WO2013137053A1

WO2013137053A1 - Vacuum pump

Info

Publication number: WO2013137053A1
Application number: PCT/JP2013/055929
Authority: WO
Inventors: 田中　克典
Original assignee: ナブテスコオートモーティブ株式会社
Priority date: 2012-03-13
Filing date: 2013-03-05
Publication date: 2013-09-19
Also published as: JP2013189912A

Abstract

The present invention prevents a decline in the durability of a vacuum pump by suppressing damage to a rotor and a side plate by using a simple configuration. A vacuum pump is provided with a casing body (22) attached to an electric motor (10), and a hollow cylinder chamber (S) formed in the casing body (22) and having openings on both ends of the casing body (22). The output shaft (12) of the electric motor (10) is provided with a rotor (27) that is rotatably driven inside the cylinder chamber (S) along with the output shaft (12), and a pair of side plates (25, 26) for blocking the openings of the cylinder chamber (S). The tip part (12A) of the output shaft (12) is provided with a male screw (12B). A female screw (27D) formed in a shaft hole (27A) of the rotor (27) engages with the male screw (12B). The male screw (12B) is provided with a nut (70) for fixing the rotor (27) by tightly abutting the front-end surface (27G) of the rotor (27).

Description

Vacuum pump

The present invention relates to a vacuum pump having a rotor attached to a rotating shaft of a driving machine.

In general, a casing main body attached to a driving machine, a hollow cylinder chamber formed in the casing main body and having openings at both ends of the casing main body, and provided on a rotating shaft of the driving machine to be rotationally driven in the cylinder chamber. There is known a vacuum pump including a rotor and a pair of side plates that close an opening of a cylinder chamber. This type of vacuum pump is used, for example, to generate a vacuum for operating a brake booster of an automobile, and obtains a vacuum by driving a rotor with a drive unit such as an electric motor in a cylinder chamber of a casing. (For example, refer to Patent Document 1).

US Pat. No. 6,491,501

By the way, in a small vacuum pump that operates a brake booster of an automobile, a small and lightweight rotor is used. Therefore, the rotor is not fixed to the rotating shaft, and the axial direction of the rotating shaft is not fixed. It was movably provided. Furthermore, since the rotor is provided at the tip of the rotating shaft, when the rotor is rotated by driving a drive machine, the rotor is likely to move to the tip of the rotating shaft as it rotates and protrude. . For this reason, during operation of the vacuum pump, the rotor comes into contact with the side plate on the front side (the tip side of the rotating shaft), so that the rotor and the side plate are damaged by wear and the durability of the vacuum pump is reduced. Was assumed.
The present invention has been made in view of the above-described circumstances, and an object of the present invention is to prevent damage to the rotor and the side plate with a simple configuration and prevent deterioration of the durability of the vacuum pump.

In order to achieve the above object, the present invention provides a casing body attached to a driving machine, a hollow cylinder chamber formed in the casing body and having openings at both ends of the casing body, and a rotating shaft of the driving machine. In a vacuum pump comprising a rotor that is provided to be rotated and driven in the cylinder chamber, and a pair of side plates that close the opening of the cylinder chamber, the rotating shaft includes a male screw at a distal end portion. A female screw formed in the shaft hole of the rotor is engaged, and a nut that fixes the rotor in close contact with the front end surface of the rotor is provided.

According to this configuration, since the rotor and the nut are provided on the male screw of the rotating shaft, the movement of the rotor in the radial direction and the thrust direction of the rotating shaft is restricted by the effect of a so-called double nut. For this reason, the contact between the rotor and the side plate is prevented with a simple configuration, whereby wear of the rotor and the side plate is suppressed, and the durability of the vacuum pump can be improved.

In this configuration, according to the present invention, the rotor is fastened to the male screw of the rotating shaft until it abuts on the side plate located on the drive machine side, and in this state, the nut is moved until a predetermined reference value is exceeded. The rotor is fixed to the rotating shaft in close contact with the front end surface. According to this configuration, the rotor can be easily positioned with respect to the rotating shaft, and the assembly work of the pump can be performed in a short time without being an expert.

Further, the present invention is characterized in that a concave portion is formed around the shaft hole in the front end surface of the rotor, and the nut is engaged with the male screw of the rotating shaft in the concave portion. According to this configuration, the nut can be engaged with the rotation shaft without projecting the tip end portion of the rotation shaft from the front end surface of the rotor, and the configuration of the vacuum pump can be simplified.

According to the present invention, the rotating shaft includes a male screw at a tip, and a female screw formed in the shaft hole of the rotor is engaged with the male screw, and the rotating shaft is in close contact with the front end surface of the rotor. Since the nut for fixing the rotor is provided, the rotor is restricted from moving in the radial direction and the thrust direction of the rotating shaft. Therefore, the contact between the rotor and the side plate is prevented with a simple configuration, so that wear of the rotor and the side plate is suppressed, and the durability of the vacuum pump can be improved.

It is a schematic diagram of a brake device using the vacuum pump concerning this embodiment. It is side part fragmentary sectional drawing of a vacuum pump. It is the figure which looked at the vacuum pump from the front side. It is a disassembled side view which shows the connection structure of a rotor and an output shaft.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram of a brake device 100 using a vacuum pump 1 according to an embodiment of the present invention as a negative pressure source. The brake device 100 includes, for example, front brakes 2a and 2b attached to left and right front wheels of a vehicle such as an automobile, and rear brakes 3a and 3b attached to left and right rear wheels. These brakes are connected to each other by a master cylinder 4 and a brake pipe 9, and each brake is operated by hydraulic pressure sent from the master cylinder 4 through the brake pipe 9.
The brake device 100 includes a brake booster (brake booster) 6 connected to the brake pedal 5, and the vacuum tank 7 and the vacuum pump 1 are connected in series to the brake booster 6 through an air pipe 8. It is connected. The brake booster 6 uses the negative pressure in the vacuum tank 7 to boost the pedaling force of the brake pedal 5, and it is sufficient to move the piston (not shown) of the master cylinder 4 with a small pedaling force. The brake force can be pulled out.
The vacuum pump 1 is disposed in the engine room of the vehicle, discharges the air in the vacuum tank 7 to the outside of the vehicle, and puts the vacuum tank 7 in a vacuum state. Note that the range of use of the vacuum pump 1 used in an automobile or the like is, for example, −60 kPa to −80 kPa.

2 is a side partial sectional view of the vacuum pump 1, and FIG. 3 is a view of the vacuum pump 1 of FIG. 2 as viewed from the front side (right side in the figure). However, FIG. 3 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. 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.

As shown in FIG. 2, the vacuum pump 1 includes an electric motor (driving machine) 10 and a pump main body 20 that operates using the electric motor 10 as a driving source. The electric motor 10 and the pump main body 20 are integrated with each other. In a connected state, it is fixedly supported on a vehicle body such as an automobile.

The electric motor 10 has an output shaft (rotary 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 side (front side). The output shaft 12 functions as a drive shaft that drives the pump main body 20, and rotates with reference to a rotation center X1 extending in the front-rear direction. A rotor 27 of the pump body 20 is connected to the tip end portion 12A of the output shaft 12 so as to be integrally rotatable.
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. 3, 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 of the opening outward. ing. The cover body 61 has a disc portion (wall surface) 61A formed to have substantially the same diameter as the opening of the case body 60, and extends in an axial direction from the periphery of the disc portion 61A. And a bent portion 61C formed by bending the outer periphery of the cylindrical portion 61B outward. The disc part 61 A and the cylindrical part 61 B enter the case body 60, and the bent part 61 C is fixed in contact with the peripheral part 60 A of the case body 60. Thereby, one end part (front end) of the case 11 is recessed inward in the electric motor 10, and the fitting hole part 63 to which the pump main body 20 is attached by spigot fitting is formed.
Further, a through hole 61D through which the output shaft 12 passes and an annular bearing holding portion 61E extending inward of the case main body 60 are formed around the through hole 61D at the approximate center of the disc part 61A. The outer ring of the bearing 62 that supports the output shaft 12 is held on the inner peripheral surface 61F of the bearing holding portion 61E.

As shown in FIG. 2, the pump main body 20 is integrally cast in the casing main body 22 and the casing main body 22 fitted in the fitting hole 63 formed on the front side of the case 11 of the electric motor 10. The cylinder portion 23 that forms the cylinder chamber S and the pump cover 24 that covers the casing 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. 3, the casing body 22 is made of, for example, a metal material having high thermal conductivity such as aluminum, and the shape seen 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. 2, the vacuum suction nipple 30 is a straight pipe extending upward, and a negative pressure is applied to one end 30A of the vacuum suction nipple 30 from an external device (for example, the vacuum tank 7 (see FIG. 1)). A tube or tube for supplying air is connected.

The casing body 22 is formed with a hole 22B with respect to the axial center X2 extending in the front-rear direction, and a cylindrical cylinder 23 is integrally cast into the hole 22B. Specifically, in a state where the cylinder part (cylinder liner) 23 is set in a mold, a casing body 22 (casing 31) in which the cylinder part 23 is integrally cast is cast by pouring water into the mold. The In the present embodiment, the cylinder portion 23 is integrally cast into the casing main body 22. However, the present invention is not limited to this, and the cylinder portion 23 is press-fitted into the hole 22 B of the cylinder main body 22 that has been cast in advance. It is also good.
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 eccentric so that the outer peripheral surface 27B of the rotor 27 centered on the rotation center X1 is in contact with the inner peripheral surface 23A of the cylinder portion 23 formed with reference to the shaft center X2.

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. The cylinder part 23 and the rotor 27 may be made of different materials as long as they are metal materials having substantially the same thermal expansion coefficient.
Moreover, since the cylinder part 23 can be accommodated within the longitudinal range of the casing body 22 by casting the cylinder part 23 integrally in the hole 22B formed in the casing body 22, the cylinder part 23 is prevented from protruding from the casing main body 22, and the casing main 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 A of the casing body 22, and the opening 23 B of the cylinder portion 23. Discharge ports 22 C and 23 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.

The

side plates

25 and 26 for closing the opening of the cylinder chamber S are disposed at the rear end and the front end of the cylinder part 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 seal rings 25A and 26A, respectively. It is pressed. 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.

The rotor 27 is disposed in the cylinder chamber S. The rotor 27 has a columnar shape extending along the rotation center X1 of the electric motor 10, and has a shaft hole 27A through which the output shaft 12 that is a drive shaft of the pump body 20 is inserted, and radial direction from the shaft hole 27A. A plurality of guide grooves 27C are provided at equidistant intervals around the shaft hole 27A at intervals in the circumferential direction.

The length of the rotor 27 in the front-rear direction is set to be approximately equal to the length of the cylinder chamber S of the cylinder portion 23, that is, the distance between the mutually facing inner surfaces of the two

side plates

25, 26. And the

side plates

25 and 26 are substantially closed.
Further, as shown in FIG. 3, 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. 3, a crescent-shaped space is formed between the outer peripheral surface 27 B of the rotor 27 and the inner peripheral surface 23 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 arranged so as to be able to protrude and retract from guide grooves 27 C provided in the rotor 27. As the rotor 27 rotates, each vane 28 protrudes outward along the guide groove 27 C by centrifugal force, and the tip of the vane 28 comes into contact with the inner peripheral surface 23 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, 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, a large space can be secured in the casing main body 22 in the direction opposite to the eccentricity of the cylinder portion 23, and the discharge ports 23 C and 22 C are provided in this space along the peripheral edge of the cylinder portion 23. An expansion chamber 33 communicated with is formed.
The expansion chamber 33 is formed as a large closed space along the peripheral edge of the cylinder portion 23 from below the cylinder portion 23 to above the output shaft 12, and communicates with an exhaust port 24 A formed in the pump cover 24. ing. 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 22 C and 23 C, an expansion chamber 33, and an exhaust port 24 A formed in the casing body 22 and the cylinder part 23, respectively.

In the present embodiment, by disposing the cylinder portion 23 eccentrically from the rotation center X1 of the rotor 27, a large space can be secured in the peripheral portion on the rotation center X1 side of the cylinder portion 23 in the casing body 22. For this reason, since the expansion chamber 33 can be formed integrally with the casing body 22 by forming the large expansion chamber 33 in this space, there is no need to provide the expansion chamber 33 outside the casing body 22. The main body 22 can be downsized, and the vacuum pump 1 can be downsized.

The pump cover 24 is disposed on the front side plate 26 via a seal ring 26A, 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 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.

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 this embodiment, the electric motor 10 has a 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. 2, a cylindrical fitting portion 22 F projecting rearward around the cylinder chamber S is integrally formed on the back surface of the casing body 22. The fitting portion 22 F is formed concentrically with the rotation center X 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 body 22 into the fitting hole portion 63 of the electric motor 10, and the electric motor 10 and the pump body 20 can be aligned. Assembly work can be performed easily. Further, 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 35 is disposed in the seal groove 22E.

By the way, in a small vacuum pump used for a brake device of an automobile, a small and light rotor is generally used. Further, in order to improve the efficiency of the assembly work of the pump, the rotor is connected to the output shaft. It is not fixed and is provided so as to be movable in the axial direction of the output shaft. In addition, since the rotor is so-called cantilevered at the tip of the output shaft of the electric motor, when the rotor is rotated, the rotor tends to protrude toward the tip of the output shaft as it rotates. It was. For this reason, in the conventional configuration, it is assumed that the rotor and the side plate are damaged by wear due to the contact of the rotor with the front side plate during operation of the vacuum pump, and the durability of the vacuum pump is lowered. Is done.

To solve this problem, the rotor and output shaft are connected by a spline, the rotor is fixed in the radial direction, a push nut is attached to the tip of the output shaft, and the rotor moves in the axial (thrust) direction. The structure which regulates to do is considered.
In this configuration, there is an advantage that the push nut can easily prevent the rotor from protruding toward the tip end side of the output shaft with rotation.
However, since the rigidity of the push nut itself is low, the push nut elastically changes due to the stress of the rotor, so that the rotor moves in the axial direction by the elastic change. According to this, it was assumed that the performance of the vacuum pump may vary due to the rotor moving slightly in the cylinder chamber. For this reason, this structure has a feature in the connection structure between the rotor 27 and the output shaft 12.

FIG. 4 is an exploded side view showing a connection structure between the rotor 27 and the output shaft 12.
A male screw 12B is formed at the distal end portion 12A of the output shaft 12, and this male screw 12B engages with a female screw 27D provided in a part of a shaft hole 27A penetrating the rotor 27 in the axial direction. The rotor 27 is connected to the rotor 27 so as to be integrally rotatable. Further, the male screw 12 B of the output shaft 12 is engaged with a nut 70 on the distal end side of the rotor 27, so that the movement of the rotor 27 toward the distal end side of the output shaft 12 is restricted.

The output shaft 12 is formed such that the distal end portion 12A has a smaller diameter than the base portion 12C, and a male screw 12B is formed on the outer peripheral surface of the reduced diameter distal end portion 12A.
On the other hand, the shaft hole 27A of the rotor 27 includes a shaft holding portion 27E into which the base portion 12C of the output shaft 12 is fitted, and a hole portion 27F having a diameter smaller than that of the shaft holding portion 27E, and the inner peripheral surface of the hole portion 27F. The female screw 27D described above is formed. The shaft holding portion 27E is longer in the axial direction than the hole portion 27F in which the female screw 27D is formed. Specifically, the shaft holding portion 27E is longer than half of the entire length of the rotor 27. Further, the shaft holding portion 27E is formed to have substantially the same diameter as the base portion 12C of the output shaft 12. Thereby, since the rotor 27 is fitted to the base portion 12C of the output shaft 12 over more than half of the entire length, the inclination of the rotor 27 is prevented.

Further, a cylindrical recess 27H having a diameter larger than that of the hole 27F (and the shaft holding part 27E) is formed around the hole 27F on the front end surface 27G of the rotor 27. In the recess 27H, the tip end portion of the male screw 12B of the output shaft 12 screwed into the female screw 27D of the shaft hole 27A extends, and the nut 70 is screwed into the male screw 12B in the recess 27H.
In the present embodiment, the length of the shaft end of the output shaft 12 extending into the recess 27H and the thickness of the nut 70 are set to be substantially the same as or slightly smaller than the depth of the recess 27H. The output shaft 12 and the nut 70 do not protrude from the surface 27G.
The inner diameter of the recess 27H is set to a size that allows the nut 70 disposed in the recess 27H to be tightened with a jig (for example, a socket wrench).

The nut 70 is provided with a through hole 70A in the approximate center and a female screw 70B formed on the inner surface of the through hole 70A. By tightening the female screw 70B to the male screw 12B of the output shaft 12, the end surface 70C of the nut 70 The concave portion 27H is in close contact with the bottom surface 27H1. In this configuration, when the female screw 27D of the rotor 27 and the female screw 70B of the nut 70 are screwed into the male screw 12B of the output shaft 12, respectively, the rotor 27 and the nut 70 exhibit a so-called double nut effect. For this reason, the rotor 27 is restricted from moving in the radial direction and the thrust direction with respect to the output shaft 12, thereby preventing contact between the rotor 27 and the

side plates

25, 26 with a simple configuration. 27 and the

side plates

25 and 26 are prevented from being worn, and the durability of the vacuum pump 1 can be improved.
Further, in this configuration, since the rotor 27 is prevented from moving in the axial direction in the cylinder chamber, variations in the performance of the vacuum pump based on this movement can be suppressed.

In the present embodiment, the male screw 12B of the output shaft 12 described above is formed as a left-hand screw (reverse screw), and when the pump is viewed from the front side, the rotor 27 is positioned in the same direction as the output shaft 12 ( The rotor 27 is connected to the output shaft 12 by being rotated counterclockwise.
In this configuration, every time the vacuum pump 1 is stopped, the rotor 27 is subjected to a force that is screwed into the output shaft 12. Therefore, even in a device that repeatedly starts and stops like the vacuum pump 1, the rotor 27 and the nut The loosening of 70 can be prevented.

Next, the procedure for assembling the rotor 27 will be described.
First, the output shaft 12 is inserted into the shaft hole 27 A of the rotor 27. When the shaft end of the output shaft 12 reaches the hole 27F, the rotor 27 is turned counterclockwise while holding the output shaft 12 so as not to rotate using a jig (not shown), Screw into the output shaft 12.
In this case, since the length of the rotor 27 is set to be substantially the same as the length of the cylinder chamber S (FIG. 2), the rotor 27 is tightened until the rear end surface 27I of the rotor 27 contacts the rear side plate 25. Thus, the front end surface 27G of the rotor 27 and the opening of the cylinder chamber S are substantially flush with each other.

Subsequently, the nut 70 is locked to the output shaft 12. When the rotor 27 is fastened to the output shaft 12 until the rotor 27 comes into contact with the side plate 25, the tip of the male screw 12B of the output shaft 12 extends into a recess 27H formed in the rotor 27.
Next, the output shaft 12 and the rotor 27 are held so as not to rotate using a jig, and in this state, the nut 70 is screwed in until the nut 70 contacts the bottom surface 27H1 of the recess 27H of the rotor 27. 70 is locked to the external thread 12B of the output shaft 12.
In this case, the nut 70 is attached to the output shaft 12 using a dedicated jig (not shown) that can measure the tightening torque. By tightening until the tightening torque exceeds a predetermined threshold, the rotor 27 is positioned by being sandwiched between the rear side plate 25 and the nut 70. For this reason, the rotor 27 can be easily positioned with respect to the output shaft 12 by a simple operation of tightening the rotor 27 on the output shaft 12 until it contacts the side plate 25. Further, by tightening the nut 70 to the bottom surface 27H1 of the recess 27H of the rotor 27 until it exceeds a predetermined reference value, it can be easily determined that the positioning of the rotor 27 is completed depending on whether or not this reference value is exceeded. In addition, the pump can be assembled in a short time even if it is not an expert.

As described above, according to the present embodiment, the casing body 22 attached to the electric motor 10 and the hollow cylinder chamber S formed in the casing body 22 and having openings at both ends of the casing body 22 are provided. The output shaft 12 of the electric motor 10 includes a rotor 27 that is rotationally driven in the cylinder chamber S together with the output shaft 12, and a pair of

side plates

25 and 26 that close the opening of the cylinder chamber S. The front end portion 12A is provided with a male screw 12B. The male screw 12B is engaged with a female screw 27D formed in the shaft hole 27A of the rotor 27, and is fixed in close contact with the front end surface 27G of the rotor 27. Since the nut 70 is provided, the rotor 27 and the nut 70 engaged with the male screw 12B of the output shaft 12 are so-called double nuts. By effective, it is regulated that the rotor 27 is moved in the radial direction and the thrust direction of the output shaft 12. For this reason, contact between the rotor 27 and the

side plates

25 and 26 is prevented with a simple configuration, so that wear of the rotor 27 and the

side plates

25 and 26 is suppressed, and durability of the vacuum pump 1 is improved. Can do.
Furthermore, in this embodiment, since the rotor 27 is prevented from moving in the axial direction in the cylinder chamber S, variations in the performance of the vacuum pump 1 based on this movement can be suppressed.

Further, according to the present embodiment, the rotor 27 is fastened to the male screw 12B of the output shaft 12 until it contacts the rear side plate 25 located on the electric motor side, and in this state, the nut 70 is set to a predetermined reference value. Since the nut 70 is tightened and locked to the output shaft 12 while being in close contact with the end face of the rotor 27 until exceeding the output shaft 12, the rotor 27 is tightened to the output shaft 12 until it contacts the side plate 25. Thus, positioning of the rotor 27 with respect to 12 can be performed easily. Further, by tightening the nut 70 in close contact with the end face of the rotor 27 until it exceeds a predetermined reference value, it can be easily determined that the positioning of the rotor 27 has been completed based on whether or not this reference value has been exceeded. Even if it is not an expert, the assembly | attachment operation | work of a pump can be performed in a short time.

Further, according to the present embodiment, the front end surface 27G of the rotor 27 is formed with the recess 27H around the shaft hole 27A into which the output shaft 12 is tightened, and the nut 70 is inserted into the male screw of the output shaft 12 in the recess 27H. 12B, the nut 70 can be locked to the output shaft 12 without protruding the front end portion 12A of the output shaft 12 from the front end surface 27G of the rotor 27, and the configuration of the vacuum pump 1 is simplified. Can be achieved.

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. In the above-described embodiment, the rotor 27 is brought into contact with the side plate 25 to position the rotor 27 with respect to the output shaft 12. As a positioning method of the rotor 27, the front end surface 27G of the rotor 27 is a cylinder. It is desirable that it does not protrude beyond the front end surface of the portion 23. For this reason, it is also possible to position the rotor 27 with respect to the output shaft 12 by confirming the positions of the front end surfaces of the cylinder portion 23 and the rotor 27.

1 Vacuum pump 6 Brake booster (brake booster)
7 Vacuum tank 9 Brake piping 10 Electric motor (driving machine)
11 Case 12 Output shaft (Rotating shaft)
12A Front end portion 12B Male screw 20 Pump body 22 Casing body 23 Cylinder portion 25 Side plate 26 Side plate 27 Rotor

27A Shaft hole

27D Female screw 27F Shaft holding portion 27G Front end surface 27H Recessed portion 27H1 Bottom surface (end surface)
27I Rear end face 28 Vane 70 Nut 70B Female thread 100 Brake device

Claims

A casing main body attached to the drive machine, a hollow cylinder chamber formed in the casing main body and having openings at both ends of the casing main body, and provided on a rotation shaft of the drive machine to be rotationally driven in the cylinder chamber. In a vacuum pump comprising a rotor and a pair of side plates that close the opening of the cylinder chamber,
The rotating shaft includes a male screw at a tip portion, and a female screw formed in a shaft hole of the rotor is engaged with the male screw, and a nut that fixes the rotor in close contact with the front end surface of the rotor. A vacuum pump characterized by being provided.
The rotor is fastened to the male screw of the rotating shaft until it abuts on the side plate located on the drive machine side, and in this state, the nut is brought into close contact with the front end surface of the rotor until a predetermined reference value is exceeded. The vacuum pump according to claim 1, wherein a rotor is fixed to the rotating shaft.
The vacuum according to claim 1 or 2, wherein a concave portion is formed around the shaft hole in the front end surface of the rotor, and the nut is engaged with the male screw of the rotating shaft in the concave portion. pump.