Internal spline expansion mandrel structure

Abstract

The utility model discloses an internal spline expansion mandrel structure which is characterized in that the internal spline expansion mandrel structure comprises an expansion mandrel, an internal spline expansion sleeve and two fastening springs, the internal spline expansion sleeve is composed of three equally-divided arc-shaped parts, limiting grooves are formed in the positions, close to the ends, of the two sides of the internal spline expansion sleeve in the axis direction, the number of the fastening springs is two, and the fastening springs are annularly arranged in the limiting grooves in a sleeved mode respectively. The internal spline expansion sleeve is arranged on the expansion core shaft in a sleeving mode, the expansion core shaft is provided with a conical part making contact with the inner conical face of the internal spline expansion sleeve, a pressing nut is arranged at the small end, close to the conical part, of the expansion core shaft, and the internal spline expansion sleeve expands in the radial direction by screwing down the pressing nut. An elastic jacking mechanism is arranged at the large end, close to the conical part, of the expansion core shaft. The internal spline gear clamp has the beneficial effects that the clamp can eliminate a positioning gap of an internal spline gear through the expandable internal spline expansion sleeve, the mandrel is in surface contact with the internal spline gear, the clamping stability is high, and positioning is convenient in a bolt tightening expansion mode.

Description

Technical Field

[0001] The utility model relates to the field of clamps, in particular to an internal spline expansion mandrel structure. Background Art

[0002] Some gears, such as gearbox shift gears, engineering machinery output gears, etc., include external teeth and internal splines. In order to ensure the smoothness of the gear transmission process, the coaxiality requirements of the internal splines and external teeth are relatively high. The process route of gears is generally: forging-normalizing-turning-hobbing-boring internal splines-carburizing and quenching-grinding external teeth. In order to ensure the coaxiality requirements, the positioning accuracy of the external gear grinding fixture must be high. The existing internal spline gear processing is mainly positioned by a tapered mandrel, and the coaxiality of the tapered mandrel and the internal spline is ensured by the contact between the tapered mandrel and the inner circular surface of the internal spline. However, in this positioning method, the tapered mandrel and the internal spline are only in line contact, so the clamping stability is poor, and the contact surface between the tapered mandrel and the internal spline is prone to skew, which causes the problem of poor coaxiality when processing the external teeth of the internal spline gear. Summary of the invention

[0003] In view of the above-mentioned deficiencies in the prior art, the utility model provides an internal spline expansion mandrel structure, which has a simple structure, high positioning accuracy and good clamping stability.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] A structure of an internal spline expanding core shaft, characterized in that it includes an expanding core shaft, an internal spline expanding sleeve, and a tightening spring, the internal spline expanding sleeve being composed of three equally divided arc-shaped parts, the internal spline expanding sleeve having limit grooves on both sides near the ends along the axial direction, two tightening springs being respectively annularly sleeved in the limit grooves so that the three arc-shaped parts of the internal spline expanding sleeve are brought closer to the axis center, the internal spline expanding sleeve being sleeved on the expanding core shaft, the expanding core shaft having a tapered portion contacting the inner tapered surface of the internal spline expanding sleeve, a clamping nut being arranged at the small end of the expanding core shaft near the tapered portion, tightening the clamping nut causes the internal spline expanding sleeve to expand radially, and an elastic tightening mechanism being arranged at the large end of the expanding core shaft near the tapered portion.

[0006] Furthermore, a first washer is provided between the clamping nut and the end surface of the internal spline expansion sleeve.

[0007] Furthermore, the elastic tightening mechanism includes a tightening spring, a second washer, and a tightening nut. The tightening spring is sleeved on the expanding shaft. The second washer is arranged between the end face of the internal spline expansion sleeve and the tightening spring. The tightening nut is threadedly connected to the end of the expanding shaft.

[0008] Furthermore, the outer peripheral surface of the internal spline expansion sleeve has a tooth structure adapted to the internal spline.

[0009] The beneficial effects of the utility model include: the clamp can eliminate the positioning clearance of the internal spline gear through the expandable internal spline expansion sleeve, and there is surface contact between the core shaft and the internal spline gear, the clamping stability is high, and the positioning is convenient by tightening and expanding the bolts. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a structural schematic diagram of the utility model;

[0011] Figure 2 It is a cross-sectional structural schematic diagram of the utility model. DETAILED DESCRIPTION

[0012] The present invention will be further described in detail below in conjunction with specific embodiments and accompanying drawings.

[0013] A kind of Figure 1-2 The internal spline expansion core shaft structure shown includes an expansion core shaft 1, an internal spline expansion sleeve 4, and a fastening spring 5. The internal spline expansion sleeve 4 is an annular sleeve composed of three equally divided independent arc-shaped parts. The internal spline expansion sleeve 4 has an annular limit groove near the end on both sides along the axial direction. Two fastening springs 5 ​​are annularly sleeved in the limit groove, so that the three arc-shaped parts of the internal spline expansion sleeve 4 are close to the axis and maintain an annular state. The internal spline expansion sleeve 4 is sleeved on the expansion core shaft 1. The expansion core shaft 1 has a tapered portion that contacts the inner conical surface of the internal spline expansion sleeve 4. The tapered portion squeezes the inner conical surface to make the internal spline expansion sleeve 4 expand radially.

[0014] A clamping nut 7 is provided on the small end of the expanding core shaft 1 near the tapered portion. Tightening the clamping nut 7 causes the internal spline expansion sleeve 4 to expand radially. An elastic tightening mechanism is provided on the large end of the expanding core shaft 1 near the tapered portion. When the clamping nut 7 is loosened, the internal spline expansion sleeve 4 automatically shrinks inward to reduce its outer diameter under the action of the elastic tightening mechanism.

[0015] Furthermore, a first washer 8 is provided between the clamping nut 7 and the end surface of the internal spline expansion sleeve 4 to facilitate the tightening nut 7 to be screwed.

[0016] The elastic tightening mechanism includes a tightening spring 3, a second washer 6, and a tightening nut 2. The tightening spring 3 is sleeved on the expansion mandrel 1. The second washer 6 is arranged between the end surface of the inner spline expansion sleeve 4 and the tightening spring 3. The tightening nut 2 is threadedly connected to the end of the expansion mandrel 1. The tightening nut 2 serves to limit the end of the tightening spring 3. The end of the expansion mandrel 1 has a clamping portion for easy clamping.

[0017] In order to improve the positioning accuracy of the internal spline gear, the outer peripheral surface of the internal spline expansion sleeve 4 of this embodiment has a tooth structure adapted to the internal spline, and the pitch circle of the internal spline is positioned by the tooth structure, and the positioning accuracy is higher.

[0018] The technical solutions provided by the embodiments of the present invention are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the embodiments of the present invention. The description of the above embodiments is only applicable to help understand the principles of the embodiments of the present invention. At the same time, for those skilled in the art, according to the embodiments of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. An internal spline expansion mandrel structure, characterized in that: The invention comprises an expansion shaft (1), an internal spline expansion sleeve (4), and a tightening spring (5). The internal spline expansion sleeve (4) is composed of three equally divided arc-shaped parts. The internal spline expansion sleeve (4) has limit grooves on both sides near the end along the axial direction. There are two tightening springs (5), which are respectively annularly sleeved in the limit grooves so that the three arc-shaped parts of the internal spline expansion sleeve (4) are close to the axis. The internal spline expansion sleeve (4) is sleeved on the expansion shaft (1). The expansion shaft (1) has a conical part that contacts the inner conical surface of the internal spline expansion sleeve (4). A clamping nut (7) is arranged at the small end of the expansion shaft (1) near the conical part. Tightening the clamping nut (7) causes the internal spline expansion sleeve (4) to expand radially. An elastic tightening mechanism is arranged at the large end of the expansion shaft (1) near the conical part.

2. The internal spline expansion mandrel structure according to claim 1, characterized in that: A first washer (8) is provided between the clamping nut (7) and the end surface of the internal spline expansion sleeve (4).

3. The internal spline expansion mandrel structure according to claim 1, characterized in that: The elastic tightening mechanism comprises a tightening spring (3), a second washer (6), and a tightening nut (2); the tightening spring (3) is sleeved on the expanding shaft (1); the second washer (6) is arranged between the end surface of the internal spline expansion sleeve (4) and the tightening spring (3); and the tightening nut (2) is threadedly connected to the end of the expanding shaft (1).

4. The internal spline expansion mandrel structure according to claim 1, characterized in that: The outer peripheral surface of the internal spline expansion sleeve (4) has a toothed structure adapted to the internal spline.

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