Description:

Field of invention

The present invention relates to a ceiling fan including double die casted rotor integrated top end shield. More particularly, the present invention discloses a rotor integrated top end shield employing double die casting method and using two dissimilar aluminium alloy in fabrication of the same.

Background Art

Conventionally, the ceiling fan is designed by using Die casted Top end shield, die casted rotor and die casted bottom end shield. All the three components are assembled to complete the motor assembly.

With above construction type, disadvantage is that rotor is sandwich between top end shield and bottom and due course of time the system gets its own stress and wear resulting in rotor getting loose and resulting in noise and performance related issues start coming in fan. The separate rotor is an additional part which if not fitted properly in top & bottom end shield spigot can generate touch noise during operation.

The integrated rotor into Top end shield ensures that concentricity is maintained during machining thus maintaining co-axiality between bearing housing & rotor ID which is very critical for fan operation. The process of direct die casting of rotor pack with top end shield as insert die casting can resolve this. But due to new energy efficiency norms, it is challenging to use general die casting aluminium alloy for both rotor and top end shield. Hence a need is arising to have system which can utilize two different material properties and full fill the structural as well as electrical performance requirement.

In a prior art, a Chinese utility model application CN215646453U discloses Motor casing. The utility model solves the problem that the upper shell and the lower shell are manually clamped to prevent the upper shell from shifting relative to the lower shell after the upper shell and the lower shell are aligned when the existing motor shell is assembled, has high installation efficiency and can realize quick assembly.

In another prior art, a Chinese utility model application CN210867357U discloses a motor and ceiling fan, the motor includes: the motor comprises a shaft, a motor shell, a stator component and a rotor component, wherein the stator component and the rotor component are arranged in the motor shell; the motor shell comprises an upper shell and a lower shell, at least one of the upper shell and the lower shell can rotate and is a rotary shell, and the rotary shell is made of cast aluminium material; the rotor assembly comprises a rotor core and a cast aluminium conductor; the rotor iron core is composed of wound silicon steel sheets; the rotor iron core and the cast aluminium conductor are fixed on the rotary type shell, and the cast aluminium conductor and the rotary type shell are integrally cast and molded; the stator assembly comprises a stator core and a stator winding, the stator core is composed of wound silicon steel sheets, and the stator winding is wound on the stator core. In the utility model, the rotary shell is exposed in the air, the heat dissipation effect is better, and the working efficiency, reliability and stability of the motor are improved; in addition, cost and installation of the core are saved.

Summary of Invention

Therefore such as herein described there is provided a ceiling fan including rotor integrated top end shield. The rotor integrated top end shield is manufactured employing double die casting method and using two dissimilar aluminium alloy during fabrication.

Also herein described there is provided a method for manufacturing a ceiling fan comprising the steps of : providing die casted rotor pack and die cast bottom end shield; performing double die casting with said die casted rotor as insert to die cast top end shield integrated with said die casted rotor; and assembling the rotor integrated top end shield with bottom end shield.

The purpose of the present invention is to provide a robust as well as optimum efficiency design to ceiling fan Rotor and Top end shield by using two different grade of aluminium alloy (LM0 & LM24). The LM0 grade of aluminium possess better electrical conductivity for rotor & the another aluminium alloy LM24 give required structural strength to Top end shield.

Brief Description of Accompanying Drawings

Fig 1 illustrated the conventional general design wherein the assembly is comprising Rotor and Top end shield as two different components.as prior art;

Fig 2 illustrates the concept of integrated Rotor and Top end shield in accordance with the present invention;

Fig 3 illustrates the conventional process of Top end shield and Rotor pack pressure die casting as prior art;

Fig 4 illustrates the process to integrated Die casted rotor into the Top end shield during pressure die casting in accordance with the present invention.

Detailed Description

In the conventional general design and as shown in fig. 1, the assembly comprises of rotor and top end shield as two different components. As the system has three different parts the chances of misalignment are quite high, resulting uneven air gap between rotor stator, hence the efficiency of motor gets affected. Mostly to make efficient rotor, 3-piece construction is used where rotor sandwich between top end shield and bottom end shield. But this construction is not giving robust design.

The above issue can resolve by integrating rotor with Top end shield and get it die casted so that there is no scope of rotor get loose during life cycle of ceiling fan. In normal ceiling fan this can be done with using one single aluminium alloy for Top end shield and rotor and die cast them as insert die casting. In the herein proposed concept the Rotor and Top end shield get integrated so the chances of misalignment are reduced. Also, in this concept both rotor and top end shield have two different material to get advantage of alloy properties as shown in fig 2.

But using single alloy for both top end shield and rotor is not provide a good energy efficiency as we cannot use a pure grade aluminium for structural strength, we need to use pure grade aluminium and the same time this grade is not suitable for top end shield to provide required strength to structure, hence there is need to utilize two different material characteristic to achieve performance as well as strength of design. This method suffices both requirements.

The term double die casting implies first rotor get die casted and then the entire die casted rotor used as insert and in second die casting shot it get casted with Top end shield. Currently this process has not used in ceiling fan industry.

In the convention process for manufacturing and assembling process of Top end shield and Rotor pack pressure die casting
Step 1 : Steel Rotor Pack from press tool
Step 2: Rotor pack used as an insert to die cast Top end shield along the rotor. Aluminium alloy LM 24 is used to die cast rotor alongwith top end shield
Step 3 – Casted top end shield machined as per the assembly requirements.
Step 4- Assembly of top end shield, rotor and the bottom end shield.

The present invention proposes to Double Die casted Rotor integrated Top end shield of Ceiling Fan with two dissimilar Aluminium alloy. The purpose of the present invention is to provide a robust as well as optimum efficiency design to ceiling fan Rotor and Top end shield by using two different grade of aluminium alloy (LM0 & LM24). The LM0 grade of aluminium is known for better electrical conductivity of rotor & LM24 to give structural strength to Top end shield.

The improved process to integrae Die casted rotor into the Top end sheild during pressure die casting includes the steps of :

Step 1 – Steel Rotor pack from press tool
Step 2 – Rotor pack die casted with alloy LM 0
Step-3 – Die casted rotor used as an insert to die cast top end shield alongwith die casted rotor. Aluminium alloy LM-24 used to die cast top end shield alongwith previously die casted rotor.
Step 4 – Casted top end shield machined as per assembly requirement.
Step 5 – Assembly for the integrated rotor and top end shield with the die cast bottom end shield.

Technical advancement and economic significance

Inventive step:

• Energy efficient motor.
• Structurally stable system. Helps to improve life cycle of product.
• Ease in mass production, as once rotor integrated with Top end shield, machining of critical dimensions can be done with lesser setup.
• Overall motor efficiency can be improved by 4-5% with same active material usage.
• As rotor and top is act as one piece. Expensive machining operations are not required to achieve critical tolerance range.

Many modifications may readily be contemplated by those skilled in the art to which the invention relates. Many further modifications may readily be contemplated. The description set out above is particularly applicable to high rate clarification applications. However, in conventional clarification where the upstream or downstream processes herein described are not used, the teachings according to the invention may have considerable merit and are also applicable. The specific embodiments described, therefore, should be taken as illustrative of the invention only and not as limiting its scope as defined herein

, Claims:
1. A ceiling fan comprising of :
an integrated die casted Top end shield and rotor; and
a die casted bottom end shield; wherein the said integration of rotor and top end shield is carried out employing double die casting.

2. The ceiling fan as claimed in claim 1, wherein the said rotor and top end shield are made using two dissimilar aluminium alloy during fabrication.

3. The ceiling fan as claimed in claim 1, wherein said rotor is die-casted with aluminium alloy LM 0.

4. The ceiling fan as claimed in claim 1, wherein said top end shield is die-casted with aluminium alloy LM 24.

5. The method for manufacturing a ceiling fan comprising the steps of :

providing die casted rotor pack and die cast bottom end shield;
performing double die casting with said die casted rotor as insert to die cast top end shield integrated with said die casted rotor; and
assembling the rotor integrated top end shield with bottom end shield.
6. The method for manufacturing a ceiling fan as claimed in claim 5, wherein the said rotor and top end shield are made using two dissimilar aluminium alloy during fabrication.

7. The method for manufacturing a ceiling fan as claimed in claim 5, wherein said rotor is die-casted with aluminium alloy LM 0.

8. The method for manufacturing a ceiling fan as claimed in claim 5, wherein said top end shield is die-casted with aluminium alloy LM 24.