JP4423069B2 - Turbine pump - Google Patents

Description

  The present invention relates to a turbine pump applicable to a fuel pump for pumping and supplying fuel in a fuel tank to an automobile internal combustion engine.

  Conventionally, various turbine pumps have been proposed, and Patent Document 1 discloses an example applied to an electric motor fuel pump as an example. As shown in FIG. 1 of Patent Document 1, the fuel pump uses a configuration in which a shaft of an electric motor and an impeller are coupled by a connecting member, and the rotation of the shaft is transmitted to the impeller through the connecting member. . This is because when the impeller is provided with a connecting hole and the shaft is directly connected to the connecting hole, the connecting hole wears due to relative movement when the shaft is tilted. Impeller wear is mitigated by interposing a connecting member formed of a material between the shaft and the impeller.

Therefore, in Patent Document 1, as shown in FIG. 1 and FIG. 14, a shaft coupling hole that engages with a shaft and receives a motor driving force is provided at a central portion of a disk-shaped connection member. A joint protrusion is provided on the circumferential portion to transmit the motor driving force to the impeller. The motor driving force is transmitted to the connecting member by the engagement between the shaft and the shaft coupling hole, and the motor driving force is transmitted from the connecting member to the impeller by the engagement between the joint protrusion and the joint hole provided in the impeller.
JP-A-10-115265 (FIGS. 1 and 14)

  However, in the conventional electric motor fuel pump, the joint protrusion is formed with a drop prevention protrusion, and the joint protrusion is inserted into the joint hole while being bent, and the impeller is held by engaging the drop prevention protrusion with the impeller. However, since the motor driving force is transmitted to the impeller, when the motor driving force increases, the joint protrusion also increases, so the joint protrusion becomes difficult to bend and the impeller is difficult to be assembled to the connecting member. It was.

  Therefore, the present invention has been made in view of the above-described circumstances, and an object of the present invention is to improve the assembly workability when holding the impeller on the connecting member without being affected by the driving force. It is to provide a turbine pump.

  In order to achieve the above object, the invention according to claim 1 is formed in a central portion of a connection member, and is formed in a shaft coupling hole with which a tip end portion of a rotating shaft is engaged, and formed in the connection member. While the portion is provided with a locking claw, the locking claw is inserted into the holding hole formed in the connecting member and locked in the opening edge of the holding hole formed in the impeller, and inserted into the driving hole formed in the impeller. However, it is intended to provide a drive protrusion that contacts the impeller drive wall formed in the drive hole when the rotation shaft rotates.

  According to the above configuration, by separately providing the holding protrusion and the driving protrusion on the connection member, it is possible to improve the assembly workability when holding the impeller on the connection member without being affected by the motor driving force. .

  The invention according to claim 2 is characterized in that, in the turbine pump according to claim 1, the holding projection is formed in a shape that is more flexible than the driving projection.

  According to the above configuration, since the holding protrusion is formed in a shape that is more flexible than the driving protrusion, it does not require excessive labor when assembling the impeller and the connecting member, so that the assembling workability is improved. The

  Furthermore, the invention described in claim 3 is to provide the protrusion driving surface perpendicularly to the connecting hole driving wall of the shaft connecting hole.

  According to the above configuration, the gap between the connecting member and the impeller is used to absorb the inclination of the rotating shaft and the impeller, so that the tolerance for misalignment of the shaft bearing is relaxed, and the cost is reduced without increasing the accuracy of each part. Can be manufactured.

  Hereinafter, the case where the turbine pump according to the present invention is applied to a fuel pump for automobiles will be described with reference to the drawings.

  1 is a cross-sectional view of a fuel pump showing an embodiment of the present invention, FIG. 2 is a perspective view of a connecting member, FIG. 3 is a front view of an impeller, and FIG. 4 shows a state where a rotating shaft, a connecting member, and an impeller are connected. FIG. 5 is a cross-sectional view taken along line AA in FIG. 4 showing a state where the rotation axis is tilted, and FIG. 6 is a cross-sectional view taken along line BB in FIG. 4 showing a state where the rotation axis is tilted. It is.

  The fuel pump 1 according to this embodiment is disposed in a fuel tank (not shown) of an automobile and supplies fuel to an engine (not shown) via a fuel pipe (not shown).

  As shown in FIG. 1, the fuel pump 1 is configured by housing a pump unit 30 and a drive motor 20 as a drive unit for driving the pump unit 30 in a housing 11.

  The fuel pump 1 is supplied with electric power for operating the drive motor 20 from an external wiring (not shown) via the connector 12. When the fuel pump 1 is operated, the pump unit 30 sucks fuel from the introduction port 14 and supplies fuel to the engine (not shown) from the supply port 15 through the fuel chamber 13 formed in the fuel pump 1. .

  The pump unit 30 includes a casing 31 including a pump casing 32 and a pump cover 33, and an impeller 40 having a disk shape that is housed in a circular impeller chamber 34 formed in the casing 31. It is made of a material with excellent fuel properties.

  Further, a pump flow path 35 through which fuel flows is formed in a circumferential portion of the impeller chamber 34 over a predetermined angle range. The start end of the pump flow path 35 is formed in the pump cover 33 and communicates with a suction port (not shown) that leads to the introduction port 14, and the end is formed in the pump casing 32 and discharge port (not shown) that leads to the fuel chamber 13. ).

  A large number of blade pieces 42 are arranged on the front and back of the circumference of the disc-shaped main body 41 of the impeller 40 over the entire circumference. When the impeller 40 rotates, the fuel introduced into the pump unit 30 is increased in pressure by the centrifugal force generated by the rotation of the impeller 40, the blade piece 42, and the pump flow path 35, and the pump flow path 35 is opened. It is discharged from the discharge port. Further, an insertion hole 43 into which the rotating shaft 21 of the drive motor 20 is inserted is provided at the center of the impeller 40.

  The driving force of the drive motor 20 is transmitted to the impeller 40 via a connection member 50 provided at the tip of the rotary shaft 21 of the drive motor 20.

  The rotating shaft 21 is a cylindrical bar, and a notch 23 is provided at the tip 22 so that the tip 22 has a substantially D-shaped cross section.

  The connection member 50 is formed of a material having elasticity, and a shaft connection hole 52 is provided at the central portion of the substantially disc-shaped main body 51 to engage the tip portion 22 of the rotary shaft 21. Further, two holding projections 55 and two drive projections 57 are alternately arranged on the circumferential portion of one surface of the main body 51, and the projection drive of the two opposing drive projections 57 is performed. A plane including the surface 58 is provided so as to be orthogonal to the notch wall 53 of the shaft connection hole 52 as the connection hole drive wall.

  The shaft coupling hole 52 is a hole having a substantially D shape including a circumferential wall 54 and a planar cutout wall 53, and the distal end portion 22 of the rotating shaft 21 is fitted therein.

  The holding projection 55 is formed so as to be more easily bent than the drive projection 57, and a locking claw 56 is provided at the tip portion. The holding projection 55 is inserted into the holding hole 44 while being bent. When the distal end portion 22 of the holding projection 55 passes through the holding hole 44, the holding projection 55 is restored, and the locking claw 56 is formed in the impeller 40. The impeller 40 is held by the connecting member 50.

  With the impeller 40 held by the connecting member 50, the drive protrusion 57 is inserted into the drive hole 46 formed in the impeller 40. When the rotating shaft 21 rotates, the protrusion driving surface 58 of the driving protrusion 57 contacts the impeller driving wall 47 forming the driving hole 46, and the driving force input from the notch wall 53 is transmitted to the impeller 40.

  When the impeller 40 tries to swing in the direction along the notch wall 53 in a state where the fuel pump 1 is in operation, the rotary shaft 21 is driven by the clearance between the shaft coupling hole 52 and the rotary shaft 21 as shown in FIG. Is absorbed, and wear of the impeller 40 and the impeller chamber 34 is prevented.

  Further, when the impeller 40 tries to swing in a direction perpendicular to the notch wall 53, the rotation shaft 21 is in contact with the notch wall 53 and the circumferential wall 54, so that the inclination of the impeller 40 cannot be absorbed. . However, in the present embodiment, the protrusion driving surface 58 of the driving protrusion 57 is provided so as to be perpendicular to the notch wall 53 of the shaft connection hole 52, so that as shown in FIG. The inclination of the impeller 40 is absorbed by the clearance with the drive hole 46, and wear of the impeller 40 and the impeller chamber 34 is prevented.

  Therefore, since the impeller 40 can absorb the inclination of the impeller 40 with respect to the direction along the notch wall 53 and the direction perpendicular to the notch wall 53, the impeller 40 swings during operation of the fuel pump 1. Even in this case, wear of the impeller 40 and the impeller chamber 34 is prevented.

  In this embodiment, the holding projection 55 and the driving projection 57 are separately provided on the connection member 50, thereby improving the assembly workability when holding the impeller on the connection member without being affected by the motor driving force. Can do.

  Since the holding protrusion 55 is formed in a shape that is more flexible than the driving protrusion 57, an unnecessary work is not required when assembling the impeller 40 and the connecting member 50, and assembling workability is improved.

  Since the inclination of the impeller 40 is absorbed by utilizing the gap between the connecting member 50 and the impeller 40, the tolerance for misalignment of the shaft bearing is relaxed, and the accuracy of each component can be reduced.

  In the pump portion of the present embodiment, the case of the connection member 50 in which the drive protrusion and the holding protrusion are separately provided has been described. However, the drive protrusion also when the single protrusion has the functions of the drive protrusion and the holding protrusion. By providing the projection driving surface 58 of the shaft 57 so as to be perpendicular to the notch wall 53 of the shaft connecting hole 52, it is possible to prevent the impeller and the impeller chamber from being worn and damaged.

It is sectional drawing of the fuel pump which shows one Embodiment of this invention. It is a perspective view of a connection member. It is a front view of an impeller. It is a top view which shows the state which the rotating shaft, the connection member, and the impeller connected. It is sectional drawing along the AA line of FIG. 4 which shows the state in which the rotating shaft inclined. FIG. 5 is a cross-sectional view taken along line BB in FIG. 4 showing a state in which the rotation axis is inclined.

Explanation of symbols

1 ... Turbine pump (fuel pump)
20 ... Drive unit (drive motor)
DESCRIPTION OF SYMBOLS 21 ... Rotary shaft 22 ... Tip part 40 ... Impeller 41 ... Main body part 42 ... Blade piece 44 ... Holding hole 45 ... Opening edge 46 ... Drive hole 47 ... Impeller drive wall 50 ... Connection member 52 ... Shaft connection hole 53 ... Connection hole drive Wall (notched wall)
55 ... Holding projection 56 ... Locking claw 57 ... Drive projection 58 ... Projection drive surface

Claims (3)

An impeller having a large number of blade pieces on the circumferential portion of the main body having a substantially disk shape, a drive unit having a rotation shaft for driving the impeller, and the impeller and the rotation shaft, A turbine pump including a connection member that transmits a driving force of the driving unit to the impeller,
A shaft coupling hole formed in a central portion of the connection member and engaged with a tip of the rotating shaft;
A holding projection formed on the connecting member and provided with a locking claw at the tip portion, the locking claw being locked to an opening edge of a holding hole formed in the impeller;
A drive protrusion formed on the connecting member and inserted into a drive hole formed on the impeller and contacting an impeller drive wall forming the drive hole when the rotating shaft rotates is provided. Turbine pump. The turbine pump according to claim 1, wherein
The turbine pump according to claim 1, wherein the holding protrusion is formed more easily than the driving protrusion. The turbine pump according to claim 1 or claim 2,
A turbine pump characterized in that a plane including a projecting drive surface of the opposing drive projection is provided so as to be orthogonal to a connection hole drive wall of a shaft connection hole.