Radial piston pump

Details Radial piston pump Radial piston pump

1999-11-04

2001-06-05

Ryznic, John E. (Department: 3745)

Expansible chamber devices

Relatively movable working members

Interconnected with common rotatable shaft

C384S447000, C384S564000

Reexamination Certificate

active

06240826

ABSTRACT:

FIELD OF THE INVENTION
The invention concerns a radial piston pump comprising a rotating pump shaft having an end portion connected to a rotationally fixed eccentric ring, said radial piston pump further comprising an eccentric bearing arranged on an outer peripheral surface of the eccentric ring, the eccentric bearing comprising a needle roller bushing having radially inward directed flanges between which bearing needle rollers are arranged for rolling, at least one pump plunger arranged in a pump housing and extending radially of the pump shaft being supported by an end face on the needle roller bushing, while the end portion of the pump shaft is supported in a housing via an adjacent second support bearing.
BACKGROUND OF THE INVENTION
A radial piston pump of the pre-cited type is known from EP O 539 849 B1. FIG. 3 of this prior art document shows a pump shaft whose end portion is retained in a housing via a support bearing which is configured as a ball bearing. An eccentric bearing comprises an eccentric ring which is pressed onto the end portion. The outer peripheral surface of the eccentric ring forms the inner raceway for cage-guided bearing needle rollers. The outer raceway for these bearing needle rollers is formed by a sheet metal bushing having radially inward directed flanges. The axial retention of this eccentric bearing is assured by two radially outward directed flanges of the eccentric ring which overlap the radially inward directed flanges of the needle roller bushing.
A drawback of this prior art is that the bearing arrangement requires a considerable amount of mounting work because two bearings, namely a support bearing and an eccentric bearing have to be handled and mounted separately. A further drawback is that the heavy, solid eccentric ring can cause vibration problems in the bearing arrangement. In addition, this type of mounting arrangement requires a large design space. Finally, manufacturing is also more expensive due to the large number of separate components.
OBJECTS OF THE INVENTION
It is therefore an object of the invention to create an improved eccentric and support bearing arrangement for a radial piston pump.
This and other objects and advantages of the invention will become obvious from the following detailed description.
SUMMARY OF THE INVENTION
The invention achieves the above objects by the fact that the eccentric ring and an inner ring of the support bearing are configured as a one-piece bushing shaped without chip removal, said bushing being force-locked on the pump shaft by a centric region, and both the centric region and an eccentric region of the bushing comprise a radially outward directed flange on an outer end so that an inseparable assembly consisting of the eccentric bearing and the support bearing is formed.
The advantage of the solution of the invention is firstly that a customer-oriented, ready-to-mount assembly consisting of the support and eccentric bearing is created which substantially simplifies the mounting procedure. In place of the hitherto usual stocking and handling of two different bearings, only one bearing arrangement is now required. A second advantage is that the vibration problems of the eccentric bearing are decisively reduced because the chiplessly shaped bushing has a substantially smaller mass so that its mass moment of inertia is also decisively reduced.
According to a further feature of the invention, the support bearing is a chiplessly shaped needle roller bearing whose needle roller bushing comprises radially inward directed flanges between which bearing needle rollers are guided in a cage for rolling.
One advantage of this support bearing is that it is manufactured without chip removal which is substantially cheaper than the fabrication of a solid bearing, and the second advantage is its economy of weight.
According to another feature of the invention, the flange of the needle roller bushing of the eccentric bearing adjacent to the housing has a radial dimension so as to slightly overlap the needle roller bushing of the support bearing. This prevents the eccentric bearing from slipping axially over the support bearing during transportation of the assembly. In addition, this also guarantees an axial support (abutment) of the eccentric bearing on the flange of the support bearing during operation.
According to still another feature of the invention, the flange of the eccentric region of the bushing has a variable radial dimension. This enables a simple compensation of errors of balance caused by the eccentricity so that a particularly low-vibration operation of the eccentric bearing is enabled. Moreover, this flange also serves to stiffen the eccentric region.
Finally, the radial piston pump of the invention is intended for use in anti-locking systems of vehicle brakes or in high-pressure cleaning appliances.
To obtain a high fluid pressure, the piston pumps of such high-pressure cleaning appliances are driven by an electric motor and, if necessary, by a high-speed transmission. On the one hand, the use of a radial piston pump of the invention reduces the rotating mass and, on the other hand, as a further advantage, the weight of the high-pressure cleaning appliance as a whole is also reduced.


REFERENCES:
patent: 5230275 (1993-07-01), Hodge et al.
patent: 5348382 (1994-09-01), Ebaugh et al.
patent: 0539849 (1993-05-01), None

Affiliated with

Also associated with

Rating

Radial piston pump does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Radial piston pump, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Radial piston pump will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2527333