Spring pre-tightening structure of drilling and tapping main shaft

Abstract

The spring pre-tightening structure of the drilling and tapping spindle comprises an outer sleeve, a mandrel, a middle spacer ring and a ball bearing, a rear labyrinth cover is arranged at the top end of the outer sleeve, a nut is arranged between an inner ring of the rear labyrinth cover and the side wall of the mandrel, a rear spacer ring is arranged on the mandrel, an inner ring of the ball bearing is connected between the middle spacer ring and the rear spacer ring in an abutting mode, and the inner ring of the ball bearing abuts against the side wall of the mandrel. The ball bearing is sleeved with a rear bearing bin, the inner periphery of the bottom of the rear bearing bin is provided with a lower annular step part, the rear spacer ring is sleeved with a rear bearing gland, the inner periphery of the bottom of the rear bearing gland is provided with an upper annular step part, the inner periphery of the top end of the outer sleeve is provided with an annular containing groove, and the rear spacer ring and the rear bearing bin are both arranged on the annular containing groove. Spring containing grooves are evenly distributed in the bottom end of the annular containing groove, springs are arranged in the spring containing grooves, the outer ring of the ball bearing abuts against the position between the upper annular step part and the lower annular step part, the diameter of the main shaft can be reduced, and the operation precision of the main shaft is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of drilling and tapping spindles, in particular to a spring pre-tightening structure of the drilling and tapping spindle. Background Art

[0002] A drilling and tapping spindle is a spindle used on CNC machine tools to rotate drilling and tapping tools to machine workpieces. To reduce bearing clearance and stabilize spindle rotation, a spring preload is incorporated into the spindle. However, existing drilling and tapping spindles use springs mounted on spacer rings, necessitating the use of larger diameter spacer rings. This results in a larger and heavier spindle, making it less compact and impacting spindle precision. Summary of the Invention

[0003] The problem to be solved by the utility model is to provide a spring pre-tightening structure for a drilling and tapping spindle, thereby reducing the diameter of the spindle, improving the compactness of the structure, and improving the operating accuracy of the spindle.

[0004] To solve the above technical problems, a spring pre-tightening structure of a drilling and tapping spindle provided by the utility model is provided, which includes an outer sleeve, a core shaft movably arranged in the outer sleeve, a middle spacer ring sleeved on the core shaft, and a plurality of ball bearings sleeved on the core shaft. The top end of the outer sleeve is fixedly connected to a rear labyrinth cover, a nut is provided between the inner ring of the rear labyrinth cover and the side wall of the core shaft, a rear spacer ring is sleeved on the core shaft, the inner ring of the ball bearing abuts between the middle spacer ring and the rear spacer ring, a rear bearing bin is sleeved on the ball bearing, and the bottom of the rear bearing bin A lower annular step is provided on the inner circumference, a rear bearing cover is provided on the rear spacer ring, an upper annular step is provided on the inner circumference of the bottom of the rear bearing cover, an annular accommodating groove is provided on the inner circumference of the top end of the outer sleeve, the rear spacer ring and the rear bearing magazine are both provided on the annular accommodating groove, spring accommodating grooves are evenly distributed on the bottom end of the annular accommodating groove, a spring is provided in the spring accommodating groove, the spring abuts between the bottom end of the rear bearing magazine and the bottom of the spring accommodating groove, and the outer ring of the ball bearing abuts between the upper annular step and the lower annular step.

[0005] Preferably, a plurality of annular grooves are provided on the outer edge of the rear bearing compartment, and a sealing ring is provided on the annular groove to abut against the inner side wall of the annular accommodating groove.

[0006] Preferably, a rear water retaining ring fixedly connected to the nut is sleeved on the core shaft.

[0007] The beneficial effects of the present invention are as follows: the present invention provides a spring pre-tightening structure for a drilling and tapping spindle, which compresses the inner ring of the ball bearing through the rear spacer ring and the middle spacer ring, and the spring applies elastic force to the rear bearing compartment, and compresses the outer ring of the ball bearing through the upper annular step portion and the lower annular step portion, thereby forming a floating pre-tightening function for the ball bearing, reducing the internal clearance of the bearing, ensuring stable rotation of the spindle, and increasing the upper limit of the spindle speed; the outer ring of the ball bearing is embedded between the upper annular step portion, the lower annular step portion, and the inner wall of the rear bearing compartment, and the rear bearing compartment and the rear bearing pressure cover are arranged on the annular accommodating groove, which can reduce the diameter of the outer sleeve, and the spring accommodating groove is arranged at the bottom of the annular accommodating groove, and the spring is placed in the spring accommodating groove, which can reduce the wall thickness and diameter of the spacer ring, making the structure of the spindle more compact, effectively reducing the diameter and volume of the spindle, reducing the weight of the spindle, and improving the working stability and operation accuracy of the spindle. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 The schematic diagram of the appearance structure of the utility model is illustrated.

[0009] Figure 2 A cross-sectional view illustrating the present invention is shown.

[0010] Figure 3 The schematic diagram of the exploded structure of the present invention is illustrated.

[0011] Figure 4 This utility model is illustrated Figure 2 Schematic diagram of the partially enlarged structure of part A in the middle.

[0012] Explanation of the accompanying figures: outer sleeve 1, annular accommodating groove 100, spring accommodating groove 101, core shaft 2, middle spacer ring 3, ball bearing 4, rear labyrinth cover 5, nut 6, rear spacer ring 7, rear bearing compartment 8, lower annular step 80, annular groove 800, rear bearing pressure cover 9, upper annular step 90, spring 10, rear water retaining ring 11. DETAILED DESCRIPTION

[0013] To make the purpose, technical solutions and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments.

[0014] Based on the described embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without creative work shall fall within the scope of protection of the present disclosure.

[0015] refer to Figure 1-Figure 4 .

[0016] The utility model provides a spring pre-tightening structure for a drilling and tapping spindle, comprising an outer sleeve 1, a core shaft 2 movably arranged in the outer sleeve 1, a middle spacer ring 3 sleeved on the core shaft 2, and a plurality of ball bearings 4 sleeved on the core shaft 2. The top end of the outer sleeve 1 is fixedly connected to a rear labyrinth cover 5, a nut 6 is provided between the inner ring of the rear labyrinth cover 5 and the side wall of the core shaft 2, a rear spacer ring 7 is sleeved on the core shaft 2, the inner ring of the ball bearing 4 abuts between the middle spacer ring 3 and the rear spacer ring 7, a rear bearing bin 8 is sleeved on the ball bearing 4, and a lower annular step portion 80 is provided on the inner circumference of the bottom of the rear bearing bin 8. A rear bearing cover 9 is sleeved on the rear spacer ring 7, and an upper annular step portion 90 is provided on the inner circumference of the bottom of the rear bearing cover 9. An annular accommodating groove 100 is provided on the inner circumference of the top end of the outer sleeve 1. The rear spacer ring 7 and the rear bearing magazine 8 are both arranged on the annular accommodating groove 100. Spring accommodating grooves 101 are evenly distributed at the bottom end of the annular accommodating groove 100. A spring 10 is provided in the spring accommodating groove 101. The spring 10 abuts between the bottom end of the rear bearing magazine 8 and the bottom of the spring accommodating groove 101, and the outer ring of the ball bearing 4 abuts between the upper annular step portion 90 and the lower annular step portion 80.

[0017] The specific usage principle is that the inner ring of the ball bearing 4 is compressed by the rear spacer ring 7 and the middle spacer ring 3, the spring 10 applies elastic force to the rear bearing chamber 8, and the outer ring of the ball bearing 4 is compressed by the upper annular step 90 and the lower annular step 80, thereby forming a floating pre-tightening function for the ball bearing 4, reducing the internal clearance of the bearing, ensuring stable rotation of the main shaft, and increasing the upper limit of the main shaft speed; the outer ring of the ball bearing 4 is embedded between the upper annular step 90, the lower annular step 80, and the inner wall of the rear bearing chamber 8, the rear bearing chamber 8 and the rear bearing pressure cover 9 are arranged on the annular accommodating groove 100, which can reduce the diameter of the outer sleeve 1, and the spring accommodating groove 101 is arranged at the bottom of the annular accommodating groove 100, and the spring 10 is placed in the spring accommodating groove 101, which can reduce the wall thickness and diameter of the spacer ring, making the structure of the main shaft more compact, effectively reducing the diameter and volume of the main shaft, reducing the weight of the main shaft, and improving the working stability and operation accuracy of the main shaft.

[0018] Based on the above embodiment, a plurality of annular grooves 800 are provided on the outer edge of the rear bearing bin 8, and a sealing ring is provided on the annular groove 800 to abut against the inner wall of the annular receiving groove 100 to prevent processing waste liquid and metal powder from entering through the gap between the inner wall of the annular receiving groove 100 and the outer wall of the rear bearing bin 8, thereby avoiding affecting the normal operation of the ball bearing 4 and improving the service life of the main shaft.

[0019] Based on the above embodiment, a rear water retaining ring 11 fixedly connected to the nut 6 is provided on the core shaft 2 to prevent processing waste liquid from entering the main shaft through the gap between the nut 6 and the core shaft 2 and the gap between the rear labyrinth cover 5 and the nut 6, thereby ensuring stable operation of the main shaft and improving the service life of the main shaft.

[0020] The above embodiments are merely descriptions of preferred embodiments of the present invention and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary engineering technicians in this field should fall within the scope of protection determined by the claims of the present invention.

Claims

1. A spring preload structure for a drilling spindle, comprising an outer sleeve, a core shaft movably disposed in the outer sleeve, a spacer ring sleeved on the core shaft, and a plurality of ball bearings sleeved on the core shaft, characterized in that: The top end of the outer sleeve is fixedly connected to the rear labyrinth cover, and a nut is provided between the inner ring of the rear labyrinth cover and the side wall of the core shaft, and a rear spacer ring is sleeved on the core shaft, and the inner ring of the ball bearing abuts between the middle spacer ring and the rear spacer ring, and the ball bearing is sleeved on the rear bearing magazine, and the bottom inner circumference of the rear bearing magazine is provided with a lower annular step portion, and the rear spacer ring is sleeved on the rear bearing pressure cover, and the bottom inner circumference of the rear bearing pressure cover is provided with an upper annular step portion, and the top inner circumference of the outer sleeve is provided with an annular receiving groove, and the rear spacer ring and the rear bearing magazine are both provided on the annular receiving groove, and the bottom end of the annular receiving groove is evenly distributed with spring receiving grooves, and a spring is provided in the spring receiving groove, and the spring abuts between the bottom end of the rear bearing magazine and the bottom of the spring receiving groove, and the outer ring of the ball bearing abuts between the upper annular step portion and the lower annular step portion.

2. The spring pre-tightening structure of the drilling and tapping spindle according to claim 1, characterized in that: The outer edge of the rear bearing compartment is provided with a plurality of annular grooves, and the annular grooves are provided with sealing rings that abut against the inner side walls of the annular accommodating grooves.

3. The spring pre-tightening structure of the drilling and tapping spindle according to claim 2, characterized in that: The core shaft is sleeved with a rear water retaining ring fixedly connected to the nut.

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