CN212704433U

CN212704433U - Pre-tightening mechanism for gear and rack and pneumatic chuck

Info

Publication number: CN212704433U
Application number: CN202021711743.7U
Authority: CN
Inventors: 王永虎; 王慧庆
Original assignee: Shandong Dysenbote Intelligent Equipment Co ltd
Current assignee: Shandong Dysenbote Intelligent Equipment Co ltd
Priority date: 2020-08-17
Filing date: 2020-08-17
Publication date: 2021-03-16
Anticipated expiration: 2030-08-17

Abstract

The utility model relates to a pre-tightening mechanism and a pneumatic chuck for a gear rack, wherein the pre-tightening mechanism comprises a rack A, a rack B and a rack pre-tightening box; a gear, a bearing, a pre-tightening shaft and a pre-tightening bearing are arranged in the rack pre-tightening box, the gear is fixed at the middle position in the box body through the bearing, the pre-tightening shaft is respectively arranged at two sides of the box body, the pre-tightening bearings are arranged at two ends of the pre-tightening shaft, the pre-tightening bearings are pressed through one end of a spring piece, and the other end of the spring piece is arranged on the box body through a screw; the rack A and the rack B penetrate through the box body from two opposite sides and are meshed with the gear, and the back surfaces of the rack A and the rack B are respectively pressed by the pre-tightening bearings. The pre-tightening mechanism applies pressure to the rack in the gear and rack centering mechanism in advance, so that the rack keeps pressure on the gear all the time in the movement process, thereby eliminating the gap and improving the centering precision.

Description

Pre-tightening mechanism for gear and rack and pneumatic chuck

Technical Field

The utility model relates to a pretensioning mechanism and air chuck for rack and pinion, in particular to gear and rack's pretensioning mechanism on tubular product cutting field air chuck belongs to air chuck technical field.

Background

Chucks are mechanical devices used to clamp workpieces on machine tools. The machine tool accessory clamps and positions a workpiece by utilizing the radial movement of movable clamping jaws uniformly distributed on a chuck body. The chuck generally comprises a chuck body, movable jaws and a jaw driving mechanism 3. The diameter of the chuck body is 65 mm at least and can reach 1500 mm at most, and a through hole is formed in the center of the chuck body so as to facilitate the workpiece or bar stock to pass through; the back part is provided with a cylindrical or short conical structure and is connected with the end part of a main shaft of the machine tool directly or through a flange plate. Chucks are commonly used in lathes, cylindrical grinders and internal grinders, and may also be used in conjunction with various indexing devices for milling and drilling machines.

The chuck can be divided into a manual chuck, a pneumatic chuck, a hydraulic chuck, an electric chuck and a mechanical chuck from the aspect of using power, wherein the working principle of the pneumatic chuck is that compressed air drives a piston in a cylinder to move so as to realize the clamping action of the chuck.

The existing pneumatic chuck adopts a gear and rack centering synchronous mechanism in some cases, but the rack and the gear are not pre-tightened, and the rack cannot be tightly meshed with the gear at all times in the movement process due to manufacturing and assembling errors. Furthermore, as the rack and the gear wear, the correct meshing relationship cannot be maintained for a long time, and these factors affect the centering and synchronizing effect.

SUMMERY OF THE UTILITY MODEL

To the not enough of prior art, the utility model provides a pretension mechanism for rack and pinion.

The technical scheme of the utility model as follows:

a pre-tightening mechanism for a gear rack comprises a rack A, a rack B and a rack pre-tightening box;

a gear, a bearing, a pre-tightening shaft and a pre-tightening bearing are arranged in the rack pre-tightening box, the gear is fixed at the middle position in the box body through the bearing, the pre-tightening shaft is respectively arranged at two sides of the box body, the pre-tightening bearings are arranged at two ends of the pre-tightening shaft, the pre-tightening bearings are pressed through one end of a spring piece, and the other end of the spring piece is arranged on the box body through a screw;

the rack A and the rack B penetrate through the box body from two opposite sides and are meshed with the gear, and the back surfaces of the rack A and the rack B are respectively pressed by the pre-tightening bearings.

Preferably, the rack pre-tightening box comprises an upper cover and a lower cover, and the upper cover and the lower cover are connected through bolts to form the box body.

Preferably, two ends of the gear are in key connection with the inner ring of the bearing, and the two bearings are fixedly installed in grooves formed in the upper cover and the lower cover respectively.

Preferably, two ends of the pre-tightening shaft are positioned in limiting grooves formed in the upper cover and the lower cover.

Preferably, the pre-tightening bearing is a ball bearing.

Preferably, the screw is in threaded connection with the box body. The advantage of this design is that the pressure of the preload bearing can be adjusted by the screw, thereby adjusting the tightness of the engagement between the rack and the pinion.

Preferably, the pre-tightening shaft is provided with a clamping groove, and one end of the spring piece is inserted into the clamping groove. The advantage of this design is, when the spring leaf compresses tightly the pretension axle, in spring leaf one end inserted the draw-in groove, can prevent the excessive rocking of pretension bearing.

A pneumatic chuck comprises the pre-tightening mechanism.

The technical characteristics and beneficial effect of the utility model:

1. the utility model discloses pretension mechanism, it adopts the pretension bearing to compress tightly the rack back to increase the engaging force between rack and the gear, prevent excessively loosely. In addition, the engaging force between the rack and the gear can be adjusted through the screw, and the phenomenon of over-looseness or over-tightness is prevented.

2. The pre-tightening mechanism applies pressure to the rack in the gear and rack centering mechanism in advance, so that the rack keeps pressure on the gear all the time in the movement process, thereby eliminating the gap and improving the centering precision.

3. The utility model discloses pretension mechanism structural design scientific and reasonable, installation convenient to use has good economic benefits and market value, is worth popularizing and applying.

Drawings

Fig. 1 is an overall schematic view of the pretensioning mechanism of the present invention;

FIG. 2 is a cross-sectional view taken along line A-A of FIG. 1;

fig. 3 is a schematic diagram of the pre-tightening of the upper and lower racks and the gear of the present invention;

wherein: 1-rack A, 2-rack B, 3-rack pre-tightening box, 4-screw, 5-spring piece, 6-pre-tightening bearing, 7-pre-tightening shaft, 8-upper cover, 9-lower cover, 10-bearing and 11-gear.

Detailed Description

The present invention will be further described, but not limited to, by the following examples in conjunction with the accompanying drawings.

Example 1:

as shown in fig. 1 to 3, the present embodiment provides a pretensioning mechanism for a rack and pinion, comprising a rack a1, a rack B2 and a rack pretensioning box 3;

a gear 11, a bearing 10, a pre-tightening shaft 7 and a pre-tightening bearing 6 are arranged in the rack pre-tightening box 3, the gear 11 is fixed at the middle position in the box body through the bearing 10, the pre-tightening shaft 7 is arranged on two sides of the box body respectively, the pre-tightening bearings 6 are arranged at two ends of the pre-tightening shaft 7, the pre-tightening bearings 6 are pressed through one ends of spring pieces 5, and the other ends of the spring pieces 5 are arranged on the box body through screws 4;

the rack A1 and the rack B2 penetrate through the box body from two opposite sides and are meshed with the gear 11, and the back surfaces of the rack A1 and the rack B2 are respectively pressed by the pretension bearing 6.

As shown in fig. 2, the rack pre-tightening box 3 comprises an upper cover 8 and a lower cover 9, and the upper cover 8 and the lower cover 9 are assembled into a box body through bolt connection.

Two ends of the gear 11 are connected with inner rings of the bearings 10 through keys, and outer rings of the two bearings 10 are respectively and fixedly installed in grooves formed in the upper cover 8 and the lower cover 9, so that the gear 11 is prevented from shaking.

The pre-tightening bearing 6 is a ball bearing, the cost is low, the pre-tightening shaft 7 is sleeved with two pre-tightening bearings 6, two ends of the pre-tightening shaft 7 are located in a limit groove formed in the box body, and the pre-tightening shaft 7 has small movement in the limit groove.

The screw 4 is in threaded connection with the box body. The pressure of the pre-tightening bearing 6 can be adjusted through the screw 4, so that the meshing tightness between the rack and the gear can be adjusted.

Because the pre-tightening bearing 6 compresses the back of the rack to increase the meshing force between the rack and the gear, the rack and the gear are meshed without gaps, and excessive looseness is prevented. The engaging force between the rack and the gear can be adjusted through the screw, and the phenomenon of over-looseness or over-tightness is prevented. The gear and rack centering structure adopts pre-tightening, so that the meshing clearance is effectively eliminated, the centering precision is improved, and the abrasion clearance generated in the working process can be compensated.

Example 2:

the pretensioning mechanism as in embodiment 1, except that: the pre-tightening shaft 7 is provided with a clamping groove, and one end of the spring piece 5 is inserted into the clamping groove. When the spring piece 5 compresses the pre-tightening shaft 7, one end of the spring piece is inserted into the clamping groove, so that the pre-tightening bearing 6 can be prevented from excessively shaking on the pre-tightening shaft 7.

Example 3:

an air chuck comprising the pretensioning mechanism of embodiment 1 or embodiment 2. The pneumatic chuck is arranged on a laser cutting machine tool, and when the pneumatic chuck is used for clamping a pipe, the pipe can be prevented from being damaged by overlarge clamping force.

The above description is only for the specific embodiments of the present invention, the protection scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention should be covered by the protection scope of the present invention.

Claims

1. A pre-tightening mechanism for a gear rack is characterized by comprising a rack A, a rack B and a rack pre-tightening box;

2. The pretensioning mechanism for a rack and pinion as claimed in claim 1, wherein the rack pretensioning box comprises an upper cover and a lower cover, and the upper cover and the lower cover are assembled into a box body through bolt connection.

3. The pre-tightening mechanism for the gear rack as claimed in claim 2, wherein two ends of the gear are connected with the inner ring of the bearing through keys, and the two bearings are respectively and fixedly arranged in the grooves formed in the upper cover and the lower cover.

4. The pre-tightening mechanism for the gear rack as claimed in claim 2, wherein two ends of the pre-tightening shaft are positioned in limit grooves formed in the upper cover and the lower cover.

5. The pretensioning mechanism for a rack and pinion as claimed in claim 1, wherein the pretensioning bearing is a ball bearing.

6. The pretensioning mechanism for a rack and pinion of claim 1, wherein the screw is threadedly connected to the cassette.

7. The pre-tightening mechanism for the rack and pinion of claim 1, wherein the pre-tightening shaft is provided with a slot, and one end of the spring plate is inserted into the slot.

8. An air chuck comprising a pretensioning mechanism for a rack and pinion as claimed in any one of claims 1-7.