Fixture for dynamic balancing of high-pressure compressor rotor

Abstract

The present invention discloses a fixture for dynamic balancing of a high-pressure compressor rotor, which includes a positioning sleeve, a bushing, an end cover, a process bushing, an adjusting pad, a mandrel nut, a bearing cover and a face gear plate mounted on a mandrel assembly. A ball bearing connected to the large outer diameter end of the high-pressure compressor rotor is assembled in the positioning sleeve, and the axial displacement of the ball bearing is restricted by the bushing and the end cover. The face gear plate and the process bushing are used for installing a cylindrical roller bearing, and the face gear plate is connected to the small outer diameter end of the high-pressure compressor rotor through the face teeth on its own surface. The present invention can efficiently capture the rotation center of the small outer diameter end of the high-pressure compressor rotor, and at the same time, in cooperation with the imbalance requirements of the bearing cover and the face gear plate, and the mass difference of each connecting part, the imbalance measurement of the high-pressure compressor rotor under the balance speed condition can be realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of aero-engine manufacturing, and specifically relates to a fixture for dynamic balancing of a high-pressure compressor rotor. Background Art

[0002] As Figure 1 shown, it is a schematic diagram of the structure of a high-pressure compressor rotor. When assembling an aero-engine, it is required to perform dynamic balancing on the high-pressure compressor rotor, and at a balancing speed of 1100 r / min, the unbalance amount ≤ 5 g·cm. Due to limitations in aspects such as the part structure and the structure of the dynamic balancing machine, it is impossible to directly conduct a dynamic balancing test on the part. The specific reasons are Figure 1 that there are no suitable shoulder structures at the axial two ends of the high-pressure compressor rotor in Figure 1 (the upper end and the lower end in Figure 1 ) to be placed on the bearing blocks of the dynamic balancing machine. On the other hand, the existing dynamic balancing machines do not have a dedicated connection structure to fix and install the high-pressure compressor rotor, resulting in the inability to directly drive the high-pressure compressor rotor to reach the balancing speed. Summary of the Invention

[0003] Aiming at Figure 1 the limitation problems in aspects such as the structure of the high-pressure compressor rotor and the structure of the dynamic balancing machine in Figure 1 , the present invention aims to provide a fixture for dynamic balancing of a high-pressure compressor rotor, which has a high fitting precision with the high-pressure compressor rotor, and the unbalance amount of the fixture itself is less than 0.5 g·cm, thereby meeting the dynamic balancing test requirements of the high-pressure compressor rotor.

[0004] The technical solution of the present invention is as follows:

[0005] A fixture for dynamic balancing of a high-pressure compressor rotor includes

[0006] a mandrel assembly. The cylindrical surfaces at the first axial end and the second axial end of the mandrel assembly are respectively connected to a balancing machine through balancing machine bearing blocks, and a tapered center hole serving as a benchmark for fixture manufacturing and inspection is provided on each of the end faces at the first axial end and the second axial end of the mandrel assembly;

[0007] a positioning sleeve. The positioning sleeve is sleeved on the mandrel assembly and is close to one side of the first axial end of the mandrel assembly. An annular positioning protrusion is provided on the end face at the first axial end of the positioning sleeve, and the second axial end of the positioning sleeve is rigidly connected to the mandrel assembly;

[0008] a ball bearing. The outer steel sleeve of the ball bearing is installed in the positioning sleeve by interference fit, and the end face at the first axial end of the ball bearing is closely attached to the annular positioning protrusion of the positioning sleeve. The inner steel sleeve of the ball bearing forms a hole-shaft fit with the large outer diameter end in the axial direction of the high-pressure compressor rotor;

[0009] A bushing, the bushing is placed inside the positioning sleeve, and the first axial end of the bushing is in close contact with the end face of the second axial end of the ball bearing;

[0010] An end cover, the end cover is placed inside the positioning sleeve and is rigidly connected to the positioning sleeve, and one end of the end cover is pressed against the second axial end of the bushing;

[0011] A process bushing, the process bushing is sleeved on the mandrel assembly and is close to one side of the second axial end of the mandrel assembly;

[0012] A cylindrical roller bearing, the inner steel sleeve of the cylindrical roller bearing is installed on the process bushing;

[0013] A face gear disk, the face gear disk is sleeved on the outer steel sleeve of the cylindrical roller bearing by interference fit, the face gear disk is a disk, and there is a circle of face teeth on the surface of the disk along the circumferential direction of the disk, and the face gear disk forms a face gear spline fit with the small outer diameter end of the axial direction of the high-pressure compressor rotor through the face teeth on the surface;

[0014] A bearing cover, the bearing cover is sleeved on the mandrel assembly and is rigidly connected to the end face of the face gear disk;

[0015] A mandrel nut, the mandrel nut is sleeved on the mandrel assembly and is in close contact with the process bushing.

[0016] Further, the second axial end of the positioning sleeve is rigidly connected to the mandrel assembly by screws, and the end cover is rigidly connected to the positioning sleeve by screws.

[0017] Further, the cone angle of the conical tip hole is 60°.

[0018] Further, the bearing cover is rigidly connected to the end face of the face gear disk by screws.

[0019] Further, an adjusting pad is also arranged between the mandrel nut and the process bushing, and the end face of the adjusting pad is in close contact with the inner steel sleeve of the cylindrical roller bearing.

[0020] Further, the face gear disk is also connected to the high-pressure compressor rotor through a connecting nut and a connecting screw.

[0021] Further, the unbalance of the bearing cover and the face gear disk is less than one-tenth of the unbalance of the high-pressure compressor rotor.

[0022] Further, the face teeth on the surface of the face gear disk are straight teeth.

[0023] Compared with the prior art, the present invention has the following characteristics:

[0024] (1) In the present invention, the connection between the dynamic balance fixture and the balancing machine is two cylindrical surfaces (shaft shoulder structures) on the mandrel assembly. The traditional inspection reference should be the rotational centers of the left and right cylindrical surfaces. However, for the convenience of manufacturing and inspection, the present invention uniformly uses the rotational center of the tapered tip hole used in manufacturing as the manufacturing and inspection reference. At the same time, a relatively high-precision runout tolerance is required for the two cylindrical surfaces, and all subsequent machining is based on the tip hole, maintaining a high degree of coaxiality.

[0025] (2) In the present invention, the dynamic balance fixture and the small outer diameter end of the high-pressure compressor rotor in the axial direction adopt a straight-tooth end-tooth disk fit. Using the self-centering principle of the end-tooth disk, with a high-precision fit of the straight teeth, the rotational center of the small outer diameter end of the high-pressure compressor rotor can be efficiently captured.

[0026] (3) Only the end-tooth disk, bearing cover, and connecting screws in the dynamic balance fixture of the present invention are involved in the dynamic balance. Therefore, only the unbalance of the bearing cover and the end-tooth disk itself needs to be restricted. For example, it is required to be less than one-tenth of the unbalance of the high-pressure compressor rotor. In addition, the mass difference of the connecting screws and nuts is restricted. The number of variables to be controlled is small, and it is easy to achieve the goal that the unbalance of the fixture itself is less than 0.5 g·cm. Description of the Drawings

[0027] Figure 1 is a schematic diagram of the assembly state of the dynamic balance fixture and the high-pressure compressor rotor in the present invention;

[0028] Figure 2 is a schematic diagram of the tapered tip hole and cylindrical surface at the first axial end of the mandrel assembly in the present invention;

[0029] Figure 3 is a schematic diagram of the tapered tip hole and cylindrical surface at the second axial end of the mandrel assembly in the present invention;

[0030] Figure 4 is a partial schematic diagram of the connection between the second axial end of the mandrel assembly, the process bushing, the end-tooth disk, the adjustment pad, the bearing cover, and the mandrel nut in the present invention;

[0031] Figure 5 is a part schematic diagram of the end-tooth disk;

[0032] Figure 6 is a part schematic diagram of the high-pressure compressor rotor;

[0033] In the figure, 1 - positioning sleeve, 2 - bushing, 3 - end cover, 4 - process bushing, 5 - adjustment pad, 6 - mandrel nut, 7 - bearing cover, 8 - end-tooth disk, 9 - connecting nut, 10 - connecting screw, 11 - process cylinder, 12 - mandrel assembly. Detailed Embodiments

[0034] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. However, it should not be understood that the scope of the subject matter of the present invention is limited to the following embodiments. Without departing from the above technical idea of the present invention, all modifications, substitutions, and changes made according to ordinary technical knowledge and customary means in the art are included in the scope of the present invention.

[0035] As Figure 6 shown, it is a high-pressure compressor rotor part that needs to be dynamically balanced in the present invention. It can be seen from the figure that the upper end of the high-pressure compressor rotor is a shaft-shaped large outer diameter end, and the lower end is an axial small outer diameter end. When the balance speed of the high-pressure compressor rotor is 1100 r / min, the unbalance requirement is ≤ 5 g.cm.

[0036] As Figures 1 to 5 shown, the fixture for the dynamic balance of the high-pressure compressor rotor includes a positioning sleeve 1, a bushing 2, an end cover 3, a process bushing 4, an adjusting pad 5, a mandrel nut 6, a bearing cover 7, a face gear disk 8, a nut 9, a screw 10, a process cylinder 11, and a mandrel assembly 12.

[0037] Among them, the mandrel assembly 12 is mainly composed of a hollow stepped shaft and a disk part connected to the first axial end of the hollow stepped shaft. The disk part is connected to the hollow stepped shaft by screws. The mandrel assembly 12 is connected to the balance machine shaft bearing seat through the cylindrical surfaces at both axial ends of the hollow stepped shaft ( Figure 1 the two φ40g5 (-0.009 / -0.02) in

[0038] ), and is locked and fixed on the balance machine by screws;

[0039] Among them, the process bushing 4 is installed on the hollow stepped shaft at the axial other end of the mandrel assembly 12. The cylindrical roller bearing is assembled on the outer surface of the outer ring of the process bushing 4. The outer steel sleeve of the cylindrical roller bearing is in interference fit with the inner hole of the end-tooth disk 8. The bearing cover 7 is connected to the surface of the end-tooth disk 8 by screws. There is a circle of end-face straight teeth on the surface of the end-tooth disk 8 that is concentric with the end-tooth disk 8 and distributed on the circumference. The end-tooth disk 8 forms a spline fit with the high-pressure compressor rotor through the straight teeth on the end face, maintaining a relatively high fitting accuracy. The axial positions of the process bushing 4, the end-tooth disk 8, and the cylindrical roller bearing are controlled by the mandrel nut 6 and the adjusting pad 5.

[0040] As Figure 2 and Figure 3 shown, the inspection reference of the dynamic balance fixture is two conical center holes at both ends of the mandrel assembly 12. The connection between the dynamic balance fixture and the balancing machine is a cylindrical surface of φ40g5 (-0.009 / -0.02). According to the traditional method, the inspection reference should be the rotation center of the φ40g5 (-0.009 / -0.02) cylindrical surfaces at the left and right ends of the mandrel assembly. However, for the convenience of manufacturing and inspection in the present invention, the rotation center of the 60° center holes used for manufacturing is unified as the manufacturing and inspection reference. At the same time, a relatively high-precision runout tolerance is required for the two φ40g5 (-0.009 / -0.02) cylindrical surfaces to achieve high coaxiality.

[0041] As Figure 4 and Figure 5 shown, the present invention aligns the center of the high-pressure compressor rotor through the end-tooth disk 8. The dynamic balance machine fixture and the small outer diameter end of the high-pressure compressor rotor in the axial direction are matched by the straight teeth of the end-tooth disk 8. Utilizing the self-centering principle of the end teeth of the end-tooth disk 8, the rotation center of the small outer diameter end can be efficiently captured under the high-precision fit of the straight teeth on the end face.

[0042] On the other hand, since only the bearing cover 7, the end-tooth disk 8, the connecting nut 9, and the connecting screw 10 in the dynamic balance fixture participate in the dynamic balance test (the remaining components do not participate in rotation), therefore, in order to achieve the goal that the unbalance amount is ≤ 5 g.cm when the balance speed of the high-pressure compressor rotor is 1100 r / min, the dynamic balance fixture of the present invention only needs to require that the self-unbalance amounts of the bearing cover 7 and the end-tooth disk 8 are less than 0.5 g.cm, the mass difference of each single-piece connecting nut 9 is not greater than 0.05 g, and the mass difference of each single-piece screw and the connecting screw 10 is not greater than 0.05 g to achieve the goal.

[0043] The content not described in detail in the specification of the present invention belongs to the prior art well-known to those skilled in the art. Although the illustrative specific embodiments of the present invention are described above for the understanding of those skilled in the art of the present technology, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those of ordinary skill in the art of the present technology, as long as various changes are within the spirit and scope of the present invention defined and determined by the appended claims, these changes are obvious, and all inventions created using the concept of the present invention are within the scope of protection.

Claims

1. A fixture for dynamic balancing of a high-pressure compressor rotor, characterized in that: including a mandrel assembly (12), the cylindrical surfaces of the first axial end and the second axial end of the mandrel assembly (12) are respectively connected to a balancing machine through balancing machine bearing pedestals, and a tapered center hole serving as a reference for fixture manufacturing and inspection is respectively provided on the end face of the first axial end and the end face of the second axial end of the mandrel assembly (12); a positioning sleeve (1), the positioning sleeve (1) is sleeved on the mandrel assembly (12) and is close to one side of the first axial end of the mandrel assembly (12), an annular positioning projection is provided on the end face of the first axial end of the positioning sleeve (1), and the second axial end of the positioning sleeve (1) is rigidly connected to the mandrel assembly (12); a ball bearing (13), the outer steel sleeve of the ball bearing (13) is installed in the positioning sleeve (1) by interference fit, and the end face of the first axial end of the ball bearing (13) abuts against the annular positioning projection of the positioning sleeve (1), and the inner steel sleeve of the ball bearing (13) forms a hole-shaft fit with the large outer diameter end of the high-pressure compressor rotor in the axial direction; a bushing (2), the bushing (2) is placed inside the positioning sleeve (1), and the first axial end of the bushing (2) abuts against the end face of the second axial end of the ball bearing (13); an end cover (3), the end cover (3) is placed inside the positioning sleeve (1) and is rigidly connected to the positioning sleeve (1), and one end of the end cover (3) presses against the second axial end of the bushing (2); a process bushing (4), the process bushing (4) is sleeved on the mandrel assembly (12) and is close to one side of the second axial end of the mandrel assembly (12); a cylindrical roller bearing, the inner steel sleeve of the cylindrical roller bearing is installed on the process bushing (4); a face gear (8), the face gear (8) is sleeved on the outer steel sleeve of the cylindrical roller bearing by interference fit, the face gear (8) is a disc, and there is a circle of face teeth along the circumferential direction of the disc and on the surface of the face gear (8), and the face gear (8) forms a face spline fit with the small outer diameter end of the high-pressure compressor rotor through the face teeth on the surface, and the face gear (8) is also connected to the high-pressure compressor rotor through a connecting nut (9) and a connecting screw (10); a bearing cover (7), the bearing cover (7) is sleeved on the mandrel assembly (12) and is rigidly connected to the end face of the face gear (8); a mandrel nut (6), the mandrel nut (6) is sleeved on the mandrel assembly (12) and abuts against the process bushing (4); the unbalance of the bearing cover (7) and the face gear (8) is less than one-tenth of the unbalance of the high-pressure compressor rotor.

2. The fixture for dynamic balancing of a high-pressure compressor rotor according to claim 1, wherein: The second axial end of the positioning sleeve (1) is rigidly connected to the mandrel assembly (12) by screws, and the end cover is rigidly connected to the positioning sleeve (1) by screws.

3. The fixture for dynamic balancing of a high-pressure compressor rotor according to claim 1, wherein: The taper angle of the tapered center hole is 60°.

4. The fixture for dynamic balancing of a high-pressure compressor rotor according to claim 1, characterized in that: The bearing cover (7) is rigidly connected to the end face of the face gear (8) by screws.

5. The fixture for dynamic balancing of a high-pressure compressor rotor according to claim 1, characterized in that: An adjusting pad (5) is further arranged between the mandrel nut (6) and the process bushing (4), and the end face of the adjusting pad (5) abuts against the inner steel sleeve of the cylindrical roller bearing.

6. The fixture for dynamic balancing of a high-pressure compressor rotor according to claim 1, wherein: The face teeth on the surface of the face gear (8) are straight teeth.

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