Description:
TECHNICAL FIELD
[001] The subject matter in general relates to the field of worm gear transmission. More particularly, but not exclusively, the subject matter relates to achieving better efficiency and better endurance in the worm gear transmission.
BACKGROUND
[002] Background description includes information that may be useful in understanding the present subject matter. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed subject matter, or that any publication specifically or implicitly referenced is prior art.
[003] Referring to FIG. 1, disclosed is a worm gear transmission 100. The worm gear transmission 100 is an arrangement in which a worm 102, in the form of a screw, meshes with a worm gear 104. They are configured to transfer motion in 90 degrees. The worm gear transmission 100 shown in FIG. 1 has a gear module of 0.5.
[004] The 0.5 module worm 102 of the worm gear transmission 100 has a lead angle ? of 4.25°. The pitch diameter d1 of the 0.5 module worm 102 is 6.75 mm. The rotations per minute (RPM) n1 of the 0.5 module worm 102 is 1300. The helix angle ? of the 0.5 module worm gear 104 is same as that of the lead angle ? of the worm 102, 4.25°. The effective pressure angle ?n of the worm gear transmission 100 is calculated using the formula,
Effective pressure angle ?n = tan -1 (tan ?*cos ?)
[005] Thus, the effective pressure angle ?n for the 0.5 module worm gear transmission 100 obtained is 14.47°.
[006] The sliding velocity VS of the worm gear transmission 100 is calculated using the formula,
VS = (V1/cos ?), wherein V1 Stands for worm tangential velocity
V1 = (pd1n1/60000) = 0.459 m/s
[007] Thus, the sliding velocity VS for the 0.5 module worm gear transmission 100 obtained is 0.46 m/s ˜ 0.5 m/s.
[008] Referring to FIG. 3, considering the “B” curve (for steel worm 102) the coefficient of friction f for the 0.5 module worm gear transmission 100 is found to be 0.06.
[009] The efficiency ? for the worm gear transmission 100 is calculated using the formula,
? = [(cos ?n - f*tan ?) / (cos ?n + f*cot ?)]
[0010] Substituting the values, the efficiency ? for the 0.5 module worm gear transmission 100 is found to be in the range 50-60%, for example, 54%. Thus, the efficiency of the 0.5 module worm gear transmission 100 is very low which also reduces the endurance of the worm gear transmission 100.
[0011] Therefore, there is a need for a worm gear transmission that can solve the above mentioned technical problems.
OBJECTS OF THE DISCLOSURE
[0012] In view of the foregoing limitations inherent in the state of the art, some of the objects of the present disclosure, which at least one embodiment herein satisfy, are listed herein below.
[0013] It is an object of the present disclosure to provide an improved worm gear transmission.
[0014] It is another object of the present disclosure to increase the efficiency of the worm gear transmission.
[0015] It is another object of the present disclosure to increase the endurance of the worm gear transmission.
[0016] These and other objects and advantages of the present invention will be apparent to those skilled in the art after a consideration of the following detailed description taken in conjunction with the accompanying drawings in which a preferred form of the present invention is illustrated.
SUMMARY
[0017] This summary is provided to introduce concepts related to a worm gear transmission. The concepts are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
[0018] The present disclosure relates to a worm gear transmission to achieve better efficiency and better endurance. The worm gear transmission comprises a worm and a worm gear. The worm comprises a worm lead angle of 7.28°, a pitch diameter of 6.25mm and rotations per minute of 1300. The worm gear comprises a helix angle of 7.28°. The worm gear transmission has a gear module of 0.8 and pressure angle of the worm gear transmission is 20°.
[0019] Other objects, features and advantages of the present disclosure will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating specific embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF DRAWINGS
[0020] While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter that is regarded as forming the present subject matter, it is believed that the present disclosure will be better understood from the following description taken in conjunction with the accompanying drawings, where like reference numerals designate like structural and other elements, in which:
[0021] FIG. 1 discloses a conventional 0.5 module worm gear transmission 100;
[0022] FIG. 2 discloses a 0.8 module worm gear transmission 200, in accordance with an embodiment;
[0023] FIG. 3 is graph indicating sliding velocity VS and corresponding coefficient of friction f, in accordance with an embodiment; and
[0024] FIG. 4 is a comparison of reliability test of the 0.5 module worm gear transmission 100 and the 0.8 module worm gear transmission 200, in accordance with an embodiment.
DETAILED DESCRIPTION
[0025] The detailed description of various exemplary embodiments of the disclosure is described herein with reference to the accompanying drawings. It should be noted that the embodiments are described herein in such details as to clearly communicate the disclosure. However, the amount of details provided herein is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[0026] It is also to be understood that various arrangements may be devised that, although not explicitly described or shown herein, embody the principles of the present disclosure. Moreover, all statements herein reciting principles, aspects, and embodiments of the present disclosure, as well as specific examples, are intended to encompass equivalents thereof.
[0027] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising”, “includes”, “consisting” and/or “including” when used herein, specify the presence of stated features, integers, steps, operations, elements and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof.
[0028] It should also be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two figures shown in succession may, in fact, be executed concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved.
[0029] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It will be further understood that terms, e.g., those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
[0030] Referring to FIG. 2, disclosed is a worm gear transmission 200 comprising a worm 202 and a worm gear 204. The worm 202 meshes with the worm gear 204. They are configured to transfer motion in 90 degrees.
[0031] In an embodiment, the worm gear transmission 200 has a gear module of 0.8.
[0032] The 0.8 module worm 202 of the worm gear transmission 200 has a lead angle ? of 7.28°. The pitch diameter d1 of the 0.8 module worm 202 is 6.25 mm. The rotations per minute (RPM) n1 of the 0.8 module worm 202 is 1300. The helix angle ? of the 0.8 module worm gear 204 is same as that of the lead angle ? of the worm 202, 7.28°. The effective pressure angle ?n of the worm gear transmission 200 is calculated using the formula,
Effective pressure angle ?n = tan -1 (tan ?*cos ?)
[0033] Thus, the effective pressure angle ?n for the 0.8 module worm gear transmission 200 obtained is 19.85°.
[0034] The sliding velocity VS of the worm gear transmission 200 is calculated using the formula,
VS = (V1/cos ?), wherein V1 Stands for worm tangential velocity
V1 = (pd1n1/60000) = 0.425 m/s
[0035] Thus, the sliding velocity VS for the 0.8 module worm gear transmission 200 obtained is 0.428 m/s ˜ 0.4 m/s.
[0036] Referring to FIG. 3, considering the “B” curve (for steel worm 202) the coefficient of friction f for the 0.8 module worm gear transmission 200 is found to be 0.05.
[0037] The efficiency ? for the worm gear transmission 200 is calculated using the formula,
? = [(cos ?n - f*tan ?) / (cos ?n + f*cot ?)]
[0038] Substituting the values, the efficiency ? for the 0.8 module worm gear transmission 200 is found to be in the range 68-75%, for example, 70%. Thus, the efficiency of the 0.8 module worm gear transmission 200 is 1.3 times more than the efficiency of the 0.5 module worm gear transmission 100. The increase in efficiency also increases the endurance of the worm gear transmission 200.
[0039] Referring to FIG. 4, both the 0.5 module worm gear transmission 100 and the 0.8 module worm gear transmission 200 are subjected to 1000000 test cycles. From the figures, it is clear that the teeth on the 0.5 module worm gear transmission 100 are worn out compared to the teeth on the 0.8 module worm gear transmission 200.
TECHNICAL ADVANTAGE
[0040] The present disclosure proposes an improved worm gear transmission.
[0041] The present disclosure proposes to increase the efficiency of the worm gear transmission.
[0042] The present disclosure proposes to increase the endurance of the worm gear transmission.
[0043] Furthermore, each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the “invention” may in some cases refer to certain specific embodiments only. In other cases, it will be recognized that references to the “invention” will refer to subject matter recited in one or more, but not necessarily all, of the claims.
[0044] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all groups used in the appended claims.
[0045] Furthermore, those skilled in the art can appreciate that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be combined into other systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may subsequently be made by those skilled in the art without departing from the scope of the present disclosure as encompassed by the following claims.
[0046] The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.
[0047] While the foregoing describes various embodiments of the present disclosure, other and further embodiments of the present disclosure may be devised without departing from the basic scope thereof. The scope of the present disclosure is determined by the claims that follow. The present disclosure is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

Claims:We claim:
1. A worm gear transmission (200) comprising:
a worm (202) comprising,
a worm lead angle (?) of 7.28°;
a pitch diameter (d1) of 6.25mm; and
rotations per minute (RPM) (n1) of 1300; and
a worm gear (204) with a helix angle (?) of 7.28°, wherein,
the worm gear transmission (200) has a gear module of 0.8; and
pressure angle (?) of the worm gear transmission (200) is 20°.

2. The worm gear transmission (200) as claimed in claim 1, wherein effective pressure angle (?n) of the worm gear transmission (200) is 19.85°.

3. The worm gear transmission (200) as claimed in claim 1, wherein worm tangential velocity (V1) is 0.425 m/s.

4. The worm gear transmission (200) as claimed in claim 1, wherein sliding velocity (VS) of the worm gear (204) is 0.428 m/s.

5. The worm gear transmission (200) as claimed in claim 1, wherein efficiency (?) of the worm gear (204) is in range 68-75%, particularly, 70%.