Dynamic and static pressure main shaft unit with cavity on outer circle

Abstract

The utility model discloses an outer circle open cavity type dynamic and static pressure main shaft unit which comprises a main shaft body, a bearing and an oil return cylinder, a circle of annular groove is formed in the outer surface of the main shaft body in the circumferential direction, the bearing is arranged on the periphery of the annular groove in a sleeved mode and used for covering the annular groove, and the end cover face of the bearing is tightly attached to a protruding end ring on the outer wall of the main shaft body. A second oil return groove is formed in the inner wall of a shaft barrel port of the bearing, a first oil return groove is formed in the side, close to the middle section of the main shaft body, of the annular groove, and when the first oil return groove is aligned with the second oil return groove, the second oil return groove communicates with the interior of the annular groove through the first oil return groove. Oil directly flows back into the oil return barrel through the first oil return groove and the second oil return groove, the backflow path is short, the oil is not prone to overflowing towards the other end close to the end ring, sealing between the oil return barrel and the bearing is enhanced through the sealing sleeve and the second O-shaped ring, and therefore the oil leakage situation is effectively reduced, and the service life of the oil return barrel is prolonged. And a sealing element is not required to be arranged at the outer end for sealing.

Description

Technical Field

[0001] The utility model relates to the technical field of dynamic and static pressure spindles, in particular to an external circular open cavity type dynamic and static pressure spindle unit. Background Art

[0002] The dynamic and static pressure spindle is a device that uses hydraulic pressure to achieve high-precision machining. Its working principle is to form an oil film between the spindle and the bearing through hydraulic pressure, so that the spindle can remain stable when rotating at high speed. Some dynamic and static pressure spindle unit structures in the prior art include a spindle, a bearing, and an oil supply device. An oil cavity is opened on the outer surface of the spindle journal, and several circumferentially evenly distributed oil cavities and oil inlet holes are opened. The oil supply device directly supplies oil to the oil cavity through the oil inlet holes, and the oil in the bearing and the spindle journal flows back to the oil tank through the gaps at both ends of the bearing. It is used to solve the problem that the copper sleeve is easily deformed when clamped during processing by opening several oil cavities on the inner circle of the traditional bearing copper sleeve.

[0003] However, after the oil cavity is opened on the main shaft surface, the oil is easy to flow out from the gaps at both ends of the bearing. At this time, seals need to be installed at both ends of the bearing for sealing, which is prone to oil leakage.

[0004] Therefore, we propose an external cylindrical open cavity dynamic and static pressure spindle unit to solve the above problems. Utility Model Content

[0005] The purpose of the utility model is to provide an external cylindrical open cavity type dynamic and static pressure spindle unit to solve the problems raised in the above background technology.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] An outer cylindrical open cavity type dynamic and static pressure spindle unit comprises a spindle body, a bearing and an oil return cylinder, wherein a ring groove is provided on the outer surface of the spindle body along the circumferential direction, and the bearing is sleeved on the outer periphery of the ring groove to cover the ring groove, the end cover surface of the bearing is in close contact with the end ring protruding on the outer wall of the spindle body, and an oil return groove 2 is provided on the inner wall of the shaft cylinder port of the bearing, an oil return groove 1 is provided on one side of the ring groove close to the middle section of the spindle body, and when the oil return groove 1 is aligned with the oil return groove 2, the oil return groove 2 is connected with the inside of the ring groove through the oil return groove 1, an axial oil inlet hole is provided in the axial direction inside the spindle body, and a plurality of radial oil inlet holes are provided in the radial direction at the axial oil inlet hole passing through the ring groove, which are connected to the ring groove;

[0008] A sealing sleeve is sleeved on the outer periphery of the shaft cylinder end of the bearing, and an oil return cylinder is sleeved on the outer periphery of the bearing. When the two ends of the oil return cylinder are respectively locked and connected with the edges of the end covers of the bearings on both sides by a plurality of sets of bolts and nuts, the oil return cylinder presses the sealing sleeve, and an oil return pipe is connected to the outer wall of the oil return cylinder.

[0009] In a further embodiment, the cross section of the annular groove has a vertical surface on one side close to the end ring and an inclined surface on the other side.

[0010] In a further embodiment, the sealing sleeve has a hollow truncated cone structure, and the outer diameter of the sealing sleeve close to the end ring is larger than the outer diameter of the other end.

[0011] In a further embodiment, a plurality of O-rings are evenly inlaid on the outer side wall of the sealing sleeve.

[0012] In a further embodiment, a plurality of O-rings 2 are embedded on both end surfaces of the oil return cylinder, the plurality of O-rings 2 are arranged in concentric circles, and the end cover of the bearing is in close contact with the O-rings 2.

[0013] In a further embodiment, the inner wall of the oil return cylinder adopts an inclined structure, and the inner wall of the oil return cylinder is inclined toward the oil return pipe, so that the oil return pipe is at the lowest point of the inner wall of the oil return cylinder.

[0014] Compared with the prior art, the beneficial effects of the utility model are:

[0015] The utility model provides the oil return groove one and the oil return groove two so that the oil in the ring groove tends to flow toward the middle section of the main shaft body. The oil directly flows back to the inside of the oil return cylinder through the oil return groove one and the oil return groove two. The reflux distance is short, so it is not easy to overflow to the other end of the end ring close to the oil return cylinder. The sealing sleeve and the O-ring two are used to enhance the sealing between the oil return cylinder and the bearing, thereby effectively reducing the occurrence of oil leakage. There is no need to provide a sealing member at the outer end, and the utility model is more practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of the utility model;

[0017] Figure 2 This is a schematic diagram of the main shaft structure of the utility model;

[0018] Figure 3 This is a schematic diagram of the installation structure of the main shaft body, bearing and sealing sleeve of the utility model;

[0019] Figure 4 It is a schematic diagram of the cross-sectional structure of the utility model;

[0020] Figure 5 It is a schematic diagram of the partially cutaway structure of the utility model.

[0021] In the figure: 1. main shaft body; 11. end ring; 12. ring groove; 121. oil return groove 1; 13. radial oil inlet hole; 14. axial oil inlet hole; 2. bearing; 21. oil return groove 2; 3. oil return cylinder; 31. oil return pipe; 4. sealing sleeve; 41. O-ring 1; 5. O-ring 2. DETAILED DESCRIPTION

[0022] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0023] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0024] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0025] See also Figure 1-5The outer cylindrical open cavity type dynamic and static pressure spindle unit comprises a spindle body 1, a bearing 2 and an oil return cylinder 3. A ring groove 12 is provided on the outer surface of the spindle body 1 along the circumferential direction, and the bearing 2 is sleeved on the outer periphery of the ring groove 12 to cover the ring groove 12. The end cover surface of the bearing 2 is in close contact with the end ring 11 protruding on the outer wall of the spindle body 1. An axial oil inlet hole 14 is provided in the spindle body 1 along the axial direction, and the axial oil inlet hole 14 penetrates the ring groove 12 and a plurality of radial oil inlet holes 13 are provided in the radial direction. The oil is input into the axial oil inlet hole 14 by the tail end of the spindle body 1, and the oil is input into the ring groove 12 through the radial oil inlet hole 13 to form an oil film between the spindle body 1 and the bearing 2. An oil return hole 14 is provided on the inner wall of the shaft cylinder port of the bearing 2. Groove 21, an oil return groove 121 is opened on one side of the annular groove 12 close to the middle section of the main shaft body 1, and when the oil return groove 121 is aligned with the oil return groove 21, the oil return groove 21 is connected with the annular groove 12 through the oil return groove 121, so that the oil is discharged from the annular groove 12 through the oil return groove 121 and the oil return groove 21, and the outer periphery of the shaft cylinder end of the bearing 2 is sleeved with a sealing sleeve 4, and the oil return cylinder 3 is sleeved on the outer periphery of the bearing 2, and the oil return cylinder 3 flows back into the inside of the oil return cylinder 3, and the outer wall of the oil return cylinder 3 is connected with an oil return pipe 31 for discharging the refluxed oil, and the two ends of the oil return cylinder 3 are respectively locked and connected with the edges of the end covers of the bearings 2 on both sides by a number of sets of bolts and nuts, and when the oil return cylinder 3 is locked, the oil return cylinder 3 presses the sealing sleeve 4, thereby enhancing the seal and reducing the possibility of oil leakage.

[0026] See also Figure 5 In order to further facilitate the reflux of oil, the cross section of the annular groove 12 is set to have a vertical surface on one side close to the end ring 11 and an inclined surface on the other side, so that when the main shaft body 1 rotates, the oil tends to flow back to the inclined surface, thereby facilitating the oil to flow out of the reflux groove.

[0027] See also Figure 4 In order to facilitate the oil discharge from the oil return cylinder 3, the inner wall of the oil return cylinder 3 is arranged to adopt an inclined structure. From the cross section, it can be seen that the inner wall of the oil return cylinder 3 is inclined in a funnel shape, and the inner wall of the oil return cylinder 3 is inclined toward the oil return pipe 31, so that the oil return pipe 31 is at the lowest point of the inner wall of the oil return cylinder 3, thereby facilitating the oil flow to the oil return pipe 31 for discharge.

[0028] See also Figure 2-5 In order to further improve the effect of preventing oil leakage, the outer shape of the sealing sleeve 4 is set to adopt a hollow truncated cone structure, and the outer diameter of the sealing sleeve 4 close to the end ring 11 is larger than the outer diameter of the other end. At the same time, a number of O-rings 41 are evenly inlaid on the outer wall of the sealing sleeve 4. When the oil return cylinder 3 presses the O-ring 41 and the sealing sleeve 4 along the axial direction, the sealing performance is stronger.

[0029] See also Figure 5Furthermore, in order to enhance the sealing, a plurality of O-rings 5 ​​are embedded on both end surfaces of the oil return cylinder 3, and the plurality of O-rings 5 ​​are arranged in concentric circles, and the end cover of the bearing 2 is in close contact with the O-rings 5, thereby enhancing the sealing on the radial side.

[0030] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention. Any reference numeral in a claim should not be regarded as limiting the claim to which it relates.

[0031] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. An external cylindrical open cavity type dynamic and static pressure spindle unit, comprising a spindle body (1), a bearing (2) and an oil return cylinder (3), characterized in that: The outer surface of the main shaft body (1) is provided with a ring groove (12) along the circumferential direction, and the bearing (2) is sleeved on the outer periphery of the ring groove (12) to cover the ring groove (12). The end cover surface of the bearing (2) is in close contact with the end ring (11) protruding on the outer wall of the main shaft body (1), and the inner wall of the shaft barrel port of the bearing (2) is provided with a second oil return groove (21). The side of the ring groove (12) close to the middle section of the main shaft body (1) is provided with a first oil return groove (121), and when the first oil return groove (121) is aligned with the second oil return groove (21), the second oil return groove (21) is connected to the inside of the ring groove (12) through the first oil return groove (121). The inside of the main shaft body (1) is provided with an axial oil inlet hole (14) along the axial direction, and the axial oil inlet hole (14) passes through the ring groove (12) and a plurality of radial oil inlet holes (13) are provided along the radial direction to communicate with the ring groove (12); The outer periphery of the shaft cylinder end of the bearing (2) is sleeved with a sealing sleeve (4), and the oil return cylinder (3) is sleeved on the outer periphery of the bearing (2). When the two ends of the oil return cylinder (3) are respectively connected to the edges of the end covers of the bearings (2) on both sides by means of a plurality of sets of bolts and nuts for locking, the oil return cylinder (3) presses the sealing sleeve (4), and the outer wall of the oil return cylinder (3) is connected with an oil return pipe (31).

2. The external cylindrical open cavity type dynamic and static pressure spindle unit according to claim 1, characterized in that: The cross section of the annular groove (12) has a vertical surface on one side close to the end ring (11) and an inclined surface on the other side.

3. The external cylindrical open cavity type dynamic and static pressure spindle unit according to claim 1, characterized in that: The outer shape of the sealing sleeve (4) adopts a hollow truncated cone structure, and the outer diameter of the sealing sleeve (4) close to the end ring (11) is larger than the outer diameter of the other end.

4. The external cylindrical open cavity type dynamic and static pressure spindle unit according to claim 1, characterized in that: A plurality of O-rings (41) are evenly inlaid on the outer side wall of the sealing sleeve (4).

5. The external cylindrical open cavity type dynamic and static pressure spindle unit according to claim 1, characterized in that: A plurality of O-rings (5) are inlaid on both end surfaces of the oil return cylinder (3), the plurality of O-rings (5) are arranged in a concentric circle, and the end cover of the bearing (2) is tightly attached to the O-rings (5).

6. The external cylindrical open cavity type dynamic and static pressure spindle unit according to claim 1, characterized in that: The inner wall of the oil return cylinder (3) adopts an inclined structure, and the inner wall of the oil return cylinder (3) is inclined toward the oil return pipe (31), so that the oil return pipe (31) is located at the lowest point of the inner wall of the oil return cylinder (3).

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