High-precision direct-drive static pressure support structure of numerical control rotary table

Abstract

The application discloses a high-precision direct-drive static pressure supporting structure of a numerical control rotary table, which comprises a base, a brake holding mechanism, a torque motor, a motor connecting piece, a workbench, a bearing fixing piece and a static pressure bearing, wherein the base is provided with a vertical through installation cavity; the brake holding mechanism is vertically installed in the middle of the installation cavity; the torque motor is located in the installation cavity and fixedly connected with the base through a stator; the motor connecting piece is located in the installation cavity and distributed at intervals around the brake holding mechanism, and the motor connecting piece is fixedly connected with a rotor of the torque motor; the workbench is fixedly connected with the motor connecting piece and extends out of the installation cavity; the bearing fixing piece is located in the installation cavity and distributed at intervals around the motor connecting piece, and the bearing fixing piece is fixedly connected with the base; and the static pressure bearing is installed on the bearing fixing piece and located between the workbench and the motor connecting piece, so that working oil films are formed in the gap between the static pressure bearing and the workbench and in the gap between the static pressure bearing and the motor connecting piece after oil is fed, and the rotary precision is improved.

Description

Technical Field

[0001] This invention relates to the field of machine tool functional components technology, and more specifically to a high-precision direct-drive hydrostatic support structure for a CNC rotary table. Background Technology

[0002] The CNC rotary table is one of the key functional components of a machining center. It provides the machine tool with a rotation axis and bears the weight of the workpiece. The positioning accuracy and rotational dynamic accuracy of the rotary table directly affect the machining accuracy of the workpiece, especially for high-precision machine tools. However, the accuracy of existing rotary tables needs to be improved and cannot meet the requirements of high-end machine tools.

[0003] Therefore, providing a high-precision direct-drive hydrostatic support structure for CNC rotary tables is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] In view of this, the present invention provides a high-precision direct-drive hydrostatic support structure for CNC rotary tables to improve rotational accuracy.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A high-precision direct-drive hydrostatic support structure for a CNC rotary table includes a base, a brake mechanism, a torque motor, a motor connector, a worktable, a bearing fixture, and a hydrostatic bearing. The base has a vertically penetrating mounting cavity. The brake mechanism is vertically mounted in the center of the mounting cavity. The torque motor is located within the mounting cavity, and its stator is fixedly connected to the base. The motor connector is located within the mounting cavity and spaced around the brake mechanism, and is fixedly connected to the rotor of the torque motor. The worktable is fixedly connected to the motor connector and extends out of the mounting cavity. The bearing fixture is located within the mounting cavity and spaced around the motor connector, and is fixedly connected to the base. The hydrostatic bearing is mounted on the bearing fixture and located between the worktable and the motor connector, so that after oil is introduced, a working oil film is formed in the gap between the hydrostatic bearing and the worktable, and in the gap between the hydrostatic bearing and the motor connector.

[0007] By adopting the above technical solutions, the beneficial effects of the present invention are as follows:

[0008] The working oil film bears the working load to form a stable hydrostatic oil film support, thereby ensuring the high rigidity and high rotational accuracy of the turntable.

[0009] Furthermore, it also includes an oil pan, which is located within the mounting cavity and spaced around the motor connector, and below the bearing fixture. The oil pan is fixedly connected to the base, thereby forming a first oil pool between the oil pan and the bearing fixture. The base has a second oil pool leading to the outside. A first oil return channel is formed between the hydrostatic bearing and the motor connector, and a second oil return channel is formed between the hydrostatic bearing and the worktable. The first oil return channel and the second oil return channel are connected. The first oil return channel is connected to the first oil pool, and the second oil return channel is connected to the second oil pool. The first oil pool and the second oil pool are connected through an oil passage hole on the base, thereby forming an oil unloading circuit.

[0010] The beneficial effect of adopting the above-mentioned further technical solution is to realize the oil drain circuit of zero-pressure hydraulic oil and ensure smooth hydraulic oil return. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0012] Figure 1 The attached figure is a schematic diagram of the overall structure of a high-precision direct-drive hydrostatic support structure for a CNC rotary table provided by the present invention.

[0013] Figure 2 The attached figure is a front view of a high-precision direct-drive hydrostatic support structure for a CNC rotary table provided by the present invention;

[0014] Figure 3 The attached image is... Figure 2 Sectional view of AA;

[0015] Figure 4 The attached image is... Figure 3 A magnified structural diagram of part A in the middle. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] like Figure 1-4As shown in the figure, this invention discloses a high-precision direct-drive hydrostatic support structure for a CNC rotary table, including a base 1, a brake mechanism 2, a torque motor 3, a motor connector 4, a worktable 5, a bearing fixing component 6, and a hydrostatic bearing 7. The base 1 has a vertically penetrating mounting cavity; the brake mechanism 2 is vertically installed in the middle of the mounting cavity; the torque motor 3 is located in the mounting cavity and its stator is fixedly connected to the base 1; the motor connector 4 is located in the mounting cavity and is spaced around the brake mechanism 2, and is fixedly connected to the rotor of the torque motor 3; the worktable 5 is fixedly connected to the motor connector 4 and extends out of the mounting cavity; the bearing fixing component 6 is located in the mounting cavity and is spaced around the motor connector 4, and is fixedly connected to the base 1; the hydrostatic bearing 7 is installed on the bearing fixing component 6 and is located between the worktable 5 and the motor connector 4, so that after oil is introduced, a working oil film is formed in the gap between the hydrostatic bearing 7 and the worktable 5 and the gap between the hydrostatic bearing 7 and the motor connector 4 to bear the working load. This invention employs a closed-loop adaptive internal feedback throttling control hydrostatic bearing technology to achieve automatic adjustment of the hydraulic oil film gap and automatic feedback of the oil film pressure (an axial oil film is formed between the top of the hydrostatic bearing 7 and the bottom of the worktable 5, and between the bottom of the hydrostatic bearing 7 and the top of the motor connector 4; a radial oil film is formed between the sidewall of the hydrostatic bearing 7 and the sidewall of the worktable 5; there are several groups of oil chambers in the circumferential direction of the hydrostatic bearing 7, and each group of corresponding oil chambers has a throttling device; under the action of the throttling device, the radial oil film pressure is automatically adjusted according to the change of external load, and the axial oil film pressure is automatically adjusted according to the change of external load in the same way), forming a stable hydrostatic oil film support, thereby ensuring the high rigidity and high rotational accuracy of the turntable.

[0018] Specifically, it also includes an oil pan 8, which is located inside the mounting cavity and spaced around the motor connector 4, and below the bearing fixing member 6. The oil pan 8 is fixedly connected to the base 1, thereby forming a first oil pool 9 between the oil pan 8 and the bearing fixing member 6. The base 1 has a second oil pool that leads to the outside. The gap between the hydrostatic bearing 7 and the motor connector 4 forms a first oil return channel, and the gap between the hydrostatic bearing 7 and the worktable 5 forms a second oil return channel. The first oil return channel and the second oil return channel are connected. The first oil return channel is connected to the first oil pool 9, and the second oil return channel is connected to the second oil pool. The first oil pool 9 and the second oil pool are connected through an oil passage hole opened on the base 1, thereby forming an oil unloading circuit, thus realizing the oil discharge circuit of zero-pressure hydraulic oil and ensuring smooth hydraulic oil return.

[0019] Specifically, the brake mechanism 2 expands its elastic sleeve to lock the motor connector 4 (the brake mechanism 2 consists of an elastic sleeve and a fixing component; after the pressure oil is supplied, the elastic sleeve expands and contacts the motor connector 4, and the motor connector 4 is locked by friction), thereby ensuring the stability and reliability of the turntable positioning and processing.

[0020] Specifically, in this embodiment, the fixed connection method is all bolt connection.

[0021] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0022] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high-precision direct-drive hydrostatic support structure for a CNC rotary table, characterized in that, The device includes a base, a brake mechanism, a torque motor, a motor connector, a worktable, a bearing fixture, and a hydrostatic bearing. The base has a vertically penetrating mounting cavity. The brake mechanism is vertically mounted in the center of the mounting cavity. The torque motor is located within the mounting cavity, and its stator is fixedly connected to the base. The motor connector is located within the mounting cavity and spaced around the brake mechanism, and is fixedly connected to the rotor of the torque motor. The worktable is fixedly connected to the motor connector and extends out of the mounting cavity. The bearing fixture is located within the mounting cavity and spaced around the motor connector, and is fixedly connected to the base. The hydrostatic bearing is mounted on the bearing fixture and located between the worktable and the motor connector, so that after oil is introduced, a working oil film is formed in the gap between the hydrostatic bearing and the worktable, and in the gap between the hydrostatic bearing and the motor connector. It also includes an oil pan located within the mounting cavity and spaced apart around the motor connector, and below the bearing fixture. The oil pan is fixedly connected to the base, thereby forming a first oil pool between the oil pan and the bearing fixture. The base has a second oil pool opening to the outside. A first oil return channel is formed between the hydrostatic bearing and the motor connector, and a second oil return channel is formed between the hydrostatic bearing and the worktable. The first oil return channel and the second oil return channel are connected. The first oil return channel is connected to the first oil pool, and the second oil return channel is connected to the second oil pool. The first oil pool and the second oil pool are connected through an oil passage hole on the base, thereby forming an oil unloading circuit.

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