Field of the invention

[0001] The present invention relates to electrical machines. More particularly, the present invention relates to a brush holder for an electrical machine.

Background of the invention

[0002] Electrical machines (such as electric motors, generators or transformers etc.) are machines which are operated in combination with electricity. The electric motors and generators are used to convert electrical energy into mechanical energy and mechanical energy to electrical energy respectively. The primary components of electric motors and generators are armature coil, Field coils magnets, shaft and brushes. The brushes in the electric motors are used to for transmission of electrical current coming from the machine's rotating part (i.e., shaft and armature) and vice versa in generators. The brushes are mounted within the electrical machines over one or more brush holders. The brush holder is a structure within which a brush can slide in a direction perpendicular to the moving surface of an electrical machine. The brush holder provides support to the brushes and also assist in application of force over the brushes.

[0003] In existing electrical machines, the brush holders are made of Brass material with the help of sheet metal process. The problem with existing brass brush holders is that they are unable to sustain higher operating temperatures. Also, the sheet metal process for manufacturing the brush holders is a complex process and hence costly.

[0004] Therefore, there is a need for a brush holder for electrical machines which overcomes one or more drawbacks of the above-mentioned prior art.

Objects of the invention

[0005] The object of the present invention is to provide a brush holder for an electrical machine.

[0006] Another object of the present invention is to provide a brush holder for an electrical machine, which prevents failure due to high temperature.

[0007] Yet another object of the present invention is to provide a brush holder for an electrical machine, that is highly durable and is capable of w withstanding mechanical stress and impacts.

[0008] Another one object of the present invention is to provide a brush holder for an electrical machine, which is eco-friendly. [0009] Further object of the present invention is to provide a brush holder for an electrical machine, which is cost effective.

[0010] One more object of the present invention is to provide a brush holder for an electrical machine.

Summary of the invention

[0011] According to the present invention, a brush holder for an electrical machine is provided. The electrical machine is a DC motor used in drilling machines. The electrical machine includes a body. The body is having a left side portion and a right-side portion. The left side portion and the right-side portion together constitutes a housing or a frame of the body of the electrical machine. The base or mounting structure is configured on the left side portion and the right-side portion of the body. The base or mounting structure is configured to place a plurality of brush holder thereon. In the present invention two brush holders are arranged on the base or mounting structure. Specifically, one brush holder is arranged on the right-side portion of the body and the other brush holder is arranged on the left side portion of the body. The brush holders are provided with channels or grooves for keeping the brushes therein. The channels or grooves are provided with slots, intended to occupy a plurality of brushes.

[0012] The brush holders are made of a high strength Sheet

Moulding Compound (SMC) material. The Sheet Moulding Compound (SMC) material is capable of withstanding higher operating temperatures created due to the continuous electrical flow and mechanical actions in the electrical machine. The brush holders are manufactured by a moulding process. The moulding process is capable of creating small and compact sized brush holder suitable for the electrical machine. The SMC (Sheet Moulding Compound) material is a polymer made of composite material which includes a thermosetting resin and fillers along with fibre reinforcement. The moulding process involves forming the SMC (Sheet Moulding Compound) material into a brush holder structure by plastic moulding. The plastic moulding includes injection moulding, transfer moulding, compression moulding, extrusion moulding, reaction moulding or a combination thereof.

Brief Description of drawings

[0013] The advantages and features of the present invention will be understood better with reference to the following detailed description and claims taken in conjunction with the accompanying drawings, wherein like elements are identified with like symbols, and in which:

[0014] Figure 1 shows an isometric view of a brush holder for an electrical machine in accordance with the present invention;

[0015] Figure 2 shows a detailed view of the brush holder in accordance with the present invention as shown in figure 1 ; and [0016] Figure 3 shows an exploded view of the brush holder in accordance with the present invention as shown in figure

Detailed description of the invention

[0017] An embodiment of this invention, illustrating its features, will now be described in detail. The words "comprising," "having," "containing," and "including," and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items.

[0018] The present invention relates to an electrical machine. More particularly, the present invention relates to a brush holder for an electrical machine that can withstand higher operating temperatures.

[0019] The terms “first,” “second,” and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another, and the terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items. [0020] The disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms.

[0021] Referring to figures 1, 2 and 3, a brush holder (10) for an electrical machine (100) in accordance with the present invention is illustrated. The electrical machine (100) is a DC motor, DC generator, AC motor or AC generator. In the present embodiment, the electrical machine (100) is a DC motor used in drilling machines.

[0022] The electrical machine (100) includes a body (200). The body (200) comprises a left side portion (20a) and a right-side portion (20b). The left side portion (20a) and the right-side portion (20b) together constitutes a housing or a frame (not shown) of the body (200) of the electrical machine (100). It is obvious for a person skilled in an art to choose materials for the housing or frame depending on their strength and durability. Common materials include metals such as aluminium or steel. The base or mounting structure (50) is configured on the left side portion (20a) and the right-side portion (20b) of the body (200). The purpose of this base or mounting structure is to support a plurality of brush holders. In the present invention two brush holders (10) are arranged on the base or mounting structure (50). Specifically, one brush holder (10a) is arranged on the left-side portion (20a) of the body (200) and the other brush holder (10b) is arranged on the right-side portion (20b) of the body. The brush holders (10a, 10b) are provided with channels or grooves (not shown) for keeping the brushes (not shown) therein. The channels or grooves are provided with slots (not shown), intended to occupy a plurality of brushes.

[0023] In the present invention, the brush holder (10) is manufactured using a moulding process by using a robust Sheet Moulding Compound (SMC) material known for its high strength. The Sheet Moulding Compound (SMC) material is capable of withstanding higher operating temperatures created due to the continuous electrical flow and mechanical actions in the electrical machine (100).

[0024] The Sheet Moulding Compound (SMC) material is a polymer including a thermosetting resin, fillers along with fibre reinforcement. The thermosetting resin is the primary binding component in the Sheet Moulding Compound (SMC) material. Thermosetting resins are polymers that undergo a chemical reaction called curing or cross-linking when subjected to heat and pressure during the manufacturing process. The curing process irreversibly hardens the resin by giving solid and rigid properties to the Sheet Moulding Compound (SMC) material. It is obvious for a person skilled in an art to use common thermosetting resins such as polyester, vinyl ester, or epoxy resins. Fillers are added to the Sheet Moulding Compound (SMC) material to enhance its properties. Fillers are solid materials that improve the material's stiffness, dimensional stability, and resistance to shrinkage for the Sheet Moulding Compound (SMC) material. Common filler materials include calcium carbonate, talc, or glass microspheres. Further Fiber reinforcement is done for providing enhanced strength, rigidity, and impact resistance to the Sheet Moulding Compound (SMC) material. Fiber reinforcement consists of continuous or chopped glass fibres incorporated into the SMC mixture.

[0025] The moulding process is done for shaping the Sheet

Moulding Compound (SMC) material into brush holder (10). The moulding process involves various plastic moulding techniques. The techniques include injection moulding, transfer moulding, compression moulding, extrusion moulding, reaction moulding, or even a combination of these methods. The moulding process creates small and compact sized brush holder (10) suitable for the electrical machine.

[0026] Therefore, the brush holder (10) disclosed in the present invention provides an advantage of being capable of resisting high temperature, due to which the operating life of the brushes also increase. Also, the brush holder (10) requires cost effective process for manufacturing, thereby resulting in the reduced cost of the brush holder (10) as compared to the existing brush holders made by sheet metal processes.

[0027] The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, and to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but such omissions and substitutions are intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention