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CN-122014818-A - Supporting mechanism of large-span ball screw

CN122014818ACN 122014818 ACN122014818 ACN 122014818ACN-122014818-A

Abstract

The invention discloses a supporting mechanism of a large-span ball screw, which belongs to the technical field of ball screw supporting mechanisms and comprises a supporting wheel set, a propping assembly, a pressing part and a pressing part, wherein the supporting wheel set is tangent to the ball screw, the propping assembly is arranged below the supporting wheel set and is used for applying propping force for propping the ball screw to the supporting wheel set, the pressing part is arranged on a screw nut in threaded connection on the ball screw, when the screw nut passes over the supporting wheel set, the pressing part applies pressing force to the supporting wheel set to enable the supporting wheel set to leave the position, the supporting wheel set can provide continuous and adjustable upward supporting force for the large-span ball screw by utilizing a gas-liquid supercharging principle, and automatic pressing avoidance and quick reset after the supporting mechanism passes through the screw nut can be realized without additional sensors or power sources.

Inventors

  • CHENG SHAOHUA
  • CHENG KANGYONG

Assignees

  • 蚌埠精科机床制造有限公司

Dates

Publication Date
20260512
Application Date
20260228

Claims (10)

  1. 1. A support mechanism for a large-span ball screw, comprising: The supporting wheel set is tangent to the ball screw; The abutting assembly is arranged below the supporting wheel set and is used for applying an abutting force for abutting the ball screw to the supporting wheel set; the pressing part is arranged on a screw nut in threaded connection with the ball screw; when the screw nut passes through the upper part of the supporting wheel set, the pressing part applies pressing force to the supporting wheel set, so that the supporting wheel set is at a yielding position.
  2. 2. The support mechanism for a large span ball screw as in claim 1 wherein said support wheelset comprises: The base frame (1), wherein the base frame (1) is a rectangular frame with an opening at the upper side, and the base frame (1) is positioned below the ball screw; The two support shafts (2) are respectively and rotatably arranged inside two ends of the base frame (1), the axes of the support shafts (2) are parallel to the axes of the ball screw, and the two support shafts (2) are tangential to the ball screw; The guide parts are arranged on two end faces of the base frame (1) and are matched with the pressing parts.
  3. 3. The support mechanism for a large-span ball screw as recited in claim 2, wherein said guide portion comprises: the two rollers (3) are respectively rotatably arranged on two end faces of the base frame (1).
  4. 4. A support mechanism for a large span ball screw as in claim 3 wherein said hold down comprises: the base sleeve (4) is fixedly arranged on the outer side of the screw nut; the two fixing plates (5), the two fixing plates (5) are respectively fixedly installed on two sides of the base sleeve (4), and when the screw nut passes through the upper part of the supporting wheel set, the fixing plates (5) apply downward propping force to the rolling shaft (3).
  5. 5. The supporting mechanism of a large span ball screw as claimed in claim 4, wherein both ends of the lower side surface of the fixing plate (5) are provided with inclined surfaces inclined upward.
  6. 6. A supporting mechanism for a large span ball screw as claimed in claim 2, characterized in that the upper side of the base frame (1) is provided with grooves adapted to the ball screw.
  7. 7. The support mechanism for a large span ball screw as recited in claim 1, wherein said abutment assembly comprises: The pressure supply part is used for providing a power source; the hydraulic cylinder assembly (6), the piston rod of the hydraulic cylinder assembly (6) is connected with the supporting wheel group through the connecting part; The pressure supply part applies pressure to hydraulic oil in the hydraulic cylinder assembly (6), so that a piston rod of the hydraulic cylinder assembly (6) extends out to apply upward abutting force to the supporting wheel set.
  8. 8. The support mechanism for a large-span ball screw as recited in claim 7, wherein said pressure supply portion comprises: and one end of the nitrogen accumulator is connected with a nitrogen source through a gas valve, and the other end of the nitrogen accumulator is connected with a hydraulic cylinder assembly (6) through an oil valve.
  9. 9. The support mechanism for a large span ball screw as in claim 8 wherein said nitrogen accumulator comprises: The piston (8) is slidably mounted in the shell (7), the piston (8) divides the inner space of the shell (7) into a gas storage space for storing nitrogen and an oil storage space for storing oil, and the piston (8) slides in the shell (7) to realize expansion and contraction of a piston rod of the hydraulic cylinder assembly (6).
  10. 10. The support mechanism for a large-span ball screw as recited in claim 7, wherein said connecting portion comprises: The base plate (9), the base plate (9) is fixedly installed on the supporting wheel group; The two ends of the convex elastic rods (10) are fixedly connected with the base plate (9) and the piston rod of the hydraulic cylinder assembly (6) respectively; The two ends of the concave elastic rods (11) are fixedly connected with the base plate (9) and the piston rod of the hydraulic cylinder assembly (6) respectively; Wherein, a plurality of evagination bullet pole (10) and a plurality of indent bullet pole (11) are all evenly distributed along the circumference of the piston rod of pneumatic cylinder subassembly (6), and a plurality of evagination bullet pole (10) and a plurality of indent bullet pole (11) are crisscross to be distributed, fixed mounting has elastic rod (12) between evagination bullet pole (10) and indent bullet pole (11), the cross section of elastic rod (12) is oval, and elastic rod (12) are established to hollow structure.

Description

Supporting mechanism of large-span ball screw Technical Field The invention relates to the technical field of ball screw supporting mechanisms, in particular to a supporting mechanism of a large-span ball screw. Background Along with the continuous upgrading and advancing of the numerical control machine tool manufacturing industry, the larger the machine tool is, the longer the ball screw is, which is a main transmission part, but along with the lengthening of the ball screw, a plurality of problems can be generated, and the defects are concentrated on the aspects of structural stability, precision control, process cost and the like, and are specifically as follows: the critical rotation speed is low and easy to resonate, the critical rotation speed is greatly attenuated along with the increase of the span, the bending resonance is easy to be caused by the high-speed operation and easy to approach the natural resonance frequency, and the structural failure is caused when the bending resonance is serious. The structure rigidity is poor and easy to deform, the length-diameter ratio is easy to exceed a critical value, the dead weight can lead the screw to sag and deform, the dynamic instability can be amplified, the positioning precision can be reduced, the unbalanced load abrasion can be aggravated, and even the permanent deformation is caused. The transmission part is easy to break, the ball circulation structure of the nut is easy to break the ball taking teeth or the ball is easy to be blocked due to impact load when the nut runs at high speed, and the static rigidity of a feeding system can be greatly reduced due to the reduction of the number of the balls. The cost and the technological requirements are high, the process control difficulty of heat treatment, precise grinding and the like is high during manufacturing, defects such as cracks and the like are easy to generate, the subsequent maintenance is required to maintain and replace parts regularly, and the optimization measures for solving the problems of deflection and the like can additionally increase the cost. The precision is easily affected by the fact that if the performance is improved by increasing the pretensioning force, the pitch change is caused, the precision life of the screw is shortened, and meanwhile, the movement noise can be increased. In order to reduce the problems, an auxiliary supporting mechanism of the ball screw is added at present to support the ball screw with a large span, so that the stability, the rigidity and the precision under the high-speed working condition are ensured. The traditional lead screw supporting mode generally adopts a mode of matching a linear sliding rail with an adjusting gasket, and the mode has high manufacturing precision requirement and high cost. In order to solve the problem of the traditional screw rod supporting mode, the invention provides a supporting mechanism of a large-span ball screw rod. Disclosure of Invention Aiming at the technical defects, the invention aims to provide the supporting mechanism of the large-span ball screw, which can provide continuous and adjustable upward supporting force for the large-span ball screw by utilizing the gas-liquid supercharging principle, and can realize automatic downward pressing avoidance and rapid reset after passing of the supporting mechanism when a screw nut passes without an additional sensor or a power source, thereby obviously reducing the complexity of the system and the maintenance cost compared with the traditional linear slide rail supporting mode. In order to solve the technical problems, the invention adopts the following technical scheme that the invention provides a supporting mechanism of a large-span ball screw, which comprises: The supporting wheel set is tangent to the ball screw; The abutting assembly is arranged below the supporting wheel set and is used for applying an abutting force for abutting the ball screw to the supporting wheel set; the pressing part is arranged on a screw nut in threaded connection with the ball screw; when the screw nut passes through the upper part of the supporting wheel set, the pressing part applies pressing force to the supporting wheel set, so that the supporting wheel set is at a yielding position. Preferably, the support wheel set includes: The base frame is a rectangular frame with an opening at the upper side, and is positioned below the ball screw; The two support shafts are respectively and rotatably arranged in two ends of the base frame, the axes of the support shafts are parallel to the axes of the ball screw, and the two support shafts are tangential to the ball screw; and the guide parts are arranged on two end surfaces of the base frame and are matched with the pressing parts. Preferably, the guide part includes: The two rollers are respectively rotatably arranged on two end faces of the base frame. Preferably, the pressing portion includes: The base sleeve is fixedly arranged on