Fuel pump assembly
A fuel pump assembly has a pump mounted to an electric motor by a spring clamp device preferably having a plurality of arms spaced circumferentially around the pump and extending axially generally parallel to an axis of rotation of the motor, from a common base member. The base member is preferably received by the motor, and each arm preferably has a clip which projects radially inward to contact an outboard end face of the pump. The clips are preferably disengageable from the pump and exert a controlled force on the pump, thus producing a consistent and controlled clamping force across the housing encasement to eliminate any potential distortion of the preferably plastic housing.
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The present invention relates generally to a fuel pump assembly and more particularly to a spring clamp device for securing a motor to a pump of the assembly.
BACKGROUND OF THE INVENTIONPrior art automotive fuel pump assemblies typically have an electric motor with a stator and an armature with a drive shaft connected to a fuel pump between inlet and outlet end caps which are all received inside of a metallic sleeve extending axially along the entire length of the assembly. The ends of the sleeve are rolled over and project radially inward of the end caps to generally align and hold the assembly together and prevent de-coupling of the pump from the motor. During manufacturing, the various components of the pump and motor and the end caps are all assembled inside the sleeve and then both of its ends are rolled over the end caps thus securing all of the components of the pump and motor together in axial alignment.
Unfortunately, this process requires the entire assembly be purchased from a single manufacturer who assembles and/or produces both pump and motor components. Furthermore, rolling the ends of the sleeve places a compressive force on the internal components which is not easily controlled or consistently repeated. Excessive stress placed upon the plastic components of the pump can degrade pump performance. Yet further, the sleeve-type of pump and motor assembly is expensive to manufacture and can not be repaired without destroying the sleeve.
SUMMARY OF THE INVENTIONA fuel pump assembly has a pump coupled to an electric motor by a spring clamp device preferably having a plurality of arms spaced circumferentially around the pump and motor and extending generally axially and parallel to an axis of rotation of the motor, from a common first member and to a plurality of second members. The first member spans radially and is preferably received by the motor, and the plurality of second members preferably project radially inward from the respective arms to contact an outboard face of the pump. The second members are preferably disengageable clips which exert a controlled force upon the pump, thus exhibiting a consistent and controlled stress across the pump encasement to eliminate any potential distortion of the preferably plastic encasement.
Objects, feature, and advantages of this invention include a fuel pump assembly which can be dis-assembled without destroying any of the assembly components, the motor and pump can be separately manufactured and pre-assembled, and the pump encasement can be made of relatively inexpensive plastic without concern of distortion. Operation reliability and performance is improved, and the assembly is rugged, durable, maintenance free, of relatively simple design, inexpensive to manufacture and assemble, and in service has a long useful life.
BRIEF DESCRIPTION OF THE DRAWINGSThese and other objects, features and advantages of this invention will be apparent from the following detailed description of the presently preferred embodiments and best mode, appended claims, and accompanying drawings in which:
Referring in more detail to the drawings,
Referring to
Referring to
Each clip 72 has a contact portion 74 which projects radially inward from its associated flex arm 68 and preferably angles axially inward at an angle 78 preferably about five degrees when in a disengaged state (as best shown in
During assembly of the fuel pump assembly 20, a downward projecting cylindrical shoulder 84 of the motor housing 32, disposed concentrically about the shaft 34, is received in the base plate 62 of the spring clamp device 26 through a central hole 86 (as best shown in
With the pump 24 coupled to the motor drive shaft 34 and the flex arms 68 released, the cam-like bends 80 of the clips 72 are preferably in biased contact with a slightly rounded peripheral edge 81 of the pump encasement 38 but not yet in direct contact with the outboard face 46. An external force applied in a radially inward direction against the mid-section of each bowed flex arm 68 causes the flex arms to generally straighten and the contact portions 74 of the clips 72 to align parallel with the imaginary plane 76 (as best shown in
Skilled persons will understand that the orientation of the spring clamp device 26″ relative to the motor 22″ and pump 24″ could be reversed so that the clips 72″ engage the motor end cap or surface 28″ and the base plate 62″ is attached to the pump base 48″ or overlies and engages to the pump end cap 52″ (as best shown in
While the forms of the invention herein disclosed constitute presently preferred embodiments, many others are possible. It is not intended herein to mention all the possibly equivalent forms or ramifications of the invention and it is understood that the terms used herein are merely descriptive rather than limiting and that various changes may be made without departing from the spirit or scope of the invention.
Claims
1. An electric motor pump assembly comprising:
- a pump;
- a separate electric motor coupled to the pump along an axis of rotation; and
- a spring clamp device having; a base member carried by one of the pump and the motor; at least two flex arms each carried by the base member and circumferentially spaced apart and extending axially along at least one portion of the pump and motor; and a clip projecting radially inward from each flex arm adjacent a distal end of the flex arm and received by the other of the pump and motor.
2. The pump assembly set forth in claim 1 comprising:
- an inboard end cap of the motor axially facing the pump; and
- at least one fastener engaging the base member to the inboard end cap.
3. The pump assembly set forth in claim 2 wherein the base member is substantially disposed axially between the pump and motor.
4. The pump assembly set forth in claim 3 wherein the at least one fastener threads into the inboard end cap.
5. The pump assembly set forth in claim 1 wherein the flex arm is bowed radially outward when the spring clamp device is in a disengaged state.
6. The pump assembly set forth in claim 1 comprising a contact portion of the clip projecting radially inward from the flex arm and projecting slightly axially inward with respect to the axis of rotation when the spring clamp device is in a disengaged state, and the contact portion being biased directly against the other of the pump and motor when the spring clamp device is in an engaged state by the flex arm.
7. The pump assembly set forth in claim 6 comprising a distal tab projecting substantially axially outward from the contact portion for moving the clip radially outward against the radially inward biasing force of the flex arm to release the spring clamp device from the other of the pump and motor.
8. The pump assembly set forth in claim 1 wherein the at least two flex arms are equally spaced circumferentially about the motor and pump and are each bowed radially outward.
9. The pump assembly set forth in claim 8 comprising a contact portion of the clip projecting radially inward from each one of the plurality of flex arms and projecting slightly axially inward with respect to the axis of rotation when the spring clamp device is in the disengaged state, and the contact portion being biased directly against the other of the pump and motor when the spring clamp device is in an engaged state by the respective plurality of flex arms.
10. The pump assembly set forth in claim 9 comprising a distal tab projecting substantially axially outward from the contact portion of the clip for moving the clip radially outward against the radially inward biasing force of each one of the at least two flex arms to release the spring clamp device from the other of the pump and motor.
11. The pump assembly set forth in claim 1 comprising:
- an inboard end cap of the motor axially facing the pump;
- an opposite outboard end cap of the motor;
- an outboard face of the pump facing axially from the motor; and
- the base member being in biased contact with the outboard end cap when the clips are in biased contact with the outboard face.
12. The pump assembly set forth in claim 11 wherein the base member is planar and annular in shape.
13. A spring clamp device for preventing de-coupling of a pump from a motor of a pump sub-assembly and along an axis of rotation, the spring clamp device having:
- a base member spanning radially with respect to the axis of rotation;
- a plurality of arms projecting axially from the first member and spaced circumferentially from one-another about the pump sub-assembly; and
- a clip projecting radially with respect to the axis of rotation and from a distal end of each one of the plurality of arms.
14. The spring clamp device set forth in claim 13 comprising an engaged state wherein the base member and the clips are biased axially away from one-another by at least a portion of the pump sub-assembly.
15. The spring clamp device set forth in claim 14 comprising:
- a disengaged state wherein each one of the plurality of arms are bowed radially outward with respect to the axis of rotation; and
- the engaged state causing each one of the plurality of arms to be less bowed than when in the disengaged state.
16. The spring clamp device set forth in claim 14 comprising:
- the base member being in contact with an outboard surface carried by the pump sub-assembly;
- the clips being in biased contact with an opposite outboard face carried by the pump sub-assembly; and
- wherein the pump sub-assembly extends axially between the outboard surface and the outboard face.
17. The spring clamp device set forth in claim 13 comprising:
- the base member being in contact with an outboard surface carried by the motor;
- the clips being in biased contact with an outboard face carried by the pump; and
- wherein the outboard surface faces axially away from to the outboard face.
18. The spring clamp device set forth in claim 13 comprising:
- the base member being engaged to the motor via at least one fastener; and
- the clips being in biased contact with an outboard face carried by the pump.
19. The spring clamp device set forth in claim 13 wherein the base member, the plurality of arms and the clips are unitarily formed together from a single stamping of metal.
Type: Application
Filed: Oct 13, 2004
Publication Date: Apr 20, 2006
Applicant:
Inventors: Kevin Israelson (Cass City, MI), Ronald Roche (Cass City, MI)
Application Number: 10/964,140
International Classification: F04B 17/00 (20060101); F01B 23/08 (20060101);