Static pressure spindle

Abstract

The utility model discloses a static pressure main shaft, which comprises a shaft casing and a main shaft rotatably arranged in the shaft casing in a penetrating manner, the main shaft is provided with two shaft sleeves spaced along the axial direction of the main shaft, the inner wall of the shaft casing is provided with a static pressure part corresponding to the shaft sleeves, an oil film gap is arranged between the static pressure part and the shaft sleeves, and the oil film gap is arranged along the axial direction of the main shaft. A first oil return groove and a second oil return groove which are communicated with the oil film gap are formed in the positions, located on the two sides of the static pressure part, of the inner wall of the shaft shell respectively, an oil inlet hole and an oil return hole are formed in the shaft shell, the oil inlet hole is communicated with the oil film gap, and the oil return hole is communicated with the first oil return groove and the second oil return groove. The static pressure main shaft has the advantages that the circulation speed of pressure oil in an inner oil way of the static pressure main shaft can be increased, the stability of an oil film can be kept, heat dissipation of the main shaft can be accelerated, and therefore the main shaft is prevented from being damaged due to overheating.

Description

Technical Field

[0001] The utility model relates to the technical field of mechanical processing, in particular to a static pressure spindle. Background Art

[0002] A hydrostatic spindle utilizes hydrostatic bearings instead of traditional rolling bearings. Due to its advantages such as high rotational precision, strong vibration resistance, and low friction, it has become widely used in spindle design. The design of the spindle's internal oil circuit, a key component of the oil supply system, influences actual production operations.

[0003] The design of the oil return circuit influences the proper circulation of pressurized oil, oil pressure stability, oil temperature rise, cooling of the static pressure system, and oil spills and leaks. However, the issue of pressurized oil circulation speed is often overlooked by designers, yet it can cause significant problems in actual production operations. For example, if the pressurized oil circulates too slowly within the spindle's internal oil circuit, it can easily accumulate inside the spindle, affecting its proper operation. Furthermore, the pressurized oil cannot dissipate the heat generated by the spindle in a timely manner, potentially causing system overheating and damage to the spindle's internal structures. Utility Model Content

[0004] The purpose of the utility model is to provide a hydrostatic spindle, which can increase the circulation speed of pressure oil in the internal oil circuit of the hydrostatic spindle, which not only helps to maintain the stability of the oil film, but also can accelerate the heat dissipation of the spindle, thereby avoiding overheating and damage to the spindle.

[0005] The utility model is realized through the following technical solutions.

[0006] A static pressure main shaft comprises a shaft housing and a main shaft rotatably arranged in the shaft housing, the main shaft being provided with two shaft sleeves spaced apart along the axial direction of the main shaft, the inner wall of the shaft housing being provided with a static pressure portion corresponding to the shaft sleeve, an oil film gap being provided between the static pressure portion and the shaft sleeve, and along the axial direction of the main shaft, the inner wall of the shaft housing being provided with a first oil return groove and a second oil return groove respectively on both sides of the static pressure portion, and an oil inlet hole and an oil return hole being provided on the shaft housing, the oil inlet hole being connected to the oil film gap, and the oil return hole being connected to the first oil return groove and the second oil return groove.

[0007] As a further improvement of the present invention, the static pressure part is an annular protrusion provided on the inner wall of the shaft housing, an opening adapted to the shaft sleeve is formed on the static pressure part, and the wall surface of the static pressure part close to the shaft sleeve is loosely matched with the shaft sleeve to form the oil film gap.

[0008] As a further improvement of the present invention, a through hole is provided inside the shaft housing, and end covers are detachably fixed at both ends of the shaft housing. A mounting hole is provided on the end cover, and the through hole and the mounting hole are coaxially arranged. The main shaft is passed through the through hole and the two mounting holes.

[0009] As a further improvement of the present invention, along the axial direction of the main shaft, there is a spacing distance between the static pressure part and the adjacent end cover, and one end of the static pressure part close to the adjacent end cover is surrounded by the adjacent end cover and the inner wall of the shaft housing to form the second oil return groove.

[0010] As a further improvement of the present invention, the first oil return groove is an annular groove that is recessed inward relative to the inner wall of the shaft housing, and the first oil return groove is provided on a side of the static pressure portion away from the adjacent end cover.

[0011] As a further improvement of the present invention, the sleeve is tapered, the cross-sectional area of the sleeve gradually decreases along the axial direction of the main shaft, and the opening is configured as a tapered opening adapted to the sleeve.

[0012] As a further improvement of the present invention, an oil outlet hole is provided on the wall surface of the static pressure portion close to the shaft sleeve, and the oil outlet hole is connected to the oil inlet hole.

[0013] As a further improvement of the present invention, an inwardly recessed pressure oil groove is provided on the wall surface of the static pressure portion close to the shaft sleeve, and the oil outlet hole is formed on the bottom wall of the pressure oil groove.

[0014] As a further improvement of the present invention, the pressure oil grooves are provided in plurality, each of the pressure oil grooves is provided with an oil outlet hole, and each of the oil outlet holes on the shaft housing is provided with an oil inlet hole, and the plurality of pressure oil grooves are arranged at intervals along the circumference of the main shaft.

[0015] As a further improvement of the present invention, the shaft sleeve and the main shaft are interference fit.

[0016] Beneficial effects of the utility model:

[0017] The pressure oil can flow to the oil return hole through the first oil return groove and the second oil return groove, so that the pressure oil can quickly flow out of the hydrostatic spindle, which helps to speed up the speed of the pressure oil flowing out of the hydrostatic spindle, and then speed up the circulation speed of the pressure oil in the hydrostatic spindle. On the one hand, it can avoid the accumulation of pressure oil in the shaft housing, thereby maintaining the stability of the oil film. On the other hand, it can speed up the heat dissipation of the spindle and avoid overheating damage to the spindle. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The following is a detailed description of preferred embodiments of the present invention with reference to the accompanying drawings to help understand the purpose and advantages of the present invention, wherein:

[0019] Figure 1 This is a structural diagram of a static pressure spindle of the utility model;

[0020] Figure 2 Schematic diagram of the structure of the shaft housing;

[0021] Figure 3 It is a cross-sectional view showing the oil return hole, the oil outlet hole, the first oil return groove, and the second oil return groove being connected;

[0022] Figure 4 It is a cross-sectional view showing the oil inlet and the oil outlet being connected;

[0023] Figure 5 for Figure 4 Schematic diagram of the structure of part A. DETAILED DESCRIPTION

[0024] The present invention will be described in further detail below based on the accompanying drawings and implementation examples.

[0025] In this specification, directional terms such as up, down, left, right, front, back, front, back, top, and bottom, which are mentioned or may be mentioned, are defined relative to the configurations shown in the accompanying drawings. The terms "inside" and "outside" refer to directions toward or away from the geometric center of a specific component, respectively. These are relative concepts and may vary depending on the location and usage of the component. Therefore, these or other directional terms should not be construed as restrictive.

[0026] This embodiment provides a static pressure spindle, referring to Figures 1 to 5 , including a shaft housing 1 and a main shaft 2 rotatably arranged in the shaft housing 1, two shaft sleeves 3 spaced apart along the axial direction of the main shaft 2 are provided on the main shaft 2, and a static pressure portion 11 is provided on the inner wall of the shaft housing 1 corresponding to the shaft sleeve 3, and an oil film gap is provided between the static pressure portion 11 and the shaft sleeve 3. Along the axial direction of the main shaft 2, a first oil return groove 12 and a second oil return groove 13 communicating with the oil film gap are respectively provided on both sides of the static pressure portion 11 on the inner wall of the shaft housing 1, and an oil inlet hole 14 and an oil return hole 15 are provided on the shaft housing 1. The oil inlet hole 14 communicates with the oil film gap, and the oil return hole 15 communicates with the first oil return groove 12 and the second oil return groove 13.

[0027] When the hydrostatic spindle in this embodiment is actually used, the external oil supply equipment delivers pressurized oil to the oil film gap through the oil inlet hole 14, so that an oil film is formed between the hydrostatic part 11 and the shaft sleeve 3, and the pressurized oil will flow out under the action of pressure, and the outflowing pressurized oil will be collected in the first return oil groove 12 and the second return oil. Moreover, since the first return oil groove 12 and the second return oil groove 13 are both connected to the return oil hole 15, that is, the pressurized oil in the first return oil groove 12 and the second return oil groove 13 can all flow out from the shaft housing 1. In this process, the pressurized oil can bring the heat on the shaft sleeve 3 out to the outside of the shaft housing 1, which helps to reduce the operating temperature of the spindle 2, thereby avoiding overheating and damage to the spindle 2.

[0028] In this embodiment, since the pressure oil can flow to the oil return hole through the first oil return groove 12 and the second oil return groove 13, the pressure oil can quickly flow out of the hydrostatic spindle, which helps to speed up the speed of the pressure oil flowing out of the hydrostatic spindle, and then speed up the circulation speed of the pressure oil in the hydrostatic spindle. On the one hand, it can avoid the accumulation of pressure oil in the hydrostatic spindle, thereby maintaining the stability of the oil film. On the other hand, it can speed up the heat dissipation of the spindle 2, thereby avoiding overheating and damage to the spindle 2.

[0029] In this embodiment, connecting holes are provided on the groove walls of the first oil return groove 12 and the second oil return groove 13, and the connecting holes are connected to the oil return hole 15, that is, the pressure oil in the first oil return groove 12 and the second oil return groove 13 can be output from the oil return hole 15.

[0030] In this embodiment, the static pressure portion 11 is an annular protrusion provided on the inner wall of the shaft housing 1. An opening 111 is formed on the static pressure portion 11 to adapt to the shaft sleeve 3. The wall surface of the static pressure portion 11 close to the shaft sleeve 3 is gap-matched with the shaft sleeve 3 to form an oil film gap.

[0031] In this embodiment, a through hole 17 is provided inside the shaft housing 1, and end covers 4 are detachably fixed at both ends of the shaft housing 1. The end covers 4 are provided with mounting holes 41. The through hole 17 and the mounting holes 41 are coaxially arranged, and the main shaft 2 is passed through the through hole 17 and the two mounting holes 41. The end cover 4 here is beneficial to the later maintenance and cleaning of the hydrostatic main shaft on the one hand, and can seal the hydrostatic main shaft on the other hand, thereby avoiding leakage of pressure oil.

[0032] In this embodiment, along the axial direction of the main shaft 2, there is a spacing distance between the static pressure part 11 and the adjacent end cover 4. One end of the static pressure part 11 close to the adjacent end cover 4 is enclosed by the adjacent end cover 4 and the inner wall of the shaft housing 1 to form a second oil return groove 13, which is convenient for processing the shaft housing 1.

[0033] In this embodiment, the first oil return groove 12 is configured as an annular groove that is recessed inward relative to the inner wall of the shaft housing 1. The first oil return groove 12 is disposed on the side of the static pressure portion 11 away from the adjacent end cover 4. The structure of the annular groove makes it easier to confine the pressure oil within the first oil return groove 12, thereby reducing the risk of pressure oil leakage.

[0034] In this embodiment, the sleeve 3 is tapered, with its cross-sectional area gradually decreasing toward the center of the main shaft 2. Accordingly, the opening 111 is configured as a tapered opening 111 adapted to fit the sleeve 3. The edge of the static pressure portion 11 near the sleeve 3 is also tapered. The tapered sleeve 3 can bear both axial and radial loads, thereby reducing local stress concentration and increasing service life.

[0035] In this embodiment, an oil outlet hole 16 is provided on the wall surface of the static pressure part 11 close to the sleeve 3 side, and the oil outlet hole 16 is connected to the oil inlet hole 14. In addition, an inwardly recessed pressure oil groove 112 is provided on the wall surface of the static pressure part 11 close to the sleeve 3 side. The oil outlet hole 16 is formed on the bottom wall of the pressure oil groove 112. When the pressure oil flows out of the oil outlet hole 16, it will first diffuse and fill the pressure oil groove 112. The pressure oil in the pressure oil groove 112 has a higher oil pressure, so that it can withstand a larger load.

[0036] In this embodiment, there are multiple pressure oil grooves 112, and each pressure oil groove 112 is provided with an oil outlet hole 16. Each oil outlet hole 16 on the shaft housing 1 is provided with an oil inlet hole 14, and multiple pressure oil grooves 112 are arranged at intervals along the circumference of the main shaft 2. That is, the multiple pressure oil grooves 112 can evenly distribute the pressure on the shaft sleeve 3, thereby improving the bearing capacity of the shaft sleeve 3.

[0037] In this embodiment, the shaft sleeve 3 and the main shaft 2 are fixed by means of interference fit, so as to ensure that the relative position between the shaft sleeve 3 and the main shaft 2 is stable.

[0038] Finally, it should be noted that the above implementation cases are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above implementation cases, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the above implementation cases, or replace some of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the implementation cases of the present invention.

Claims

1. A hydrostatic spindle, characterized in that: The invention comprises a shaft housing (1) and a main shaft (2) rotatably arranged in the shaft housing (1), wherein the main shaft (2) is provided with two shaft sleeves (3) spaced apart along the axial direction of the main shaft (2), and the inner wall of the shaft housing (1) is provided with a static pressure portion (11) corresponding to the shaft sleeve (3), and an oil film gap is provided between the static pressure portion (11) and the shaft sleeve (3), and along the axial direction of the main shaft (2), the inner wall of the shaft housing (1) is provided with a first oil return groove (12) and a second oil return groove (13) respectively on both sides of the static pressure portion (11) and connected to the oil film gap, and an oil inlet hole (14) and an oil return hole (15) are provided on the shaft housing (1), wherein the oil inlet hole (14) is connected to the oil film gap, and the oil return hole (15) is connected to the first oil return groove (12) and the second oil return groove (13).

2. The hydrostatic spindle according to claim 1, characterized in that: The static pressure portion (11) is an annular protrusion provided on the inner wall of the shaft housing (1). An opening (111) adapted to fit the shaft sleeve (3) is formed on the static pressure portion (11). The wall surface of the static pressure portion (11) close to the shaft sleeve (3) is gap-matched with the shaft sleeve (3) to form the oil film gap.

3. The hydrostatic spindle according to claim 2, characterized in that: A through hole (17) is provided inside the shaft housing (1), and end covers (4) are detachably fixed at both ends of the shaft housing (1). The end covers (4) are provided with mounting holes (41). The through hole (17) and the mounting holes (41) are coaxially arranged, and the main shaft (2) is inserted into the through hole (17) and the two mounting holes (41).

4. The hydrostatic spindle according to claim 3, characterized in that: Along the axial direction of the main shaft (2), there is a spacing distance between the static pressure portion (11) and the adjacent end cover (4), and an end portion of the static pressure portion (11) close to the adjacent end cover (4) is enclosed by the adjacent end cover (4) and the inner wall of the shaft housing (1) to form the second oil return groove (13).

5. The hydrostatic spindle according to claim 4, characterized in that: The first oil return groove (12) is an annular groove that is recessed inwardly relative to the inner wall of the shaft housing (1). The first oil return groove (12) is provided on a side of the static pressure portion (11) away from the adjacent end cover (4).

6. The hydrostatic spindle according to claim 2, characterized in that: The shaft sleeve (3) is tapered, and the cross-sectional area of the shaft sleeve (3) gradually decreases along the axial direction of the main shaft (2). The opening (111) is configured as a tapered opening (111) adapted to the shaft sleeve (3).

7. The hydrostatic spindle according to claim 2, characterized in that: An oil outlet hole (16) is provided on the wall surface of the static pressure portion (11) on the side close to the shaft sleeve (3), and the oil outlet hole (16) is connected to the oil inlet hole (14).

8. The hydrostatic spindle according to claim 7, characterized in that: An inwardly recessed pressure oil groove (112) is provided on the wall surface of the static pressure portion (11) close to the shaft sleeve (3), and the oil outlet hole (16) is formed on the bottom wall of the pressure oil groove (112).

9. The hydrostatic spindle according to claim 8, characterized in that: The pressure oil grooves (112) are provided in a plurality, and each of the pressure oil grooves (112) is provided with an oil outlet hole (16). The shaft housing (1) is provided with an oil inlet hole (14) corresponding to each of the oil outlet holes (16). The plurality of pressure oil grooves (112) are arranged at intervals along the circumference of the main shaft (2).

10. The hydrostatic spindle according to any one of claims 1 to 9, characterized in that: The shaft sleeve (3) and the main shaft (2) are interference fit.

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