CN218102919U

CN218102919U - Coaxial jig for realizing coaxial non-clamping installation between end cover bearing chamber and bearing

Info

Publication number: CN218102919U
Application number: CN202221093166.9U
Authority: CN
Inventors: 王方; 王天
Original assignee: Zhuhai Enpower Electric Co Ltd
Current assignee: Zhuhai Enpower Electric Co Ltd
Priority date: 2022-05-09
Filing date: 2022-05-09
Publication date: 2022-12-20
Anticipated expiration: 2032-05-09

Abstract

The utility model relates to a motor assembly field specifically discloses a realize the axialization tool of coaxial no card installation between end cover bearing room and the bearing, and the axialization tool includes: the first coaxial structure and the bearing chamber on the end cover form a first coaxial body, and the second coaxial structure and the rotating shaft with the bearing form a second coaxial body; the first coaxial structure is coaxially connected with the second coaxial structure; the first coaxial structure and the end cover and the second coaxial structure and the rotating shaft are respectively in separable connection, the installation sequence can be selected to be preferential, and the first coaxial structure and the second coaxial structure form a coaxial body in sequence, so that the bearing slides into the bearing chamber along the axial direction. Through the coaxialization jig, the first coaxialization structure and the first radial positioning structure as well as the second coaxialization structure and the first radial positioning structure sequentially form a coaxial body, the mounting precision between the bearing chamber and the rotating shaft on the end cover is met, and the production efficiency is greatly improved.

Description

Coaxial jig for realizing coaxial non-clamping installation between end cover bearing chamber and bearing

Technical Field

The utility model relates to a motor assembly field especially relates to decide the rotor assembly in-process, realize the coaxial tool of coaxial no card installation between end cover bearing room and the bearing.

Background

In the prior art, an electric machine can convert electric energy into mechanical energy, and is suitable for various new energy power transportation tools, such as new energy automobiles, new energy yachts, new energy aircrafts and the like.

The motor includes rotor, stator, bearings, front and back end covers and other parts, the rotor is a rigid body comprising iron core and rotating shaft and with mass center in the rotating axis to reach dynamic balance, bearings are set in two ends of the rotating shaft, bearing chambers are set on the front and back end covers separately, and the front and back bearing chambers are opposite and are set into the front and back bearings separately as the support and location of the rotating shaft.

In the process of mounting and producing the motor, after the front bearing is pressed into the shaft extension, the shaft extension and the front bearing are sleeved with the front end cover. The front end cover is difficult to meet the installation requirement of coaxiality before being assembled into the shaft extension until becoming a single group and between the front end cover and the shaft extension, so that a front bearing chamber and a front bearing are clamped and cannot be installed smoothly, and the production efficiency is low.

Similarly, the situation that the rear bearing chamber is clamped with the rear bearing and cannot be smoothly installed exists in the assembly between the rear end cover and the rear bearing, and needs to be solved.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a axialization tool, the special solution when not enough (perhaps front end housing slope) of axiality between pivot cover hole to the end cover and the pivot.

In order to realize the above purpose of the utility model, the technical scheme of the utility model is that:

realize the axialization tool of coaxial no card installation between end cover bearing chamber and the bearing, be applied to the end cover installation process of deciding arbitrary end on rotor assembly production line, the rotor, the axialization tool includes:

the first coaxial structure is adapted to a first radial positioning structure preset on the end cover and can form a first coaxial body with the bearing chamber on the end cover;

the second coaxial structure is matched with a second radial positioning structure preset on the rotating shaft and can form a second coaxial body with the rotating shaft;

the first coaxial structure is coaxially connected with the second coaxial structure;

the first coaxial structure and the end cover, and the second coaxial structure and the rotating shaft are respectively in separable connection;

the first coaxial body and the second coaxial body are assembled in a preferred order to form a coaxial body so that the bearing slides into the bearing chamber in the axial direction.

In a first embodiment, the first coaxial structure comprises a cylinder;

the second coaxial structure is a cylindrical cavity coaxially arranged in the cylinder, the cylindrical cavity is opened at the bottom surface of the cylinder, the diameter of the opening is equal to that of the cylindrical cavity, the second radial positioning structure is the outer side surface of the rotating shaft, and the cylindrical cavity is sleeved on the rotating shaft in advance to form a second coaxial body;

the first radial positioning structure is a hole wall of a rotating shaft sleeve hole in the end cover, the end cover and the second coaxial body move oppositely along the axis, and the cylinder is sleeved in the rotating shaft sleeve hole to form the first coaxial body.

Preferably, an axial connection length not less than 7 mm is arranged between the cavity wall of the cylindrical cavity and the rotating shaft.

Preferably, a guide post capable of being guided into the shaft end blind hole of the rotating shaft in a sliding mode is installed in the cylindrical cavity, and a radial gap is formed between the guide post and the shaft end blind hole. A radial gap is arranged between the guide post and the shaft end blind hole, and the effect of auxiliary guiding can be increased under the condition that the cylindrical cavity and the rotating shaft are abraded.

Further, the guide post is slidable along an axis within the cylindrical cavity. It is ensured that the bottom surface of the cylindrical body can stably abut against the upper surface of the front bearing.

And the guide post is provided with a sliding limiting part, a lower stop block of the sliding limiting part is arranged in the cylindrical cavity, when the limiting block slides downwards to abut against the lower stop block, the lower surface of the guide post protrudes out of the lower edge in the cylindrical cavity. The guide post can preferentially enter the blind hole at the shaft end to perform radial auxiliary positioning, and particularly, after the cavity wall of the cylindrical cavity is worn in use, the auxiliary positioning effect of the guide post is highlighted.

In addition, the cylinder cavity is provided with an upper stop block of the sliding limiting part, when the bottom surface of the cylinder is abutted to the upper end surface of the front bearing, an axial gap is formed between the sliding limiting part and the upper stop block above the sliding limiting part.

A second embodiment is also provided, wherein the first coaxial structure comprises a cylinder;

the first radial positioning structure is a positioning groove which is arranged on the end cover and is coaxial with the rotating shaft sleeve hole, and the cylinder is placed in the positioning groove in advance to form the first coaxial body;

the second coaxial structure is coaxially arranged in a cylindrical cavity inside the cylinder, the cylindrical cavity is opened at the bottom surface of the cylinder, the diameter of the opening is equal to that of the cylindrical cavity, the second radial positioning structure is the outer side surface of the rotating shaft, and the first coaxial body is formed by sleeving the cylindrical cavity on the rotating shaft along the axis.

This solution is particularly suitable, in particular, when the axial depth of the spindle housing hole is less than 7 mm.

The difference from the second scheme is that a pressing mechanism for fixing the cylinder is arranged on the end cover.

Preferably, the exhaust device further comprises an exhaust hole, the exhaust hole is located at the top of the cylinder, and the exhaust hole is communicated with the cylinder cavity.

In addition, the top of axialization tool still is equipped with the handle portion of being convenient for load and unload the axialization tool, the effect of handle portion is: the coaxialization jig can be kept vertical by utilizing the full-circumference symmetry and the dead weight of the coaxialization jig, so that the coaxialization jig can be sleeved into the shaft extension and taken out conveniently.

Preferably, the cylinder and the cylindrical cavity can be integrally processed or assembled in a split structure, and the coaxiality between the cylinder and the cylindrical cavity is less than or equal to 0.02 mm in any processing mode, so that the smooth assembly of the end cover is facilitated.

In addition, the cylindrical cavity is provided with an upper stop block of the sliding limiting part, when the bottom surface of the cylinder abuts against the upper end surface of the front bearing, an axial gap is formed between the sliding limiting part and the upper stop block above the sliding limiting part, and the guide column is provided with a sliding space upwards along the axis in the cylindrical cavity, so that the bottom surface of the cylinder can be ensured to stably abut against the upper surface of the front bearing.

Description of the drawings: installation between front end housing and the front bearing, installation between rear end housing and the rear bearing are applicable to the technical scheme of the utility model.

The utility model has the advantages that: through the coaxialization jig, the first coaxialization structure, the first radial positioning structure, the second coaxialization structure and the first radial positioning structure sequentially form a coaxial body, the mounting precision between a bearing chamber and a rotating shaft on an end cover is met, the bearing slides into the bearing chamber along the axial direction, and the production efficiency is greatly improved. Even if the end cover is in an inclined state, the inclined state of the end cover can be corrected through the coaxialization effect, so that the end cover is kept in a coaxial state, and the bearing can smoothly slide into a bearing chamber at the bottom of the end cover.

Compared with the prior art, the utility model discloses can satisfy manual/semi-automatic installation end cover, under the condition that does not increase equipment investment, eliminate because the end cover axiality can not satisfy the installation requirement, and, the card negative effects that the bearing inner race brought during the end cover slope.

And, in the cylinder cavity, install the guide post of slidable leading-in the axle head blind hole of axle extension, the guide post can preferentially get into the axle head blind hole carries out radial assistance-localization real-time, especially when the chamber wall of cylinder cavity is after the use wearing and tearing, the salient effect of guide post assistance-localization real-time prolongs the life of axialization tool.

Drawings

Fig. 1 is a schematic view of a first embodiment of a semi-finished product in which a front end cover is assembled to a rotor.

FIG. 2 is a schematic illustration of the tip cap undergoing tilt (one of the examples of misalignment) during assembly to the rotor.

Fig. 3 is an assembly diagram of the embodiment of the present invention, in which the coaxial jig makes the shaft extension and the front end cover group form a whole coaxial structure.

Fig. 4 is a schematic view of the front end cap of fig. 3 assembled in place and the coaxialization jig not taken out.

Fig. 5 is a partially enlarged view of a portion B (visual scale) in fig. 4.

Fig. 6 is a schematic view of a coaxial jig having a handle portion and an exhaust hole according to an embodiment of the present invention.

Fig. 7 is a schematic view of a pre-assembled coaxialization fixture on the shaft extension according to one embodiment of the present invention.

Fig. 8 is a schematic view of the embodiment of fig. 7 with the front end cap assembled in place along the coaxial fixture.

Fig. 9 is a schematic view of the sliding position-limiting part of the coaxialization jig in the embodiment of fig. 7 sliding downward to the position of the lower stop block by its own weight.

Fig. 10 is a schematic view of the embodiment of fig. 7, in which the coaxialization jig is placed on the shaft-extending end surface, and the slide limiting portion is pushed upwards to a proper position.

Fig. 11 is a schematic diagram showing the deviation of the axis of the front end cover by X mm from the outer ring of the front bearing during the assembly of the front end cover to the rotor in the second embodiment.

Fig. 12 is a schematic view of a front end cap.

Fig. 13 is a schematic view of the front end cap with a coaxial jig mounted thereon to form a first coaxial body.

FIG. 14 is a schematic view of the first coaxial shaft of FIG. 13 moving downward in preparation for loading into a single set of rotors.

Fig. 15 is a schematic view of the pressing mechanism of fig. 14 with the addition of a coaxial jig (cylinder).

Wherein the reference numerals are:

1. a front end cover; 100. a bearing chamber; 110. the rotating shaft is sleeved into the hole; 120. an oil seal groove;

2. extending a shaft; 200. a shaft end blind hole; 3. a front bearing; 4. a rotor;

5. a coaxialization jig; 500. a cylinder; 510. a cylindrical cavity; 520. an exhaust hole;

530. visual scale marks; 540. a handle part; 550. a guide post; 560. a slide limit part;

570. a lower stop block; 580. an upper stop block; 590. avoiding the groove;

6. a pressing mechanism.

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

Detailed Description

As shown in fig. 1-15, the coaxial jig for realizing coaxial non-clamping installation between the end cover bearing chamber and the bearing is applied to the end cover installation procedure at any end of a stator and rotor assembly production line and a rotor. Now, the embodiment is described by taking the assembly end of the front end cover as an example:

for convenience of description, the first embodiment assumes that the axis of the rotating shaft is upward, the bearing chamber 100 on the front end cover 1 is downward, and the coaxialization jig 5 includes:

the cylinder 500, the inside cylindrical cavity 510 that is equipped with of cylinder 500, the bottom surface in cylinder 500 of cylindrical cavity 510 opening, the diameter of open-ended equals the diameter of cylindrical cavity 510, can be in advance set up on the axle extension 2 between the chamber wall of cylindrical cavity 510 and the axle extension 2 circumference have radial clearance and radial positioning, this radial clearance is less than or equal to 0.03 millimeter, still be equipped with the axiality between cylinder 500 and the cylindrical cavity 510, generally the axiality is below 0.02 millimeter, connect the sleeve on the axle extension 2 with cylinder 500 separable connection earlier, because of having the axiality of the aforesaid settlement, cylinder 500 and axle extension 2 connect earlier and become the second coaxial body. A radial clearance is set below 0.03 mm between the cylinder 500 and the rotating shaft sleeve hole 110 on the front end cover 1, the rotating shaft sleeve hole 110 slides relatively along the cylinder 500 axially, the cylinder 500 becomes a sliding guide post of the rotating shaft sleeve hole 110 on the front end cover 1, at this time, the front end cover 1 and the second coaxial body form a first coaxial body, and due to the coaxial connection of the first coaxial body and the second coaxial body, the front bearing 3 slides into the bearing chamber 100 at the bottom of the front end cover 1 smoothly, and the coaxial non-clamping installation between the front end cover 1 and the front bearing 3 is realized. Even if the front cover 1 is in the inclined state, the coaxialization function can correct the inclined state of the front cover 1, so that the front cover 1 keeps the coaxial state, and the front bearing 3 smoothly slides into the bearing chamber 100 at the bottom of the front cover 1.

On the basis of the above embodiment, an axial connection length L is provided between the cavity wall of the cylindrical cavity 510 and the shaft extension 2, and generally L is greater than or equal to 7 mm, so as to ensure that the cylinder 500 is connected with the shaft extension 2 without shaking.

Differences from the above embodiments include:

in one embodiment, the gas exhaust device further comprises a gas exhaust hole 520, the gas exhaust hole 520 is located at the top of the cylinder 500, the gas exhaust hole 520 is communicated with the cylindrical cavity 510, and when the cylindrical cavity 510 is sleeved in the shaft extension 2, gas in the cylindrical cavity 510 can be exhausted, so that the cylinder 500 is assembled in place.

In the second embodiment, the outer surface of the cylinder 500 is provided with visual scale lines 530, and the visual scale lines 530 are generally flush with the top of the front end cover 1, so as to facilitate checking whether the front end cover 1 is assembled in place.

In the third embodiment, the top of the coaxial jig 5 is further provided with a handle 540 for facilitating the assembly and disassembly of the coaxial jig 5.

In the fourth embodiment, the cylinder 500 and the cylindrical cavity 510 may be integrally machined or assembled together, and in any machining manner, the coaxiality between the cylinder 500 and the cylindrical cavity 510 is less than or equal to 0.02 mm, which is beneficial to forming the second coaxial body.

Fifth embodiment, a guiding post 550 slidably guiding the shaft end blind hole 200 of the shaft extension 2 is installed in the cylindrical cavity 510, a radial gap is provided between the guiding post 550 and the shaft end blind hole 200, the radial gap is less than 0.03 mm, and under the condition that the cylindrical cavity 510 and the shaft extension 2 are worn, the auxiliary guiding function can be increased.

In the sixth embodiment, as shown in fig. 7 and 8, the guide post 550 is slidable along the axis in the cylindrical cavity 510, and the bottom surface of the cylindrical body 500 can be surely stably abutted against the upper surface of the front bearing 3.

As shown in fig. 2 and fig. 9, the difference from the sixth embodiment lies in that the guiding post 550 is provided with a sliding limiting portion 560, a lower stopper 570 of the sliding limiting portion 560 is arranged in the cylindrical cavity 510, when the limiting block slides downwards to abut against the lower stopper 570, the lower surface of the guiding post 550 protrudes out of the lower edge in the cylindrical cavity 510 by a protruding length H57, the diameter of the guiding post 550 is D5, the diameter of the shaft end blind hole 200 is D2, and a radial gap of 0.03 mm or less is arranged between D5 and D2, so that the guiding post 550 can preferentially enter the shaft end blind hole 200 to perform radial auxiliary positioning.

As shown in fig. 7 to 10, the cylindrical cavity 510 is provided with an upper stopper 580 of the slide restricting portion 560, and when the bottom surface of the cylindrical body 500 abuts against the upper end surface of the front bearing 3, an axial gap H58 is provided between the slide restricting portion 560 and the upper stopper 580 above the same, and the guide post 550 has a sliding space in the cylindrical cavity 510 in the axial direction, so that the bottom surface of the cylindrical body 500 can be surely abutted against the upper surface of the front bearing 3.

The assembly steps of the above embodiment are:

step 1: the coaxialization jig 5 is sleeved on the shaft extension 2 in advance by lifting the lifting handle part 540;

step 2: the front end cover 1 is sleeved into the shaft extension 2, so that the front bearing 3 smoothly slides into the bearing chamber 100 at the bottom of the front end cover 1;

and step 3: checking whether the visual scale mark 530 of the coaxialization jig 5 is flush with the top of the front end cover 1;

and 4, step 4: the jig for axialization 5 is removed from the shaft by lifting up the handle part 540.

The above-described embodiments are also applicable to the mounting process of the rear end cap, the rear bearing housing, and the rear bearing.

In a second embodiment, as shown in fig. 11 to 15, for convenience of description, assuming that the axis of the rotating shaft is upward and the bearing chamber 100 on the front end cover 1 is downward, the coaxializing jig 5 includes:

the cylinder 500 is detachably preset in the oil seal groove 120 on the front end cover 1 for radial positioning, coaxiality and radial clearance are arranged between the outer side face of the cylinder 500 and the inner wall of the oil seal groove 120, the coaxiality is generally less than or equal to 0.02 mm, the radial clearance is less than or equal to 0.03 mm, an axial matching section is arranged between the cylinder 500 and the inner wall of the oil seal groove 120, the length of the axial matching section is W, the general W is equal to the depth of the oil seal groove 120, the bottom face of the cylinder 500 is abutted to the bottom of the oil seal groove 120, positioning between the cylinder 500 and the oil seal groove 120 can be ensured by the axial matching section under the supporting condition of the bottom of the oil seal groove 120, so far, the front end cover 1 and the cylinder 500 are preassembled through the inner wall of the oil seal groove 120, and the front end cover 1 and the cylinder 500 become a first same shaft body.

The inside coaxial cylinder cavity 510 that is equipped with of cylinder 500, cylinder cavity 510 opening is in the bottom surface of cylinder 500, open-ended diameter equals the diameter of cylinder cavity 510, move to the axle along the axis and stretch 2 on when first coaxial body, the medial surface of cylinder cavity 510 and the axle stretch 2 between be equipped with radial positioning's clearance and can the relative slip, first coaxial body embolias the axle and stretches 2 when, also constitute the coaxial body with the axle, because the axis coincidence of first coaxial body and second coaxial body, make front bearing 3 slide the bearing chamber 100 of front end housing 1 bottom smoothly, realize coaxial no card installation between front end housing 1 and the front bearing 3. Even if the front cover 1 is in the inclined state, the coaxialization function can correct the inclined state of the front cover 1, so that the front cover 1 keeps the coaxial state, and the front bearing 3 smoothly slides into the bearing chamber 100 at the bottom of the front cover 1.

This embodiment is particularly suitable when the axial depth of the spindle entry hole 110 is less than 7 mm.

Further, the diameter of the cylindrical cavity 510 is equal to or larger than the diameter of the shaft-insertion hole 110 in the front end cap 1.

The difference from the above embodiment is that the coaxial jig 5 further includes an air vent 520, the air vent 520 is located at the top of the cylinder 500, the air vent 520 is communicated with the cylindrical cavity 510, when the cylindrical cavity 510 is sleeved into the shaft extension 2, air in the cylindrical cavity 510 can be exhausted, and it is ensured that the coaxial body formed by preassembling the front end cap 1 and the cylinder 500 is assembled in place, as shown in fig. 4-6, which is an embodiment of the air vent 520.

In a preferred embodiment, the outer surface of the cylinder 500 is provided with visual graduations 530. The generally visual scale 530 is flush with the top of the front end cap 1 to facilitate inspection of the front end cap 1 in place.

As shown in fig. 4 and 5, the upper portion of the cylinder 500 is provided with a circumferential knurl, the height of the knurl is G, the value range of G is generally 10-30 mm, and the tool 5 has an anti-slip function, so that the tool can be taken and placed smoothly before and after assembly.

In addition, in order to adapt to various shapes of the shaft extensions 2, the side surface of the cylindrical cavity 510 is provided with an avoiding groove 590 avoiding the convex part on the shaft extension 2.

In a preferred embodiment, the radial clearance between the side surface of the cylindrical cavity 510 and the shaft extension 2 is less than or equal to 0.03 mm.

And coaxiality is set between the cylinder 500 and the cylinder cavity 510, and the coaxiality is less than or equal to 0.02 mm.

The length W of the axial matching section of the first coaxial body is larger than or equal to 7 mm, so that the inclined state of the front end cover 1 can be better corrected, and the front end cover 1 can be kept in a coaxial state.

As shown in fig. 15, the difference from the second scheme is that the front end cover 1 is provided with a pressing mechanism 6 for fixing the cylinder 500, and the pressing mechanism 6 may adopt a fastening manner in the prior art, as long as the first coaxial body is not separated in the process of assembling the shaft extension 2, which is not described again.

In addition, the smoothness of the inner side surface of the cylindrical cavity, such as the smoothness Ra0.8-Ra1.6, is improved, so that the sliding friction force between the cylindrical cavity and the shaft extension can be greatly reduced, and the guide-in is convenient.

Also, as shown in fig. 9 to 10, the top of the cylinder 500 is provided with a handle 540, particularly a rotatable handle 540, the axis of the rotation shaft of which is perpendicular to the axis of the rotor 4, and the axis of the handle 540 intersects with the axis of the rotor 4.

In addition, the assembly steps of the second embodiment are:

step 1: the coaxialization jig 5 is pre-arranged in the oil seal groove 120 on the front end cover 1 by lifting the lifting handle part 540;

step 2: the front end cover 1 is sleeved into the shaft extension 2, so that the front bearing 3 smoothly slides into a bearing chamber 100 at the bottom of the front end cover 1;

and 4, step 4: the jig for coaxialization 5 is removed from the rotor single group by lifting the handle portion 540.

Similarly, the above embodiments are also applicable to the mounting process of the rear end cover, the rear bearing chamber and the rear bearing, and are not described herein again.

The above embodiments are only preferred embodiments of the present invention, not limiting the scope of the present invention, and all the equivalent changes made by the shape, structure and principle of the present invention change the inclination angle of the axis of the rotor 4 (not necessarily vertically upwards), and all should be covered in the protection scope of the present invention.

Claims

1. Realize the axialization tool of coaxial no card installation between end cover bearing chamber and the bearing, be applied to end cover installation process of deciding arbitrary end on rotor assembly production line, the rotor, its characterized in that, the axialization tool includes:

the second coaxial structure is matched with a second radial positioning structure preset on the rotating shaft and can form a second coaxial body with the rotating shaft; the first coaxial structure is coaxially connected with the second coaxial structure;

the first coaxial structure and the end cover, and the second coaxial structure and the rotating shaft are respectively in separable connection; the first coaxial body and the second coaxial body can be assembled in a preferred order to form the coaxial body.

2. The axialization jig of claim 1, wherein the first axialization structure comprises a cylinder;

3. The coaxialization jig according to claim 2, wherein a guide post capable of being slidably guided into the shaft end blind hole of the rotating shaft is installed in the cylindrical cavity, and a radial gap is formed between the guide post and the shaft end blind hole.

4. The coaxialization jig according to claim 3, wherein the guide post is slidable along an axis within the cylindrical cavity.

5. The coaxialization jig according to any one of claims 3 and 4, wherein the guide post is provided with a sliding limiting part, a lower stop block of the sliding limiting part is arranged in the cylindrical cavity, and when the limiting block slides downwards to abut against the lower stop block, the lower surface of the guide post protrudes out of the lower edge in the cylindrical cavity.

6. The coaxialization jig according to claim 5, wherein the cylindrical cavity is provided with an upper stopper of the slide limiting portion, and when the bottom surface of the cylinder abuts against the upper end surface of the front bearing, an axial gap is provided between the slide limiting portion and the upper stopper above the slide limiting portion.

7. The coaxialization jig according to claim 1,

the first coaxial structure comprises a cylinder;

the first radial positioning structure is a positioning groove which is arranged on the end cover and is coaxial with the rotating shaft sleeving hole, and the cylinder is arranged in the positioning groove in advance to form the first coaxial body;

8. The coaxialization jig according to claim 7, wherein the end cap is provided with a pressing mechanism for fixing the cylinder.

9. The coaxialization jig according to any one of claims 2 and 7, further comprising an exhaust hole, wherein the exhaust hole is located at the top of the cylinder and is communicated with the cylinder cavity.

10. The coaxialization jig according to any one of claims 2 and 7, wherein a handle portion for facilitating mounting and dismounting of the coaxialization jig is further provided at a top portion of the coaxialization jig.