is a figure which shows the connection structure of an electric motor and a pump main body, B is a modification of the connection structure.

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 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 of arrow R in FIG. 2 (counterclockwise), thereby rotating the rotor 27 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 body 22 is formed in the upper portion of the casing body 22, and a vacuum suction nipple (suction pipe) 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. It is possible to prevent contact with the inner peripheral surface 23A. Further, since the cylinder portion 23 and the rotor 27 have the same thermal expansion coefficient, the clearance between the side surface of the rotor 27 and side plates 25 and 26 (described later) disposed at the rear end and the front end of the cylinder portion 23 is stabilized. be able to.
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.

In general, since aluminum has a larger coefficient of thermal expansion than iron, when the pump body 20 becomes hot, the press-fitting allowance of the cylinder portion 23 tends to decrease. For this reason, in this structure, the cylinder part 23 is formed with an opening (communication hole) 23B connected to the communication hole 22A of the casing body 22, and the other end (tip) 30B of the vacuum suction nipple 30 is formed in the opening 23B. Are arranged to engage. According to this, even if the press-fitting allowance of the cylinder part 23 is reduced due to thermal expansion, the other end 30B of the vacuum suction nipple 30 is engaged with the opening 23B of the cylinder part 23. Prevention can be realized.
In addition, discharge holes 22C and 23C that pass through the casing body 22 and the cylinder part 23 and discharge air compressed in the cylinder chamber S are provided in the lower part of 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. For this reason, the casing body 22 is formed with an expansion chamber 33 communicating with the discharge ports 23C and 22C in the direction opposite to the direction in which the cylinder portion 23 is eccentric. The expansion chamber 33 is formed in a crescent shape along the outer peripheral surface of the cylinder portion 23, and portions near the discharge ports 23 </ b> C and 22 </ b> C further bulge downward, and an exhaust port 24 </ b> A formed in the pump cover 24. Communicating with In this configuration, since the cylinder portion 23 is eccentrically formed in the casing body 22 with respect to the rotation center X1, the expansion chamber 33 communicating with the discharge ports 23C and 22C is formed in the casing body 22. Can do. For this reason, it is not necessary to provide the expansion chamber 33 outside the casing body 22, the casing body 22 can be downsized, and the vacuum pump 1 can be downsized. Further, the air discharged from the discharge ports 23C and 22 is introduced into the expansion chamber 33 and expands, whereby noise is reduced.

  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 34. 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 35 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 the outside of the machine into the pump. A check valve 29 is attached.

FIG. 3 is a perspective view of the casing body 22 as seen from the back.
As described above, the vacuum pump 1 is configured by connecting the electric motor 10 and the pump main body 20, and the rotor 27 and the vane 28 connected to the output shaft 12 of the electric motor 10 are the cylinder portion of the pump main body 20. 23 slides in. For this reason, it is important to assemble the pump body 20 in accordance with the rotation center X1 of the output shaft 12 of the electric motor 10.
For this reason, in the present embodiment, as described above, the electric motor 10 has the fitting hole 63 formed around the rotation center X1 of the output shaft 12 on one end side of the case 11. On the other hand, as shown in FIG. 3, a cylindrical fitting portion 22 </ b> F that protrudes rearward around the cylinder chamber S is integrally formed on the back surface of the casing body 22. The fitting portion 22 </ b> F is formed concentrically with the rotation center X <b> 1 of the output shaft 12 of the electric motor 10, and has an outer diameter that fits in the fitting hole portion 63 of the electric motor 10.
For this reason, in this configuration, the center position can be easily adjusted by simply fitting the fitting portion 22F of the casing main body 22 into the fitting hole portion 63 of the electric motor 10, so that the electric motor 10 and the pump main body 20 Can be easily assembled. In addition, a seal groove 22E is formed around the fitting portion 22F on the back surface of the casing body 22, and an annular seal material 36 is disposed in the seal groove 22E.

In this configuration, since the electric motor 10 and the pump main body 20 can be temporarily fixed by fitting them together, the casing main body 22 and the case 11 of the electric motor 10 are combined with a bolt 34 for fixing the pump cover 24. Can be fixed.
Specifically, as shown in FIG. 4A, a female screw portion 60A1 is provided on the peripheral edge portion 60A of the case main body 60, and the bolt 34 is screwed to the female screw portion 60A1, whereby the pump cover 24, The casing body 22 and the case 11 of the electric motor 10 are fixed together. In this case, the pump cover 24, the casing body 22, and the case 11 of the electric motor 10 can be firmly fixed by forming the female screw portion 60 </ b> A <b> 1 to be thicker than the peripheral thickness 60 </ b> A.
Further, as shown in FIG. 4B, the female screw portion 60A1 may be formed so as to protrude toward the casing body 22, and the female screw portion 60A1 may be accommodated in the hole 60C1 formed in the bent portion 61C of the cover body 61. . According to this configuration, the female thread portion 60A1 does not protrude from the surface of the vacuum pump 1 and is exposed, so that the design can be improved.

  As described above, according to the present embodiment, in the vacuum pump 1 including the rotor 27 and the vane 28 in the casing, the casing is formed of a material having higher thermal conductivity than the rotor 27 and the vane 28. Since the casing main body 22 and the cylinder portion 23 that is press-fitted into the casing main body 22 and the rotor 27 and the vane 28 slide are provided, the cylinder portion 23 is press-fitted into the casing main body 22 to constitute the casing 31. The casing 31 can be downsized. Further, since the casing body 22 is also formed of a material having high thermal conductivity for the rotor 27 and the vane 28, the heat generated when the rotor 27 and the vane 28 are driven can be quickly transmitted to the casing body 22, thereby the casing. Heat can be sufficiently radiated from the main body 22.

  Further, according to the present embodiment, the casing main body 22 and the cylinder part 23 include the communication hole 22A and the opening 23B that penetrate the casing main body 22 and the cylinder part 23 and communicate with the cylinder part 23, respectively. Since the vacuum suction nipple 30 is press-fitted into 22A and the other end 30B of the vacuum suction nipple 30 is engaged with the opening 23B of the cylinder portion 23, for example, the casing main body 22 has aluminum with a high thermal expansion coefficient, the cylinder portion 23 has When iron having a low thermal expansion coefficient is used, even if the press-fitting allowance of the cylinder portion 23 is reduced due to thermal expansion, the other end 30B of the vacuum suction nipple 30 is engaged with the opening 23B of the cylinder portion 23. It is possible to prevent the portion 23 from rotating and coming off.

  Further, according to the present embodiment, since the cylinder portion 23 is formed of a material having a thermal expansion coefficient substantially equal to that of the rotor 27, the clearance between the side surface of the rotor 27 and the side plates 25 and 26 due to temperature change. And the contact between the inner peripheral surface 23A of the cylinder part 23 and the outer peripheral surface 27 of the rotor 27 can be prevented.

  In addition, according to the present embodiment, the cylinder body 23 is arranged in the casing body 22 at a position eccentric from the rotation center X1 of the rotor 27, and the cylinder section 23 is arranged at the peripheral edge of the cylinder section 23 on the rotation center X1 side. Since the expansion chamber 33 communicating with the expansion chamber 33 is formed, it is not necessary to provide the expansion chamber 33 outside the casing body 22, so that the casing body 22 can be downsized and the vacuum pump 1 can be downsized. Can do.

  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 the present embodiment, a vane type vacuum pump is used as the vacuum pump 1, but a scroll type may be used as long as it includes a rotary compression element.

DESCRIPTION OF SYMBOLS 1 Vacuum pump 10 Electric motor 20 Pump main body 22 Casing main body 22A Communication hole 22B Hole part 22C Discharge hole 22F Fitting part 23 Cylinder part 23B Opening (communication hole)
23C Discharge port 24 Pump cover 27 Rotor (rotary compression element)
28 Vane (Rotary compression element)
30 Vacuum suction nipple (suction pipe)
30B The other end (tip)
31 Casing 33 Expansion chamber 63 Fitting hole 60A1 60C1 Hole P Compression chamber S Cylinder chamber X1 Center of rotation X2 Axis center

Claims (4)

In a vacuum pump with a rotary compression element in the casing,
The casing includes a casing body and a cylinder portion that is disposed in the casing body and on which the rotary compression element slides, and the casing body and the cylinder portion pass through the casing body and the cylinder portion, respectively, and A vacuum pump comprising a communication hole communicating with a cylinder part, a suction pipe provided in the communication hole, and a tip of the suction pipe engaged with the communication hole of the cylinder part . 2. The vacuum pump according to claim 1, wherein the casing includes a casing main body formed of a material having higher thermal conductivity than the rotary compression element, and a cylinder portion press-fitted into the casing main body. .   The vacuum pump according to claim 1 or 2, wherein the cylinder part is formed of a material having a thermal expansion coefficient substantially equal to that of the rotary compression element.   In the casing body, the cylinder portion is arranged at a position eccentric from the rotation center of the rotary compression element, and an expansion chamber communicating with the cylinder portion is formed at a peripheral portion of the cylinder portion on the rotation center side. The vacuum pump according to any one of claims 1 to 3.

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