Hard tooth surface compound gear

Abstract

The utility model discloses a hard tooth surface compound gear which comprises a gear body and a tooth surface, the working surface of the gear body is provided with a gear part, the gear body is made of metal materials with certain strength and hardness, and the gear body has good plasticity. The gear surface is made of a metal material with higher strength and hardness, the wear resistance of the gear surface is better than that of the gear body, the gear surface is deposited on the outer surface of the working surface of the gear body by adopting an electroplating process to form the compound gear, and the gear body is prepared based on the high-strength and high-hardness material through an efficient machining process; and a layer of tooth surface is deposited on the outer surface of the working surface of the gear body, so that composite material combination is firmer, the production efficiency is high, machining is convenient, thermal deformation and subsequent grinding finish machining processes are omitted, and meanwhile, the machining process is better in economical efficiency.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of gear machining, particularly to a hard tooth surface composite gear. BACKGROUND

[0002] At present, gears are mainly made of metal or engineering plastics. Metal materials are mainly used to make gears with high strength and hardness. Most gears with high hardness and precision are made of metal materials. Metal gears are mainly manufactured by hobbing, which has high processing cost and leads to high cost of metal gears. Engineering plastic materials are mainly used to make gears with low requirements for strength and hardness. Engineering plastic gears are mainly obtained by injection molding. The production rate of engineering plastic gears is generally high, and the cost is low, but the force that can be transmitted is small, and the application field is limited. Ordinary metal gears have low processing productivity, high cost and poor economy.

[0003] The existing gear and its processing method, such as Chinese patent application No. CN201610895798, utility model name "a forging method for 17CrNiMo6 steel wind power gear" of Taiyuan University of Science and Technology, provides a process route for manufacturing gears by using 17CrNiMo6 material to forge blanks and then heat treating and machining the blanks into gears. The gear body and the gear ring made in this way are made of the same material and have a large weight, which reduces the mechanical efficiency of the transmission system and has a high manufacturing cost. The Chinese utility model patent application No. CN201610549713, utility model name "aluminum-based composite material for automobile transmission gear and preparation method thereof" of Anhui Ruilin Auto Parts Co., Ltd. is prepared from the following raw materials by weight: aluminum 95-98, germanium 0.1-0.14, manganese 1-1.2, titanium 0.13-0.16, copper 0.3-0.35, lithium 0.04-0.06, zinc 0.2-0.3, hexadecyl trimethyl ammonium bromide 0.06-0.1, graphene oxide 3-5, zirconium hydride 5-8, hexachloroethane 0.85-1, calcareous shale 0.4-0.6, sodium alginate 0.24-0.3, calcium silicide 0.2-0.4, silicon dioxide 2.3-2.4, etc. Although a complex material formula is used and the casting process is improved, the comprehensive performance of the aluminum alloy is improved, but the yield strength of the material is only 231MPa, and the tensile strength is only 258MPa. The impact resistance of the working teeth of the aluminum alloy gear is lower than that of forged steel, and the wear resistance after surface oxidation treatment is still not comparable to that of alloy steel. However, the existing gear processing technology is complex and the composite material is not firmly combined, so it needs to be improved. SUMMARY

[0004] The utility model discloses a purpose is to provide a kind of hard tooth surface composite gear and its processing method, by efficient processing technology based on high strength high hardness material preparation gear body, then utilize electroplating process, deposit a layer of tooth surface on the gear body working face outer surface, not only composite material is more firm, production efficiency is high, it is convenient to process, heat deformation and subsequent grinding finish processing technology are saved, while the processing technology economy is better.

[0005] The above technical purpose of the utility model is realized by the following technical scheme: a kind of hard tooth surface composite gear, including gear body and tooth surface, the working face of gear body has gear part, the gear body adopts metal material with certain strength and hardness, the tooth surface adopts higher strength and hardness metal material and the wear resistance of tooth surface is better than gear body, the gear body has good plasticity, tooth surface is deposited to the working face outer surface of gear body by electroplating process to form composite gear.

[0006] Further, the thickness of the tooth surface is 10-20 microns.

[0007] Further, the material of the tooth surface is electroplated chromium or electroplated copper.

[0008] Further, the material of the gear body is structural steel or aluminum alloy.

[0009] Further, the profile curve of the gear body is obtained by equidistant offset from gear theoretical profile curve.

[0010] Further, the offset amount of the equidistant offset is the plating thickness at the gear division circle.

[0011] Further, the profile curve of the gear body is obtained by subtracting the plating thickness value of each position from gear theoretical profile curve, and the plating thickness is the thickness of the tooth surface.

[0012] A processing method of a hard tooth surface composite gear, characterized in that it comprises the following steps:

[0013] S1: determining the profile curve of the gear body: determining the profile curve of the gear body by subtracting the thickness of the tooth surface at each position from the gear theoretical profile curve or by equidistant offset from the gear theoretical profile curve;

[0014] S2: processing the gear body: if an equal-section gear body is needed, first obtain an equal-section bar material profile by extrusion process, the cross-sectional profile curve of the bar material profile is the same as the profile curve of the gear body, and then cut the bar material profile into a single gear body; if a non-equal-section gear body is needed, first cut a single gear body blank, and then obtain the gear body by cold heading process or extrusion process

[0015] S3: preparing the composite gear: depositing a layer of tooth surface on the working face outer surface of the gear body through electroplating process to form the composite gear.

[0016] Further, the thickness of the tooth surface is 10-20 microns.

[0017] Further, the material of the tooth surface adopts electroplated chromium or electroplated copper.

[0018] Further, the material of the gear body adopts structural steel or aluminum alloy.

[0019] In summary, the utility model has the following beneficial effects:

[0020] 1, the utility model discloses can adopt electroplating, extrusion, cold upsetting etc.

[0021] 2, the utility model discloses the body material adopts extrusion, cold upsetting etc.

[0022] 3, the utility model discloses the electroplating process makes the tooth surface wear-resistant metal deposit to the gear body, compared with the prior art of the structural steel or alloy steel heat treatment to enhance the hardness of the tooth surface strength, has more convenient, no thermal deformation, does not need subsequent grinding finishing etc.

[0023] 4, the utility model discloses the electroplating process makes the tooth surface wear-resistant metal deposit to the gear body, compared with the PVD method in the gear plating film method, has the economy good, the simple advantage such as shielding non-plating auxiliary tooling.

[0024] 5, the utility model discloses can adopt aluminum alloy etc. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical scheme in the embodiment of the utility model or prior art, the following will be briefly introduced to the drawing needed to be used in the embodiment or prior art description, and obviously, for those skilled in the art, other drawings can also be obtained according to these drawings.

[0026] Figure 1 It is the structure schematic view of the composite gear of the utility model;

[0027] Figure 2 It is the schematic view of the gear body of the body;

[0028] Figure 3 It is the schematic view of the tooth surface;

[0029] Figure 4 is a profile curve contrast diagram of gear tooth portion;

[0030] In the figure, 1, tooth surface; 2, gear body; 3, actual profile curve of gear; 4, profile curve of gear body; 5, single-sided gear actual profile curve; 6, symmetry line of gear tooth; 7, theoretical profile curve of gear. DETAILED DESCRIPTION

[0031] The utility model will be further explained in connection with the drawings below.

[0032] Embodiment 1

[0033] This embodiment is aimed at gear with low precision requirement, and the influence of gear structure on plating layer is ignored, and the plating layer is approximately equal in thickness.Taking a spur gear with external gear tooth as an example, Figure 1 is a structure schematic view when the utility model is used as an external gear, the tooth surface 1 is deposited on the outside of the gear body 2, and the gear body 2 is processed with a shaft hole and other structures according to requirements.

[0034] As shown in Figure 1 , a hard tooth surface composite gear comprises a tooth surface 1 and a gear body 2, the gear body 2 is a metal material with good plasticity and certain strength and hardness, the gear body 2 is suitable for plastic deformation processing technology, the gear body 2 has a profile curve similar to that of a gear, the tooth surface 1 is a layer of metal with high strength and hardness on the circumferential surface of the gear, and the tooth surface 1 is deposited on the gear body 2 through electroplating technology.

[0035] The hard tooth surface composite gear is designed in this way, the main purpose of which is to enable the hard tooth surface composite gear to adopt a high production efficiency manufacturing process, simplify the manufacturing process, reduce the production equipment investment, and the like, so that the hard tooth surface composite gear has the advantages of low production cost and good economy, meanwhile, the tooth surface and the base body adopt different materials, the comprehensive cost of the materials can also be reduced under the premise of meeting respective use requirements, and the economy of the hard tooth surface composite gear is further improved.

[0036] In specific implementation, preferably, the gear body 2 shown in Figure 1 , Figure 2 is first manufactured, and then the tooth surface 1 is deposited on the gear body 2 through electroplating technology.

[0037] The gear body 2 is mainly obtained in two steps, first, an equal-section bar material is obtained by using an extrusion process, and then the bar material is cut into a single piece of the body, the cross-sectional profile curve of the bar material is the same as the profile curve of the gear body 2. Preferably, the material of the gear body 2 is aluminum alloy.

[0038] Preferably, the tooth surface 1 is obtained by electroplating chromium.

[0039] Since gears with low precision requirements are ignored, the influence of gear structure on electroplating is ignored, and the plating is approximated as having a uniform thickness. The contour curve of the body can be simply obtained by offsetting the theoretical contour curve of the gear through equidistant offset. The offset amount of this equidistant offset is generally the plating thickness at the pitch circle of the gear, that is, the thickness of the tooth surface 1 at the pitch circle. The contour curve of the gear body 2 is obtained by offsetting the theoretical contour curve of the gear through equidistant offset.

[0040] Let's take the profile curve of the tooth portion of an involute standard spur gear as an example to illustrate, such as... Figure 4 As shown, Figure 4 To the right of the symmetry line 6 of the gear teeth are the theoretical gear profile curve 7 and the profile curve 4 of the gear body 2. For clarity, the actual gear profile curve 3 is not drawn on the right side. To the left of the symmetry line 6 of the gear teeth are the theoretical gear profile curve 7, the profile curve 4 of the gear body 1, and the actual profile curve 5 of the gear on one side. The theoretical gear profile curve 7 is only for design purposes and does not appear in the actual gear. Ideally, the actual gear profile curve 3 would appear at the position of the theoretical gear profile curve 7. In this example, the influence of the gear structure on the electroplating layer, i.e., the influence on the tooth surface 1, is ignored. The profile curve 4 of the gear body 2 is simply obtained by offsetting the theoretical gear profile curve 7 at equal intervals. In actual production, tooth surfaces 1 of unequal thickness are added to the profile curve 4 of the gear body 2 to obtain the actual gear profile curve 3. The actual gear profile curve 3 deviates from the theoretical gear profile curve 7, resulting in an error. Since this error is relatively small, it is acceptable in some applications where high precision is not required.

[0041] Example 2

[0042] This embodiment is designed for scenarios with high precision requirements. The profile curve of the gear body 2 is not simply obtained by offsetting the theoretical gear profile curve at equal intervals. Instead, the profile curve of the gear body 2 is obtained by subtracting the tooth surface thickness 1 at each position from the theoretical gear profile curve. The tooth surface thickness 1 at each position is affected by changes in gear size and structural shape, and needs to be measured and adjusted in actual production.

[0043] After determining the contour curve of the gear body 2, the gear body 2 can be machined according to the contour curve, and then the tooth surface 1 can be deposited onto the gear body 2 through an electroplating process. The principle and process are the same as in Example 1. The difference between Example 1 and Example 2 is that the contour curve of the gear body 2 is not obtained by equidistant offset from the theoretical contour curve of the gear, but is calculated based on the actual thickness of the plating layer, i.e., the actual thickness of the tooth surface 1.

[0044] Example 3

[0045] This embodiment is mainly aimed at the scenario of double gear, helical gear, herringbone gear, and other scenarios requiring non-equal cross-section gear body. The bar material is first cut into single body rough material, and then the gear body 2 is obtained through cold heading process or extrusion process. Other principles and embodiments 1 and 2 are the same.

[0046] Embodiment 4

[0047] The material of the gear body 2 is structural steel, which generally has a low carbon content and is easy to be plastically deformed. Generally, the comprehensive performance of structural steel is better than that of aluminum alloy, and the plastic forming of aluminum alloy is easier.

[0048] Embodiment 5

[0049] The tooth surface 1 is obtained by electroplating copper, and copper is more firmly combined with some substrates.

[0050] The above is only a preferred embodiment of the present application, so equivalent changes or modifications made according to the structure, features and principles described in the patent application range of the present application are included in the patent application range of the present application.

Claims

1. A hardened face composite gear comprising a gear body (2) and a tooth face (1), the working face of the gear body (2) having a gear portion, characterized in that: The gear body (2) is made of metal material with certain strength and hardness, the gear body (2) has plasticity, the gear surface (1) is made of metal material with higher strength and hardness, and the wear resistance of the gear surface (1) is better than that of the gear body (2), the gear surface (1) is deposited on the working surface outer surface of the gear body (2) by electroplating process to form a composite gear.

2. A hardened face composite gear according to claim 1, wherein: The thickness of the gear surface (1) is 10-20 microns.

3. A hardened face composite gear according to claim 1, wherein: The material of the gear surface (1) is electroplated chromium or electroplated copper.

4. A hardened face composite gear according to claim 1, wherein: The material of the gear body (2) is structural steel or aluminum alloy.

5. A hardened face composite gear according to claim 1, wherein: The profile curve of the gear body (2) is obtained by equidistant offset from the gear theoretical profile curve.

6. A hardened face composite gear according to claim 5, wherein: The offset amount of the equidistant offset is the plating thickness at the gear division circle.

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