CN103883356B - Blade pneumatic motor - Google Patents

Abstract

The invention discloses a high-performance blade air motor, which includes a casing, a rotor, blades, a sealing strip, an air distribution cone and a spacer. Inside, the vane is placed in the hollow ring at the opposite corner of the housing, and is also located in the groove of the rotor, and forms an angle with the rotor. One plane of the vane fits with the side of the round table of the oil distribution cone, and the sealing strip is located between the rotor and the rotor. Between the blades, one side of the flat surface is attached to the rotor, and the side of the circular table surface is attached to the circular table surface E1 of the blade. The spacer is located in the hollow ring at the opposite corner of the shell, just filling the shell, the blade, and the rotor. and the gap formed by the sealing strip. All sealing parts of the present invention are surface seals; small volume, large torque, high efficiency; high specific power; compact structure, relatively easy processing; low cost, long life.

Description

A vane air motor

technical field

The invention relates to an air motor, in particular to a high-performance vane air motor.

Background technique

The structure of the existing vane air motor is that the rotor is eccentrically placed in the cylinder body, and the vanes are placed in the rotor radially or at a certain angle with the rotor radius. When working, the vanes are thrown out under the action of springs or air pressure, forming a sealed cavity. This type of vane air motor is sealed by a contact line between the vane and the cylinder block, so the sealing performance is poor, the output torque is low, and there is a lot of friction between the vane, the rotor and the cylinder block during rotation, causing the vane The overall wear of the air motor is fast, the life is short, and the efficiency is low. In addition, in order to ensure that the blades can safely enter and exit the rotor during rotation, the rotor must have a considerable diameter, which is bound to be large in size and low in specific power. Although there is a double-blade air motor, since there are only two blades, the output torque fluctuates greatly. , The output torque is also owed.

Contents of the invention

The purpose of the present invention is to provide a high-performance vane air motor that can achieve high specific power, large output torque, small output torque pulsation, all sealing parts are surface seals, and is not easy to wear.

In order to achieve the above purpose, the technical scheme adopted by the present invention is as follows: high-performance vane air motor, including housing, rotor, vane, sealing strip, air distribution cone and cushion block, the rotor is located at the center, the housing is located outside, and the air distribution cone is located at the In the hollow circular table at both ends of the rotor, the blades are placed in the hollow ring at the opposite corner of the housing, and are also located in the groove of the rotor, and form an angle with the rotor. One plane of the blade is in contact with the side of the circular table of the oil distribution cone. The sealing strip is located between the rotor and the blade, the flat side of which is attached to the rotor, and the side of the circular table is attached to the circular table E1 of the blade. The pad is located in the hollow ring at the opposite corner of the shell, just filling The void formed by the casing, vanes, rotor and seal strips.

In the above-mentioned high-performance vane air motor, the vane is a quarter circle, and there are four identical pieces, one of which is composed of two planes A1, B1, cylinder C1, spherical surface D1 and two circular table surfaces E1, Enclosed by J1; among them, C1 is a cylindrical surface whose center is the spherical center O1 and whose radius is the same as that of the cylindrical surface E4 of the hollow ring of the housing, and D1 is a spherical surface whose spherical center is O1 and the radius is the same as that of the rotor table C2. , E1 and J1 are circular table tops, the diameters of the upper and lower bottom surfaces are straight line R1S1 and straight line M1N1 respectively, and M1R1 and N1S1 are the side generatrices; the two planes A1 and B1 are parallel; the distance between the two parallel planes A1 and B1 is The thickness of the blade, the thickness of the blade is equal to the width of the hollow ring of the shell;

There are eight same sealing strips, one of which is a round table on the E1 side, the diameters of its upper and lower bottom surfaces are straight lines R1S1 and P1Q1 respectively, P1R1 and N1S1 are its side busbars, and the K1 side is a plane, passing through the center of the ball O1 The axis is parallel to the plane, and its vertical distance is half of the thickness of the cross plate perpendicular to the rotor. G1 is a spherical surface whose center is O1 and the radius is equal to the radius of the rotor center table C2. F1 is a sphere whose center is O1 and the radius is equal to the rotor line segment O2M2. The two surfaces of H1 and I1 are parallel planes, and its semi-length OP1 is equal to the radius of the casing cylinder F4. R1 and S1 are two slopes equal to the slope of the middle surface D4 to B4. The sealing strip The width is equal to the thickness of the blade; both the blade and the sealing strip are axisymmetric;

In the middle of the rotor is a waist-drum-shaped ball table with two spherical crowns cut off in parallel at both ends. An orthogonal cross plate is inserted symmetrically in the middle of the table. A2 and B2 are parallel circular planes, and C2 and D2 are spherical surfaces whose center is O2. I2 and J2 are two planes perpendicular to each other. One blade and two sealing strips are vertically placed in the groove between I2 and J2, which are just completely sealed. E2 and F2 are the central axis passing through the radius of O2 and the cylindrical surface of the shell F4 Cylindrical surfaces with the same radius, G2 and H2 are the sides of two identical hollow circular pedestals. The upper and lower bottoms of one hollow circular pedestal are the circular plane B2 and the circular surface with the straight line K2L2 as the diameter. The length of the straight line segment of K2M2 is the width of the rotor. The entire rotor is not only symmetrical about the center O2 of the ball table, but also axisymmetric;

The gas distribution cone is a circular platform, which has two identical ones. The radii of the upper and lower bottoms A3 and B3 of one circular platform are respectively equal to the radii of the upper and lower bottoms of the rotor hollow circular platform G2 and H2, and the height is also the same as that of the rotor hollow circular platform side G2. It is equal to the height of H2, and one side is a plane C3 intercepted by a plane. This plane can be parallel to the busbar on the side of the gas distribution cone, or not parallel to the busbar on the side of the gas distribution cone. The widest part of the plane C3 The width is not greater than the thickness of the cross plate perpendicular to the rotor, and the plane C3 fits with the corresponding parallel planes C4 and D4 of the shell ring;

The shell is a waist drum-shaped spherical surface with two spherical caps cut off in parallel at both ends, the thickness is equal to the width K2M2 of the rotor, A4 and B4 are two parallel circular planes with equal radii, F4 is a cylindrical surface, and its central axis passes through O4 , the radius is equal to the radius of the left and right outer cylinders E2 and F2 of the rotor, the opposite corner of the shell cylinder is a hollow ring, the width of the ring is equal to the thickness of the blade, and the two sides C4 and D4 of the hollow ring are parallel circles Ring plane, E4 is the cylindrical surface whose central axis passes through O4, located on the diagonal of the shell, its outer diameter is equal to the outer diameter of the blade cylindrical surface C1, and larger than the outer diameter of the shell spherical surface F4, the ring is parallel to C4 The two planes of D4 and C3 on the side of one gas distribution cone and the corresponding plane on the side of the other gas distribution cone fit together, and the whole shell is symmetrical about the center O4 of the ball table;

The spacer is a section of ring, which has the same four pieces in total. One of the outer side A5 is a cylindrical surface with a radius equal to the outer diameter of the housing diagonal ring E4, and the inner side B5 is a spherical surface with a radius equal to the rotor line segment O2M2 in Figure 4. Its upper and lower thicknesses are the same as The cross plate width K2M2 orthogonal to the rotor is equal, the two waists C5 and D5 are circular table tops, the diameters of the bottom surface and the lower bottom surface of the circular table top are straight lines P1Q1 and M1N1 respectively, M1P1 is its side busbar, and the shape of the spacer is axisymmetric.

The advantage that the present invention has is:

1) All seals are face seals;

2) Small size, large torque and high efficiency;

3) Large specific power;

4) Compact structure, relatively easy processing;

5) Low cost and long life.

Description of drawings

The present invention will be further described below in conjunction with drawings and embodiments.

Fig. 1 is the schematic diagram of blade and sealing strip shape of the present invention;

Fig. 2 is the left view of Fig. 1;

Fig. 3 is a schematic diagram of the S direction and the T direction of Fig. 1;

Fig. 4 is a schematic diagram of the rotor shape of the present invention;

Fig. 5 is a W-W sectional schematic diagram of Fig. 4;

Fig. 6 is a schematic diagram of the gas distribution cone shape of the present invention;

Figure 7 is a schematic diagram of the P direction in Figure 6

Figure 8 is a top view of the housing of the present invention;

Fig. 9 is a front view of the casing of the present invention;

Fig. 10 is the M-M sectional schematic diagram of Fig. 9;

Figure 11 is a schematic diagram of the overall structure of the present invention;

Fig. 12 is a schematic diagram of the K direction of Fig. 11;

Fig. 13 is the N-N sectional schematic diagram of Fig. 11;

Fig. 14 is a schematic diagram of the operating principle of the present invention;

Fig. 15 is a U-U sectional schematic diagram of Fig. 11;

Fig. 16 is a schematic diagram of the principle of the working process of the present invention;

Fig. 17 is a V-V cross-sectional schematic diagram of Fig. 14;

Fig. 18 is a schematic diagram of the principle of the working process of the present invention.

In the figure: 1. Shell, 2. Rotor, 3. Blade, 4. Sealing strip, 5. Air distribution cone, 6. Spacer.

detailed description

The structure of the present invention is shown in Figure 14, the rotor 2 is located at the center, the housing 1 is located outside, the gas distribution cone 5 is located in the hollow circular table at both ends of the rotor 2, and the blades 3 are placed on the hollow ring at the opposite corner of the housing 1 ( Guide groove), and also located in the groove of rotor 2, and form an angle with rotor 2, a plane of blade 3 fits with the side of the round platform of oil distribution cone 5, and sealing strip 4 is located between rotor 2 and blade 3 , the plane side of which fits the rotor 2, and the round table side fits the round table E1 of the blade 3, and the spacer 6 is located in the hollow ring at the opposite corner of the housing 1, just filling the housing 1, the blade 3. The vacancy formed by the rotor 2 and the sealing strip 4.

Figures 1 and 3 show the shapes of the blade 3 and the sealing strip 4 of the present invention. The blade 3 is a quarter circle or approximately a quarter circle, and there are four same pieces in total. One of the blades 3 is surrounded by two planes A1, B1, cylinder C1, spherical D1 and two circular table surfaces E1, J1. Wherein, C1 is the cylindrical surface whose center is the center of the sphere O1 and whose radius is the same as the radius of the cylindrical surface E4 of the hollow ring of the housing 1, and D1 is the same as the radius of the ball table C2 of the rotor 2 in Fig. 5 with the center of the sphere being O1 E1 and J1 are circular table surfaces, the diameters of the upper and lower bottom surfaces are straight line R1S1 and straight line M1N1 respectively, and M1R1 and N1S1 are the side generatrices; the two planes A1 and B1 are parallel; the diameters of the two parallel planes A1 and B1 The distance is the thickness of the blade 3, and the thickness of the blade 3 is equal to the width of the hollow ring of the casing 1 in FIG. 9 .

There are eight same sealing strips 4, one of which is a round table on the E1 side, the diameters of its upper and lower bottom surfaces are straight lines R1S1 and P1Q1 respectively, P1R1 and N1S1 are its side bus bars, and the K1 side is a plane, passing through the center of the sphere O1. The axis (as shown in Figure 1) is parallel to the plane, and its vertical distance is half of the thickness of the cross plate perpendicular to the rotor 2 in Figure 5. G1 is a spherical surface whose center is O1 and the radius is equal to the radius C2 of the rotor 2 center table in Figure 5 , F1 is the spherical surface whose center is O1 and the radius is equal to the line segment O2M2 of the rotor 2 in Figure 4, the two surfaces H1 and I1 are parallel planes, and its half-length OP1 is equal to the radius of the cylindrical surface F4 of the housing 1 in Figure 9, R1 and S1 are two For an inclined plane whose slope is equal to that of surface D4 to B4 in Figure 9, the width of the sealing strip 4 (that is, the distance between planes H1 and I1) is equal to the thickness of the blade 3; both the blade 3 and the sealing strip 4 are axisymmetric.

4 and 5 show the shape of the rotor 2 of the present invention. In the middle of the rotor 2 is a waist-drum-shaped ball table with two spherical crowns cut off in parallel at both ends. An orthogonal cross plate is inserted symmetrically in the middle of the table. A2 and B2 are parallel circular planes. C2 and D2 are spherical surfaces with the center of the ball being O2. I2 and J2 are two planes perpendicular to each other. The entire figure in Figure 1, that is, a blade 3 and two sealing strips 4 are vertically placed in the groove between I2 and J2, just completely close, E2 and F2 are the central axis Through the cylindrical surface whose radius O2 is the same as that of the shell 1 cylindrical surface F4, G2 and H2 are the side surfaces of two identical hollow circular pedestals, and the upper and lower bottoms of one hollow circular pedestal are respectively the circular plane B2 and the circular surface with the straight line K2L2 as the diameter, The length of the straight line segment of K2M2 is the width of the rotor 2, and the entire rotor 2 is not only symmetrical about the center O2 of the table, but also axisymmetric.

Figure 6 and Figure 7 show the shape of the gas distribution cone 5 of the present invention. The gas distribution cone 5 is a round table, and there are two identical ones. The radii of the upper and lower bottoms A3 and B3 of one round table are respectively equal to the radii of the upper and lower bottoms of the rotor 2 hollow round table side G2 and H2, and the height is also the same as that of the rotor 2 hollow round table side. The heights of G2 and H2 are equal, and one side is a plane C3 that is cut by a plane. This plane can be parallel to the busbar on the side of the gas distribution cone 5 round platform, or not parallel to the busbar on the side of the gas distribution cone 5 round platform. The plane C3 is the most The width of the wide part is not greater than the thickness of the cross plate orthogonal to the rotor 2, and the spatial position of the plane C3 is determined as follows: after assembly, the plane C3 and the corresponding parallel planes C4 and D4 of the ring of the shell 1 are guaranteed to fit together, point The circular table surface from D3 to E3 is the exhaust surface, the circular table surface from point D3 to E3 is 135 degrees, the circular table surface from point F3 to G3 is the air intake surface, and the circular table surface from F3 to G3 is less than 135 degrees.

Fig. 8, Fig. 9 and Fig. 10 show the shape of the casing 1 of the present invention. Shell 1 is a waist drum-shaped spherical surface with two spherical caps cut off in parallel at both ends, and its thickness is equal to the width K2M2 of rotor 2. A4 and B4 are two parallel circular planes with equal radii. F4 is a cylindrical surface, and its central axis passes through O4 , the radius is equal to the radius of the left and right outer cylinders E2 and F2 of the rotor 2, the opposite corner of the cylinder of the housing 1 is a hollow ring, the width of the ring is equal to the thickness of the blade 3, and the two sides C4 and D4 of the hollow ring are Parallel torus plane, E4 is the cylindrical surface whose central axis passes through O4, located on the diagonal of the shell 1, its outer diameter is equal to the outer diameter of the cylindrical surface C1 of the blade 3, and is larger than the outer diameter of the spherical surface F4 of the shell 1 , the spatial positions of the two planes C4 and D4 parallel to the circular ring are determined as follows: ensure that the two planes C4 and D4 fit together with the plane C3 on the side of one gas distribution cone 5 and the corresponding plane on the side of the other gas distribution cone 5 . The entire shell 1 is symmetrical about the center O4 of the table.

Figure 13 shows the shape of the spacer 6 of the present invention. Pad block 6 is a section of ring, which has the same four pieces. One of the outer sides A5 is a cylindrical surface with a radius equal to the outer diameter of the diagonal ring E4 of the housing 1, and the inner measurement B5 is a spherical surface with a radius equal to the line segment O2M2 of the rotor 2 in Figure 4. Its upper and lower thickness is equal to the width K2M2 of the cross plate orthogonal to the rotor 2. The two waists C5 and D5 are circular table tops. The diameters of the upper and lower bottom surfaces of the circular table are respectively straight lines P1Q1 and M1N1 (as shown in Figure 1), and M1P1 is It is the side generatrix, and the pad 6 is axisymmetric in shape.

Operation principle of the present invention is as follows:

As shown in Figure 16, at one end of the air motor, the rotor 2, the blade 3, the sealing strip 4, the air distribution cone 5 and the housing 1 divide the air chamber into five independent sealed chambers Q1, Q2, Q3, Q4 and Q5.

At one end of the rotor 2, when the rotor 2 is at the intake starting position (as shown in Figure 15), high-pressure gas enters the air chamber Q1 from the air inlet surface of the air distribution cone, as shown in Figure 16, and the air chambers Q4 and Q5 are already full High-pressure air, while the air chambers Q2 and Q3 are low-pressure air. The pressure difference formed by the five air chambers generates torque on the rotor 2, causing the rotor 2 to rotate counterclockwise, and then pushes the blade 3 to rotate counterclockwise. When the rotor 2 rotates counterclockwise, the low-pressure air in the air chambers Q2 and Q3 is discharged through the exhaust surface of the air distribution cone 5 . When the high-pressure gas continues to enter the air chambers Q1, Q4 and Q5 from the air intake surface of the distribution cone 5, the rotor 2 continues to rotate counterclockwise.

When the rotor 2 turns to the position shown in Figure 16 and continues to rotate counterclockwise, the air chamber Q4 changes from the high-pressure intake chamber to the low-pressure exhaust chamber, while the high-pressure air continues to enter the air chambers Q1 and Q5, and the air chambers Q2 and Q3 remain It is a low-pressure exhaust chamber. The torque generated by the air pressure difference continues to push the rotor 2 to rotate counterclockwise. When the rotor 2 rotates counterclockwise to the position shown in Figure 17, the low-pressure air in the exhaust chamber Q2 is exhausted, while Q1 and Q5 are still high-pressure intake chambers, and Q3 and Q4 are still It is a low-pressure exhaust chamber. At this time, high-pressure gas enters a new high-pressure air intake chamber from the air intake surface of the gas distribution cone 5, pushing the rotor 2 to continue to rotate counterclockwise.

When the rotor 2 rotates to the position shown in Figure 18 and continues to rotate, chamber Q5 changes from a high-pressure intake chamber to a low-pressure exhaust chamber. At this time, Q1 is still a high-pressure intake chamber, Q3 and Q4 are still low-pressure exhaust chambers, and the high-pressure The air continues to enter the new high-pressure air intake chamber, pushing the rotor 2 to continue to rotate counterclockwise.

When the rotor 2 turns counterclockwise to the position shown in Figure 15, the low-pressure air in the exhaust chamber Q3 is exhausted, while Q1 is still a high-pressure intake chamber, Q4 and Q5 are still low-pressure exhaust chambers, and the high-pressure air is still entering a new high-pressure intake chamber. The air cavity pushes the rotor 2 to continue to rotate counterclockwise.

When the rotor 2 rotates to the position shown in Figure 16 and continues to rotate, the cavity Q1 changes from a high-pressure intake cavity to a low-pressure exhaust cavity. Repeatedly, the rotor 2 is constantly rotated counterclockwise. On the other end of the air motor, the situation is exactly the same as this one.

The above-mentioned embodiments are used to illustrate the present invention, rather than to limit the present invention. Within the spirit of the present invention and the protection scope of the claims, any modification and change made to the present invention will fall into the protection scope of the present invention.

Claims (1)

1. a kind of blade pneumatic motor is it is characterised in that include housing（1）, rotor（2）, blade（3）, sealing strip（4）, distribution Cone（5）And cushion block（6）, rotor（2）Positioned at housing（1）Center, housing（1）Externally-located, distribution is bored（5）Positioned at rotor（2）Two In the open circles table top of end, blade（3）It is placed in housing（1）In diagonal hollow ring, it also is located at rotor simultaneously（2）Groove Interior, and and rotor（2）At an angle, blade（3）A plane and distribution bore（5）Frustum cone side fit, sealing strip （4）Positioned at rotor（2）And blade（3）Between, its plane side and rotor（2）Laminating, round table surface side then with blade（3）'s Round table surface E1 is fitted, cushion block（6）Positioned at housing（1）In diagonal hollow ring, just fill up by housing（1）, blade（3）, turn Son（2）And sealing strip（4）The vacancy being formed；

Described blade（3）Circular for a quarter, total identical four, wherein a piece of blade（3）By two planes A1, B1 and Cylinder C1, sphere D1 and two round table surface E1, J1 enclose and form；Wherein, cylinder C1 be center be centre of sphere O1, radius and housing（1） The cylinder E4 of hollow ring radius identical cylinder, sphere D1 is the centre of sphere is O1 radius and rotor（2）Sphere C2 radius phase With sphere, the upper bottom surface diameter of round table surface E1 and round table surface J1 is all straight line R1S1, the going to the bottom of round table surface E1 and round table surface J1 The diameter in face is all straight line M1N1, and the side bus of round table surface E1 is straight line M1R1, and the side bus of round table surface J1 is straight line N1S1；Plane A1 is parallel with plane B1；The distance of plane A1 and plane B1 is blade（3）Thickness, blade（3）Thickness and housing （1）Hollow ring width equal；

Described sealing strip（4）Total identical eight, wherein one sealing strip（4）The face contacting with round table surface E1 be round platform Face, the diameter of the upper bottom surface of this round table surface is straight line R1S1, and the diameter of bottom surface is straight line P1Q1, the side bus of this round table surface It is straight line P1R1, the diameter parallel of plane K1 of this round table surface and excessively centre of sphere O1, plane K1 is vertical with the axis crossing centre of sphere O1 Distance is rotor（2）The half of orthogonal four-bladed vane thickness of slab, sphere G1 is the centre of sphere is O1 radius and rotor（2）The sphere C2 at center The equal sphere of radius, sphere F1 is the centre of sphere is that O1 radius is equal to rotor（2）The sphere of line segment O2M2, plane H1 and plane I1 are put down OK, its half long OP1 and housing（1）Cylinder F4 radius is equal, and inclined-plane R1 and inclined-plane S1 is two gradients with plane D4 for disk The equal inclined-plane of the gradient of B4；Sealing strip（4）Width and blade（3）Thickness is equal；Blade（3）And sealing strip（4）It is axle Symmetrically；

Described rotor（2）Central is the parallel dolioform billiard table cutting out two spherical crowns in two, such as symmetrical insertion one in the middle of billiard table Orthogonal four-bladed vane, disk A2 is parallel with disk B2, and sphere C2 and sphere D2 is the sphere that the centre of sphere is O2, plane I2 peace Face J2 is mutually perpendicular to, a blade（3）With two sealing strips（4）In groove between plane I2 and plane J2 for the arranged orthogonal, Just completely closely sealed, cylinder E2 and cylinder F2 is that central shaft crosses centre of sphere O2, radius and housing（1）Cylinder F4 radius identical post Face, side G2 and side H2 are two identical hollow round table surface, and upper and lower two bottoms of one of hollow round table are round respectively Plane B2 and the disc with straight line K2L2 as diameter, the length of straigh line of straight line K2M2 is rotor（2）Width, whole rotor （2）Not symmetrical only about centre of sphere O2, it is also axial symmetry；

Described distribution cone（5）It is a round platform, total identical two, the radius of upper bottom surface A3 of one of round platform and rotor （2）The radius of the side G2 of hollow round table and side H2 upper bottom surface is equal, the radius of bottom surface B3 and rotor（2）Hollow round table The radius of side G2 and side H2 bottom surface is equal, height and rotor（2）The height phase of the side G2 of hollow round table and side H2 Deng one side is plane C3 cut by a plane phase；This plane C3 is bored with distribution（5）The bus of frustum cone side is parallel, or not With distribution cone（5）The bus of frustum cone side is parallel；The width of plane C3 the widest part is not more than rotor（2）Orthogonal four-bladed vane plate Thickness, plane C3 and corresponding housing（1）Annulus parallel plane C4 and plane D4 fit；

Described housing（1）It is parallel dolioform sphere, thickness and the rotor cutting out two spherical crowns in two（2）Width K2M2 phase Deng disk A4 is parallel with disk B4 and radius is equal, and the central shaft of cylinder F4 crosses center of circle O4, radius and rotor（2）Left and right The radius of the cylinder E2 in outside and cylinder F2 is equal, housing（1）Cylinder is diagonally a hollow ring, annular width and blade （3）Thickness is equal, and two sides of hollow ring are plane C4 and plane D4, and plane C4 is parallel with plane D4, housing（1）'s The central shaft of the cylinder E4 of hollow ring passes through center of circle O4, positioned at housing（1）Diagonal on, its external diameter and blade（3）Cylinder The external diameter of C1 is equal, and is more than housing（1）The external diameter of sphere F4, plane C4 and distribution cone（5）The plane C3 laminating of side, puts down Face D4 and another distribution cone（5）The respective planes laminating of side, whole housing（1）Symmetrical with regard to billiard table center O4；

Cushion block（6）It is one section of annulus, total identical four, the outside of wherein is radius and housing（1）Hollow ring The equal cylinder A5 of cylinder E4 external diameter, inner side is that radius is equal to rotor（2）The sphere B5 of line segment O2M2, its upper and lower thickness with turn Son（2）Orthogonal four-bladed vane width K2M2 is equal, and two waists are round table surface C5 and round table surface D5, this round table surface upper bottom surface and going to the bottom The diameter in face is straight line P1Q1 and straight line M1N1 respectively, and straight line M1P1 is then its side bus, cushion block（6）It is shaped as axial symmetry.