DE1777223A1 - Automatic device for pressing ball bearing inner rings - Google Patents

Description

8 MÜNCHEN 23, den o _{fi q iqfi} o

LEOPOLDSTR. 20 / IV * ^Ό * ^J

(Concordiahous)

PATENT LAWYER phone 396451. _ "_

Dß ERNST STURM Telegram address: Isarpatent | / / /

Deutsche Bank AG. Munich KIo. No. 21/34120 Postal checking account: Munich 91707

Applicant in: Uzina RULMMTUL,

BrasOV / Romania Str. 13 Decembrie, 96

Automatic device for pressing

Ball bearing inner races ™

The invention "relates to a device operated by a press" for the production of inner rings of radial-axial rolling bearings with plastically deformed raceways through plastic Cold forming of short pipe blanks.

The production of rolling bearing rings by plastic deformation of the raceway by hot rolling of rings with a rectangular initial cross section is known. However, heating Λ will damage the surface of the material to be rolled, which will result in subsequent chip removal with increased allowance for the purpose of removing the damaged surface and heat treatment of its own unevenness.

It is also known that cold rolling by inserting one of the raceway corresponding profile role in the trapped in a rotating device and radially pressing ring

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this role with increasing force on the rotating ring. This process results in increased wear and tear on the tools, due to the high specific pressures.

Both rolling processes for rolling bearing rings still have the disadvantage that at the point where the rolling roller penetrates the steel, the material is pushed out laterally and thus displacements in the structure take place, which promote fatigue of the material.

The device according to the invention eliminates these disadvantages by a single pressing step in which both shoulders of the The raceway of the ring is formed at the same time and the material is deformed in its entirety solely by pressure which results in a compaction of the material without flowing away from the deformation tool. During the Deformation inevitably encircles the material progressively around the tool.

Since drawn tube is used as the raw material , the initial grain structure of the roller bearing steel is converted into a fiber structure by rolling and is further improved by drawing the tube. This accentuated fiber course gives the pressed blanks of the rolling bearing rings certain properties, whereby the invention specifies the type of favorable arrangement in the blanks formed into iC ball bearing rings *

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BAD ORiQiNAL

In order to achieve the maximum service life of the rolling bearings, practical operating experience shows that the fiber orientation is so must be arranged that when machining by cutting the blank, the fibers neither obliquely nor radially out of the Escape the running groove so as not to be cut.

The signs of fatigue, - the failure of a ball bearing occur first on the inner ring. Hence the Favorable: the arrangement of the fiber orientation in the case of inner rings is displayed and appropriately.

G-- bearing trough rings, the fiber course of which is precisely adapted to the profile of the raceway (ring in section seen), are cold-pressed from precision tube, whereby the inner diameter of the tube etv. ^{r is} larger than the desired inner diameter of the pren-blank, the cut-out diameter is somewhat smaller than the runway diameter and the length corresponds to the volume of the projecting c-ut s pri clvt.

During the automatic sequence of the pressing process, parts of such tubes "0" are placed in the feed magazine A of the device (Fig. 1).

The parts are placed piece by piece through a hole in the base plate: brought. LIn mandrel 1 is inserted into it and then plastic deformation takes place by axial compression of the parts between two surfaces (base plate and ram 3).

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The raceway is formed by an annular die 2, which consists of two parts with a toroidal cross-section ". This "move at the same time as ram 3 and holder speed the same along the parts downwards. This matrix is attached in such a way that it is always halfway up is located between the two axial pressure surfaces (ram and base plate).

After pressing, the two parts of the die are removed radially from each other and the mandrel 1 withdraws from the pressed ring.

The die that forms the raceway of the ring is solid and rigid, made up of two segments, it is guided laterally and radially from each of a piston rod 4 of the cylinder 5 actuated. The opposite side of the piston rod 4 is in the closed state of the die by a wedge 6, which is through the Piston of a cylinder 7 is actuated, and the inclined plane 8 is locked.

When the die is opened, the wedge 6 releases an opening in the inclined plane, through which the piston rod 4 retracts can.

In the practical application of automatic pressing, shown as an example in Fig. 1, the device is through a press operated with the appropriate pressure force. The press j

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lifts (arrow "S") and lowers (arrow "J") the plunger 3 of the device. The movements of the other elements of the device are made by hydraulic or pneumatic forces via various Piston controlled.

The axial movement of the raceway frame with lockable The die, at half the ram speed, takes place via the gears 9 and racks 10 with a ratio of 1: 2. the small gears 9 engage in the racks attached to the rigid frame of the die. The large gears 9 engage in the racks attached to the ram 3,

The pneumatic or hydraulic control of the device elements is controlled centrally by a distributor P, the depending on the cycle of the press and device is actuated by a timing relay R (Pig. 4).

By distributing the pressure by means of distributor P in the two directions a or b, the two movement cycles of the pressing process become causes.

Pressure in port a causes cycle I ₁ , namely:

Radial approach of the die segments 2 and their locking by wedge 6 and rod 4.

Material transport from the feed magazine A to the press station by the transport system 11. 109840/0530

Extending the centering mandrel 1

Lowering the ram with simultaneous lowering of the die Via gear wheels 9 and rack 10.

At the end of this cycle the ring is finished pressed.

Pressure in connections Td causes cycle II, namely:

Withdrawal of transport 11,

Unlocking of the die and radial retraction of the die segments.

Pulling in the centering mandrel 1 "up to the level of the pressing surface of the ram%

Lifting the press ram and the die frame, actuating the lever 12 to remove the pressed blanks from the Remove the base plate of the device.

In the pictures 2 and 5 the top views of the inlet and Discharge devices shown.

The pressing is carried out cold.

The new process has compared to the known manufacturing process the following advantages:

- It results in lines running exactly parallel to the profile and Raceway of the pressed ring.

- The ball bearing rings can be made with minimal allowance for

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machining post-processing are produced, i.e. low Ketal consumption and workload.

- The pressing takes place in the cold state, i.e. H. much lower operating costs (tools and thermal energy) in comparison for plastic hot deformation.

- The deformation takes place only by compressive loading of the material and the tools, whereby the plastic deformation takes place progressively throughout the bulk of the material. This leads to the compression of the material without any structural shifts.

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Claims (4)

■ - 8 - Patents' claims 1. Method and automatic device for cold pressing of ball bearing inner rings, characterized in that a short, smooth tube (θ) is used as the blank, which is centered on the device by a mandrel (1) in the axis of the ram (3), with the pressing of the blank takes place axially between a base plate of the device and a plunger (3), namely under simultaneous axial displacement of a segment that encloses the pipe blank, the die for the raceway of the pressed ring-forming die ring (2). 2. Automatic device for pressing ball bearing inner rings according to claim 1, characterized in that the system of forming the raceway of the ring to be pressed by Compression and locking is rigidly consolidated, using hydraulic or pneumatic power. 3. Automatic device for pressing ball bearing inner rings according to claim 1 and 2, characterized in that the pipe blanks are brought to pressed parts from a feed magazine (A) by a transporter (11), the lowering of the ram 3 takes place under the power of the press used and the movement of the track frame with 109840 / Q530 lockable die at half the speed of the Pressesels with gears (9) with a ratio of 1: 2 and Toothed racks 10, or any other system ^ which the ratio of the speeds between the ram and running track frame with lockable die ensures takes place. 4. Automatic device for pressing ball bearing inner rings, according to claim 1 to 3 _t, characterized in that the finished pressed ring remaining on the base plate is ejected by means of a piston and lever (12) controlled by a central control system (P) of the automatic puncture sequence of the device will. 109840/0530 Blank page