CN112211975A

CN112211975A - A self-lubricating ball screw pair

Info

Publication number: CN112211975A
Application number: CN202011061486.1A
Authority: CN
Inventors: 李焕; 邓俊钧; 刘广博; 董毅; 包荣嘉; 何学妃
Original assignee: NINGBO SHUANGMA MACHINERY INDUSTRY CO LTD
Current assignee: NINGBO SHUANGMA MACHINERY INDUSTRY CO LTD
Priority date: 2020-09-30
Filing date: 2020-09-30
Publication date: 2021-01-12
Also published as: WO2022068128A1

Abstract

The invention discloses a self-lubricating ball screw pair, which comprises a screw and a rotating nut, wherein the rotating nut is provided with an internal thread mounting hole which is communicated from left to right and is matched with the screw, and the rotating nut is installed on the screw through the internal thread mounting hole in a threaded manner. The self-lubricating nut has the advantages that self-lubricating can be realized when the rotary nut rotates relative to the screw rod, the structure is simple, and the automation degree, the working efficiency and the service life of equipment can be improved.

Description

Self-lubricating ball screw pair

Technical Field

The invention relates to a ball screw, in particular to a self-lubricating ball screw pair.

Background

The ball screw is a transmission element most commonly used in tool machines and precision machines, and has a main function of converting rotational motion into linear motion or converting torque into axial repetitive force, and has advantages of high precision, reversibility and high efficiency, and is widely used in various industrial equipment and precision instruments due to its small frictional resistance. The ball screw is easy to cause insufficient lubrication due to centrifugal force in the high-speed rotation process, balls are easy to transfer from rolling to sliding, the use precision of the ball screw can be influenced, meanwhile, insufficient lubrication also easily causes the increase of friction between the screw and the nut, and the friction is increased to easily accelerate the abrasion of the ball screw. Based on this, how to lubricate the ball screw well is the key to ensure the stable operation of the ball screw.

At present, for the lubrication of the ball screw, one or two oil inlets communicated with an inner cavity of the nut are usually drilled on the side wall of the nut, an oil delivery pipe is connected to the oil inlets through an oil inlet nozzle arranged on the oil delivery pipe, and lubricating oil enters the screw nut pair from the oil inlets through the oil delivery pipe. Above-mentioned lubricated mode, the structure and operation are all comparatively simple, but when the nut takes place to rotate, because be fixed connection between oil inlet nozzle and defeated oil pipe and the nut, just so can make defeated oil pipe rotate together and twine on the nut along with the nut, defeated oil pipe is in case take place to twine, just can't last lubrication to the lead screw nut pair, this just makes this lubricated mode only be fit for supply lubricating oil when the nut stops to rotate, this degree of automation, work efficiency and the life who has greatly restricted equipment.

Disclosure of Invention

The invention aims to solve the technical problem of providing a self-lubricating ball screw pair with a simple structure, which can realize automatic lubrication of a screw nut pair when a nut rotates, thereby being beneficial to improving the automation degree, the working efficiency and the service life of equipment.

The technical scheme adopted by the invention for solving the technical problems is as follows:

the utility model provides a self-lubricating ball screw pair, includes lead screw and swivel nut, swivel nut have about link up with lead screw matched with internal thread mounting hole, swivel nut pass through internal thread mounting hole spiro union install the lead screw on realize with the lead screw between be connected, swivel nut's outside cup joint and be provided with an shell body, the shell body with swivel nut between be rotatable coupling, swivel nut's lateral wall with the inside wall of shell body before be provided with an inclosed annular oil-filled chamber, annular oil-filled intracavity pack and be provided with lubricating oil, swivel nut's lateral wall on be provided with at least one with the oil inlet that internal thread mounting hole communicates, the oil inlet be located annular oil-filled chamber in.

The swivel nut with the shell body between realize rotatable coupling through the bearing that two intervals set up around, the bearing the outer lane with the inside wall fixed connection of shell body, the bearing the inner circle with swivel nut's lateral wall fixed connection, two the bearing between form annular oil-filled chamber, the inlet port be located two the bearing between. The rotation between shell body and the swivel nut is realized through the bearing and is connected, simple structure, and the rotation is connected stably, and is with low costs.

The rotary nut comprises a mounting flange and a nut main body which are coaxially arranged from front to back in sequence, the outer diameter of the mounting flange is larger than that of the nut main body, the bearing is arranged on the nut main body, the front end surface of the bearing positioned at the front end abuts against the rear end surface of the mounting flange, and a first sealing element is arranged between the outer side wall of the mounting flange and the inner side wall of the outer shell;

the rear end of the nut body is coaxially provided with a rear limiting ring, the rear end surface of the bearing positioned at the rear end is abutted against the front end surface of the rear limiting ring, and a second sealing element is arranged between the outer side wall of the rear limiting ring and the inner side wall of the outer shell;

the rear end of nut main part extend backward and be provided with the locking installation department that has the external screw thread, the locking installation department on the spiro union be provided with external screw thread matched with lock nut, lock nut's preceding terminal surface with the rear end face of back spacing ring laminate mutually. The installation of giving two bearings through mounting flange and back spacing ring has played location and limiting displacement, and back spacing ring passes through lock nut locking fixed, through the cooperation of first sealing member and second sealing member, realizes the sealed to annular oil charge chamber, simple structure, and the installation is stable and sealed firm.

And a third sealing element is arranged between the inner side wall of the rear limiting ring and the outer side wall of the nut body. The sealing performance of the annular oil filling cavity is further ensured by the third sealing piece.

The inner cavity of the outer shell comprises a first cavity, a second cavity, a third cavity, a fourth cavity and a fifth cavity which are coaxially arranged from front to back in sequence, wherein the inner diameter of the first cavity is larger than that of the second cavity, the inner diameter of the second cavity is larger than that of the third cavity, the inner diameter of the fifth cavity is larger than that of the fourth cavity, and the inner diameter of the fourth cavity is larger than that of the third cavity; the mounting flange be located first cavity in, first sealing member set up mounting flange's lateral wall with the inside wall of first cavity between, two the bearing install respectively the second cavity with the fourth cavity in, back spacing ring install the fifth cavity in, the second sealing member set up back spacing ring the lateral wall with the inside wall of fifth cavity between, the nut main part with the third cavity between form annular oil-filled chamber. The inner cavity structure design is convenient for positioning and mounting the bearing.

The oil inlet holes are distributed uniformly along the axial direction of the rotating nut. The inlet port is a plurality of for it is more abundant to lubricate, and a plurality of inlet port equipartitions distribute, realize that swivel nut and lead screw can both be fully lubricated everywhere, ensure lubricated effect.

The central axes of the oil inlet holes are positioned in the same longitudinal plane. When the lubricating area is not overlapped with the roller path of the ball, a plurality of oil inlet holes can be arranged in the same longitudinal plane, so that the production and the manufacture are convenient.

The oil inlet holes are distributed in different longitudinal planes. When the lubrication area overlaps with the ball tracks, in order to avoid the ball tracks, the oil inlet holes need to be distributed in different longitudinal planes during design.

The oil inlet hole is an eccentric hole with a central axis not intersected with the central axis of the internal thread mounting hole. The oil inlet is designed to be an eccentric hole, so that the centrifugal force is overcome, the eccentric hole can utilize the rotation of the rotating nut to enable lubricating oil and the rotating nut to generate a relative motion trend, the lubricating oil is enabled to automatically enter the rotating nut through the eccentrically arranged oil inlet, and controllable automatic lubrication can be realized when a sealing oil ring is externally formed, so that the oil inlet effect and the oil inlet efficiency are ensured.

The central axis of the oil inlet hole is parallel to the tangent line of the internal thread mounting hole. When the central axis of the oil inlet hole is parallel to the tangent line of the internal thread mounting hole, the oil inlet effect and the oil inlet efficiency are optimal.

Compared with the prior art, the invention has the advantages that: an outer casing is established to outside cover at swivel nut, form an inclosed annular oil-filled chamber that is used for filling lubricating oil between outer casing and the swivel nut, be provided with the inlet port that communicates with the internal thread mounting hole of swivel nut on the swivel nut, the inlet port is located annular oil-filled intracavity, be rotatable coupling between swivel nut and the outer casing, when the relative lead screw of swivel nut rotates, the outer casing is motionless, lubricating oil in the annular oil-filled chamber is brought into from the inlet port between swivel nut and the lead screw through swivel nut's rotation, realize the self-lubricating, moreover, the steam generator is simple in structure, be favorable to improve equipment's degree of automation, work efficiency and life thereof.

Drawings

FIG. 1 is a schematic cross-sectional view of the present invention;

FIG. 2 is a schematic cross-sectional view of a spin nut of the present invention;

FIG. 3 is a schematic cross-sectional view of the outer housing of the present invention;

FIG. 4 is a schematic cross-sectional view of the present invention showing a rotating nut rotating clockwise, having a plurality of oil inlets located in different longitudinal cross-sections, and having a central axis of the oil inlets in a non-tangential direction, immersed in lubricating oil;

FIG. 5 is a schematic cross-sectional view of the present invention showing a rotating nut rotating clockwise, having a plurality of oil inlets located in different longitudinal cross-sections, and having a central axis of the oil inlet being a tangential direction, immersed in lubricating oil;

FIG. 6 is a schematic cross-sectional view of the present invention showing a rotating nut rotating clockwise, a plurality of oil inlets being located in the same longitudinal cross-section, and the central axis of the oil inlets being tangential, immersed in lubricating oil;

FIG. 7 is a schematic cross-sectional view of the present invention showing a rotating nut rotating counterclockwise, having a plurality of oil inlets located in different longitudinal cross-sections, and having a central axis of the oil inlet in a non-tangential direction, immersed in lubricating oil;

FIG. 8 is a schematic cross-sectional view of the present invention showing a rotating nut rotating counterclockwise, having a plurality of oil inlets located in different longitudinal cross-sections, and having a central axis of the oil inlet being a tangential direction, immersed in lubricating oil;

FIG. 9 is a schematic cross-sectional view of the present invention showing a rotating nut rotating counterclockwise, having a plurality of oil inlets located in the same longitudinal cross-section and the central axis of the oil inlets being in the tangential direction, immersed in lubricating oil.

Detailed Description

The invention is described in further detail below with reference to the accompanying examples.

The first embodiment is as follows: as shown in the figure, a self-lubricating ball screw is vice, including lead screw 1 and swivel nut 2, swivel nut 2 has about link up with lead screw 1 matched with internal thread mounting hole 21, swivel nut 2 passes through internal thread mounting hole 21 spiro union install on lead screw 1 realize with lead screw 1 between be connected, swivel nut 2's outside is cup jointed and is provided with an outer shell body 3, be rotatable coupling between outer shell body 3 and the swivel nut 2, be provided with an inclosed annular oil-filled chamber 23 before swivel nut 2's lateral wall and outer shell body 3's the inside wall, the intussuseption of annular oil-filled chamber 23 is filled with lubricating oil 4, be provided with at least one inlet port 22 that is linked together with internal thread mounting hole 21 on swivel nut 2's the lateral wall, inlet port 22 is arranged in.

In this embodiment, the swivel nut 2 and the outer housing 3 are rotatably connected by two bearings 5 arranged at a distance from each other, the outer ring of each bearing 5 is fixedly connected to the inner side wall of the outer housing 3, the inner ring of each bearing 5 is fixedly connected to the outer side wall of the swivel nut 2, an annular oil-filled cavity 23 is formed between the two bearings 5, and the oil inlet 22 is located between the two bearings 5. The rotation between the outer shell 3 and the rotating nut 2 is realized through the bearing 5, the structure is simple, the rotation connection is stable, and the cost is low.

In this specific embodiment, the rotating nut 2 includes a mounting flange 201 and a nut main body 202 coaxially arranged from front to back in sequence, the outer diameter of the mounting flange 201 is larger than the outer diameter of the nut main body 202, the bearing 5 is arranged on the nut main body 202, the front end face of the bearing 5 located at the front end abuts against the rear end face of the mounting flange 201, and a first sealing member 6 is arranged between the outer side wall of the mounting flange 201 and the inner side wall of the outer housing 3;

the rear end of the nut body 202 is coaxially provided with a rear limiting ring 7, the rear end surface of the bearing 5 positioned at the rear end abuts against the front end surface of the rear limiting ring 7, and a second sealing element 8 is arranged between the outer side wall of the rear limiting ring 7 and the inner side wall of the outer shell 3;

the rear end of the nut body 202 extends backward to be provided with a locking installation part 203 with external threads, the locking installation part 203 is screwed with a locking nut 9 matched with the external threads, and the front end face of the locking nut 9 is attached to the rear end face of the rear limiting ring 7. The installation of two bearings 5 has played location and limiting displacement through mounting flange 201 and back spacing ring 7, and back spacing ring 7 is fixed through lock nut 9 locking, through the cooperation of first sealing member 6 and second sealing member 8, realizes the sealed to annular oil-filled chamber 23, simple structure, and the installation is stable and sealed firm.

In this particular embodiment, a third seal 71 is provided between the inner sidewall of the rear retainer ring 7 and the outer sidewall of the nut body 202. The sealing of the annular oil-filled chamber 23 is further ensured by the third seal 71.

In this specific embodiment, the inner cavity of the outer housing 3 includes a first cavity 31, a second cavity 32, a third cavity 33, a fourth cavity 34 and a fifth cavity 35 coaxially arranged from front to back, the inner diameter of the first cavity 31 is larger than the inner diameter of the second cavity 32, the inner diameter of the second cavity 32 is larger than the inner diameter of the third cavity 33, the inner diameter of the fifth cavity 35 is larger than the inner diameter of the fourth cavity 34, and the inner diameter of the fourth cavity 34 is larger than the inner diameter of the third cavity 33; the mounting flange 201 is located in the first cavity 31, the first sealing element 6 is arranged between the outer side wall of the mounting flange 201 and the inner side wall of the first cavity 31, the two bearings 5 are respectively arranged in the second cavity 32 and the fourth cavity 34, the rear limiting ring 7 is arranged in the fifth cavity 35, the second sealing element 8 is arranged between the outer side wall of the rear limiting ring 7 and the inner side wall of the fifth cavity 35, and the annular oil-filled cavity 23 is formed between the nut body 202 and the third cavity 33. The inner cavity structure design is convenient for positioning and mounting the bearing 5.

In this embodiment, the oil inlet hole 22 is plural, and the plural oil inlet holes 22 are uniformly distributed in the axial direction of the spin nut 2. The oil inlet 22 is a plurality of for it is more abundant to lubricate, and a plurality of oil inlet 22 equipartitions distribute, realize that swivel nut 2 and lead screw 1 can both be fully lubricated everywhere, ensure lubricated effect.

In this embodiment, the plurality of oil inlet holes 22 are distributed in different longitudinal planes. When the lubrication region overlaps with the ball raceways, the oil inlet holes 22 need to be distributed in different longitudinal planes in order to avoid the ball raceways at the time of design.

In this embodiment, the oil inlet hole 22 is an eccentric hole whose central axis does not intersect with the central axis of the internally threaded mounting hole 21. The oil inlet hole 22 is designed to be an eccentric hole, so that the centrifugal force is overcome, the eccentric hole can utilize the rotation of the swivel nut 2 to enable the lubricating oil 4 and the swivel nut 2 to generate a relative movement trend, the lubricating oil 4 is enabled to automatically enter the swivel nut 2 through the eccentrically arranged oil inlet hole 22, controllable automatic lubrication can be realized when a sealing oil ring is externally formed, and therefore the oil inlet effect and the oil inlet efficiency are ensured.

In this embodiment, the central axis of the oil inlet hole 22 is parallel to the tangent of the internally threaded mounting hole 21. When the central axis of the oil inlet hole 22 is parallel to the tangent of the internal thread mounting hole 21, the oil inlet effect and the oil inlet efficiency are optimal.

Before the oil filling device is used, lubricating oil can be automatically pumped into the annular oil filling cavity 23 through the outer shell through the lubricating pump, so that the rotating nut 2 is semi-soaked in the lubricating oil, the number and the aperture of the oil inlet holes 22 can be automatically set according to specific lubricating requirements and processing requirements, the opening position of the oil inlet holes 22 is determined according to the rotating direction of the rotating nut 2, and the lubricating oil can be ensured to automatically enter the rotating nut 2 through the oil inlet holes along with the rotation of the rotating nut 2.

Example two: the other portions are the same as those of the first embodiment, except that the central axes of the oil inlet holes 22 are located in the same longitudinal plane. When the lubrication area is not overlapped with the ball grooves, the oil inlet holes 22 can be arranged in the same longitudinal plane, which is convenient for production and manufacture.

Claims

1. A self-lubricating ball screw pair, comprising a lead screw and a rotating nut, wherein the rotating nut has a left and right through inner thread mounting hole that matches the lead screw, and the rotating nut passes through the The internal thread mounting hole is screwed and installed on the lead screw to realize the connection with the lead screw. It is characterized in that an outer casing is provided on the outer sleeve of the rotating nut. There is a rotatable connection between the rotating nuts, the outer side wall of the rotating nut and the inner side wall of the outer casing are provided with a closed annular oil-filled cavity, and the annular oil-filled cavity is filled with lubricating oil. Oil, the outer side wall of the rotating nut is provided with at least one oil inlet hole that communicates with the inner thread mounting hole, and the oil inlet hole is located in the annular oil-filled cavity.

2. A self-lubricating ball screw pair according to claim 1, characterized in that a rotatable connection is achieved between the rotating nut and the outer casing through two bearings arranged at intervals in the front and rear, and the The outer ring of the bearing is fixedly connected with the inner side wall of the outer casing, the inner ring of the bearing is fixedly connected with the outer side wall of the rotating nut, and the annular oil filling is formed between the two bearings. cavity, and the oil inlet hole is located between the two bearings.

3. A self-lubricating ball screw pair according to claim 2, characterized in that the rotating nut comprises a mounting flange and a nut body arranged coaxially from front to back in sequence, and the outer portion of the mounting flange is The diameter is larger than the outer diameter of the nut body, the bearing is arranged on the nut body, the front end surface of the bearing located at the front end is abutted and installed on the rear end surface of the mounting flange, the A first seal is arranged between the outer side wall of the mounting flange and the inner side wall of the outer casing;

The rear end of the nut body is coaxially provided with a rear limit ring, and the rear end surface of the bearing located at the rear end is abutted and installed on the front end surface of the rear limit ring. A second sealing member is arranged between the outer side wall and the inner side wall of the outer casing;

The rear end of the nut main body is provided with a locking mounting portion with an external thread extending backward, and a locking nut matched with the external thread is screwed on the locking mounting portion. The front end surface of the locking nut is abutted with the rear end surface of the rear limit ring.

4 . The self-lubricating ball screw pair according to claim 3 , wherein a third sealing member is arranged between the inner side wall of the rear limit ring and the outer side wall of the nut body. 5 .

5. A self-lubricating ball screw pair according to claim 3, wherein the inner cavity of the outer casing comprises a first chamber, a second chamber, a third The chamber, the fourth chamber and the fifth chamber, the inner diameter of the first chamber is larger than the inner diameter of the second chamber, and the inner diameter of the second chamber is larger than the third chamber The inner diameter of the fifth chamber is larger than the inner diameter of the fourth chamber, and the inner diameter of the fourth chamber is larger than the inner diameter of the third chamber; the mounting flange is located at In the first chamber, the first seal is arranged between the outer side wall of the mounting flange and the inner side wall of the first chamber, and the two bearings are respectively installed in the said first chamber. In the second chamber and the fourth chamber, the rear limit ring is installed in the fifth chamber, and the second seal is arranged on the outside of the rear limit ring The annular oil-filled cavity is formed between the wall and the inner side wall of the fifth chamber, and between the nut body and the third chamber.

6 . The self-lubricating ball screw pair according to claim 1 , wherein there are a plurality of oil inlet holes, and the plurality of oil inlet holes are evenly distributed along the axial direction of the rotating nut. 7 . .

7 . The self-lubricating ball screw pair according to claim 6 , wherein the central axes of the plurality of oil inlet holes are located in the same longitudinal plane. 8 .

8 . The self-lubricating ball screw pair according to claim 6 , wherein a plurality of the oil inlet holes are distributed in different longitudinal planes. 9 .

9. A self-lubricating ball screw pair according to claim 1 or 6, wherein the oil inlet hole is an eccentric hole whose central axis does not intersect with the central axis of the inner thread mounting hole.

10 . The self-lubricating ball screw pair according to claim 9 , wherein the central axis of the oil inlet hole is parallel to the tangent of the internal thread mounting hole. 11 .