Description:TECHNICAL FIELD
[0001] The present disclosure, in general, relates to a locking arrangement of thrust collar in vertical synchronous motor and more particularly to the novel and better locking arrangement of thrust collar in vertical synchronous motors with brushless excitation, where lock nut is used with lock washer for locking the thrust collar that is already shrink-fitted on the shaft of the vertical synchronous motor.
BACKGROUND
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] The vertical synchronous motors for lift irrigation pumps are equipped with a top thrust and guide bearing arrangement and bottom guide bearing arrangement. For transmitting the axial load (including rotor weight and thrust load) to the top (NDE) thrust bearing, a thrust collar is mounted on the shaft. Thrust collar is shrink-fitted on the shaft and additionally, it is locked using a split-half locking ring.
[0004] Moreover, the thrust collar is a rotating part and hence the contact surface between the thrust collar and the locking ring needs to be truly flat for proper locking of thrust collar, which also implies that the contact surfaces must have a very fine surface finish. In order to achieve such surface finish, there is a need for precision machining, which in turn needs additional time and incurs more cost that also delays the overall manufacturing.
[0005] Hence, some of the prior art proposes an arrangement for locking of thrust collar by using Locknut and lock washer. This arrangement helps in reducing the manufacturing processes and in turn, assembly time.
[0006] However, in the case of vertical synchronous motors with brushless excitation, the exciter is also mounted above the thrust collar due to which the use of lock nut and lock washer arrangement is not feasible.
[0007] The present invention deals with the solution to the above problem and provides a novel arrangement that has been developed to facilitate the use of lock nut and lock washer arrangement in vertical synchronous motors with brushless excitation.
SUMMARY
[0008] This summary is provided to introduce concepts related to provide a novel locking arrangement in vertical synchronous motors with brushless excitation comprising the lock nut and the lock washer assembly.
[0009] The novel locking arrangement in vertical synchronous motor with brushless excitation comprising a shaft having a plain section and a stepped section and, a top thrust bearing that supports axial load, a thrust collar that is shrink-fitted to the shaft, a locknut and a lock washer that tightly lock the thrust collar shrink-fitted on the shaft, an exciter rotor hub that is mounted above the thrust collar upon which the brushless exciter rotor is assembled.
[0010] In an embodiment, the present disclosure defines the shaft having a diameter of 215 mm is stepped to form a stepped shaft having a diameter of 200 mm.
[0011] In an embodiment, the present disclosure defines the shaft having a diameter of 215 mm is of length 556 mm.
[0012] In an embodiment, the present disclosure defines the stepped shaft having diameter 200 mm is of length 198 mm.
[0013] In an embodiment, the present disclosure defines the threaded section that is provided after the stepped shaft having minor diameter ranges between 186.752 mm to 187.252 mm and the major diameter ranges between 190 mm to 190.768 mm.
[0014] In an embodiment, the present disclosure defines the threaded section that is of length 62mm.
[0015] In an embodiment, the present disclosure defines the exciter rotor hub having mounting diameters 177mm and 175mm.
[0016] In an aspect, the present disclosure defines the redesigned shaft and the mounting section of the shaft having a diameter of 215 mm is stepped to form a stepped shaft having diameter 200 mm that suits the Locknut and Lock washer arrangement.
[0017] Similarly, the diameter of the step for mounting of the Exciter Rotor hub is also reduced ranges between 175-177 mm that facilitates the insertion of Lock washer and Locknut from the top (NDE).
[0018] Moreover, a new Exciter Rotor hub has been designed where the inner diameter of the hub corresponds to the mounting diameter in the new shaft. Accordingly, a new Exciter Rotor assembly has been made which includes the new Exciter Rotor hub.
[0019] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The illustrated embodiments of the subject matter will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and methods that are consistent with the subject matter as claimed herein, wherein:
[0021] Figure 1 illustrates the sectional view of the existing Thrust collar locking arrangement using the split-half locking ring.
[0022] Figure 2 illustrates the existing shaft with provision for the split-half locking ring.
[0023] Figure 3 illustrates the existing exciter rotor hub with a mounting diameter of 192mm and 190mm.
[0024] Figure 4 illustrates the sectional view of the newly developed thrust collar locking arrangement using Locknut and Lock washer.
[0025] Figure 5 illustrates the new shaft with provision for Locknut and Lock washer.
[0026] Figure 6 illustrates the New Exciter Rotor Hub with mounting Diameter 177mm and 175mm.
DETAILED DESCRIPTION
[0027] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered 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.
[0028] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. In addition, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0029] The present disclosure aims to solve the technical problem of providing a precision machining that increases the manufacturing cost as well as the assembly time required.
[0030] FIG. 1 shows the Sectional view of Thrust collar locking arrangement (100) using the Split-half locking ring (108) as per existing practice. For transmitting the axial load (including rotor weight and thrust load) to the top thrust bearing (104), a thrust collar (106) is shrink-fitted on the shaft (102) and additionally, it is locked using a split-half locking ring (108). The Exciter rotor hub (110) is mounted above the thrust collar (106) upon which the Brushless exciter rotor is assembled.
[0031] Moreover, the Thrust collar (106) is a rotating part and hence the contact surface between the thrust collar (106) and the split-half locking ring (108) needs to be truly flat for proper locking of thrust collar (106) over the shaft (102), which implies that the contact surfaces must have very fine surface finish. The surface finish involves precision machining, which requires additional time and delays the overall manufacturing.
[0032] FIG.2 shows the shaft (102) with provision for Split-half Locking ring (108) as per existing practice. The shaft (102) step with diameter 200 mm called as stepped shaft (112) is provided for shrink fitting the Thrust collar (106), while the stepped shaft (114) of 170 mm diameter is provided for a split-half locking ring (108). Similarly, the shaft steps of diameters 192mm and 190mm are provided for the mounting of Exciter Rotor Hub (110).
[0033] Figure.3: shows the Exciter Rotor Hub (110) with mounting diameters 192mm and 190mm as per existing practice. The brushless exciter rotor is assembled on the Exciter rotor hub (110), which itself is shrink-fitted on the shaft (102) steps corresponding to the diameter 192mm and 190mm.
[0034] Figure.4: shows the sectional view of newly developed Thrust collar locking arrangement (200) using Locknut (208a) and Lock washer (208b) for transmitting the axial load (including rotor weight and thrust load) to the top thrust bearing (204), a thrust collar (206) that is shrink-fitted on the shaft (202) and additionally it is locked using a Locknut (208a) and Lock washer (208b). The Exciter rotor hub (210) is mounted above the thrust collar (206) upon which the Brushless exciter rotor is assembled.
[0035] Moreover, the locking arrangement using Locknut (208a) and Lock washer (208b) is a sturdier method for locking and it does not involve any precision machining thereby reducing the manufacturing processes and in turn, a reduction in assembly time is achieved.
[0036] Figure.5: shows the new shaft (202) with provision for lock nut (208a) and lock washer (208b). The shaft (202) is stepped to form a stepped shaft (212) with a diameter 200 mm is provided for shrink fitting the thrust collar (206). The stepped shaft (212) is of length 198mm. After the stepped shaft, a threaded section M190X3(214) having minor diameter ranges between 186.752 mm to 187.252 mm and the major diameter ranges between 190 mm to 190.768 mm is provided for engagement of the Locknut (208a) and Lock washer (208b). Similarly, the exciter rotor hub (210) having mounting diameters 177mm and 175mm in which the brushless exciter rotor is mounted. The exciter rotor hub (210) has been designed to allow easy insertion of Locknut (KM38) and Lock washer (MB38) into position from the top (NDE).
[0037] Figure.6: shows the new Exciter Rotor Hub (210) with mounting Diameter 177mm and 175mm. The new brushless exciter rotor is assembled on the new Exciter rotor hub (210), which itself is shrink-fitted on the shaft steps corresponding to the Diameters 177mm and 175mm.
[0038] Thus, with the locknut, the lock washer, and its installation described in the present disclosure, various technical problems of the state of the art are resolved. In addition, although a number of exemplary components are described herein, those skilled in the art can appreciate that the locknut and the lock washer can be used under heavy axial load conditions, without deviating from the scope of the subject matter of the present disclosure.
[0039] Further, it will be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described or shown herein, embody the principles of the invention and are included within its scope.
[0040] Furthermore, all examples recited herein are principally intended expressly to be only for pedagogical purposes to aid the reader in understanding the principles of the invention and the concepts contributed by the inventor(s) to furthering the art and are to be construed as being without limitation to such specifically recited examples and conditions. In addition, the various embodiments described herein are not necessarily mutually exclusive, as some embodiments can be combined with one or more other embodiments to form new embodiments.
[0041] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention 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:1. The novel locking arrangement (200) in vertical synchronous motor with brushless excitation comprising
a shaft (202) having a stepped portion and a plain portion;
a top thrust bearing (204);
a thrust collar (206) wherein the thrust collar (206) is shrink-fitted to the shaft (202);
a locknut (208a) and a lock washer (208b), wherein the locknut (208a) and the lock washer (208b) tightly lock the thrust collar (206) shrink-fitted on the shaft (202);
an exciter rotor hub (210), wherein the exciter rotor hub (210) is mounted above the thrust collar (206) upon which the brushless exciter rotor is assembled.
2. The novel locking arrangement (200) as claimed in claim 1, wherein the shaft (202) having a diameter of 215 mm is stepped to form a stepped shaft (212) having a diameter of 200 mm.
3. The novel locking arrangement (200) as claimed in claim 1, wherein the shaft (202) having a diameter of 215 mm is of length 556 mm.
4. The novel locking arrangement (200) as claimed in claim 2, wherein the stepped shaft (212), having a diameter 200 mm is of length 198 mm.
5. The novel-locking arrangement (200) as claimed in claim 1, wherein the threaded section (214) is provided after the stepped shaft (212) having minor diameter ranges in between 186.752 mm to 187.252 mm and the major diameter ranges in between 190 mm to 190.768 mm.
6. The novel-locking arrangement (200) as claimed in claim 4, wherein the threaded step section is of length 62mm.
7. The novel-locking arrangement (200) as claimed in claim 1, wherein the exciter rotor hub (210) having mounting diameters 177mm and 175mm.