Description:FIELD
The present disclosure relates to gear trains and, more particularly, to a gear train of a servomotor.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
Presently, servomotors are used in a wide range of applications, for example, robotics, CNC machinery, automated manufacturing, etc. The servomotors are generally used for precision angular or linear position control. A low-cost servomotor is generally made of a polymer material (e.g., plastic). These servomotors provide a gear ratio of 1:200 to 1:250. However, in most practical applications a higher gear ratio is required. To achieve a higher gear ratio, it is required to increase the size of the gear train. Further, the increase in the size of the gear train results in increase in size of the servomotor. Therefore, it would not be justifiable and economical, to increase the gear ratio of the servomotor at the cost of the size of the servomotor.
Thus, there is felt a need for a gear train for a servomotor which can provide a relatively higher gear ratio that alleviates the aforementioned drawbacks.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
An object of the present disclosure is to provide a gear train.
Another object of the present disclosure is to provide a gear train which provide a higher gear ratio.
Still another object of the present disclosure is to provide a gear train which is compact.
Still another object of the present disclosure is to provide a gear train which provides a higher torque transmission to size ratio.
Yet another object of the present disclosure is to provide a gear train which reduces the total number of components required in a gear train.
Still another object of the present disclosure is to provide a gear train which reduces the assembly time.
Yet another object of the present disclosure is to provide a gear train for a servomotor which is economical.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure envisages a gear train. The gear train is configured to be rotationally coupled to an output shaft of a motor. The gear train comprises a driving gear, a driven gear, and an intermediate compound gears arrangement.
The driving gear is configured to be mounted on the output shaft of the motor. The driven gear is configured to drive an arm mounted thereon. The intermediate compound gears arrangement is configured between the driving gear and the driven gear. Thus, the rotational motion is transmitted from the driving gear to the driven gear via the intermediate compound gears arrangement. The intermediate compound gears arrangement comprises a first gear, at least one second gear and a third gear. The first gear is configured to mesh with the driving gear, the second gear is configured to mesh with the first intermediate compound gear and the third gear is configured to mesh with the second gear. The driven gear is configured to mesh with the third intermediate compound gear.
Further, the driving gear and the intermediate compound gears arrangements are configured to produce a gear ratio ranging from 1:426 to 1:500 at the driven gear with respect to the driving gear.
In an embodiment, the rotational axis of the driving gear, the driven gear and the intermediate compound gears are parallel to the rotational axis of the output shaft.
Further, the first compound gear and the third compound gear are coaxially mounted on a first polymeric shaft, and the second intermediate compound gear and the driven gear are coaxially mounted on a second polymeric shaft.
The first compound gear facilitates power transmission from the driving gear to the second compound gear. The second compound gear facilitates power transmission from the first compound gear to the third compound gear. The third compound gear facilitates power transmission from the second compound gear to the driven gear.
In an embodiment, the gear train produces a torque in the range of 1.4 kg-cm to 1.6 kg-cm.
In another embodiment, the driving gear, the intermediate compound gears, the driven gear, the first shaft and the second shaft are of a polymeric material selected from the group consisting of nylon, acetal, or a poly carbonate.
In another embodiment, a servomotor comprises a gear train and a motor.
Advantageously, the shaft and the gears are made from nylon, thereby, it provides self-lubrication and minimizes the friction between the mating gears of the gear train.
Advantageously, the polymeric shaft provides high torque to size ratio and consumes relatively lesser power in comparison to a conventional servomotor. In addition, the polymeric shafts also help in reducing the number of components, wear between the mated gear teeth and the assembly time.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
A gear train, of the present disclosure, will now be described with the help of the accompanying drawing, in which:
Figure 1 illustrates a front exploded view of a servomotor with a gear train and an arm;
Figure 2 illustrates a front view of a set of intermediate compound gears in-line with a driving gear and a driven gear; and
Figure 3A illustrates a front view of an engagement of different gears of a gear train of Figure 2, and Figure 3B illustrates an isometric view of an engagement of different gears of a gear train of Figure 1, according to an embodiment of the present disclosure.
LIST OF REFERENCE NUMERALS
1000- servomotor
100- gear train
10- arm
12a- top housing portion
12b- mid-housing portion
12c- bottom housing portion
14- controlling circuit
16- motor
16a- motor shaft
18- driving gear
20- first intermediate compound gear
20a- first gear portion of first intermediate compound gear
20b- second gear portion of first intermediate compound gear
22- second intermediate compound gear
22a- first gear portion of second intermediate compound gear
22b- second gear portion of second intermediate compound gear
24- third intermediate compound gear
24a- first gear portion of third intermediate compound gear
24b- second gear portion of third intermediate compound gear
26- first polymeric shaft
28- second polymeric shaft
30- first recess
32- second recess
34- driven gear
36- potentiometer
DETAILED DESCRIPTION
Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms “a”, “an”, and “the” may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms “comprises”, “comprising”, “including”, and “having”, are open ended transitional phrases and therefore specify the presence of stated features, integers, steps, operations, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The particular order of steps disclosed in the method and process of the present disclosure is not to be construed as necessarily requiring their performance as described or illustrated. It is also to be understood that additional or alternative steps may be employed.
When an element is referred to as being “mounted on”, “engaged to”, “connected to”, or “coupled to” another element, it may be directly on, engaged, connected or coupled to the other element. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed elements.
The terms first, second, third, etc., should not be construed to limit the scope of the present disclosure as the aforementioned terms may be only used to distinguish one element, component, region or section from another component, region, or section. Terms such as first, second, third etc., when used herein do not imply a specific sequence or order unless clearly suggested by the present disclosure.
Terms such as “inner”, “outer”, “beneath”, “below”, “lower”, “above”, “upper”, and the like, may be used in the present disclosure to describe relationships between different elements as depicted from the figures.
Typically, servomotors provide a gear ratio of 1:200 to 1:250. However, in most practical applications a higher gear ratio is required. To achieve a higher gear ratio, it is required to increase the size of the gear train. Further, the increase in the size of the gear train results in increase in size of the servomotor. Therefore, it would not be justifiable and economical, to increase the gear ratio of the servomotor at the cost of the size of the servomotor.
To overcome the aforementioned drawbacks, the present invention envisages a gear train 100 for a servomotor 1000, which provides a relatively higher gear ratio.
The gear train 100 is configured to be enclosed in a housing, and further being configured to be rotationally coupled to an output shaft of a motor 16 within the housing.
In an embodiment, the motor 16 is selected from a group consisting of a DC motor or an AC motor.
The present disclosure will now be described with reference to Figure 1. According to the present disclosure, the gear train 100 comprises a driving gear 18, an intermediate compound gears arrangement 20, 22, 24 and a driven gear 34. The driving gear 18 is mounted on the output shaft 16a and the driven gear 34 is configured to drive an arm 10 mounted thereon. The Figure 1 illustrates a front exploded view of the servomotor 1000 with the gear train 100 and the arm 10.
The gear train 100 and the motor 16 are enclosed in the housing. The housing includes a top housing portion 12a, a mid-housing portion 12b and a bottom housing portion 12c. The bottom housing portion 12b is configured to support the motor 16, a potentiometer 36 and a controlling circuit 14. The mid housing portion 12b is fitted over the bottom housing portion 12c. The bottom housing portion 12c and the mid-housing portion 12b define a first enclosed space for the motor 16, the potentiometer 36 and the controlling circuit 14. In an embodiment, the bottom housing portion 12c and the mid-housing portion 12b together is a single unit, for enclosing the motor 16, the potentiometer 36 and the controlling circuit 14. The top housing portion 12a and the mid-housing portion 12b define a second enclosed space for enclosing the gear train 100 therewith. In an embodiment, the top housing portion 12a, mid-housing portion 12b and the bottom housing portion 12c, together is a single unit, for enclosing the motor 16, the potentiometer 36, the controlling circuit 14 and the gear train 100.
The second enclosed space includes the driving gear 18, the intermediate compound gears arrangement 20, 22, 24 and the driven gear 34.
Further, the driving gear 18 is mounted to the output shaft 16a of the motor 16. The intermediate compound gear arrangement comprises a first compound gear 20, a second compound gear 22 and a third compound gear 24. The first compound gear 20 and the third compound gear 24 are coaxially mounted to a first polymeric shaft 26, whereas the second compound gear 22 and the driven gear 34 are coaxially mounted to a second polymeric shaft 28. The operative top of the mid-housing portion 12b is provided with a first recess 30 and a second recess 32. The first recess 30 allows the mounting of the first polymeric shaft 26, whereas the second recess 32 allows the insertion of the second polymeric shaft 28, therein. Figure 2 illustrates a front view of a set of intermediate compound gears arrangement in-line with the driving gear 18 and the driven gear 34.
In an embodiment, the intermediate compound gears arrangement may include more than three compound gears.
In a preferred embodiment, the teeth of the intermediate compound gears arrangement are as follows:
Gears Teeth
Driving gear 18 10
first compound gear 20 12/55
second compound gear 22 13/53
third compound gear 24 12/52
Driven gear 34 55

In an embodiment, the intermediate compound gears arrangement 20, 22, 24 are configured to have a rotational axis of any of the intermediate compound gears 20, 22, 24 are parallel to a rotational axis of the output shaft 16a of the motor 16.
In another embodiment, the rotational axis of the driving gear 18 is parallel to the rotational axis of the driven gear 34.
The first compound gear 20 is configured with a first gear portion 20a and a second gear portion 20b. The second compound gear 22 is configured with a first gear portion 22a and a second gear portion 22b. The third compound gear 24 is configured with a first gear portion 24a and a second gear portion 24b.
The second gear portion 20b of the first compound gear 20 is configured to mesh with the driving gear 18. The first gear portion 20a of the first compound gear 20 is configured to mesh with the second gear portion 22b of the second compound gear 22. The first gear portion 22a of the second compound gear 22 is configured to mesh with the second gear portion 24b of the third compound gear 24. The first gear portion 24a of the third compound gear 24 is configured to mesh with the driven gear 34.
The first compound gear 20 facilitates power transmission from the driving gear 18 to the second compound gear 22. The second compound gear 22 facilitates power transmission from the first compound gear 22 to the third compound gear 24. The third compound gear 24 facilitates power transmission from the second compound gear 22 to the driven gear 34. Thus, the power of the motor 16 is being transmitted form the driving gear 18 to the driven gear 34 of the gear train 100.
Figure 3A illustrates a front view of an engagement of different gears of a gear train of Figure 1, and Figure 3B illustrates an isometric view of an engagement of different gears of a gear train of Figure 1.
Further, in the servomotor 1000, the output torque and the output gear ratio generated by the gear train 100 are being controlled by the potentiometer 36. The potentiometer 36 is in electrical connection with the controlling circuit 14. A user-defined input in the form of a referenced signal is being fed to the motor 16 by means of a motor driver IC (AA51880E). The driver IC is communicatively coupled with the controlling circuit 14, and the driver IC is configured to control the rotation of the motor 16 based on the user defined input. Since, the DC motor 16 is rotationally coupled to the gear train 100; therefore, power is being transmitted from the driving gear 18 to the driven gear 34. Further, the second shaft 28 extends and is coupled with the potentiometer 36. The potentiometer 36 is configured to generate an output signal in accordance with the rotation of the motor 16.
Thus, the potentiometer 36 controls the angular movement or rotation of the second shaft 28, which in turn controls the rotation of the driving gear 18, the output torque and the desired gear ratio. The gear train 100 as disclosed by the present disclosure provides a gear ratio at the driven gear 34 in the range of 1:426 to 1:500 with respect to the driving gear 18. Further, the gear train 100 produces a torque in the range of 1.4kg-cm to 1.6 kg-cm.
In an embodiment, the servomotor 1000 with the gear train 100 consumes power in the range of 6.0ma to 6.3ma. The servomotor operates on low power, therefore it is beneficial in wide range of applications where power requirement is limited.
In an embodiment, the first shaft 26, the second shaft 28, the intermediate compound gears 20, 22, 24, the driving gear 18 and the driven gear 34 are of a polymeric material selected from the group consisting of nylon, acetal, or a polycarbonate.
In a preferred embodiment, the first shaft 26, the second shaft 28, the intermediate compound gears 20, 22, 24, the driving gear 18 and the driven gear 34 are made of nylon.
Advantageously the first shaft 26, the second shaft 28, the intermediate compound gears 20, 22, 24, the driving gear 18 and the driven gear 34 are made from nylon; thereby it provides self-lubrication and minimizes the friction between the mating gears of the gear train 100.
Also, the polymeric shafts provide a high torque to size ratio and consume relatively lesser power in comparison to the conventional servomotor. In addition, the polymeric shafts as well as gears also help in reducing the number of components, wear between the mated gear teeth and reduce the assembly time.
TECHNICAL ADVANCES AND ECONOMICAL SIGNIFICANCE
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of a gear train, that:
• provide higher gear ratio;
• provides self-lubricating engagement of the gear train;
• provide better torque transmission to size ratio;
• provides an economical and serviceable assembly; and
• reduces the number of components in the gear train.
The foregoing description of the specific embodiments so fully reveals the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.
Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation. , Claims:WE CLAIM:
1. A gear train (100), configured to be rotationally coupled to an output shaft (16a) of a motor (16), said gear train (100) comprising:
• a driving gear (18) mounted on said output shaft (16a);
• a driven gear (34) configured to drive an arm (10) mounted thereon;
• an intermediate compound gears arrangement, configured between said driving gear (18) and said driven gear (34), said arrangement comprising:
o a first gear (20) configured to mesh with said driving gear (18);
o at least one second gear (22) configured to mesh with said first intermediate compound gear (20); and
o a third gear (24) configured to mesh with said second gear (22);
wherein said driven gear (34) configured to mesh with said third intermediate compound gear (24), and said driving gear (18), and said intermediate compound gears arrangement (20, 22, 24) configured to produce a gear ratio ranging from 1:426 to 1:500 at said driven gear (34) with respect to said driving gear (18).
2. The gear train (100) as claimed in claim 1, wherein said driving gear (18), said intermediate compound gears arrangement (20, 22, 24), said driven gear (34), said first shaft (26) and said second shaft (28) is of a polymeric material selected from the group consisting of nylon, acetal, or a polycarbonate.
3. The gear train (100) as claimed in claim 1, where the rotational axis of said driving gear (18), said driven gear (34) and said intermediate compound gears (20, 22, 24) are parallel to the rotational axis of said output shaft (16a).
4. The gear train (100) as claimed in claim 1, wherein said first compound gear (20) and said third compound gear (24) are coaxially mounted on a first polymeric shaft (26), and said second compound gear (22) and said driven gear (34) are coaxially mounted on a second polymeric shaft (28).
5. The gear train (100) as claimed in claim 1, wherein said first compound gear (20) facilitates power transmission from said driving gear (18) to said second compound gear (22).
6. The gear train (100) as claimed in claim 1, wherein said second compound gear (22) facilitates power transmission from said first compound gear (22) to said third compound gear (24).
7. The gear train (100) as claimed in claim 1, wherein said third compound gear (24) facilitates power transmission from said second compound gear (22) to said driven gear (34).
8. The gear train (100) as claimed in claim 1, produces a torque in the range of 1.4 kg-cm to 1.6 kg-cm.
9. A servomotor (1000) comprising a gear train (100) and a motor (16) as claimed in any one of the preceding claims 1-8.
Dated this 14th day of June, 2022

_______________________________
MOHAN RAJKUMAR DEWAN, IN/PA – 25
of R.K. DEWAN & CO.
Authorized Agent of Applicant