JPS60186365A - Method of correcting clearance between rotors for root's blower or pump - Google Patents

Abstract

PURPOSE:To make it possible to correct the clearance between rotors in pair to make the clearance uniform allower the angular phase of the rotors, by feeding a suspension liquid prepared by mixing grinding particles in a liquid into the inlet port of a casing jig to which the pair of rotors are attached, and as well by rotating the rotors at a uniform speed in the reverse directions with respect to each other to discharge the suspension liquid therefrom. CONSTITUTION:Rotors 36, 38 are rotated at the same speed with respect to each other while maintaining 90 deg. phase angle difference therebetween in the directions with respect to each other, by meshing a gear 34 with a gear 76 after a rotor assembly 50 is attached to a casing jig 52, and therefore a suspension liquid 72 is sucked and is discharged into a discharge pipe 68. Since these rotors 36, 38 are manufactured in sizes which are slightly larger than their normal sizes, there are parts where the rotor are made in direct contact with each other and where particles in the suspension liquid 72 are made compact so that the assembly 50 rotates together with elastic deformations in both rotors 36, 38, a seal member 60, a bearing 22, etc. Accordingly, upon initiation of rotation the contact area between the rotors 36, 38 is large so that a slip occurs due to a certain difference between the pheripheral speeds of both rotors. However, since the suspension liquid exists between the rotors and the rotational speeds thereof is low, no seizing occures and as well the rotors are ground by the particle therebetween.

Description

TECHNICAL FIELD The present invention relates to a method for modifying the rotor clearance of a Roots-type blower or pump, and more particularly to a method for modifying the rotor clearance of a Roots-type blower or pump, and more particularly to The present invention relates to a method of finishing the outer circumferential surface of a rotor by lapping so as to maintain a proper value with high precision.

Conventional Roots-type blower (1 pump (hereinafter simply referred to as blower L1) has a 2111 rotor of the same shape equipped with 2 to 4 blades, which are knitted together in the computer chamber of the casing.
The two rotors are rotated at the same angular velocity in opposite directions to pump fluid, and the two rotors are rotated with a constant clearance without coming into contact with each other.

Although it is desirable that the clearance between the rotors of the 2111i1 be small in order to prevent fluid leakage and improve efficiency, it is not easy to maintain the rotor clearance at a small constant value in all rotational phases of the rotor.

For this reason, conventional efforts have been made to improve the machining accuracy of each component, including the rotor, as much as possible, and to pay close attention to their assembly. In other words, in a Roots-type blower, the rotating shafts of two rotors are rotatably supported by one end plate, and the rotating shaft has the same teeth on the opposite side of the rotor with the end plate in between. Normally, several gears are fixed and meshed with each other, but this rotor subassembly assembly work uses a special jig and checks the rotor clearance with a feeler gauge etc. The reality is that it has to be done manually, and there is a strong desire to improve productivity. Moreover, even when assembled in this manner, it has been difficult to obtain an ideal blower in which the clearance is maintained at a constant minute value in all rotational phases of the rotor.

OBJECTS OF THE INVENTION The present invention has been made against the background of the above circumstances, and its purpose is to combine two rotors of the same shape with two to four blades in a rotor chamber of a casing, Gears with the same number of teeth fixed on the rotating shaft of each rotor at a position opposite to each rotor with an end plate in between are engaged with each other, so that the two rotors are rotated in opposite directions. In a Roots-type blower or pump that rotates at the same angular velocity and sucks in fluid from the inlet of the casing and discharges it from the outlet, the rotor is The purpose of the present invention is to propose a method for easily modifying the clearance.

Structure of the invention And the rotor clearance correction method according to the present invention is as follows:
(The process of assembling the rotor 1 rotation shaft and two gears described above to the end plate to form a rotor subassembly, and the process of assembling the rotor subassembly into a casing jig equipped with a rotor chamber almost the same as the casing) the step of attaching (C1 those two rotors to the
A step of supplying a suspension in which fine particles of abrasive material are mixed into the liquid to the suction port of the casing jig and discharging it from the discharge port while rotating the casing jig in opposite directions at the same angular speed through meshing gears. It is characterized by including.

Effects of the Invention With the above method, the fine particles of abrasive material (ramp agent) mixed in the suspension supplied from the suction port are sandwiched between the two rotors as the rotors rotate, and they are The outer circumferential surface of the rotor is ground (wrapped) based on the difference in circumferential speed between the two rotors. Therefore, if the particle size of the abrasive fine particles is appropriately selected in relation to the target rotor clearance, the rotor clearance can be corrected to a desired value that is approximately constant at all rotational phases of the rotor.

Please note that the rotor is manufactured to be slightly larger than the original dimensions.
In the rotor subassembly before the rotor clearance is corrected, it is normal for the rotor subassemblies to be in contact with each other, and in addition, fine particles of abrasive material are caught between the rotors.

Rotation of the rotor is allowed due to elastic deformation of the rotating shaft, bearings, etc., and grinding of the outer circumferential surface of the rotor is performed without any problem. However, it is also possible to positively interpose an elastic member that allows minute displacement of the rotating shaft in the bearing part on the casing jig side.

In addition, although the finishing allowance for each part of the rotor is usually not constant, the grinding action decreases in areas where the rotor clearance is about the size of the abrasive particles, whereas it continues to work in areas where the rotor clearance is small. Because of the grinding, the rotor clearance ultimately becomes approximately constant at all rotational phases of the rotor.

As is clear from the above description, according to the present invention, it is possible to easily manufacture a roots-type blower or pump in which the rotor clearance is maintained at a substantially constant appropriate value in all rotational phases of the rotor. Moreover, the size of the rotor clearance is determined by the size of the abrasive particles mixed into the suspension.
You can easily change it by changing ¥. Further, it is no longer necessary to monitor the machining accuracy of the rotor so strictly, and the method of the present invention can be easily carried out by automatic equipment, so that the overall number of man-hours required for manufacturing can be significantly reduced.

Embodiments Hereinafter, embodiments of the present invention will be explained in detail with reference to the drawings, but first, the structure of a roots-type blower will be briefly explained.

What is shown in FIGS. 1 and 2 is a supercharger that actively supplies air to an engine for a passenger car, and reference numeral 10 in the figures indicates a casing body. This casing body 10
is a container-shaped member with one end open, and the open end is closed with an end plate 12, and the rear cover 14 is fixed to the outside thereof, thereby forming a casing.

Two rotating shafts 16 and 18 are arranged parallel to each other within this casing, and both ends of these shafts are rotatable by the casing body 10 and the end plate 12 via bearings 20 and 22, respectively. Supported. In addition,
28 is a sealing member.

One end of the rotating shaft 16 is made to protrude to the outside of the casing, and a pulley 30 is fixed to the protruding end, to which rotational power of the engine is transmitted via a V-belt. A gear 32 is fixed to the other end of the rotating shaft 16, and this gear 32 is connected to a gear 3 fixed to the rotating shaft 18.
It is interlocked with 4. The gears 32 and 34 have the same number of teeth, so when the rotating shaft 16 is rotated, the rotating shaft 18 is rotated at the same angular velocity as the rotating shaft 16 in the opposite direction.

Cocoon-shaped rotors 36 and 3B each having two blades are fixed to the rotating shafts 16 and 18, respectively. These rotors 36 and 38 are made of aluminum alloy (or synthetic resin, etc.) and have the same shape and dimensions.
With the rotation of 6 and 18)l'l;lash S K
jIi;1!118717;l It rotates in the opposite direction at the same angular velocity, sucks in air through an inlet 40 formed in the casing body 10, and supplies it to the engine through an outlet 42.

Next, a method for correcting the rotor clearance of a supercharger having the above structure to a desired constant value will be described.

After manufacturing each component of the supercharger including the rotors 36 and 38, as shown in FIG. are assembled to the end plate 12 via the bearings 22, respectively, and the gears 32 and 34 are fixed to the ends of the rotating shaft 16 protruding from the end plate 12 to the side opposite to the rotors 36 and 38, respectively, to assemble the rotor subassembly 50. .

The assembled rotor subassembly 50 is attached to a casing jig 52 shown in FIGS. 3 and 4. The casing jig 52 is equipped with a rotor chamber 54 having the same shape as the casing of the supercharger, but is made of special steel with excellent wear resistance, and the inner circumferential surface of the rotor chamber 54 is heat-treated and then ground. ing. The casing jig 52 is shaped like a container with a bottom, and the rotating shaft 16 and the
Holes 56 and 58 are formed for accommodating the ends of the holes 8 opposite to the side supported by the end plate 12, and a sealing member 60 is attached to each open end. The sealing member 60 prevents the suspension, which will be described in detail later, from entering the gap between the inner circumferential surface of the sealing member 60 itself and the outer circumferential surfaces of the rotating shafts 16 and 18, and also prevents the rotating shafts 16 and 18 from entering between them. It has the function of rotatably supporting the shaft center while keeping it in an accurate position.

Casing cure! 81.52 is the suction port 62 and the discharge port 6
4, and a suction pipe 6 is connected to them as shown in FIG.
6 and one end of a discharge pipe 68 are connected. The other ends of the suction pipe 66 and the discharge pipe 68 are inserted into a tank 7o, and the suspension/&72 is inserted into this tank 70.
There are 7 volumes. , second suspension 72 grinding i'&' 4
> ゛゛It is mixed with fine particles of Mineura 61F cutting + 14, and the particle size of these fine particles ranges from about 10 μm to 400 #, depending on the target rotor clearance.
It is used by appropriately selecting from a wide range of mm speeds.

Therefore, the rotor subassembly 5o was installed in the casing jig 52 as described in ζ and Mi+ (the gear 34 of the rotor subassembly 5o was connected to the motor 7 with a reducer).
When the gear 76 driven by the gear 4 is engaged, the rotors 36 and 38 rotate in opposite directions at angular velocities while maintaining a phase difference of 90 degrees through the engagement of the gears 32 and 34. The suspension 72 is sucked in and discharged into the discharge pipe 68.

Since the rotors 36 and 38 are manufactured to be slightly larger than normal dimensions, and their relative phases are not precisely matched, there are portions in which they are in direct contact with each other. Furthermore, since fine particles of the abrasive material mixed in the suspension 72 are trapped between these rotors, the Rokusuba 7 assembly 50 has a rotor 36.3B and a seal member 6.
0, the bearing 22, etc. will rotate with elastic deformation.

Therefore, at the beginning of rotation, the contact surface pressure between the rotors 36 and 38 is high, and under this high contact surface pressure, slipping occurs due to the difference in circumferential speed between the rotors. Alternatively, since mineral oil is present and the rotational speed is relatively low, problems such as seizure do not occur, and grinding is performed using the abrasive particles sandwiched between the rotors 36 and 38. Note that at this time, the parts of the rotors 36 and 38 farthest from the rotation axis move a long distance while being close to or in contact with the inner peripheral surface of the rotor chamber 54, so the grinding action is 2 times more than other parts. Easy to accept. Therefore, it is desirable that the dimensions of the rotor chamber 54 of the casing jig 52 be slightly larger than the dimensions of the rotor chamber of the supercharger itself.

The outer circumferential surfaces of the rotors 36 and 38 are simultaneously ground by the grinding action of the abrasive fine particles as described above, and the rotor clearances at all rotational phases are maintained substantially constant.

In this state, the load on the motor with reduction gear 74 for driving the rotor subassembly 5o decreases, so the rotor clearance can be corrected based on the measurement results of the power consumption of the motor with reduction gear 74, the distortion of the output shaft, etc. You can tell when it's finished. Therefore, the rotor clearance correction work is completed by removing the rotor subassembly 5o from the casing jig 52 and removing the suspension liquid 72 by cleaning etc., and the rotor clearance is adjusted to a constant desired value in all rotational phases of the rotors 36 and 38. An ideal rotor subassembly 5o can be obtained. Of course, after a certain period of rotation without detecting a decrease in the load on the motor 74 with a reduction gear, the rotor subassembly 5
It is also possible to remove 0.

In the above embodiment, the suspension is sucked in and discharged with almost no resistance. However, if a restriction is provided in the discharge pipe 68 to provide resistance to the discharge of the suspension 72, it is possible to , the amount of leakage of the suspension 72 between the rotors 36 and 38 increases, and the abrasive particles contained in the suspension 72 are more likely to be caught between the rotors 36 and 38, requiring rotor clearance correction work. efficiency will be improved. Furthermore, if the suction pipe 66 is also provided with a restriction, the amount of the suspension 72 leaking from between the rotors 36 and 38 will be increased, further improving the efficiency of the rotor clearance correction work.

Conversely, if a pump or the like supplies more suspension 72 to the casing jig 52 than the discharge amount of the rotor subassembly 50, leakage occurs between the rotors 36 and 38 in the opposite direction to that in the above case. , the number of machines in which fine abrasive particles are sandwiched between both rotors increases, improving the efficiency of rotor clearance correction work.

Furthermore, in the above embodiment, the row 4 tasabua assembly 50 is mounted using a dedicated casing jig 52.
Although we decided to fix the rotor clearance by fixing the rotor clearance, it is also possible to use the casing 10 of the supercharger itself as a casing jig. The inner surface of the rotor chamber of the casing 10 is also ground, resulting in the effect that the clearance between the rotors, as well as the clearance between the rotors 36, 38 and the casing 10, can be adjusted to a constant desired value.

In addition, various modifications may be made to the present invention based on the knowledge of those skilled in the art, although it is not necessary to exemplify them individually.

It can be implemented in an improved manner.

[Brief explanation of the drawing]

1 and 2 are a front sectional view and a side sectional view showing a supercharger for a passenger car engine, which is an example of an object to which the method of the present invention is applied. FIG. 3 is a side sectional view showing the state of rotor clearance correction work in one embodiment of the present invention, and FIG. 4 is a front sectional view. FIG. 5 is a schematic front view of the apparatus used to carry out the present invention. 10: Casing 12: End play i・16.18
4 rotating shaft 32, 34: gear 36.3 (l rotor 50; rotor subassembly 52; casing jig 66: suction pipe 68; discharge pipe 70: tank 72: suspension 74: motor with reducer Applicant: Toyota Motor Corporation Company 6 Figure 1 Army 2 Figure 4)

Claims (1)

[Scope of Claims] Two rotors of the same shape each having two to four blades are combined in a rotor chamber of a casing, and each rotor has an end plate on the rotation axis of each rotor on the opposite side from each rotor. By meshing gears with the same number of teeth fixed at the position, the two rotors are rotated at the same speed in opposite directions, and the fluid is sucked from the suction port of the casing. A method for correcting the rotor clearance of a Roots-type blower or pump that discharges from a discharge port, the method comprising the steps of attaching two rotating shafts and two gears of the rotor 5 to the end play 1 to form a rotor subassembly; attaching the rotor subassembly to a casing jig having a rotor chamber substantially the same as the casing, and rotating the two rotors in opposite directions at the same speed through the Il+i engagement of the two gears; , ¥I! fine particles of abrasive material were mixed into the liquid at the suction port of the casing jig. By supplying a slurry and discharging it from the discharge port, the outer circumferential surfaces of the rotors are ground by fine particles of abrasive material sandwiched between the two rotors, thereby reducing the clearance between the rotors at every rotation of the rotors. A method for correcting a rotor clearance of a Roots-type blower or pump, comprising the step of adjusting the phase to be substantially constant.