Distributed connection ring assembly for stator assembly

A distributed connection ring assembly can be used in a stator assembly and can integrate a neutral connector and jumping winding connections in an overmolded assembly for insulation. The stator assembly including a stator core defining a plurality of slots spaced apart from each other, a plurality of bar conductors disposed in each of the slots, and a distributed connection ring assembly secured to the jumping winding connections. The distributed connection ring assembly includes an overmolded neutral connector. The distributed connection ring assembly also includes a plurality of overmolded couplers circumferentially spaced apart from one another. The overmolded couplers are coupled to the overmolded neutral connector. Each of the plurality of overmolded couplers includes a support body and a plurality of stator conductors partially disposed inside the support body. The stator conductors are electrically connected to the jumping winding connections.

TECHNICAL FIELD

The present teachings generally relate to a distributed connection assembly for securing jumping winding connections of a stator assembly of an electric machine.

BACKGROUND

An electric machine includes a stator and can convert electrical energy into mechanical energy, or vice-versa. For instance, an electric machine can covert an alternating current into mechanical energy.

SUMMARY

The presently distributed connection assembly is used in a stator assembly of an electric machine and can integrate a neutral connection and jumping winding connections in an overmolded assembly for insulation. The present application describes a stator assembly including a stator core defining a plurality of slots spaced apart from each other, a plurality of bar conductors disposed in each of the slots, a plurality of jumping winding connections coupled to the stator core; and a distributed connection assembly secured to the jumping winding connections. The distributed connection assembly includes an overmolded neutral connector. The distributed connection assembly also includes a plurality of overmolded couplers circumferentially spaced apart from one another. The overmolded couplers are coupled to the overmolded neutral connector. Each of the plurality of overmolded couplers includes a support body and a plurality of stator conductors partially disposed inside the support body. The stator conductors are electrically connected to the jumping winding connections. The support body is made of a polymeric material. The stator conductors are made of an electrically conductive material.

According to an aspect of the present disclosure, the overmolded neutral connector may have an arcuate shape. Each of the overmolded couplers may have an arcuate shape that is complementary to the arcuate shape of the overmolded neutral connector. In other words, the arcuate shape of the overmolded couplers follow (or have the same curvature as) the arcuate shape of the overmolded neutral connector. The support body may include a main body having an inner body surface and an outer body surface opposite the inner body surface. The outer body surface has a convex shape. The inner outer surface of the main body may have a concave shape. The support body may include a first end portion and a second end portion opposite the first end portion. The main body is disposed between the first end portion and the second end portion. The first end portion has a width that is smaller than a width of the main body. The second end portion of the support body may be larger than the main body.

The stator conductors includes a first bar conductor. The first bar conductor may extend solely through the first end portion of the main body. The stator conductors includes a second bar conductor. The second bar conductor may extend solely through the main body and the second end portion. As a non-limiting example, the overmolded couplers may include solely three overmolded couplers. The second end portion includes two coupling prongs spaced apart from each other to define a recess. The stator assembly may further include a plurality of terminals and a plurality of electrical leads. Each of the electrical leads is electrically connected to a respective terminal. The recess is sized to partially receive one of the electrical leads.

According to another aspect of the present disclosure, a nested connection assembly can also be used with a stator assembly. The nested connection assembly includes an overmolded neutral connector and a plurality of overmolded couplers coupled to the overmolded neutral connector. Each of the overmolded couplers includes a support body and a plurality of stator conductors coupled to the support body. The overmolded couplers are nested with each other and with the overmolded neutral connector. As a non-limiting example, the nested connection assembly may solely include two overmolded couplers coupled on top of each other. The overmolded couplers are placed on top of the overmolded neutral connector.

DETAILED DESCRIPTION

Referring to the drawings, wherein like reference numbers correspond to like or similar components throughout the several figures, and beginning withFIGS. 1 and 2, an electric machine10includes a stator assembly12and a rotor16operatively coupled to the stator assembly12. The electric machine10can be utilized in a vehicle. The vehicle can be a passenger vehicle, a commercial vehicle, or any other suitable vehicle capable of carrying people or objects. For example, the vehicle can be a battery electric vehicle, a hybrid electric vehicle including a plug-in hybrid electric vehicle, an extended range electric vehicle or any other suitable vehicles. The electric machine10can include, but is not limited to, an electric motor, a traction motor or other similar device. For example, the electric machine10can be a permanent magnet motor, an induction motor, synchronous motor, etc. The electric machine10can include any device configured to generate an electric machine torque by, for example, converting electrical energy into rotational motion. The electric machine10can be configured to receive electrical energy from a power source, such as a battery array. The power source can be configured to store and output electrical energy.

The vehicle can include an inverter for converting the direct current (DC) voltage from the battery array into alternating current (AC) voltage. The electric machine10can be configured to use the AC voltage from the inverter to generate rotational motion. The electric machine10can also be configured to generate electrical energy when provided with mechanical energy, such as the mechanical energy (torque) of an engine.

Referring toFIG. 1, the electric machine10can include a housing14. The housing14can be manufactured from any suitable material, including but not limited to aluminum, and can include any suitable size, shape and/or configuration suitable to house the internal components of the electric machine10. For example, the stator assembly12is supported by the housing14. Specifically, the stator assembly12is fixed relative to the housing14. In other words, the stator assembly12is stationary relative to the housing14.

The electric machine10also includes a rotor16rotatably supported by the housing14. The rotor16can rotate relative to the stator assembly12about a longitudinal axis18. The rotor16can include, for example, windings or permanent magnets that interact with the poles of the stator assembly12to generate rotation of the rotor16relative to the stator assembly12. The rotor16can be an interior permanent magnet, a surface permanent magnet, an induction, synchronous, reluctance or a separately-excited/wound-field rotor. The rotor16is shown schematically inFIG. 1for illustrative purposes only.

Referring toFIGS. 1, 2 and 3, the stator assembly12further includes a stator core20defining a plurality of slots22(seeFIG. 3) spaced from each other. The stator assembly12also includes a plurality of bar conductors24(FIG. 2) disposed in each of the slots22and arranged in one or more winding paths. The electric machine10can operate in response to voltage applied to the winding paths from the inverter, which creates torque-producing current in the winding paths which causes the rotor16to rotate. The bar conductors24are sometimes referred to as hairpin conductors, and can be a substantially rectangular cross-section.

The stator core20extends between a first core end32and a second core end34along the longitudinal axis18. The slots22are spaced from each other circumferentially about the longitudinal axis18and each extends between the first and second core ends32,34of the stator core20. Therefore, the slots22can extend lengthwise along the longitudinal axis18. In certain embodiments, there are exactly seventy-two slots22defined in the stator core20, and the stator core20defines eight poles.

The stator core20can include an inner stator wall36defining a stator hole38along the longitudinal axis18such that the inner stator wall36is spaced radially away from the longitudinal axis18. The rotor16is disposed in the stator hole38of the stator core20and is rotatable relative to the inner stator wall36of the stator core20when current is traveling through the stator core20. Furthermore, the slots22can intersect the inner stator wall36. The stator core20can also include an outer stator wall40opposing the inner stator wall36. Therefore, the inner stator wall36and the outer wall40are spaced from each other transverse to the longitudinal axis18. As such, the inner stator wall36defines an inner diameter, and the outer stator wall40defines an outer diameter greater than the inner diameter. The stator assembly12also includes a plurality of electrical jumper wires60electrically connected to a predetermined number of the bar conductors24in order to control the amount of current flowing through winding paths. The electrical jumper wires60have jumping winding connections61electrically connected to the terminals64to direct or transfer current into the stator core20. The jumping winding connections61(along with the electrical jumper wires60) are mechanically coupled to the stator core20. The terminals64are configured to be electrically connected to the power source (e.g., a battery pack). Electrical leads66are electrically connected the terminals64, and at least some of the jumper wires60are electrically connected to the bar conductors24.

With reference toFIGS. 2 and 4-6, the stator assembly12also includes a distributed connection assembly100that can support the electrical leads66and electrically connect the terminals64to the jumping winding connections61. The distributed connection assembly100includes an overmolded neutral connector102. The overmolded neutral connector102includes a semi-annular shape to closely follow the shape of the stator core20, thereby facilitating packaging inside a vehicle or any other housing. The distributed connection assembly100also includes a plurality of overmolded couplers104circumferentially spaced apart from one another to facilitate packaging the stator assembly12inside a vehicle of any other housing. The overmolded couplers104are identical to each other to facilitate manufacturing and are coupled to the overmolded neutral connector102. As a non-limiting example, the distributed connection assembly100includes solely three identical overmolded couplers104to minimize part count while achieving the necessary electrical connections. These three overmolded couplers104are discrete components.

With reference toFIGS. 5-7, each overmolded coupler104includes a support body106and a plurality of stator conductors108partially disposed inside the support body106. The polymeric support body106is wholly or partly made of a polymeric material and therefore does not conduct electricity. The stator conductors108are made of an electrically conductive material, such as metal, and therefore conduct electricity. The stator conductors108are electrically connected to the jumping winding connections61and the electrical leads66. As a result, electrical current can be transferred from the terminals64to the bar conductors24through the electrical jumper wires60(FIGS. 2 and 4). The polymeric support body106may have an arcuate shape that is complementary to the arcuate shape of the overmolded neutral connector102to facilitate the connection between the overmolded couplers104and the overmolded neutral connector102. In particular, the polymeric support body106includes a main portion110having an inner body surface112and an opposite, outer body surface114. The overmolded neutral connector102is closer to the inner body surface112than to the outer body surface114of the main portion110. The outer body surface114of the main portion110has a convex shape, and the inner body surface112of the main portion110has a concave shape, thereby allowing the polymeric support body106to be positioned relatively close to the overmolded neutral connector102. As a result, the space occupied by the distributed connection assembly100is minimized. The main portion110has a top body surface116and an opposite, bottom body surface118. The top body surface116and the bottom body surface118are both flat to minimize the space occupied by the overmolded coupler104.

Each polymeric support body106further includes first end portion120and a second end portion122opposite the first end portion122. The main portion110is disposed between the first end portion120and the second end portion122. Thus, the first end portion120protrudes directly from the main portion110of the polymeric support body106. The width W1of the first end portion120is smaller than the width W2of the main portion110to minimize space and weight of the overmolded coupler104. Each overmolded coupler104may include one or more stator conductors108. As a non-limiting example, a first bar conductor108a extends only through the first end portion120of the polymeric support body106in order to be electrically isolated from other stator conductors108extending through the polymeric support body106. Each overmolded coupler104also includes a second bar conductor108bwith multiple branches109. The second bar conductor108bextends only through the main portion110and the second end portion122and is therefore electrically isolated from the first bar conductor108a. The second end portion122is larger than the main portion110and includes two coupling prongs126. The two coupling prongs126are spaced apart from each other to define a recess128configured, shaped, and sized to partially receive one electrical lead66. Accordingly, the electrical leads66can be mechanically coupled to the overmolded coupler104. The electrical leads66are electrically coupled to one of the branches109of the second bar conductor108b.

The overmolded neutral connector102includes a main connector body130wholly or partly made of an electrically conductive material, such as metal. In addition, the overmolded neutral connector102includes isolation coverings132disposed around portions of the main connector body130. The isolation coverings132are wholly or partly made of a polymeric material or any other suitable electrically isolation material in order to provide electrical isolation where desired. The overmolded neutral connector102also includes protrusions134extending directly from the main connector body130. The protrusions134are wholly or partly made of an electrically conductive material, such as metal, and are configured to be electrically connected to the stator conductors108. The protrusions134are circumferentially spaced apart from each other in order to facilitate the electrical connection between the stator conductors108and the protrusions134.

With reference toFIGS. 9 and 10, a nested connection assembly200can be used with the stator assembly12and includes a plurality of overmolded couplers204and an overmolded neutral connector202. Each of the plurality of overmolded couplers204includes a support body206and a plurality of stator conductors208coupled to the support body206. The support body206is wholly or partly made of an electrically insulating material, such as a polymer, and the stator conductors208are wholly or partly made of an electrically conductive material, such as a metal. The stator conductors208are electrically connected to the terminals64. The overmolded couplers204are nested with each other and with the overmolded neutral connector202. To facilitate nesting, the support body206of each overmolded coupler204may have a planar shape. Thus, the overmolded couplers204are disposed on top of each other. The overmolded neutral connector202includes a connection body250wholly or partly made of an electrically insulation material, such as a polymer. In addition, the overmolded neutral connector202includes a neutral conductor252coupled to the connection body250. The neutral conductors252are wholly or partly made of an electrically conductive material, such as metal. The connection body250is flat to facilitate nesting with the overmolded couplers204. As a non-limiting example, the nested connection assembly200may solely include two overmolded couplers204disposed on top of each other. The two overmolded couplers204may be placed on top of the overmolded neutral connector202.

While the best modes for carrying out the teachings have been described in detail, those familiar with the art to which this disclosure relates will recognize various alternative designs and embodiments for practicing the teachings within the scope of the appended claims. The distributed connection assembly and the nested connection assembly illustratively disclosed herein may be suitably practiced in the absence of any element which is not specifically disclosed herein. Furthermore, the embodiments shown in the drawings or the characteristics of various embodiments mentioned in the present description are not necessarily to be understood as embodiments independent of each other. Rather, it is possible that each of the characteristics described in one of the examples of an embodiment can be combined with one or a plurality of other desired characteristics from other embodiments, resulting in other embodiments not described in words or by reference to the drawings.